[Centrencephalic myoclonic-astatic petit mal. Clinical and electroencephalographic long-term follow-up study in 52 patients (author's transl)].

In this report 52 patients meeting the criteria of centrencephalic myoclonic-astatic petit mal (10) at the beginning of petit mal are included. The results of clinical and encephalographic follow-up examinations are as follows: 1) The type reported here apparently has a petit mal course with peculiar characteristics, it therefore must be separated from Lennox syndrome: centrencephalic myoclonicastatic petit mal, pyknolepsia, bilateral myoclonus (impulsive petit mal). It should file under generalized primary petit mal epilepsy. 2) It is primarily defined by its EEG marker: "centrencephalic" EEG pattern (irregular and/or regular spike-wave groups, photosensibility and abnormal theta- and/or delta-rhythm). Rarely (33%) minor cerebral organic lesions as additional pathogenetic factors are uncovered by clinical and electroencephalographic examinations. 3) The clinical picture is characterized, aside from myoclonic and/or astatic seizures, by frequent absences (80%), rare tonic seizures (6%), petit mal status (25%) and mostly generalized grand mal seizures (62%). 4) There are changes of the course of the disease to Lennox syndrome (N = 6) in in children suffering from marked cerebral organic lesions at the onset of petit mal and in development of severe epilepsy. 5) Least favorite markers with respect to prognosis are concomitant grand mal seizures (p = 0,05), petit mal status (p = 0.008), additional 2/sec spike wave-pattern (spike wave Variant) in the EEG (p = 0.002) and previous seizures with focal signs. Favourite outcome of epilepsy are frequently connected to missing cerebral organic lesions (p = 0.05).