ABRET R.EEG.T. Exam — Questions and Answers

Question 1: During sleep activation, which sleep stage is most important to capture for evaluating interictal epileptiform discharges in temporal lobe epilepsy?

Stage N3 (slow-wave sleep)
Stage N1 (NREM 1)
REM sleep
Stage N2 (NREM 2) (Correct answer)

Correct answer: Stage N2 (NREM 2)

Stage N2 sleep is the most important stage for activating interictal epileptiform discharges in temporal lobe epilepsy, as spikes are significantly enhanced during NREM sleep.

Question 2: The centrotemporal spikes seen in benign childhood epilepsy with centrotemporal spikes (BECTS) have which typical characteristic?

They are maximal at occipital electrodes and occur during photic stimulation
They show a horizontal dipole with negativity at centrotemporal and positivity at frontal electrodes, activated by sleep (Correct answer)
They are continuous during wakefulness and suppressed by sleep
They are bilateral synchronous without a dipole field

Correct answer: They show a horizontal dipole with negativity at centrotemporal and positivity at frontal electrodes, activated by sleep

BECTS spikes show a characteristic tangential dipole with maximum negativity at C3/C4-T3/T4 and simultaneous positivity at frontal electrodes. They are markedly activated by drowsiness and NREM sleep.

Question 3: What EEG response is termed 'photoparoxysmal' during intermittent photic stimulation?

Generalized spike-and-wave or polyspike-and-wave discharges time-locked to flashes (Correct answer)
Increased beta activity frontally
Focal theta slowing over the occipital region
Posterior dominant rhythm attenuation

Correct answer: Generalized spike-and-wave or polyspike-and-wave discharges time-locked to flashes

A photoparoxysmal response consists of generalized epileptiform discharges (spike-wave or polyspike-wave) that are provoked by and time-locked to photic stimulation.

Question 4: A compressed spectral array (CSA) displays EEG information by showing:

Amplitude envelope of the raw EEG plotted as a single line per channel
Spike-and-wave discharge counts per epoch displayed as a histogram
Raw EEG waveforms compressed to fit on a single page per hour
Power spectral density plotted over time, with frequency on one axis and time on the other (Correct answer)

Correct answer: Power spectral density plotted over time, with frequency on one axis and time on the other

A CSA (also called a density spectral array or DSA depending on color coding) uses Fast Fourier Transform (FFT) to decompose the EEG into its component frequencies and plots the power at each frequency band over time. This allows hours of EEG to be reviewed at a glance for trends in frequency content, making it useful for detecting delayed cerebral ischemia, seizures, and drug effects.

Question 5: During a routine EEG, the standard display sensitivity is set to:

3 µV/mm
15 µV/mm
7 µV/mm (Correct answer)
50 µV/mm

Correct answer: 7 µV/mm

The standard display sensitivity for routine EEG is 7 µV/mm, which provides adequate visualization of normal brain rhythms. Sensitivity may be adjusted for high-amplitude (increase µV/mm) or low-amplitude (decrease µV/mm) activity.

Question 6: A patient who speaks only Spanish arrives for an EEG and the technologist speaks only English. Which approach best upholds informed consent standards?

Use the patient's adult family member as an informal interpreter for the consent discussion
Provide a written consent form in English and have the patient sign it
Arrange a qualified medical interpreter (in person, phone, or video) before obtaining consent (Correct answer)
Proceed without explanation since the procedure is non-invasive

Correct answer: Arrange a qualified medical interpreter (in person, phone, or video) before obtaining consent

Informed consent requires that the patient fully understands the procedure, which necessitates a qualified medical interpreter — not a family member — to avoid conflict of interest and ensure accuracy.

Question 7: What electrode application method is preferred for ambulatory EEG to ensure electrodes remain in place during extended recording?

Paste with gauze
Collodion adhesive (Correct answer)
Conductive gel alone
Saline-soaked sponges

Correct answer: Collodion adhesive

Collodion is the preferred adhesive for ambulatory EEG because it provides secure, long-lasting electrode fixation that withstands the physical activity of daily living during multi-day recordings.

Question 8: For a patient who cannot perform volitional hyperventilation (e.g., young child), an alternative activation method may include:

Applying cold water to the face
Having the child blow on a pinwheel or blow bubbles (Correct answer)
Bilateral carotid massage
Administering IV benzodiazepines

Correct answer: Having the child blow on a pinwheel or blow bubbles

Having young children blow on a pinwheel or blow bubbles is a standard pediatric technique to elicit sustained hyperventilation without requiring volitional cooperation.

Question 9: Benzodiazepine administration typically produces which EEG change that a technologist should recognize and document?

Prominent generalized theta slowing without faster activity
Suppression of all activity below 1 Hz
Appearance of triphasic waves over frontal regions
Increase in frontocentral beta activity (14–30 Hz) (Correct answer)

Correct answer: Increase in frontocentral beta activity (14–30 Hz)

Benzodiazepines (and other GABA-A agonists such as barbiturates at sub-anesthetic doses) characteristically increase fast-frequency beta activity, most prominent over frontocentral regions. Recognizing drug-induced beta prevents misinterpretation as normal or abnormal endogenous activity.

Question 10: An EEG technologist is setting up for a routine adult EEG. According to the International 10-20 System, what are the four primary anatomical landmarks used to ensure standardized and proportional electrode placement?

Nasion, inion, and both preauricular points (Correct answer)
Nasion, inion, and both mastoid processes
Vertex, inion, and both zygomatic arches
Nasion, vertex, and both temporal lobes

Correct answer: Nasion, inion, and both preauricular points

The International 10-20 System relies on four key anatomical landmarks for its measurements: the nasion (bridge of the nose), the inion (bony prominence at the back of the skull), and the left and right preauricular points (depressions just in front of the ears). These points form the basis for all subsequent measurements, ensuring that electrode placement is proportional to the patient's head size and shape.

Question 11: Sleep efficiency is calculated as:

Total sleep time divided by total recording time × 100
REM time divided by total sleep time × 100
Total sleep time divided by time in bed × 100 (Correct answer)
Sleep onset latency divided by time in bed × 100

Correct answer: Total sleep time divided by time in bed × 100

Sleep efficiency = (TST / TIB) × 100; a value ≥85% is generally considered normal in adults.

Question 12: Eye blink artifact is primarily seen at which electrode positions?

Occipital electrodes (O1, O2)
Frontal electrodes (Fp1, Fp2) (Correct answer)
Temporal electrodes (T3, T4)
Central electrodes (C3, C4)

Correct answer: Frontal electrodes (Fp1, Fp2)

Eye blink artifact produces high-amplitude positive deflections most prominent at Fp1 and Fp2 because the cornea (positive pole of the eye dipole) moves upward toward these frontopolar electrodes during blinking.

Question 13: A K-complex is defined as a well-delineated negative sharp wave followed by a positive component with a total duration of at least:

0.25 seconds
1.5 seconds
1.0 second
0.5 seconds (Correct answer)

Correct answer: 0.5 seconds

AASM criteria define a K-complex as a biphasic wave lasting ≥0.5 seconds, maximal over frontal regions.

Question 14: What feature best distinguishes a benign epileptiform transient of sleep (BETS) from a pathological epileptiform discharge?

BETS occur only during REM sleep
BETS always appear in the frontal regions
BETS have a duration greater than 200 milliseconds
BETS are typically small, isolated, and lack an after-going slow wave (Correct answer)

Correct answer: BETS are typically small, isolated, and lack an after-going slow wave

BETS (also known as small sharp spikes or SSS) are low-amplitude, brief, isolated transients without after-going slow waves, occurring during drowsiness and light sleep, and are considered benign normal variants.

Question 15: Which waveform is considered a normal variant and is characteristically seen at the vertex during stage N1 sleep?

Sleep spindle
K-complex
Vertex sharp wave (Correct answer)
Lambda wave

Correct answer: Vertex sharp wave

Vertex sharp waves (V-waves) are normal, high-amplitude transients maximal at Cz that appear during drowsiness and stage N1 sleep.

Question 16: During sleep recording, repetitive, high-amplitude spike-like potentials appearing synchronously with each heartbeat across all leads are best identified as:

Cardiac (EKG) artifact (Correct answer)
Vertex sharp waves
Frontal arousal rhythms
K-complexes

Correct answer: Cardiac (EKG) artifact

EKG artifact produces spike-like potentials synchronous with the R-wave, often mistaken for epileptiform discharges if the ECG channel is not reviewed.

Question 17: In a comatose patient, the presence of sleep architecture elements such as sleep spindles or K-complexes on EEG suggests which prognostic implication?

Relatively preserved thalamocortical function and potentially better prognosis (Correct answer)
Electrocerebral inactivity
Imminent seizure activity
Certain poor outcome

Correct answer: Relatively preserved thalamocortical function and potentially better prognosis

Preservation of sleep architecture in coma indicates intact thalamocortical circuitry and generally correlates with a more favorable neurological prognosis.

Question 18: Which normal EEG variant appearing at sleep onset consists of brief 4–6 Hz runs with a positive polarity at the vertex?

POSTS
Hypnic jerks with associated vertex potentials (Correct answer)
Wicket spikes
6 Hz spike-and-wave (phantom spike)

Correct answer: Hypnic jerks with associated vertex potentials

Hypnic jerks are sudden body twitches at sleep onset that correlate with brief vertex-maximal EEG potentials and are a normal physiologic phenomenon.

Question 19: What is the standard stimulus rate used when performing pattern reversal visual evoked potentials (VEPs) in a clinical setting?

0.1–0.5 reversals/second
10–15 reversals/second
1–2 reversals/second (Correct answer)
5–8 reversals/second

Correct answer: 1–2 reversals/second

A reversal rate of approximately 1–2 per second (1–2 Hz) is standard for pattern reversal VEPs; faster rates can cause habituation and distort the P100 latency.

Question 20: What is the most effective method for reducing 60 Hz electrical interference artifact?

Increasing the high-frequency filter to 100 Hz
Ensuring all electrode impedances are balanced and below 5 kOhm (Correct answer)
Switching to a bipolar montage
Increasing the recording sensitivity

Correct answer: Ensuring all electrode impedances are balanced and below 5 kOhm

Balanced, low impedances (below 5 kOhm) allow the differential amplifier to effectively reject common-mode 60 Hz noise. Impedance imbalance between electrodes is the primary cause of excessive 60 Hz artifact.

Question 21: The high-frequency filter (low-pass filter) in EEG recording at a typical setting of 70 Hz will:

Only display the 70 Hz component
Attenuate frequencies above 70 Hz while passing lower frequencies (Correct answer)
Block all frequencies below 70 Hz
Amplify frequencies above 70 Hz

Correct answer: Attenuate frequencies above 70 Hz while passing lower frequencies

The high-frequency (low-pass) filter attenuates signals above its cutoff frequency. At 70 Hz, it progressively reduces muscle artifact and electrical noise above 70 Hz while preserving brain activity which is predominantly below 70 Hz.

Question 22: A burst suppression pattern on EEG is most consistent with which clinical scenario?

Focal temporal lobe lesion
Benign rolandic epilepsy
Severe diffuse cerebral dysfunction such as deep anesthesia or anoxic brain injury (Correct answer)
Stage II sleep in a healthy adult

Correct answer: Severe diffuse cerebral dysfunction such as deep anesthesia or anoxic brain injury

Burst suppression indicates severely depressed cerebral activity and is seen with deep anesthesia, hypothermia, or severe anoxic-ischemic encephalopathy.

Question 23: A patient falls asleep during a routine EEG. Which feature confirms Stage N2 sleep?

Alpha attenuation only
Delta waves exceeding 50% of the epoch
Vertex waves only
Sleep spindles and K-complexes (Correct answer)

Correct answer: Sleep spindles and K-complexes

Stage N2 sleep is defined by the presence of sleep spindles (12–14 Hz) and/or K-complexes on the EEG.

Question 24: According to the 10-20 International System nomenclature, which electrode would be located over the left mid-temporal region?

C3
T4
T3 (Correct answer)
Pz

Correct answer: T3

In the 10-20 system, the letter indicates the underlying brain region ('T' for Temporal) and the number indicates the hemisphere. Odd numbers are used for the left hemisphere and even numbers for the right hemisphere. 'z' denotes the midline. Therefore, T3 is the electrode over the left mid-temporal region.

Question 25: Which of the following must be documented and excluded before an EEG can be interpreted as confirming electrocerebral inactivity?

Electrode impedances below 100 Ω at all sites
Core body temperature above 32°C, absence of CNS depressants, and no severe metabolic disturbance (Correct answer)
Presence of burst suppression for at least 30 minutes
Absence of alpha-frequency activity in posterior regions

Correct answer: Core body temperature above 32°C, absence of CNS depressants, and no severe metabolic disturbance

Before ECI can be considered confirmatory for brain death, reversible causes must be excluded: core temperature must be ≥32°C (hypothermia suppresses EEG), CNS depressant drugs must be absent or below therapeutic levels, and severe metabolic disturbances (e.g., extreme hypoglycemia) must be ruled out.

Question 26: A technologist notices intermittent square-wave transients isolated to a single electrode that disappear when the electrode impedance is rechecked and re-gelled. This is most consistent with:

Electrode pop (Correct answer)
Muscle artifact
Sweat artifact
EKG artifact

Correct answer: Electrode pop

Electrode pops are caused by intermittent loss of contact or impedance instability at a single electrode and typically resolve with re-application.

Question 27: What does the '10' and '20' refer to in the International 10-20 system?

Percentage of total skull distance between electrode sites (Correct answer)
Number of electrodes in each region
Millimeters between electrodes
Frequency bands measured at each site

Correct answer: Percentage of total skull distance between electrode sites

The 10 and 20 refer to the percentage of the total front-to-back or left-to-right skull distance used as the spacing between electrode positions.

Question 28: Which electrode placement best captures activity from the temporal lobe?

T3/T4 (T7/T8) (Correct answer)
P3/P4
F3/F4
O1/O2

Correct answer: T3/T4 (T7/T8)

T3/T4 (now called T7/T8 in the revised system) are positioned over the temporal lobes and best capture temporal lobe activity.

Question 29: Which EEG feature is a normal finding in drowsiness in adults?

Posterior slow waves of youth
K-complexes
Vertex sharp waves (Correct answer)
Sleep spindles

Correct answer: Vertex sharp waves

Vertex sharp waves (V waves) are normal transients that appear over the vertex during drowsiness and light sleep.

Question 30: A patient's qEEG panel shows the asymmetry index trending toward the right hemisphere for 45 minutes. This means:

The left hemisphere's EEG is being contaminated by right-sided muscle artifact
Seizure activity is more likely occurring over the right hemisphere
Electrode impedance is higher on the right side, inflating apparent amplitude
The right hemisphere has relatively more power (amplitude) than the left during this period (Correct answer)

Correct answer: The right hemisphere has relatively more power (amplitude) than the left during this period

An asymmetry index that trends toward one hemisphere indicates that hemisphere has proportionally greater spectral power. Persistent rightward asymmetry over 45 minutes could reflect focal seizure activity, cortical spreading depression, or a structural lesion increasing amplitude on that side. It triggers review of the raw EEG to determine the cause, but by definition it means relatively higher power on the right.

Question 31: What does a referential montage compare each electrode to?

The adjacent electrode
The opposite hemisphere electrode
The ground electrode
A common reference electrode (Correct answer)

Correct answer: A common reference electrode

In a referential montage, each active electrode is compared to a single common reference electrode, often placed at the ear or linked mastoids.

Question 32: Which artifact appears as a regular, rhythmic waveform at the same frequency as the patient's heart rate?

Pulse artifact (ECG artifact) (Correct answer)
Glossokinetic artifact
Electrode pop
Eye blink artifact

Correct answer: Pulse artifact (ECG artifact)

Pulse artifact appears as rhythmic waveforms synchronous with the cardiac cycle, caused by electrode placement over a pulsating blood vessel or by ballistocardiographic effect.

Question 33: A critically ill patient is being actively cooled to 33°C for targeted temperature management after cardiac arrest. How does this temperature affect the EEG?

Progressively slows and suppresses EEG activity; may produce burst suppression or ECI at very low temperatures (Correct answer)
Selectively abolishes sleep spindles while preserving alpha activity
Has no effect on EEG background until temperature drops below 20°C
Produces diffuse high-amplitude delta without affecting frequency

Correct answer: Progressively slows and suppresses EEG activity; may produce burst suppression or ECI at very low temperatures

Hypothermia is a potent EEG suppressant. At 33°C, background slowing and decreased amplitude are expected. As temperature falls further (below ~20°C), burst suppression and eventually ECI can occur — all reversible with rewarming. Failure to account for hypothermia when interpreting EEGs leads to false prognostication.

Question 34: Electrographic seizure activity on EEG is defined by which characteristic evolution?

Evolving pattern with change in frequency, morphology, or spatial distribution over time (Correct answer)
Static, unchanging repetitive discharges
Random isolated spikes without pattern
Only generalized tonic-clonic movements on video

Correct answer: Evolving pattern with change in frequency, morphology, or spatial distribution over time

Electrographic seizures are defined by evolution — a progressive change in frequency, amplitude, morphology, and/or spatial distribution over at least 10 seconds, distinguishing them from brief interictal discharges.

Question 35: An artifact appearing as a rhythmic, 1–3 Hz broad, high-amplitude slow-wave pattern that correlates with the patient's assisted ventilation rate is called:

Ventilator artifact (Correct answer)
Tremor artifact
Movement artifact
Cardiac artifact

Correct answer: Ventilator artifact

Ventilator artifact is caused by rhythmic chest and head movement from mechanical ventilation, producing slow waves at the ventilation rate.

Question 36: Positive occipital sharp transients of sleep (POSTS) are a normal finding seen during which sleep state?

Wakefulness with eyes open
NREM light sleep (N1-N2) (Correct answer)
REM sleep only
Deep slow-wave sleep (N3)

Correct answer: NREM light sleep (N1-N2)

POSTS are surface-positive sharp transients over the occipital regions that appear during light NREM sleep (N1 and N2). They are a normal variant and should not be confused with occipital epileptiform discharges.

Question 37: Which evoked potential modality is specifically used to assess the integrity of the auditory pathway from the cochlea through the brainstem?

Motor Evoked Potentials (MEP)
Brainstem Auditory Evoked Potentials (BAEP) (Correct answer)
Somatosensory Evoked Potentials (SSEP)
Visual Evoked Potentials (VEP)

Correct answer: Brainstem Auditory Evoked Potentials (BAEP)

BAEPs (also called ABRs) record far-field potentials generated along the auditory nerve and brainstem from cochlea to inferior colliculus.

Question 38: What is the most important factor in interpreting a neonatal EEG?

The number of electrodes used
The ambient room temperature during recording
Whether the recording is digital or analog
The conceptional age (gestational age plus postnatal age) of the infant (Correct answer)

Correct answer: The conceptional age (gestational age plus postnatal age) of the infant

Conceptional age is the single most important factor in neonatal EEG interpretation because normal EEG patterns change dramatically with brain maturation, and age-inappropriate patterns indicate abnormality.

Question 39: Which component of the EEG amplifier circuit is responsible for rejecting signals common to both inputs (such as 60 Hz power line noise)?

The low-frequency filter
The differential amplifier (Correct answer)
The analog-to-digital converter
The electrode selector matrix

Correct answer: The differential amplifier

The differential amplifier amplifies the difference between two inputs while rejecting signals that appear equally on both (common mode), which is how 60 Hz interference is suppressed.

Question 40: Sleep spindles are a hallmark of which stage of sleep?

Stage N2 sleep (Correct answer)
Stage N3 (deep slow wave sleep)
REM sleep
Stage N1 (drowsiness)

Correct answer: Stage N2 sleep

Sleep spindles (11-16 Hz bursts lasting 0.5-2 seconds) are the defining feature of Stage N2 sleep. They are generated by thalamic reticular nucleus oscillations and are best seen over central regions.

Question 41: K-complexes are characterized by which of the following features?

Continuous monomorphic theta activity in frontal regions
Low-amplitude fast activity in temporal regions during REM sleep
A biphasic wave with initial sharp negative component followed by a positive slow wave, maximal at the vertex during N2 sleep (Correct answer)
Bilateral occipital alpha bursts during drowsiness

Correct answer: A biphasic wave with initial sharp negative component followed by a positive slow wave, maximal at the vertex during N2 sleep

K-complexes are large biphasic waves with an initial sharp negative deflection followed by a slower positive component, maximal at Fz/Cz, occurring spontaneously or in response to stimuli during Stage N2 sleep.

Question 42: Stimulus-induced rhythmic, periodic, or ictal discharges (SIRPIDs) are significant in cEEG monitoring because they:

Occur only in patients with prior epilepsy
May represent seizures triggered by external stimulation and affect care decisions (Correct answer)
Are always benign and require no intervention
Indicate electrode malfunction

Correct answer: May represent seizures triggered by external stimulation and affect care decisions

SIRPIDs are pathological EEG discharges provoked by external stimuli (tactile, auditory) and their clinical significance — whether ictal or interictal — must be assessed to guide treatment.

Question 43: The electrode labeled 'Fz' in the 10-20 system is located at:

The midline frontal position (Correct answer)
The left frontotemporal junction
The right frontopolar region
The left frontal region

Correct answer: The midline frontal position

The 'z' designation indicates a midline position. Fz (frontal zero) is the midline frontal electrode positioned at 30% of the nasion-to-inion distance from the nasion.

Question 44: An EEG recording of a relaxed, awake adult with eyes closed shows a prominent 8-13 Hz rhythm in the occipital regions. This rhythm attenuates with eye opening. Which of the following best identifies this waveform?

Alpha rhythm (Correct answer)
Beta rhythm
Theta rhythm
Mu rhythm

Correct answer: Alpha rhythm

The posterior dominant alpha rhythm is the hallmark of a normal, relaxed, awake adult EEG with eyes closed. It is characterized by its frequency of 8-13 Hz, posterior location (maximal in the occipital regions), and its attenuation or blocking with eye opening or mental effort.

Question 45: What is the most appropriate low-frequency filter setting when recording neonatal EEG to capture slow cerebral activity?

10 Hz
30 Hz
1 Hz (Correct answer)
5 Hz

Correct answer: 1 Hz

A low-frequency filter of 1 Hz (or lower) is used in neonatal EEG to preserve slow background activity that is characteristic of the immature brain.

Question 46: Reflex epilepsy triggered by specific cognitive tasks (such as reading or calculating) is an example of:

Photosensitive epilepsy
Medication-induced seizures
Cognitive activation of seizures (thinking epilepsy or praxis-induced epilepsy) (Correct answer)
Normal hyperventilation response

Correct answer: Cognitive activation of seizures (thinking epilepsy or praxis-induced epilepsy)

Praxis-induced or cognitive-task-induced epilepsy is a form of reflex epilepsy where specific mental activities (reading, calculating, spatial tasks) trigger epileptiform discharges or seizures, most commonly in genetic generalized epilepsies.

Question 47: Which of the following statements is true regarding beta activity in a normal adult EEG?

It is typically highest in amplitude in the occipital regions.
It is defined as activity in the 4-7 Hz frequency range.
It is always considered an abnormal finding in an awake adult.
It is often enhanced fronto-centrally by drowsiness or certain medications like benzodiazepines. (Correct answer)

Correct answer: It is often enhanced fronto-centrally by drowsiness or certain medications like benzodiazepines.

Beta activity (>13 Hz) is a normal rhythm, typically low in amplitude and most evident in the frontal and central regions. Its amplitude can be enhanced by a state of drowsiness or by the use of sedative-hypnotic drugs, such as benzodiazepines and barbiturates.

Question 48: Which activation procedure is most effective for provoking absence seizures during a routine EEG?

Intermittent photic stimulation
Sleep deprivation
Hyperventilation (Correct answer)
Cold water caloric testing

Correct answer: Hyperventilation

Hyperventilation is the most effective provocative maneuver for absence seizures, eliciting 3 Hz spike-and-wave discharges in approximately 80-90% of patients with untreated typical absence epilepsy.

Question 49: A patient's EEG recording shows a focal discharge. To best define the point of maximum electronegativity and pinpoint the origin of the activity, which type of montage is most effective?

Laplacian montage
Bipolar 'double banana' montage
Transverse bipolar montage
Referential montage (Correct answer)

Correct answer: Referential montage

Referential montages compare the voltage of each scalp electrode to a single, common reference point. This configuration is particularly useful for determining the electrode with the highest amplitude abnormality, which helps to clarify the point of maximal electronegativity when it might be unclear on a bipolar view.

Question 50: A technologist is reviewing an EEG from an awake patient who was asked to scan a complex image. The recording shows bilateral, positive, sharply contoured waves in the occipital channels that occur only during the visual scanning task. These waveforms are most likely:

Epileptiform discharges
Vertex waves
Positive Occipital Sharp Transients of Sleep (POSTS)
Lambda waves (Correct answer)

Correct answer: Lambda waves

Lambda waves are normal, waking phenomena that are time-locked to saccadic eye movements, such as those that occur during visual scanning or reading. They are characteristically positive in polarity, have a sharp or triangular shape, and are located in the occipital regions.

Question 51: At what age does the posterior dominant rhythm typically reach the adult alpha frequency range of 8 Hz?

1 year
3 years (Correct answer)
8 years
6 months

Correct answer: 3 years

The posterior dominant rhythm gradually increases from approximately 3-4 Hz in infancy to 8 Hz by around age 3 years, continuing to increase to the full adult range of 8-13 Hz by approximately age 8-10 years.

Question 52: Which EEG frequency band is most prominent during deep NREM sleep (stage N3)?

Beta (13–30 Hz)
Theta (4–8 Hz)
Delta (0.5–4 Hz) (Correct answer)
Alpha (8–13 Hz)

Correct answer: Delta (0.5–4 Hz)

Stage N3 (slow-wave sleep) is defined by high-amplitude delta waves occupying at least 20% of the epoch.

Question 53: A patient post-cardiac arrest shows an EEG with suppression-burst ratio >50% and identical burst morphology across channels. What does this suggest?

Focal cortical dysplasia
Severe diffuse cortical injury with poor prognosis (Correct answer)
Therapeutic hypothermia artifact
Favorable prognosis for neurological recovery

Correct answer: Severe diffuse cortical injury with poor prognosis

High suppression-burst ratios with stereotyped bursts in post-cardiac arrest patients indicate severe anoxic brain injury and are associated with poor neurological outcomes.

Question 54: Generalized voltage attenuation (low-voltage EEG) with amplitudes below 20 µV throughout may be caused by:

Scalp edema, subdural fluid, or certain medications such as barbiturates (Correct answer)
Caffeine ingestion in the last hour
Photic driving response
Hyperventilation artifact

Correct answer: Scalp edema, subdural fluid, or certain medications such as barbiturates

Generalized low voltage can result from physical barriers between brain and electrodes (scalp edema, subdural effusions, thick skull) or from cortical suppression by medications like barbiturates, hypothermia, or severe diffuse brain injury.

Question 55: When performing a square wave calibration, the 'tilt' or slant on the flat top of the square wave most likely indicates a problem with:

Electrode impedance being too high
The high-frequency filter setting
The low-frequency filter (time constant) setting (Correct answer)
Amplifier gain being set too high

Correct answer: The low-frequency filter (time constant) setting

A tilted or slanted flat top on a square wave calibration signal indicates the low-frequency filter (time constant) is cutting off low-frequency components and distorting the sustained DC portion.

Question 56: What is the recommended distance between the photic stimulator and the patient's eyes during intermittent photic stimulation?

30 cm (Correct answer)
100 cm
200 cm
5 cm

Correct answer: 30 cm

The standard distance for the photic stimulator is approximately 30 cm from the patient's closed eyes, providing adequate light intensity for activation while maintaining patient comfort and safety.

Question 57: Which cortical layer contains the large pyramidal neurons (Betz cells) that give rise to corticospinal tract fibers?

Layer II
Layer IV
Layer V (Correct answer)
Layer VI

Correct answer: Layer V

Layer V (internal pyramidal layer) contains Betz cells, the large pyramidal neurons projecting to the spinal cord via the corticospinal tract.

Question 58: AAN guidelines recommend that ECI be recorded for a minimum duration of how many minutes of technically satisfactory tracing?

20 minutes
30 minutes (Correct answer)
10 minutes
60 minutes

Correct answer: 30 minutes

A minimum of 30 minutes of technically adequate recording is required. This duration helps ensure that any intermittent low-amplitude cerebral activity is not missed due to sampling too brief a window, and it provides a sufficient record for independent clinical review.

Question 59: The common mode rejection ratio (CMRR) of an EEG differential amplifier measures its ability to:

Filter out frequencies above 70 Hz
Maintain constant impedance across all electrodes
Amplify all signals equally across the frequency spectrum
Reject signals that are identical at both inputs while amplifying their difference (Correct answer)

Correct answer: Reject signals that are identical at both inputs while amplifying their difference

CMRR quantifies how effectively the differential amplifier rejects common-mode signals (those appearing equally at both inputs, such as 60 Hz noise) while preserving the differential signal (brain activity).

Question 60: Which of the following filter combinations would be most appropriate for routine clinical EEG recording to visualize cortical activity while minimizing slow-wave artifact and high-frequency noise?

Low-Frequency Filter (LFF) at 0.1 Hz, High-Frequency Filter (HFF) at 15 Hz
Low-Frequency Filter (LFF) at 1 Hz, High-Frequency Filter (HFF) at 35 Hz
Low-Frequency Filter (LFF) at 5 Hz, High-Frequency Filter (HFF) at 70 Hz
Low-Frequency Filter (LFF) at 1 Hz, High-Frequency Filter (HFF) at 70 Hz (Correct answer)

Correct answer: Low-Frequency Filter (LFF) at 1 Hz, High-Frequency Filter (HFF) at 70 Hz

Standard settings for routine EEG are a Low-Frequency Filter (LFF) of 1 Hz and a High-Frequency Filter (HFF) of 70 Hz. This 'band-pass' allows the typical range of cerebral frequencies (1-70 Hz) to be displayed while attenuating very slow activity (like sweat artifact) and very high-frequency activity (like muscle artifact). Setting the LFF too high (e.g., 5 Hz) can filter out clinically relevant delta activity, and setting the HFF too low (e.g., 15 or 35 Hz) can filter out fast activity like spikes or beta.

Question 61: During an EEG-recorded absence seizure, the 3 Hz spike-and-wave discharge is generated by abnormal oscillations between the cortex and which structure?

Thalamus (Correct answer)
Cerebellum
Hippocampus
Basal ganglia

Correct answer: Thalamus

Absence seizures arise from abnormal thalamocortical resonance, with cortical and thalamic circuits entraining at ~3 Hz spike-and-wave frequency.

Question 62: An EEG shows electrical status epilepticus during slow-wave sleep (ESES), with spike-wave index exceeding 85%. This pattern underlies which syndrome?

Ohtahara syndrome
Continuous spike-waves during slow sleep (CSWS) / Landau-Kleffner syndrome spectrum (Correct answer)
Lennox-Gastaut syndrome
Childhood absence epilepsy

Correct answer: Continuous spike-waves during slow sleep (CSWS) / Landau-Kleffner syndrome spectrum

ESES (spike-wave index > 85% during NREM sleep) is the electrographic hallmark of CSWS and Landau-Kleffner syndrome, associated with acquired cognitive or language regression.

Question 63: Lambda waves in the EEG are best elicited by which condition?

Active visual scanning of a patterned surface (Correct answer)
Auditory stimulation
Voluntary limb movement
Eye closure in a dark room

Correct answer: Active visual scanning of a patterned surface

Lambda waves are positive occipital transients that occur during active visual scanning (saccadic eye movements) of a patterned scene.

Question 64: Tracé alternant is a normal EEG pattern seen in which population?

Premature neonates during active sleep
Adults during deep anesthesia
Healthy term neonates during quiet sleep (Correct answer)
Adolescents during REM sleep

Correct answer: Healthy term neonates during quiet sleep

Tracé alternant is a normal discontinuous pattern in healthy full-term neonates during quiet (non-REM) sleep, consisting of alternating bursts of high-amplitude mixed activity and lower-amplitude periods.

Question 65: During hyperventilation, if the patient has an underlying brain tumor, you would most likely expect to see:

High-frequency gamma activity over the tumor site
Focal or lateralized slow-wave abnormality that increases in prominence (Correct answer)
Bilateral synchronous generalized slowing
Suppression of all EEG activity

Correct answer: Focal or lateralized slow-wave abnormality that increases in prominence

Focal structural lesions such as tumors typically produce focal or lateralized slow-wave abnormalities that are accentuated by hyperventilation-induced hypocapnia.

Question 66: In the International 10-20 system, what do the numbers 10 and 20 represent?

The number of electrodes used
The amplifier gain settings
The percentage of distance between skull landmarks for electrode placement (Correct answer)
The impedance levels required in kilohms

Correct answer: The percentage of distance between skull landmarks for electrode placement

The 10-20 system places electrodes at 10% and 20% intervals of the measured distances between standardized skull landmarks (nasion, inion, preauricular points).

Question 67: Which EEG pattern in a comatose patient is most associated with nonconvulsive status epilepticus (NCSE)?

Burst suppression with flat interburst intervals
Alpha coma pattern with unreactive background
Rhythmic or periodic discharges evolving in frequency or morphology (Correct answer)
Diffuse slowing with theta predominance

Correct answer: Rhythmic or periodic discharges evolving in frequency or morphology

Rhythmic or periodic discharges that evolve in frequency, morphology, or spatial distribution are the hallmark EEG feature of NCSE in critically ill patients.

Question 68: An EEG technologist discovers that a colleague has been omitting seizure events from written reports to speed up throughput. What is the most appropriate course of action?

Ignore it since the interpreting physician will catch any errors
Confront the colleague privately and ask them to stop
Begin correcting the colleague's reports without disclosure
Report the concern through the facility's established chain of command or compliance channel (Correct answer)

Correct answer: Report the concern through the facility's established chain of command or compliance channel

Omitting clinical data is an ethical and potentially legal violation requiring formal reporting through proper institutional channels.

Question 69: Temporal intermittent rhythmic delta activity (TIRDA) is significant because it:

Has a strong association with temporal lobe epilepsy even in the absence of spikes (Correct answer)
Indicates brainstem dysfunction
Is always a normal variant in elderly patients
Is caused by electrode artifact at temporal sites

Correct answer: Has a strong association with temporal lobe epilepsy even in the absence of spikes

TIRDA (temporal intermittent rhythmic delta activity) has a high correlation with temporal lobe epilepsy and is considered an epileptiform-equivalent pattern, even when no spikes or sharp waves are present.

Question 70: In a bipolar longitudinal montage, what is the typical chain order for the left hemisphere?

O1-P3-C3-F3-Fp1
Fp1-F7-T3-T5-O1
Fp1-F3-C3-P3-O1 (Correct answer)
F3-C3-P3-T3-O1

Correct answer: Fp1-F3-C3-P3-O1

The standard longitudinal bipolar (double banana) chain runs from front to back: Fp1-F3-C3-P3-O1 for the left parasagittal chain.

Question 71: The synchronization of cortical neurons necessary to produce normal resting rhythms and abnormal discharges like generalized spike-and-wave is heavily dependent on the integrity of:

The fornix and limbic pathways
Corticothalamic circuits (Correct answer)
Corticospinal tracts
Corpus callosum pathways

Correct answer: Corticothalamic circuits

Corticothalamic circuits, the reciprocal connections between the cortex and the thalamus, are fundamental for synchronizing neuronal activity across large brain regions. These circuits are responsible for pacing normal rhythms like sleep spindles and the alpha rhythm, and their dysfunction is implicated in the generation of widespread, synchronized discharges seen in generalized epilepsies.

Question 72: Slow, sinusoidal, high-amplitude waves that wax and wane over frontal electrodes in a drowsy, diaphoretic patient are most characteristic of:

Muscle artifact
Sweat artifact (Correct answer)
Eye movement artifact
Delta slowing

Correct answer: Sweat artifact

Sweat artifact produces slow (< 1 Hz), large-amplitude sinusoidal waves predominantly over frontal regions due to sweat gland activity.

Question 73: Which epileptiform feature specifically distinguishes a true spike from a sharp wave on EEG?

Presence of a following slow wave
Occurrence only during NREM sleep
Duration less than 70 ms vs. 70–200 ms (Correct answer)
Amplitude greater than 200 µV

Correct answer: Duration less than 70 ms vs. 70–200 ms

By convention, a spike has a duration of less than 70 ms, whereas a sharp wave has a duration of 70–200 ms; both may be followed by a slow wave.

Question 74: Which EEG feature differentiates true electrocerebral inactivity from a technical artifact producing an isoelectric-appearing record?

Switching to referential montage only
Increasing interelectrode distances, confirming low impedances, and testing reactivity with painful stimuli (Correct answer)
Performing a photic stimulation test
Recording for exactly 20 minutes

Correct answer: Increasing interelectrode distances, confirming low impedances, and testing reactivity with painful stimuli

Confirming ECI requires technical verification including electrode impedances <10 kΩ, interelectrode distance ≥10 cm, high sensitivity settings, and absence of reactivity to stimulation.

Question 75: A 9-month-old infant is evaluated for clusters of sudden, brief flexor spasms. The interictal EEG shows a chaotic, high-voltage, and disorganized pattern of asynchronous slow waves and multifocal spikes. Which of the following terms best describes this EEG pattern?

Triphasic waves
Hypsarrhythmia (Correct answer)
Burst-suppression
Slow spike-and-wave

Correct answer: Hypsarrhythmia

Hypsarrhythmia is the characteristic interictal EEG pattern associated with Infantile Spasms (West Syndrome). It is defined by its disorganized, high-amplitude, and chaotic appearance, with a mix of random slow waves and multifocal spikes.

Question 76: Periodic lateralized epileptiform discharges (PLEDs) are most commonly associated with which condition?

Normal drowsiness
Benign childhood epilepsy
Acute structural brain lesion such as stroke (Correct answer)
Metabolic encephalopathy

Correct answer: Acute structural brain lesion such as stroke

PLEDs (now called lateralized periodic discharges or LPDs) are strongly associated with acute destructive brain lesions, most commonly stroke, and may indicate ongoing seizure activity.

Question 77: A high-amplitude, sharply contoured discharge that appears only in a single channel and does not violate the "neighbor rule" of field spread is most likely:

A breach rhythm
An electrode artifact (Correct answer)
A vertex sharp wave
A focal interictal epileptiform discharge

Correct answer: An electrode artifact

True cerebral discharges have plausible electrical fields involving neighboring electrodes, so an isolated single-channel transient without field spread is likely artifactual.

Question 78: A 6-month-old infant is brought in for evaluation of developmental regression and clusters of flexor spasms that occur upon waking. The EEG shows a continuous, chaotic, and disorganized pattern of very high-voltage, asynchronous slow waves with multifocal spikes and sharp waves. This EEG pattern is called:

Burst-suppression
Extreme spindle coma
Tracé alternant
Hypsarrhythmia (Correct answer)

Correct answer: Hypsarrhythmia

The described EEG pattern is the classic presentation of hypsarrhythmia. It is characterized by its chaotic, disorganized, and high-amplitude ('mountainous') appearance with asynchronous slow waves and multifocal spikes. [8, 9, 10] This pattern is the interictal hallmark of West Syndrome, which includes the clinical triad of infantile spasms, hypsarrhythmia on EEG, and developmental delay or regression. [10]

Question 79: In a healthy, awake adult, the presence of excessive, generalized, and persistent theta activity (4-7 Hz) would most likely be interpreted as:

A normal posterior dominant rhythm.
A normal variant during hyperventilation.
Evidence of cerebral dysfunction. (Correct answer)
An indicator of deep relaxation.

Correct answer: Evidence of cerebral dysfunction.

While small amounts of theta activity can be normal, especially during drowsiness, excessive and persistent generalized theta activity in an awake adult is considered abnormal. It is a nonspecific indicator of generalized cerebral dysfunction or encephalopathy.

Question 80: Generalized periodic discharges (GPDs) are most classically associated with which condition?

Herpes simplex encephalitis
Acute ischemic stroke
Creutzfeldt-Jakob disease (CJD) (Correct answer)
Hypoxic-ischemic encephalopathy

Correct answer: Creutzfeldt-Jakob disease (CJD)

GPDs (formerly called generalized PLEDs or BiPLEDs) with a triphasic morphology are classically associated with CJD, though they also appear in metabolic encephalopathies.

Question 81: What is the standard calibration signal used to verify EEG amplifier function?

A 200 µV sine wave at 60 Hz
A 50 µV square wave at 1 Hz (Correct answer)
A 100 µV triangle wave at 5 Hz
A 10 µV sine wave at 10 Hz

Correct answer: A 50 µV square wave at 1 Hz

The standard calibration signal is a 50 µV square wave at 1 Hz. This verifies amplifier gain accuracy, frequency response, and channel matching across the system.

Question 82: The posterior dominant rhythm (PDR) in a healthy 8-year-old child is expected to have a frequency of approximately:

4-5 Hz
11-12 Hz
6-7 Hz
9 Hz (Correct answer)

Correct answer: 9 Hz

The frequency of the posterior dominant rhythm matures with age. It starts around 3-4 Hz in infants, reaches 8 Hz by about age 3, and typically achieves a frequency of 9 Hz by age 8. It stabilizes in the adult alpha range of 8-13 Hz in the early teen years.

Question 83: Which artifact would most likely appear as a high-amplitude, low-frequency deflection time-locked to the R-wave on ECG?

Electrode pop
Pulse artifact (Correct answer)
Sweat artifact
Chewing artifact

Correct answer: Pulse artifact

Pulse artifact is caused by scalp vessel pulsations under electrodes and appears as slow deflections synchronous with the cardiac cycle.

Question 84: During a routine EEG on a 25-year-old patient, the technologist observes intermittent bursts of 7-11 Hz, arch-shaped waves over the central head regions (C3, C4, Cz). This activity disappears when the patient is asked to make a fist. What normal EEG variant is being described?

Sleep spindles
Posterior slow waves of youth
Lambda waves
Mu rhythm (Correct answer)

Correct answer: Mu rhythm

The Mu rhythm is a normal variant found in the alpha frequency range (typically 7-11 Hz) with a characteristic arch-like or comb shape. It is located over the central regions (sensorimotor cortex) and is uniquely blocked or attenuated by contralateral motor activity, the thought of movement, or tactile stimulation, but not by eye opening.

Question 85: What is the primary purpose of the 'biological calibration' signal used in EEG systems?

To calibrate the ink-jet speed of the chart recorder
To eliminate 60 Hz interference from the recording
To verify the amplifier gain using a known physiological signal (Correct answer)
To set the low-frequency filter cutoff automatically

Correct answer: To verify the amplifier gain using a known physiological signal

Biological calibration uses a known physiological signal (such as eye blink artifact) to verify that amplifier gain and channel balance are consistent across all channels.

Question 86: Theta waves' frequency is

8–13 Hertz
More than thirteen hertz
less than four Hz
4–7 Hertz (Correct answer)

Correct answer: 4–7 Hertz

Brainwaves known as theta waves can happen during deep relaxation or light sleep. They oscillate at a rate of 4 to 7 cycles per second, with a frequency range of 4-7 Hertz. Deep concentration, improved memory, and increased creativity are all linked to this frequency range. Deep sleep is usually associated with frequencies below 4 Hertz, while wakefulness and relaxation are related with frequencies above 7 Hertz, which are connected with alpha waves. Therefore, 4–7 Hertz is the right response.

Question 87: The time constant of an EEG amplifier determines:

The maximum amplitude the amplifier can display
The number of channels that can record simultaneously
The rate at which a DC-shifted signal decays back to baseline through the low-frequency filter (Correct answer)
How quickly the amplifier reaches maximum gain

Correct answer: The rate at which a DC-shifted signal decays back to baseline through the low-frequency filter

The time constant represents the time it takes for a DC-shifted square wave calibration signal to decay to 37% of its initial value. It is directly related to the low-frequency filter setting.

Question 88: An alert and oriented adult patient provides consent for an EEG but adamantly refuses the hyperventilation (HV) activation procedure due to a history of panic attacks. Which of the following is the most appropriate course of action for the technologist?

Insist that the patient attempt HV, as it is a required part of the standard procedure.
Cancel the entire EEG study because it will be incomplete without the activation.
Respect the patient's refusal, document it on the record, and proceed with the remainder of the EEG. (Correct answer)
Ask a family member to convince the patient to perform the procedure.

Correct answer: Respect the patient's refusal, document it on the record, and proceed with the remainder of the EEG.

Competent adult patients have the right to refuse any part of a medical procedure. The technologist must respect the patient's autonomy. The proper action is to document the refusal clearly on the technologist's report and continue with the other parts of the study, such as photic stimulation and obtaining a sleep recording.

Question 89: What is the normal frequency range of the posterior dominant rhythm (alpha rhythm) in a healthy awake adult?

4-7 Hz
8-13 Hz (Correct answer)
21-30 Hz
14-20 Hz

Correct answer: 8-13 Hz

The normal adult posterior dominant rhythm falls within the alpha frequency band of 8-13 Hz, typically with a mean frequency around 10 Hz. It is best seen over the occipital regions with eyes closed.

Question 90: Which action by an EEG technologist during a video-EEG monitoring session could constitute a HIPAA violation?

Posting an anonymized educational clip on a social media platform without explicit patient authorization (Correct answer)
Reviewing the recording with the supervising neurologist on a secure workstation
Documenting behavioral events in the patient's medical record
Storing the recording on the facility's encrypted server with access restricted to the care team

Correct answer: Posting an anonymized educational clip on a social media platform without explicit patient authorization

Posting any patient recording — even anonymized — to social media without specific written HIPAA authorization is a privacy violation.

Question 91: An EEG technologist is performing a biological calibration. The patient is asked to open and close their eyes, look left and right, and clench their jaw. What is the primary purpose of this procedure?

To warm up the EEG amplifiers and ensure they are functioning.
To verify the integrity of the recording system by generating physiological artifacts and confirming correct channel derivations. (Correct answer)
To measure the baseline impedance of the scalp electrodes.
To assess the patient's level of cooperation before starting the recording.

Correct answer: To verify the integrity of the recording system by generating physiological artifacts and confirming correct channel derivations.

Biological calibration (bio-cal) is essential to ensure the entire recording pathway is functioning correctly. By having the patient perform specific actions that are known to create distinct physiological artifacts (like eye movements and muscle tension), the technologist can confirm that electrodes are correctly placed and connected to the appropriate channels in the montage, and that the amplifiers are displaying these signals as expected.

Question 92: Which artifact is most commonly encountered in ambulatory EEG recordings compared to in-lab studies?

Movement and muscle artifact (Correct answer)
60 Hz electrical interference
Electrode pop artifact
Sweat artifact

Correct answer: Movement and muscle artifact

Movement and muscle artifact are the most common artifacts in ambulatory EEG because patients are performing their normal daily activities, unlike the controlled laboratory environment.

Question 93: In the 10-20 system, which electrode is located at the vertex of the skull?

Cz (Correct answer)
Pz
C3
Fz

Correct answer: Cz

Cz is located at the vertex (top) of the skull at the intersection of the midline and a line connecting the two ears.

Question 94: In a healthy 3-year-old child, the posterior dominant rhythm (PDR) during relaxed wakefulness with eyes closed is expected to have a frequency of approximately:

6-7 Hz
10-12 Hz
8-9 Hz (Correct answer)
4-5 Hz

Correct answer: 8-9 Hz

The posterior dominant rhythm (PDR), or alpha rhythm, matures with age. It begins around 3-4 Hz at a few months of age and should reach the alpha frequency range of 8 Hz by approximately 3 years of age. [2] A PDR of 4-5 Hz would be too slow for a 3-year-old, while 10-12 Hz is more typical of an older child or adult. 6-7 Hz would be expected around 12 months of age.

Question 95: The American Clinical Neurophysiology Society (ACNS) standardized critical care EEG terminology defines a periodic discharge as a waveform recurring at a rate of at least:

≥2 Hz for ≥4 cycles
≥1 Hz for ≥6 cycles (Correct answer)
≥3 Hz for ≥3 cycles
≥0.5 Hz for ≥10 cycles

Correct answer: ≥1 Hz for ≥6 cycles

ACNS 2021 criteria define periodic discharges as recurring ≥1 Hz with ≥6 consecutive cycles showing a consistent morphology.

Question 96: Which of the following would prompt the technologist to STOP hyperventilation immediately?

The patient appears slightly drowsy
The patient reports mild tingling in the fingertips
The patient develops a tonic-clonic seizure (Correct answer)
The patient exhibits build-up of generalized slow waves

Correct answer: The patient develops a tonic-clonic seizure

A tonic-clonic seizure requires immediate cessation of HV and initiation of seizure safety protocols and notification of supervising physician.

Question 97: During hyperventilation in a normal adult, what EEG change is expected?

Onset of sleep spindles
Increased high-amplitude slow activity (Correct answer)
Complete EEG suppression
Increased beta activity

Correct answer: Increased high-amplitude slow activity

Hyperventilation causes cerebral vasoconstriction and hypocapnia, producing diffuse high-amplitude slow (delta/theta) activity in normal subjects.

Question 98: What impedance level is considered acceptable for EEG electrodes before starting a recording?

Below 500 ohms
Below 5,000 ohms (5 kΩ) (Correct answer)
Below 50,000 ohms
Below 100 kΩ

Correct answer: Below 5,000 ohms (5 kΩ)

Electrode impedances should be below 5 kΩ (and ideally matched between electrodes) to ensure low-artifact, high-quality recordings.

Question 99: A 35-year-old has a sleep onset latency to REM (SOREMP) of 8 minutes on overnight PSG. This finding is most suggestive of:

Idiopathic insomnia
Obstructive sleep apnea
Delayed sleep phase disorder
Narcolepsy (Correct answer)

Correct answer: Narcolepsy

A REM latency of ≤20 minutes (SOREMP) on nocturnal PSG is a key diagnostic criterion for narcolepsy.

Question 100: In a bipolar longitudinal (anterior-posterior) montage, a phase reversal at C3 indicates:

An artifact at the C3 electrode
Maximum negativity or positivity at C3 (Correct answer)
Activity originating from the contralateral hemisphere
The C3 electrode has high impedance

Correct answer: Maximum negativity or positivity at C3

A phase reversal occurs where adjacent channels sharing an electrode deflect in opposite directions, indicating the electrode at the reversal point has the maximum voltage for that event.

Question 101: An EEG electrode placed at C3, according to the International 10-20 System, primarily records activity from which cortical region?

The primary auditory cortex (Brodmann areas 41, 42)
The prefrontal cortex (Brodmann areas 9, 10)
The primary motor and somatosensory cortex (Brodmann areas 4, 1, 2, 3) (Correct answer)
The primary visual cortex (Brodmann area 17)

Correct answer: The primary motor and somatosensory cortex (Brodmann areas 4, 1, 2, 3)

The central electrodes (C3, Cz, C4) are situated over the Rolandic fissure (central sulcus). This area encompasses the precentral gyrus (primary motor cortex, Brodmann area 4) and the postcentral gyrus (primary somatosensory cortex, Brodmann areas 1, 2, and 3).

Question 102: In a longitudinal bipolar montage, often called a 'double banana', how are the electrodes connected?

In chains running from the left to the right side of the head.
To a single common reference electrode, such as the vertex (Cz).
Each electrode is compared to a weighted average of its surrounding electrodes.
In chains running from anterior to posterior regions of the head. (Correct answer)

Correct answer: In chains running from anterior to posterior regions of the head.

The longitudinal bipolar montage, or 'double banana', consists of chains of electrodes linked from front to back. For example, a temporal chain might connect Fp1-F7, F7-T3, T3-T5, and T5-O1. This arrangement is excellent for identifying phase reversals, which help localize the source of an abnormality between two adjacent electrodes.

Question 103: The lambda wave is a positive sharp transient that occurs in the occipital region during:

Hyperventilation
Deep sleep stage N3
Eye closure in a dark room
Active visual scanning of a complex image or environment (Correct answer)

Correct answer: Active visual scanning of a complex image or environment

Lambda waves are positive sharp transients over the occipital regions that occur during visual scanning with saccadic eye movements. They represent cortical responses to visual input during active looking.

Question 104: Which principle of biomedical ethics requires the EEG technologist to provide adequate information before obtaining consent for photic stimulation?

Autonomy (Correct answer)
Non-maleficence
Justice
Beneficence

Correct answer: Autonomy

Autonomy requires that patients receive sufficient information to make an informed decision about procedures such as photic stimulation.

Question 105: Which of the following is the LEAST likely cause of persistent 60 Hz electrical interference in an EEG recording?

The patient's rhythmic chewing or teeth clenching. (Correct answer)
A frayed power cord on the EEG machine or patient's bed.
A nearby unplugged piece of medical equipment in the room.
Unbalanced electrode impedances, with one being significantly higher than the others.

Correct answer: The patient's rhythmic chewing or teeth clenching.

Chewing and teeth clenching produce electromyographic (EMG) artifact, which is high-frequency but is generated by muscle activity and is not locked to the 60 Hz power line frequency. The other options are all common sources of electrical interference that can introduce 60 Hz noise into a recording.

Question 106: An 8-year-old child presents with frequent staring spells. The EEG recording shows bursts of generalized, synchronous, and symmetric 3 Hz spike-and-wave discharges that are easily provoked by hyperventilation. What is the most likely clinical correlation?

Childhood absence epilepsy (Correct answer)
Juvenile myoclonic epilepsy
Benign Rolandic epilepsy
Lennox-Gastaut syndrome

Correct answer: Childhood absence epilepsy

The classic EEG signature for typical childhood absence epilepsy is generalized, symmetric 3 Hz spike-and-wave discharges, often induced by hyperventilation, which correlates clinically with brief staring spells. Lennox-Gastaut syndrome presents with slow (<2.5 Hz) spike-and-wave, Benign Rolandic epilepsy shows focal centrotemporal spikes, and Juvenile myoclonic epilepsy typically has faster (>3 Hz) polyspike-and-wave discharges.

Question 107: An 82-year-old patient with severe dementia is brought from a nursing home for a routine EEG. The patient is unable to state their name or understand the procedure. Who is the most appropriate individual to provide informed consent for the EEG?

The patient, after the technologist explains in very simple terms.
The ordering neurologist who determined the procedure was necessary.
The registered nurse who accompanied the patient from the facility.
The patient's legally authorized representative or next of kin. (Correct answer)

Correct answer: The patient's legally authorized representative or next of kin.

When a patient lacks the cognitive capacity to make an informed decision, consent must be obtained from their legally authorized representative (e.g., a person with durable power of attorney for healthcare or a legal guardian). This individual is empowered to make healthcare decisions on the patient's behalf. The ordering physician determines medical necessity but cannot provide consent for the patient, and an accompanying nurse typically does not have legal authority to consent unless they are also the legal representative.

Question 108: Glossokinetic artifact is caused by movement of which structure?

The scalp muscles during frowning
The jaw muscles during chewing
The tongue, which acts as an electrical dipole (Correct answer)
The diaphragm during breathing

Correct answer: The tongue, which acts as an electrical dipole

The tongue has a tip-negative, base-positive electrical dipole. Tongue movements generate slow potentials that are transmitted to scalp electrodes, particularly in frontal and temporal regions.

Question 109: A patient undergoing a prolonged EEG develops a stage IV pressure ulcer under a scalp electrode. This outcome best represents a failure in which ethical principle?

Justice
Veracity
Autonomy
Non-maleficence (Correct answer)

Correct answer: Non-maleficence

Non-maleficence — the duty to avoid causing harm — is violated when preventable pressure injuries occur due to inadequate electrode site monitoring.

Question 110: A technologist is reviewing an EEG on a digital system and wants to enhance the visualization of a very localized, focal discharge while minimizing the influence from distant, widespread activity. Which montage would be the most appropriate choice?

Average reference montage
Laplacian montage (Correct answer)
Contralateral ear reference montage
Longitudinal bipolar montage

Correct answer: Laplacian montage

The Laplacian montage, also known as a source derivation or local average reference, is specifically designed to highlight focal activity. It calculates the voltage at each electrode relative to a weighted average of its immediate surrounding electrodes. This technique enhances localized events and reduces the effect of widespread or distant electrical fields.

Question 111: Generalized periodic discharges (GPDs) at 1-2 Hz intervals with triphasic morphology are most characteristic of which condition?

Hepatic encephalopathy (Correct answer)
Benign rolandic epilepsy
Lennox-Gastaut syndrome
Juvenile myoclonic epilepsy

Correct answer: Hepatic encephalopathy

Triphasic waves appearing as generalized periodic discharges are classically associated with metabolic encephalopathies, particularly hepatic encephalopathy, though they can be seen in other toxic-metabolic states.

Question 112: During a routine EEG, the technologist observes the patient staring blankly and becoming unresponsive. The appropriate action is to:

Wait until the episode ends to note it in the report
Disconnect the electrodes to examine the patient
Immediately stop the recording and call a code
Continue recording while testing the patient's responsiveness and documenting observations (Correct answer)

Correct answer: Continue recording while testing the patient's responsiveness and documenting observations

The technologist should keep recording to capture the EEG correlate of the clinical event while simultaneously testing responsiveness (speaking to the patient, presenting objects) and carefully documenting all observations with timestamps.

Question 113: What is the recommended minimum distance between the photic stimulator and the patient's eyes during IPS?

10 cm
5 cm
30 cm (Correct answer)
1 meter

Correct answer: 30 cm

The photic stimulator is typically placed approximately 30 cm (about 12 inches) from the patient's eyes to ensure adequate luminance without discomfort or retinal risk.

Question 114: Which scenario represents an appropriate use of physical restraint during a pediatric EEG?

Using a papoose board with parental consent and physician order when medically necessary and less restrictive methods have failed (Correct answer)
Applying wrist restraints routinely to prevent electrode displacement in all children under age 5
Using restraints whenever a child cries during electrode application
Restraining a cooperative child simply to shorten setup time

Correct answer: Using a papoose board with parental consent and physician order when medically necessary and less restrictive methods have failed

Restraint requires a physician order, parental consent, documented failure of alternatives, and must be the least restrictive option necessary.

Question 115: During a routine EEG, the patient closes his eyes and 10 Hz activity appears posteriorly. When he opens his eyes this activity disappears. This is consistent with:

Posterior slow waves of youth
Occipital seizure activity
Normal alpha rhythm with eye-opening attenuation (Correct answer)
Breach rhythm

Correct answer: Normal alpha rhythm with eye-opening attenuation

Alpha rhythm (8–13 Hz) generated in the occipital cortex is reactive to eye opening and represents a normal, awake, relaxed EEG finding.

Question 116: Two elements that are situated on different sides of the baseline.

Sharp Temporary
The epileptiform
Triphasic
Diphasic (Correct answer)

Correct answer: Diphasic

A waveform or signal that has two separate phases or components is referred to be diphasic. The two elements listed in the question are situated on different sides of the baseline in this particular situation. Since diphasic adequately represents the waveform with two phases, it is the correct response.

Question 117: Waveforms connected to and unrelated from clinical seizure symptoms.

Unusual Behavior
Interictal
The epileptiform (Correct answer)
Pyroclastic

Correct answer: The epileptiform

Waveforms indicative of epilepsy or seizure activity are referred to as "epileptiforms". When performing an electroencephalogram (EEG), a test used to identify and track seizures, these waves can be seen. Abnormal electrical discharges in the brain called epileptiform waveforms are frequently linked to clinical seizure symptoms including convulsions or loss of consciousness. Consequently, the best term to characterize waveforms linked to clinical seizure symptoms is "epileptiform".

Question 118: During an EEG on a febrile and diaphoretic patient, the technologist observes very slow, undulating, low-frequency (<0.5 Hz) waves that are widespread and cause the baselines of multiple channels to sway. This pattern is most characteristic of which type of artifact?

Pulse artifact
Sweat artifact (Correct answer)
Glossokinetic artifact
Respiration artifact

Correct answer: Sweat artifact

Sweat (perspiration) changes the electrical properties and conductivity at the skin-electrode interface. This change in impedance creates very slow, rolling baseline sway, also known as galvanic skin response (GSR), which is consistent with the described pattern.

Question 119: A wave consisting of three parts that alternate around the baseline.

Transient
Monophasic
Triphasic (Correct answer)
Polyphasic

Correct answer: Triphasic

A wave that alternates between three components around the baseline is referred to as triphasic. This indicates that the wave is composed of three separate stages, or segments, that alternate in a cyclical manner. This phrase is frequently used to characterize certain electrical or physiological waveforms, such as those in muscle activity or nerve transmission, in medical and physiological contexts.

Question 120: Photic stimulation at what flash frequency range is most likely to provoke a photoparoxysmal response in susceptible individuals?

15-20 Hz (Correct answer)
30-40 Hz
1-3 Hz
50-60 Hz

Correct answer: 15-20 Hz

The photoparoxysmal response, characterized by generalized spike-and-wave or polyspike-and-wave discharges, is most commonly elicited at flash frequencies between 15-20 Hz.

Question 121: Amplitude-integrated EEG (aEEG) is most commonly used in which clinical setting?

Intraoperative monitoring during spinal cord surgery
Outpatient ambulatory studies in adults with suspected absence epilepsy
Neonatal intensive care units for continuous cerebral monitoring of high-risk newborns (Correct answer)
Adult outpatient epilepsy monitoring units for seizure localization

Correct answer: Neonatal intensive care units for continuous cerebral monitoring of high-risk newborns

aEEG was developed specifically for continuous cerebral function monitoring in neonates. It compresses and amplitude-integrates the EEG into a single trend channel, making it practical for bedside nurses and neonatologists to monitor brain activity, detect seizures, and assess background continuity in premature and term newborns with hypoxic-ischemic encephalopathy.

Question 122: Which EEG pattern is characterized by a spike followed by a slow wave complex occurring at approximately 3 Hz?

Burst suppression
Generalized 3 Hz spike-and-wave (Correct answer)
Hypsarrhythmia
Periodic lateralized epileptiform discharges

Correct answer: Generalized 3 Hz spike-and-wave

The classic 3 Hz spike-and-wave pattern is the hallmark of childhood absence epilepsy, appearing as generalized, synchronous, bilateral discharges.

Question 123: A 68-year-old patient with a history of a craniotomy for a meningioma resection presents for a routine EEG. The recording shows a focal area of high-amplitude, sharp, and at times spiky-appearing 6-11 Hz activity directly over the surgical site. This activity is persistent across both awake and drowsy states. Which feature would most strongly differentiate this as Breach Rhythm rather than an epileptiform abnormality?

The presence of intermixed beta frequencies.
Its focal and asymmetric nature.
The high amplitude of the activity compared to the contralateral side.
The absence of an after-going slow wave. (Correct answer)

Correct answer: The absence of an after-going slow wave.

A key distinguishing feature between Breach Rhythm and a true epileptiform discharge is that Breach Rhythm consists of sharp or spiky transients that are not followed by a slow-wave component. [3, 7] While increased amplitude, focal asymmetry, and intermixed faster frequencies are all characteristic of Breach Rhythm, the lack of an associated slow wave is the most definitive feature to rule out an epileptiform spike or sharp wave. [3, 6, 7]

Question 124: Which of the following electrographic features is most characteristic of an ictal event (electrographic seizure) in a full-term neonate?

Generalized, synchronous 3 Hz spike-and-wave discharges.
Intermittent, asynchronous bursts of high-voltage slow waves mixed with spikes (Hypsarrhythmia).
Bilaterally synchronous and symmetric sleep spindles.
A sustained, rhythmic, evolving pattern of sharp waves or delta activity lasting more than 10 seconds. (Correct answer)

Correct answer: A sustained, rhythmic, evolving pattern of sharp waves or delta activity lasting more than 10 seconds.

The gold standard for identifying a neonatal electrographic seizure is the presence of a sustained, rhythmic discharge that shows clear evolution in frequency, morphology, or location and lasts for at least 10 seconds. [5, 26] Neonatal seizures are typically focal in onset and can consist of various morphologies, including rhythmic delta or sharp activity. [5] Generalized 3 Hz spike-and-wave is typical of absence seizures in older children, hypsarrhythmia is an interictal pattern, and sleep spindles are normal sleep architecture.

Question 125: In a term neonate, which finding on EEG is most consistent with hypoxic-ischemic encephalopathy (HIE)?

Continuous high-amplitude delta activity
Burst suppression with prolonged inter-burst intervals (Correct answer)
Well-organized trace alternant
Abundant sleep spindles

Correct answer: Burst suppression with prolonged inter-burst intervals

Burst suppression with prolonged inter-burst intervals (>10 seconds) in a term neonate is a marker of severe cerebral dysfunction associated with HIE.

Question 126: Which measurement is most commonly used to identify BAEP abnormalities related to central conduction?

Interpeak latencies (IPLs) between waves (Correct answer)
Stimulus intensity threshold
Absolute wave I latency alone
Peak-to-trough amplitudes

Correct answer: Interpeak latencies (IPLs) between waves

Interpeak latencies (e.g., I–III, III–V, I–V) reflect central conduction time between brainstem generators and are the primary diagnostic parameters for central pathology.

Question 127: What minimum area of synchronously active cortex is typically required to produce a detectable signal on scalp EEG?

100 cm²
25 cm²
1 cm²
6 cm² (Correct answer)

Correct answer: 6 cm²

Approximately 6 cm² (some estimates range from 6-10 cm²) of synchronously active cortex is needed to generate sufficient electrical potential to be detected through the skull, meninges, and scalp by surface electrodes.

Question 128: A technologist notices that channel 3 shows a 50% smaller deflection than all other channels during the calibration square wave. The most likely cause is:

A 60 Hz artifact contaminating channel 3
A broken or high-impedance electrode on channel 3
The notch filter being activated on channel 3
Gain set too low on the channel 3 amplifier (Correct answer)

Correct answer: Gain set too low on the channel 3 amplifier

When one channel shows a consistently smaller deflection than others during a known calibration signal, the amplifier gain for that channel is set too low.

Question 129: In cEEG monitoring, an alpha coma pattern is characterized by:

Alpha rhythm appearing only during REM sleep
Frontal alpha with preserved posterior reactivity
Diffuse, unreactive alpha-frequency activity in a comatose patient (Correct answer)
Reactive alpha in a drowsy but arousable patient

Correct answer: Diffuse, unreactive alpha-frequency activity in a comatose patient

Alpha coma features widespread alpha or alpha-like activity that is unresponsive to external stimuli, often seen after cardiac arrest or pontine lesions, and carries a poor prognosis.

Question 130: A photic driving response seen on EEG during IPS is considered normal when it occurs at:

Frequencies above 60 Hz
Harmonic or subharmonic frequencies of the flash rate over the occipital region (Correct answer)
Frontal regions only at any frequency
Only during simultaneous HV

Correct answer: Harmonic or subharmonic frequencies of the flash rate over the occipital region

Normal photic driving is a rhythmic occipital response at the flash frequency or its harmonics/subharmonics and represents normal visual cortex activation.

Question 131: Which EEG pattern during absence status epilepticus distinguishes it from typical 3-Hz absence discharges?

Discharges shift to posterior head regions
The spike component disappears leaving pure slow waves
The discharges become fragmented, irregular, and slower (< 2.5 Hz) over time (Correct answer)
Amplitude increases progressively to > 500 µV

Correct answer: The discharges become fragmented, irregular, and slower (< 2.5 Hz) over time

During prolonged absence status epilepticus, the initially regular 3-Hz spike-and-wave tends to slow, fragment, and become irregular as status continues.

Question 132: Sleep spindles are generated primarily by thalamocortical circuits involving which thalamic nucleus?

Pulvinar
Lateral geniculate nucleus
Centromedian nucleus
Reticular nucleus of the thalamus (Correct answer)

Correct answer: Reticular nucleus of the thalamus

The thalamic reticular nucleus acts as a pacemaker for sleep spindles through rhythmic inhibitory postsynaptic potentials to relay nuclei.

Question 133: Delta activity (0.5-4 Hz) in a normal awake adult EEG is considered abnormal because it typically indicates:

Normal arousal response
Increased alpha variant activity
Cortical dysfunction from structural or metabolic causes (Correct answer)
Enhanced attention and concentration

Correct answer: Cortical dysfunction from structural or metabolic causes

In awake adults, delta activity is abnormal and suggests cortical or subcortical dysfunction. Focal delta suggests structural lesion; generalized delta suggests diffuse encephalopathy or deep midline dysfunction.

Question 134: Which EEG background feature in a comatose patient after cardiac arrest is associated with the BEST neurological prognosis?

Burst suppression with identical bursts
Electrocerebral silence
Continuous background with preserved reactivity (Correct answer)
Generalized suppression <10 µV

Correct answer: Continuous background with preserved reactivity

A continuous EEG background with preserved reactivity to stimulation is the most favorable prognostic finding in post-cardiac arrest coma, suggesting intact cortical function.

Question 135: In a normal adult EEG, what is the expected effect of opening the eyes on the posterior alpha rhythm?

Alpha amplitude increases
Alpha frequency increases by 4 Hz
Alpha spreads to frontal regions
Alpha is attenuated or blocked (Correct answer)

Correct answer: Alpha is attenuated or blocked

Eye opening causes alpha blocking (Berger effect), suppressing posterior alpha due to visual cortex activation.

Question 136: On a neonatal EEG, which feature best distinguishes a seizure discharge from a normal sharp transient?

Amplitude exceeding 100 µV
Evolution in frequency, amplitude, or spatial distribution over time (Correct answer)
Presence of a post-ictal suppression lasting 1 second
Occurrence during active sleep

Correct answer: Evolution in frequency, amplitude, or spatial distribution over time

Neonatal seizures are defined by electrographic evolution — a clear change in frequency, morphology, or field — rather than by a fixed amplitude or sleep-state rule.

Question 137: According to American Clinical Neurophysiology Society (ACNS) and AAN guidelines, what is the minimum sensitivity required when recording an EEG to assess for electrocerebral inactivity (ECI)?

7 µV/mm
10 µV/mm
5 µV/mm
2 µV/mm (Correct answer)

Correct answer: 2 µV/mm

AAN/ACNS guidelines require a minimum sensitivity of 2 µV/mm (equivalent to ≤2 µV/mm) during ECI recordings so that very low-amplitude cerebral activity is not missed. Standard clinical sensitivity (7 µV/mm) would be insufficiently sensitive for this purpose.

Question 138: Which of the following best describes the neurophysiological basis for why a minimum cortical area of approximately 6-20 cm² must be synchronously activated to generate a detectable scalp EEG signal?

The specific firing frequency of pyramidal neurons
The requirement for bilateral hemispheric involvement for any recordable potential
The filtering effect of the skull and scalp, which attenuates small or asynchronous signals (Correct answer)
The high electrical impedance of the cerebrospinal fluid

Correct answer: The filtering effect of the skull and scalp, which attenuates small or asynchronous signals

The skull, dura, and scalp act as low-pass filters and have high electrical resistance, a process known as volume conduction. This significantly attenuates the electrical potentials generated by the brain. Therefore, a large area of cortex with thousands of neurons firing synchronously is required to produce a signal strong enough to overcome this impedance and be detected by scalp electrodes.

Question 139: Generalized background slowing with intermittent frontal rhythmic delta activity (FIRDA) in an adult typically indicates:

Posterior fossa tumor
Focal frontal lobe epilepsy
Normal aging changes
Diffuse encephalopathy or deep midline dysfunction (Correct answer)

Correct answer: Diffuse encephalopathy or deep midline dysfunction

FIRDA (now called generalized rhythmic delta activity with frontal predominance or GRDA) is a non-specific finding indicating diffuse cerebral dysfunction from metabolic, toxic, or structural causes affecting deep midline structures.

Question 140: A differential amplifier's ability to reject signals that are common to both of its inputs is measured by which of the following specifications?

Sensitivity
Low-Frequency Filter
Input Impedance
Common Mode Rejection Ratio (CMRR) (Correct answer)

Correct answer: Common Mode Rejection Ratio (CMRR)

The Common Mode Rejection Ratio (CMRR) is a critical specification for a differential amplifier. It quantifies how well the amplifier can cancel out identical signals (common mode) present at both input terminals, while amplifying the difference between them. A high CMRR is crucial in EEG to eliminate widespread electrical noise and interference.

Question 141: A technologist uses a short-time constant (high-pass filter increase) to reduce which type of artifact?

Electrode pop
Muscle artifact
Slow sweat artifact (Correct answer)
60 Hz line noise

Correct answer: Slow sweat artifact

Increasing the high-pass (low frequency) filter shortens the time constant and attenuates slow, DC-shift sweat artifact.

Question 142: What is the maximum recommended electrode impedance for routine EEG recording according to ACNS guidelines?

10 kOhm
1 kOhm
20 kOhm
5 kOhm (Correct answer)

Correct answer: 5 kOhm

The American Clinical Neurophysiology Society recommends electrode impedances be below 5 kOhm and balanced across all electrodes to optimize signal quality and common-mode rejection.

Question 143: A technologist notices the patient begins breathing very slowly and shallowly during hyperventilation. The best action is to:

Document it and continue without intervention
Stop the test immediately and call a physician
Increase the flash rate on the photic stimulator simultaneously
Verbally coach the patient to breathe more deeply and consistently (Correct answer)

Correct answer: Verbally coach the patient to breathe more deeply and consistently

Verbal coaching helps the patient maintain adequate depth and rate of breathing to achieve the desired hypocapnic effect.

Question 144: What is the purpose of the ground electrode in an EEG recording?

To serve as the primary reference
To measure impedance across the scalp
To detect eye movement artifacts
To reduce common-mode noise and electrical interference (Correct answer)

Correct answer: To reduce common-mode noise and electrical interference

The ground electrode helps the amplifier reject common-mode noise and electrical interference by providing a reference point for the differential amplifier.

Question 145: Positive Occipital Sharp Transients of Sleep (POSTS) and Lambda waves are two non-epileptiform patterns that share a similar morphology and occipital location. What is the primary distinguishing feature between them?

The frequency of the transients.
The polarity of the sharp component.
The symmetry of the waveforms.
The patient's state of consciousness. (Correct answer)

Correct answer: The patient's state of consciousness.

The key factor that differentiates POSTS from Lambda waves is the patient's state. Lambda waves occur exclusively during the awake state when the patient's eyes are open and they are visually scanning their environment. [38, 40] In contrast, POSTS are a hallmark of drowsiness and light sleep (N1/N2) and disappear when the patient is awake. [28, 30, 32]

Question 146: According to the American Clinical Neurophysiology Society (ACNS) guidelines, an epileptiform discharge is classified as a 'sharp wave' based on which of the following duration ranges?

> 200 milliseconds
70-200 milliseconds (Correct answer)
20-70 milliseconds
< 20 milliseconds

Correct answer: 70-200 milliseconds

A sharp wave is defined as a transient with a pointed peak and a duration of 70 to 200 milliseconds. Discharges with a duration of less than 70 ms are classified as spikes, and waves lasting longer than 200 ms are considered slow waves.

Question 147: Which antiepileptic drug effect on the EEG may be mistaken for a pathological finding if the technologist is unaware of the patient's medication list?

Valproate at therapeutic levels causing diffuse slowing that mimics metabolic encephalopathy (Correct answer)
Phenytoin toxicity causing rhythmic beta activity indistinguishable from normal
Lamotrigine causing prominent mu rhythm enhancement
Carbamazepine causing bifrontal spike-and-wave discharges

Correct answer: Valproate at therapeutic levels causing diffuse slowing that mimics metabolic encephalopathy

Valproate, even at therapeutic serum levels, can produce diffuse background slowing that resembles a mild encephalopathy. Without knowing the patient is on valproate, the EEG reader could incorrectly diagnose a metabolic or structural abnormality. This is a common source of interpretation error and underscores the importance of obtaining a complete medication history before interpreting any EEG.

Question 148: Which pattern is characterized by generalized, bisynchronous rhythmic delta activity seen predominantly over posterior head regions and is a non-epileptiform finding?

OIRDA (Occipital Intermittent Rhythmic Delta Activity) (Correct answer)
Hypsarrhythmia
PLED
GRDA

Correct answer: OIRDA (Occipital Intermittent Rhythmic Delta Activity)

OIRDA consists of occipitally predominant rhythmic delta bursts, is associated with encephalopathy or posterior fossa lesions, and is not inherently epileptiform.

Question 149: The lateral sulcus (Sylvian fissure) separates the frontal and parietal lobes above from which lobe below?

Occipital lobe
Insular lobe
Limbic lobe
Temporal lobe (Correct answer)

Correct answer: Temporal lobe

The lateral sulcus separates the frontal and parietal lobes superiorly from the temporal lobe inferiorly.

Question 150: The primary somatosensory cortex, which generates somatosensory evoked potentials recorded by EEG, is located in which gyrus?

Precentral gyrus
Angular gyrus
Postcentral gyrus (Correct answer)
Superior temporal gyrus

Correct answer: Postcentral gyrus

The postcentral gyrus (Brodmann areas 1, 2, 3) constitutes primary somatosensory cortex and is the main generator of early cortical SEP components.

Question 151: A technologist observes rhythmic, sharp-appearing transients that are most prominent in the left temporal channels and perfectly time-locked with the QRS complex on the EKG monitor. What is the most likely artifact and the best initial step to resolve it?

EKG artifact; attempt to reposition the M1/A1 or T3 electrode slightly. (Correct answer)
60 Hz interference; ensure the notch filter is enabled.
Pulse artifact; increase the low-frequency filter to 2 Hz.
IV drip artifact; check the patient's infusion pump for electrical noise.

Correct answer: EKG artifact; attempt to reposition the M1/A1 or T3 electrode slightly.

The artifact's morphology and perfect correlation with the EKG are classic signs of EKG artifact. This artifact is often most prominent on the left side because the heart's electrical field is strongest there. Slightly moving an electrode can change its orientation relative to the heart's electrical field, often reducing the artifact without altering the cerebral data.

Question 152: A rhythmic artifact at exactly 60 Hz appearing uniformly across all electrodes is most consistent with:

Cardiac artifact
Muscle artifact
AC line noise (Correct answer)
Electrode pop

Correct answer: AC line noise

60 Hz AC line noise appears as a uniform, rhythmic interference at power line frequency across all or many electrodes.

Question 153: What is the typical voltage (amplitude) range of normal alpha waves recorded from the scalp?

500–1000 µV
20–200 µV (Correct answer)
5–10 µV
200–500 µV

Correct answer: 20–200 µV

Alpha waves normally range from about 20 to 200 µV in amplitude when recorded from scalp electrodes.

Question 154: In the AASM 2007 rules, slow-wave sleep (SWS) replaced which older Rechtschaffen & Kales (R&K) staging terminology?

Stage 2 renamed to N2
Stages 3 and 4 combined into N3 (Correct answer)
Stage REM renamed to R
Stage 1 renamed to N1

Correct answer: Stages 3 and 4 combined into N3

The AASM 2007 manual merged R&K stages 3 and 4 into a single stage N3, collectively called slow-wave sleep.

Question 155: During a recording, an epileptiform discharge characterized by a sharp wave followed by a slow wave is observed. The slow wave component is physiologically understood to represent:

A prolonged afterhyperpolarization and inhibitory postsynaptic potentials (IPSPs) (Correct answer)
The summation of multiple action potentials
Artifact from patient movement following the sharp wave
A secondary burst of excitatory postsynaptic potentials (EPSPs)

Correct answer: A prolonged afterhyperpolarization and inhibitory postsynaptic potentials (IPSPs)

The slow wave following an interictal spike or sharp wave represents a period of profound inhibition. This is caused by the activation of inhibitory interneurons, leading to inhibitory postsynaptic potentials (IPSPs) and a prolonged afterhyperpolarization in the surrounding neuronal population, which temporarily suppresses excitability.

Question 156: A cEEG monitoring technologist notices sudden onset of rhythmic, evolving 2 Hz sharp-wave activity for 90 seconds followed by postictal slowing. This is best classified as:

Breach rhythm
Rhythmic delta activity
Electrographic seizure (Correct answer)
Lateralized periodic discharge

Correct answer: Electrographic seizure

An electrographic seizure requires evolution in frequency, morphology, or spatial distribution lasting ≥10 seconds, and this pattern with evolution and postictal slowing meets criteria.

Question 157: A flatline EEG tracing recorded at 2 µV/mm sensitivity is most likely artifactual rather than true ECI if which finding is present?

Activity that disappears when the technologist lifts the patient's arm off the bed (Correct answer)
Symmetric suppression bilaterally across all electrode pairs
No activity in a bipolar longitudinal montage
No change with photic stimulation at 1 Hz

Correct answer: Activity that disappears when the technologist lifts the patient's arm off the bed

If apparent flatline activity disappears when a potential movement artifact source (such as the patient's arm resting against the bed or equipment) is removed, the 'activity' was movement or ECG artifact rather than true cerebral electrical potentials. True ECI persists regardless of patient position adjustments.

Question 158: Excessive beta activity (above 25 µV) generalized across the recording is most commonly associated with:

Posterior fossa tumor
Temporal lobe epilepsy
Normal hyperventilation response
Sedative or anxiolytic medication use such as benzodiazepines (Correct answer)

Correct answer: Sedative or anxiolytic medication use such as benzodiazepines

Generalized excessive beta activity is most commonly a pharmacological effect of benzodiazepines, barbiturates, or other sedative-hypnotic medications, which enhance GABAergic inhibition and increase fast cortical activity.

Question 159: AAN guidelines for ECI recordings require a minimum interelectrode distance of at least how many centimeters to avoid missing low-amplitude activity between nearby electrodes?

15 cm
10 cm (Correct answer)
20 cm
5 cm

Correct answer: 10 cm

A minimum interelectrode distance of 10 cm is mandated so that small potential differences across brain tissue are not masked by electrodes placed too closely together. Shorter distances increase the risk of amplitude cancellation and may falsely suggest ECI.

Question 160: Which electrode placement system is universally used for routine EEG recordings?

Bipolar transverse system
Queen Square system
10-20 International System (Correct answer)
Laplacian montage

Correct answer: 10-20 International System

The 10-20 International System is the universally accepted standard for electrode placement in routine EEG.

Question 161: The mu rhythm, typically recorded over the central regions, is characterized by:

Theta bursts during hyperventilation
1-3 Hz delta activity that increases with movement
15-30 Hz beta activity maximal during sleep
An arch-shaped 8-13 Hz rhythm that attenuates with contralateral limb movement or movement planning (Correct answer)

Correct answer: An arch-shaped 8-13 Hz rhythm that attenuates with contralateral limb movement or movement planning

The mu rhythm is an 8-13 Hz arch-shaped (wicket-like) rhythm over the central (sensorimotor) cortex that blocks with contralateral movement, motor planning, or even observation of movement, reflecting sensorimotor cortex function.

Question 162: In a routine EEG report, the term 'breach rhythm' refers to:

A normal variant seen in children
Generalized slowing from metabolic encephalopathy
Enhanced amplitude and sharpening of rhythms due to a skull defect (Correct answer)
An abnormal spike-and-wave discharge

Correct answer: Enhanced amplitude and sharpening of rhythms due to a skull defect

A breach rhythm is an increase in amplitude and sharpening of EEG activity caused by a focal skull defect reducing attenuation.

Question 163: Which EEG feature is the hallmark of Stage N2 sleep?

Sleep spindles and K-complexes (Correct answer)
Delta waves >75 µV
Sawtooth waves
Alpha rhythm dropout

Correct answer: Sleep spindles and K-complexes

Stage N2 sleep is defined by the presence of sleep spindles (12–14 Hz bursts) and K-complexes on EEG.

Question 164: During an EEG recording, a patient begins to have a generalized tonic-clonic seizure. What is the technologist's first priority?

Continue recording and immediately stop all activation procedures (Correct answer)
Remove all electrodes before calling for help
Turn off the EEG machine to protect the equipment
Restrain the patient to prevent movement artifact

Correct answer: Continue recording and immediately stop all activation procedures

The technologist's first priority is to ensure patient safety while continuing the recording. This means stopping any activation procedures (hyperventilation, photic stimulation) and ensuring the patient is safe from injury, while keeping the EEG recording to capture the seizure.

Question 165: Which non-epileptiform EEG pattern is characterized by high-voltage, chaotic slow and sharp waves without organized background activity, classically seen in infantile spasms?

Burst suppression
Triphasic waves
Hypsarrhythmia (Correct answer)
GRDA

Correct answer: Hypsarrhythmia

Hypsarrhythmia is the interictal EEG hallmark of West syndrome (infantile spasms), featuring high-amplitude disorganized slow activity with multifocal spikes.

Question 166: A patient's EEG shows slow (1–2.5 Hz) spike-and-wave complexes during sleep alongside atonic and tonic seizures. Which syndrome does this pattern most suggest?

Angelman syndrome
Dravet syndrome
West syndrome
Lennox-Gastaut syndrome (Correct answer)

Correct answer: Lennox-Gastaut syndrome

Lennox-Gastaut syndrome is defined by slow (1–2.5 Hz) spike-and-wave, multiple seizure types including atonic and tonic, and intellectual disability.

Question 167: An EEG recording shows a sudden, very high-amplitude, brief transient that is strictly confined to a single channel. The transient does not have a physiological field and is not time-locked to any other event. What is the most likely cause?

An EKG artifact
An electrode artifact ('pop') (Correct answer)
A photic driving response
An epileptiform spike

Correct answer: An electrode artifact ('pop')

The key features are its confinement to a single electrode and the lack of a physiological field (i.e., it doesn't appear in adjacent channels). This is the classic presentation of an electrode artifact, often called an 'electrode pop,' which is caused by a sudden, unstable change in impedance at that one site.

Question 168: A patient on high-dose phenobarbital for status epilepticus shows a burst-suppression pattern on EEG. Which feature is most characteristic of drug-induced burst suppression compared to anoxic burst suppression?

Suppression periods are always longer than 10 seconds
Delta activity is absent during burst periods
Burst suppression is dose-dependent and reverses as the drug is metabolized (Correct answer)
Bursts are consistently asymmetric between hemispheres

Correct answer: Burst suppression is dose-dependent and reverses as the drug is metabolized

Drug-induced burst suppression (from barbiturates, propofol, or benzodiazepines) is dose-dependent and will improve as serum drug levels fall. Anoxic burst suppression following cardiac arrest is not dose-dependent and carries a far worse prognosis. This distinction is clinically critical for EEG interpretation in the ICU.

Question 169: What is the primary waveform of clinical interest in a pattern reversal visual evoked potential (VEP)?

P200
N75
P100 (Correct answer)
N145

Correct answer: P100

The P100 is the large positive peak occurring around 100 ms, generated in primary visual cortex, and is the most reliable and clinically significant component of the pattern reversal VEP.

Question 170: Which montage change is most useful for confirming that a suspected artifact is truly artifactual rather than cerebral?

Decreasing the time base
Switching from average to Laplacian reference
Switching between bipolar and referential montages (Correct answer)
Increasing the sensitivity

Correct answer: Switching between bipolar and referential montages

True cerebral activity maintains consistent field distributions across montages, while artifacts often appear or disappear inconsistently when the montage is changed.

Question 171: Vertex sharp waves (V-waves) are most prominent during which sleep stage?

N2
N3
N1 (Correct answer)
REM

Correct answer: N1

Vertex sharp waves are surface-negative transients maximal at Cz that appear during N1 sleep as a normal feature.

Question 172: Electrocerebral inactivity (ECI) on EEG requires that no cerebral electrical activity exceed what amplitude threshold?

5 µV
2 µV (Correct answer)
20 µV
10 µV

Correct answer: 2 µV

ECI is defined as no electrical activity over 2 µV recorded with electrode impedances under 10 kΩ using high-sensitivity settings and standard interelectrode distances.

Question 173: The 'mu rhythm' seen over the central scalp in a relaxed, awake subject has a frequency overlapping with which other rhythm?

Gamma
Alpha (Correct answer)
Delta
Theta

Correct answer: Alpha

The mu rhythm (8–13 Hz) overlaps the alpha frequency band but is maximal over central (C3/C4) rather than occipital electrodes.

Question 174: Which of the following is NOT a standard activation procedure in a routine adult EEG?

Hyperventilation
Photic stimulation
Sleep deprivation prior to recording
Cold caloric stimulation (Correct answer)

Correct answer: Cold caloric stimulation

Cold caloric stimulation is a vestibular bedside test, not a standard EEG activation procedure; HV, photic stimulation, and sleep deprivation are standard.

Question 175: An EEG amplifier has a CMRR of 100 dB. This means the amplifier rejects common-mode signals by a factor of approximately:

100 times
100,000 times (Correct answer)
1,000 times
10,000 times

Correct answer: 100,000 times

100 dB CMRR means common-mode signals are rejected by a factor of 10^(100/20) = 100,000 times relative to the differential signal.

Question 176: A patient with a known latex allergy is scheduled for a routine EEG. Which action is most appropriate?

Cancel the EEG and reschedule after allergy testing
Proceed normally since EEG electrodes do not contain latex
Apply standard electrodes but monitor closely for skin reactions
Use latex-free electrodes and collodion, and notify the entire team of the allergy (Correct answer)

Correct answer: Use latex-free electrodes and collodion, and notify the entire team of the allergy

Latex-free supplies must be used and all staff alerted, as some electrode caps, adhesives, and tubing may contain latex.

Question 177: Muscle artifact from the temporalis muscle can be distinguished from beta activity because muscle artifact typically:

Is enhanced by hyperventilation
Has a frequency below 8 Hz
Shows frequencies above 20 Hz with irregular sharp morphology maximal at temporal electrodes (Correct answer)
Appears only during sleep

Correct answer: Shows frequencies above 20 Hz with irregular sharp morphology maximal at temporal electrodes

Temporalis muscle (EMG) artifact produces high-frequency (typically >20 Hz) irregular, sharp activity maximal at temporal and frontal electrodes, which can obscure underlying brain activity in those regions.

Question 178: An asymmetry in the posterior dominant rhythm amplitude, with the right side consistently 50% lower than the left, suggests:

Normal variant — mild asymmetry is always benign
Left hemisphere hyperexcitability indicating seizure focus
Possible structural or functional abnormality of the right hemisphere (Correct answer)
Electrode application error only

Correct answer: Possible structural or functional abnormality of the right hemisphere

Amplitude asymmetry greater than 50% of the posterior dominant rhythm suggests dysfunction on the lower-amplitude side, potentially from a structural lesion, prior surgery, or cortical atrophy.

Question 179: During hyperventilation activation in EEG, what is the expected normal response in an adult?

Generalized slowing that resolves within 1-2 minutes after cessation (Correct answer)
Appearance of sleep spindles
Focal beta activity increase
Persistent asymmetric delta activity

Correct answer: Generalized slowing that resolves within 1-2 minutes after cessation

Normal hyperventilation response in adults produces bilateral, symmetrical, generalized slowing (buildup) that resolves within 1-2 minutes of stopping. Persistent or asymmetric slowing is abnormal.

Question 180: An EEG performed on a patient with an acute left-hemispheric stroke shows stereotyped sharp waves recurring every 1-1.5 seconds, confined to the left cerebral hemisphere. This pattern is best described as:

Triphasic Waves
Burst-Suppression
Periodic Lateralized Discharges (PLEDs) (Correct answer)
Generalized Periodic Discharges (GPDs)

Correct answer: Periodic Lateralized Discharges (PLEDs)

This pattern fits the definition of Periodic Lateralized Discharges (PLEDs), which are stereotyped, periodic complexes that are restricted to one hemisphere. They are often associated with acute structural lesions like stroke or encephalitis. GPDs are bilateral, not lateralized.

Question 181: What property of pyramidal neurons makes them the primary generators of scalp-recorded EEG signals rather than stellate cells?

Higher firing rates
Larger action potential amplitude
Open-field geometry with parallel dendrites perpendicular to cortical surface (Correct answer)
Greater absolute membrane potential

Correct answer: Open-field geometry with parallel dendrites perpendicular to cortical surface

Pyramidal neurons are arranged in parallel columns perpendicular to the cortical surface, creating open-field dipoles whose extracellular currents summate and propagate to the scalp.

Question 182: The standard paper speed (or digital equivalent time base) for routine EEG display is:

30 mm/second (Correct answer)
120 mm/second
15 mm/second
60 mm/second

Correct answer: 30 mm/second

The standard time base for routine EEG is 30 mm/second (equivalent to displaying 10 seconds per standard screen page), which provides optimal visualization of EEG waveform morphology and temporal relationships.

Question 183: Burst suppression on EEG in a critically ill patient is characterized by:

Beta-predominant activity with rare slow waves
Repetitive spike-wave complexes at 3 Hz
Continuous high-amplitude delta slowing
Alternating bursts of high-amplitude mixed activity and periods of near-flat EEG (Correct answer)

Correct answer: Alternating bursts of high-amplitude mixed activity and periods of near-flat EEG

Burst suppression consists of bursts of mixed-frequency, often high-amplitude activity alternating with periods of electrocerebral suppression (<10 µV), indicating severe cerebral dysfunction.

Question 184: An EEG on a 10-year-old child shows high-amplitude, diphasic sharp waves that occur independently over the centrotemporal regions (C3/T3 and C4/T4). The discharges become significantly more frequent during drowsiness and sleep. This pattern is pathognomonic for which epilepsy syndrome?

Self-limited Epilepsy with Centrotemporal Spikes (SeLECTS) (Correct answer)
Lennox-Gastaut Syndrome (LGS)
Juvenile Myoclonic Epilepsy (JME)
Childhood Absence Epilepsy (CAE)

Correct answer: Self-limited Epilepsy with Centrotemporal Spikes (SeLECTS)

Self-limited Epilepsy with Centrotemporal Spikes (SeLECTS), formerly known as Benign Rolandic Epilepsy, is characterized by these specific centrotemporal spikes, which show a marked increase during sleep. The location of the discharges is key to this diagnosis.

Question 185: A parent refuses to sign consent for their 8-year-old child's medically necessary EEG. Which step should the technologist take first?

Immediately seek a court order to override the parent
Document the refusal and reschedule without further action
Notify the ordering physician so that the clinical team can address the refusal and explore alternatives (Correct answer)
Perform the EEG anyway because the child's welfare supersedes parental refusal

Correct answer: Notify the ordering physician so that the clinical team can address the refusal and explore alternatives

The technologist's role is to document and escalate to the physician, who leads the discussion with the parent and determines next steps.

Question 186: What montage is typically used as the initial display for reviewing a routine EEG?

Laplacian montage
Bipolar transverse montage
Bipolar longitudinal (double banana) montage (Correct answer)
Average reference montage

Correct answer: Bipolar longitudinal (double banana) montage

The bipolar longitudinal (double banana) montage is the standard starting point for EEG review because it provides systematic anterior-to-posterior coverage, clear phase reversals for localization, and intuitive left-right comparison.

Question 187: The posterior dominant rhythm (alpha rhythm) in a normal awake adult is generated primarily by which brain structure interaction?

Basal ganglia output to frontal cortex
Hippocampal-entorhinal connections
Thalamocortical circuits involving the thalamus and occipital cortex (Correct answer)
Brainstem reticular formation alone

Correct answer: Thalamocortical circuits involving the thalamus and occipital cortex

The alpha rhythm arises from synchronized oscillations in thalamocortical loops, with the thalamic relay nuclei (particularly the pulvinar and lateral geniculate) pacing cortical neurons in the occipital visual cortex.

Question 188: What is the typical recording duration for an ambulatory EEG study?

1-2 hours
24-72 hours (Correct answer)
4-6 hours
1 week minimum

Correct answer: 24-72 hours

Ambulatory EEG studies typically record for 24-72 hours, allowing capture of events that may not occur during a brief routine recording, including sleep-wake cycles.

Question 189: According to the American Clinical Neurophysiology Society (ACNS) guidelines, interelectrode impedances should be within what range for a standard EEG recording?

Between 100 Ohms and 10,000 Ohms (10 kOhms) (Correct answer)
Above 50,000 Ohms (50 kOhms)
Exactly 5,000 Ohms (5 kOhms)
Below 100 Ohms

Correct answer: Between 100 Ohms and 10,000 Ohms (10 kOhms)

ACNS guidelines state that interelectrode impedances should be under 10,000 Ohms (10 kOhms) but over 100 Ohms. Impedances that are too high can lead to increased noise and artifact, while impedances below 100 Ohms may suggest a salt bridge or short circuit between electrodes. While values under 5 kOhms are often recommended, the acceptable range is up to 10 kOhms.

Question 190: Vertex sharp waves (V waves) during drowsiness are maximally recorded at which electrode position?

Fp1 and Fp2
T3 and T4
O1 and O2
Cz (Correct answer)

Correct answer: Cz

Vertex sharp waves are high-amplitude, surface-negative sharp transients maximal at the vertex (Cz electrode) that appear during drowsiness and Stage N1 sleep as a normal finding.

Question 191: The Delta wave frequency is

Over 13 Hertz
4–7 Hertz
8–13 Hertz
Under 4 Hertz (Correct answer)

Correct answer: Under 4 Hertz

Brainwaves known as delta waves are connected to unconsciousness and profound sleep. They occur less frequently than four times per second because their frequency range is less than four Hertz. The slowest and largest amplitude brainwaves fall within this frequency range. It's crucial to remember that delta waves are more frequently seen in newborns and early children and are normally only seen in adults during deep sleep or in specific brain illnesses.

Question 192: A patient undergoing an EEG displays rhythmic 8-13 Hz activity over the occipital regions that attenuates with eye-opening. This activity is primarily modulated by which subcortical structure?

Thalamus (Correct answer)
Hippocampus
Cerebellum
Basal Ganglia

Correct answer: Thalamus

The posterior dominant alpha rhythm, an 8-13 Hz activity seen in relaxed wakefulness, is generated through corticothalamic circuits. The thalamus acts as a pacemaker and gatekeeper, synchronizing cortical activity to produce these characteristic rhythms. The hippocampus is involved in memory, the basal ganglia in motor control, and the cerebellum in coordination; they are not the primary modulators of the alpha rhythm.

Question 193: A lateral eye movement artifact in a bipolar longitudinal montage will appear with opposite polarity at:

T7 and T8
F7 and F8 (Correct answer)
O1 and O2
Fp1 and Fp2

Correct answer: F7 and F8

Lateral eye movements produce opposite-polarity deflections at F7 and F8 because the corneal-retinal potential approaches one side and recedes from the other.

Question 194: The recommended minimum number of EEG channels for a routine clinical recording is:

16 channels (plus ECG, EOG) (Correct answer)
64 channels
8 channels
32 channels

Correct answer: 16 channels (plus ECG, EOG)

The ACNS recommends a minimum of 16 EEG channels for routine clinical recording, derived from 21 electrodes in the 10-20 system, plus additional channels for ECG, EOG, and other polygraphic recordings.

Question 195: In a referential montage, an artifact that appears identical in amplitude and polarity on ALL channels simultaneously most likely originates from:

A single scalp electrode
The reference electrode (Correct answer)
Eye blinks
Muscle activity

Correct answer: The reference electrode

When artifact appears on all channels equally in a referential montage, it is localized to the common reference electrode, not the active electrodes.

Question 196: A patient shows repeated brief arousals out of N3 sleep in the first third of the night without awakening. This pattern is most consistent with:

Sleep terror disorder (Correct answer)
Sleep-onset insomnia
REM sleep behavior disorder
Narcolepsy

Correct answer: Sleep terror disorder

Sleep terrors (NREM parasomnias) classically arise from N3 slow-wave sleep in the early part of the night with partial arousals and autonomic activation.

Question 197: What does the term 'electrocerebral inactivity' (ECI) refer to in EEG?

Background slowing to theta range
Normal low-voltage pattern during deep sleep
Intermittent suppression during burst-suppression pattern
Absence of cerebral electrical activity above 2 µV at maximum sensitivity, used as an adjunct in brain death determination (Correct answer)

Correct answer: Absence of cerebral electrical activity above 2 µV at maximum sensitivity, used as an adjunct in brain death determination

Electrocerebral inactivity is the absence of EEG activity above 2 µV when recorded with maximum sensitivity, interelectrode distances of at least 10 cm, and a recording duration of at least 30 minutes, used as an adjunct test in brain death evaluation.

Question 198: If a routine EEG is being performed to evaluate new-onset seizures, which additional procedure should the technologist prioritize?

Extended recording time to maximize the chance of capturing interictal discharges and achieving drowsiness/sleep (Correct answer)
Reducing the number of electrodes for patient comfort
Performing only photic stimulation without hyperventilation
Skipping all activation procedures

Correct answer: Extended recording time to maximize the chance of capturing interictal discharges and achieving drowsiness/sleep

For seizure evaluation, extending the recording time (beyond the standard 20-30 minutes if needed) increases the probability of capturing interictal epileptiform discharges, particularly during drowsiness and sleep when they are most likely to appear.

Question 199: Stimulation of the median nerve in a somatosensory evoked potential (SSEP) study produces a cortical response designated N20 at approximately what latency in a normal adult?

18–21 ms (Correct answer)
12–15 ms
5–10 ms
30–35 ms

Correct answer: 18–21 ms

The N20 cortical potential following median nerve stimulation peaks at approximately 18–21 ms in normal adults, reflecting conduction time from wrist to primary somatosensory cortex.

Question 200: On a qEEG trend panel, a sudden increase in the seizure probability (SP) line coincides with a visible change on the rhythmic run detector. The NEXT step for the EEG technologist should be:

Immediately notify the physician that the patient is in status epilepticus
Increase the high-frequency filter setting to reduce muscle artifact
Decrease the epoch length to improve temporal resolution of the trend
Review the corresponding raw EEG segment to confirm whether the trend reflects a true electrographic seizure or artifact (Correct answer)

Correct answer: Review the corresponding raw EEG segment to confirm whether the trend reflects a true electrographic seizure or artifact

qEEG trend algorithms are sensitive but not specific — they detect rhythmic and high-amplitude events but cannot distinguish between a true electrographic seizure and chewing artifact, electrode pop, or patient movement. The mandatory next step is always to review the raw EEG underlying the flagged epoch before any clinical action is taken.

Question 201: Which quantitative EEG (qEEG) trend is most useful for detecting secondary cerebral ischemia in subarachnoid hemorrhage patients?

Relative alpha variability (RAV) (Correct answer)
Epileptiform discharge index
Burst suppression ratio
Interhemispheric coherence

Correct answer: Relative alpha variability (RAV)

Relative alpha variability decreases prior to and during delayed cerebral ischemia in SAH patients, making it the most validated qEEG marker for vasospasm detection.

ABRET R.EEG.T. Exam

The ABRET R.EEG.T. (Registered Electroencephalographic Technologist) exam certifies competency in performing and interpreting electroencephalographic recordings, covering electrode placement, normal and abnormal waveform recognition, instrumentation, patient safety, and neuroanatomy.

200

Questions

180 min

Time Limit

70%

To Pass

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