A study of the diagnostic value of waking and sleep EEGs after sleep deprivation in epileptic patients on anticonvulsive therapy.

One hundred and twenty-seven waking and sleep EEGs were recorded from 102 epileptic patients on anticonvulsant therapy, after sleep deprivation. Epileptiform activity was found in 63% of the patients, or 57% of the records. Since in previously recorded waking EEGs epileptic discharges had been registered in 19%, or 17% respectively, the rate of increase was considerable. The rate of activation was 51% in patients without epileptic activity in their waking EEGS. Two-thirds of the epileptiform activity were already recorded in the waking EEGS, after sleep deprivation, One-third was recorded only during sleep. Epileptic discharges in the different sleep stages ranged from 25% (E) to 48% (C). On the other hand, approximately the same frequency was recorded in the separate sleep stages in patients whose waking EEGS after sleep deprivation showed epileptiform activity. The EEG changes were correlated with the different clinical parameters (type of seizure, frequency and duration of seizures, age at the first seizure and the time of examination, neurological findings, and personality changes).