Oculomotor phenomena in petit-mal

Objective: To determine the temporal relationship among behavior, eye movements and respiration during absence seizures. Method: This included simultaneous videorecording of a patientʹs face, EEG and respirogram, in 5 patients with absence seizures. Absence seizures were defined as a sudden lapse of consciousness with impairment of mental functions. Oculomotor phenomena consisted of: eye fluttering, eye deviation (conjugate lateral or upward deflection), and eye-opening. Results: Oculomotor phenomena began 1 2/3–3 s after the onset of the electrographic discharge and ended before the discharge. The most frequent events were eye-opening, stare with or without palpebral myoclonias, and tonic or clonic upward movements. Downward movement or convergence was not observed as well as head version. Respiratory changes (apnea) are the last events to occur. Conclusions: absence seizures were characterized by the onset of a 3/s spike-slow wave discharge followed by oculomotor phenomena and respiratory changes. The time course suggests that epileptic discharges precede and then involve oculomotor and respiratory brainstem centers.