Epilepsy and behaviour disorder in patients with generalised spike and wave complexes

A series of 97 cases showing bilateral synchronous spike and wave (S-W) complexes during “resting” EEG conditions or elicited on overbreathing or photic stimulation was studied in relation to seizure pattern, presence of other EEG abnormalities, topographical distribution of the S-W complexes, signs of brain damage and presence of behaviour disorder. In 82 cases S-W complexes appeared in resting EEG or on overbreathing alone whereas in fifteen cases the discharges were elicited on photic stimulation alone. Epilepsy was by far the most frequent diagnosis in the former (74 out of 82) but more than half the cases in the latter group were patients with behaviour disorder or psychosis (8 out of 15), without clinical epilepsy.