Eye Movements and Occipital Seizures in Man

Abstract

49 occipital seizures with an early (first 10 seconds) ocular deviation were recorded during stereo-EEG investigations in 16 patients. - The ictal discharge usually starts in the medial occipital cortex, below and/or above the calcarine sulcus. - In most cases (44 seizures, 14 patients), the ocular deviation were "tonic", rapid controlateral to the discharge. Most often (27 seizures, 14 patients), the eye movement was horizontal; in 3 patients (17 seizures) it was upward oblique. - A "clonic" deviation was rare (4 seizures, 4 patients), but also controlateral to the discharge, horizontal, generally slow. - Strict relationships exist between the type of the discharge and the modalities of the ocular deviation: a rapid discharge is linked to a "tonic" deviation; slow, pseudorythmic spikes are related to a "clonic" deviation. Thus, in these patients, the ocular deviation was related to the ictal involvement of the occipital, mainly medial, cortex.