Introduction: Partial benign epilepsy of childhood with occipital paroxysms (EPBI-O) described by Gastaut in 1982, has been recognized in the latest Classification of Epilepsy and Epileptic Syndromes as being a form of idiopathic partial epilepsy. In 1989 Panayiotopoulos described a different form of idiopathic occipital epilepsy.
Objective: We analyzed the electro-clinical characteristics of EPBI-O in order to identify the different forms of idiopathic occipital epilepsy.
Material and methods: This prospective study included 74 patients who fulfilled the diagnostic criteria of EPBI-O. The patients were evaluated between January 1990 and June 1996 by means of clinical and electro-encephalic examinations during a follow-up period of between 6 months and 6.5 years.
Results: We identified two groups. Group I: eighteen patients with visual crises and post-ictal migrainous episodes, with or without motor crises, predominantly when awake and with the onset of these crises at 8.7 years old. On EEG there were P-O occipital paroxysms which reacted to eyelid opening and group II: fifty-six patients with crises of vomiting followed by oculo-encephalic version, predominantly during sleep and with an average age of 4.9 years when these crises started to occur. On EEG there were occipital spikes with identical morphology to that of the benign epilepsy of childhood with spikes of Roland (EPBI-R). Two patients had associated crises of EPBI-O of Group II and EPBI-R with independent occipital and Roland spikes. These formed a third group.
Conclusions: This study confirms the existence of two variantes of EPBI-O; the 'Gastaut' type and the 'Panayiotopoulos' type with a more benign and more frequent course.