[The value of EEG after sleep deprivation for the diagnosis of epileptic seizures, epilepsy and other cerebral disorders].

114 electroencephalographic and 49 clinical criteria of 1010 patients, including 64 healthy volunteers, were evaluated by means of a computer. In 549 patients with epileptic seizures spike wave (sw) paroxysms were seen in 13.3%. Following a 24-hour period of sleep deprivation sw paroxysms were present in 24.2% cases which represents an increase of 82.0%. The number of cases with focal discharges increased in this group from 21.3% initially to 27.5% after sleep deprivation, representing an increase of only 29.1%. The percentage increase in sw paroxysms and focal discharges following sleep deprivation was approximately as marked also in patients without epileptic seizures, so that sleep deprivation was found to be equally useful in patients with non-epileptic cerebral disorders. The rate of activation is higher in children and juveniles than in adults. Similarly, it is higher in patients with awaking epilepsy than in patients with sleep epilepsy. The influence of sleep deprivation and that of sleep, respectively, upon the provocation of EEG changes was not sharply differentiated. By counting sw paroxysms in the EEG before sleep deprivation, in the waking EEG following sleep deprivation, as well as in the subsequent sleeping EEG further evidence was obtained, however, supporting the suggestion that special significance may be attributed to sleep deprivation as a provocation method. If the activation of sw paroxysms and focal changes is related to sleep and sleep stages it can be shown that their frequency decreases from stage 1 to stage 4. In particular, the short fluctuations in vigilance, the waking reactions frequently occurring under routine laboratory conditions and the transitions between sleep stages were seen to assume trigger functions.