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EPILEPSY WITH MYOCLONIC-ATONIC SEIZURES

Background

The background may be normal or show generalized slowing. Background bi-parietal theta is usually seen.

eeg
Example of bi-parietal theta.

CAUTION Focal slowing consistently over one area is not seen right arrow consider structural brain abnormality.

Interictal

Generalized spike-and-wave and polyspike-and-wave occur.

CAUTION Focal discharges are not seen right arrow consider structural brain abnormality.

Activation

Intermittent photic stimulation may trigger generalized spike-and-wave and polyspike-and-wave, and myoclonic-atonic seizures.

EEG abnormality is enhanced by sleep deprivation and by sleep. Generalized spike-and-wave often becomes fragmented with sleep deprivation or in sleep. Fragmented generalized spike-and-wave can appear focal or multi-focal but usually is not consistently seen in one area. The morphology of the focal spike-and-wave typically appears similar to the generalized spike-and-wave.

Ictal

The myoclonic component is associated with a generalized spike or polyspike. The atonic component is associated with the aftergoing high voltage slow wave.

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