EEG Abnormal Epileptiform Patterns 5

Question 1

Which EEG finding is the ictal correlate of epilepsia partialis continua (Kojewnikow syndrome)?

Accepted Answer

Continuous focal rhythmic delta activity with embedded spikes over the motor cortex

Answer

Periodic lateralized epileptiform discharges (PLEDs) at 1–2 Hz

Answer

Generalized 3-Hz spike-and-wave

Answer

Bilateral independent periodic discharges (BIPDs)

Question 2

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

Accepted Answer

Evolution in frequency, amplitude, or spatial distribution over time

Answer

Amplitude exceeding 100 µV

Answer

Occurrence during active sleep

Answer

Presence of a post-ictal suppression lasting 1 second

Question 3

Generalized paroxysmal fast activity (GPFA) during slow-wave sleep is the characteristic ictal correlate of which seizure type in Lennox-Gastaut syndrome?

Accepted Answer

Tonic seizures

Answer

Absence seizures

Answer

Myoclonic seizures

Answer

Atonic seizures

Question 4

A 6-Hz spike-and-wave burst lasting less than 2 seconds seen in a drowsy young adult is most consistent with:

Accepted Answer

Phantom spike-and-wave (benign variant)

Answer

Juvenile myoclonic epilepsy ictal discharge

Answer

Absence status epilepticus

Answer

Temporal lobe seizure onset

Question 5

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

Accepted Answer

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

Answer

Amplitude increases progressively to > 500 µV

Answer

Discharges shift to posterior head regions

Answer

The spike component disappears leaving pure slow waves

Question 6

In juvenile myoclonic epilepsy (JME), the EEG hallmark is polyspike-and-wave discharges typically at which frequency?

Accepted Answer

4–6 Hz

Answer

1–2 Hz

Answer

3 Hz

Answer

10–12 Hz

Question 7

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

Accepted Answer

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

Answer

Lennox-Gastaut syndrome

Answer

Ohtahara syndrome

Answer

Childhood absence epilepsy