Arrhythmogenic seizures: diagnosis by simultaneous EEG/ECG recording.

We studied a young man with presumably idiopathic seizures that were refractory to phenytoin therapy. Sick sinus syndrome was found after an episode of unconsciousness, but seizures continued despite the insertion of a demand ventricular pacemaker. Evaluation revealed a left temporal seizure focus, and combined EEG and ECG monitoring during a seizure revealed a left temporal paroxysmal discharge and an ictal cardiac arrhythmia. Detailed EEG and cardiac evaluation is necessary for all patients with "idiopathic" seizures.