Clinical cues for detecting ictal asystole

Objective: The occurrence of asystole during an epileptic seizure is the most dramatic manifestation of ictal bradycardia. Recognition of ictal asystole is important as treatment with both antiepileptic drugs and cardiac pacing may be necessary. The purpose of this study was to identify clinical cues to aid in the detection of ictal asystole. Methods: We analyzed the clinical and electrophysiologic features of all recorded seizures in consecutive patients diagnosed with ictal bradycardia and asystole on prolonged video-EEG/ECG monitoring over a 14 year period. Results: Twenty-nine seizures with ictal bradycardia were identified in 13 patients. Of these, 11 seizures in seven patients were associated with asystole. Bilateral transient limb movements consisting of asymmetric posturing or jerking occurred during eight episodes of ictal asystole, and loss of muscle tone occurred during four. In contrast, neither bilateral limb movement nor loss of muscle tone was observed in any of the non-asystolic seizures, whether ictal bradycardia was present or not. All patients with ictal asystole reported a history of seizure-related falls and brief body and limb jerking. Conclusions: The presence of loss of muscle tone or bilateral asymmetric jerky limb movements during a seizure suggests the possibility of ictal asystole. Video-EEG/ECG monitoring should be considered in patients with epilepsy demonstrating these clinical features to determine if ictal asystole is present.