EEG Non-Epileptiform Abnormalities 5

Question 1

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

Accepted Answer

Hypsarrhythmia

Answer

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

Question 2

Generalized rhythmic delta activity (GRDA) persisting despite stimulation is most suggestive of which condition compared to GRDA that attenuates with stimulation?

Accepted Answer

GRDA that persists is more likely ictal; GRDA that attenuates is more likely non-ictal

Answer

GRDA that does not attenuate with stimulation (non-reactive) raises concern for ictal or peri-ictal activity, while stimulus-induced attenuation suggests non-epileptiform encephalopathy.

Question 3

Which medication commonly produces diffuse beta activity as a non-epileptiform EEG abnormality?

Accepted Answer

Benzodiazepines

Answer

Benzodiazepines and barbiturates classically increase diffuse beta activity (>13 Hz), which is a drug effect rather than a pathological finding.

Question 4

An EEG showing continuous generalized polymorphic delta slowing with no clear faster frequencies in a patient with altered consciousness most likely indicates what?

Accepted Answer

Severe diffuse cortical dysfunction

Answer

Continuous generalized polymorphic delta without faster activity in a wakeful patient indicates severe diffuse encephalopathy affecting cortical function.

Question 5

TIRDA (Temporal Intermittent Rhythmic Delta Activity) is considered a non-epileptiform abnormality but is clinically significant because it is associated with which condition?

Accepted Answer

Temporal lobe epilepsy

Answer

TIRDA, while not epileptiform itself, is strongly associated with temporal lobe epilepsy and should prompt clinical correlation for seizure disorder.

EEG - Electroencephalography Practice Test

EEG - Electroencephalography Practice Test

EEG Non-Epileptiform Abnormalities 5