Videoelectrographic and clinical features in patients with ictal asystole
Schuele SU, Bermeo AC, Alexopoulos AV, Locatelli ER, Burgess RC, Dinner DS, and Foldvary-Schaefer N (2007) Videoelectrographic and clinical features in patients with ictal asystole. Neurology 69:5 434–41.
Abstract: OBJECTIVE: Ictal asystole (IA) is a rare event mostly seen in patients with temporal lobe epilepsy (TLE) and a potential contributor to sudden unexplained death in epilepsy (SUDEP). Clinical and video-electroencephalographic findings associated with IA have not been described, and may be helpful in screening for high risk patients. METHODS: A database search was performed of 6,825 patients undergoing long-term video-EEG monitoring for episodes of IA. RESULTS: IA was recorded in 0.27% of all patients with epilepsy, eight with temporal (TLE), two with extratemporal (XTLE), and none with generalized epilepsy. In 8 out of 16 recorded events, all occurring in patients with TLE, seizures were associated with a sudden atonia on average 42 seconds into the typical semiology of a complex partial seizure. The loss of tone followed after a period of asystole usually lasting longer than 8 seconds and was associated with typical EEG changes seen otherwise with cerebral hypoperfusion. Clinical predisposing factors for IA including cardiovascular risk factors or baseline ECG abnormalities were not identified. CONCLUSION: Ictal asystole is a rare feature of patients with focal epilepsy. Delayed loss of tone is distinctly uncommon in patients with temporal lobe seizures, but may inevitably occur in patients with ictal asystole after a critical duration of cardiac arrest and cerebral hypoperfusion. Further cardiac monitoring in patients with temporal lobe epilepsy and a history of unexpected collapse and falls late in the course of a typical seizure may be warranted and can potentially help to prevent sudden unexplained death in epilepsy.
Context
- Retrospective study of ictal aystole among 6,825 patients undergoing video EEG. In 10 patients episodes of asystole during seizure were identified. 8 of these patients had temporal lobe epilepsy, 2 had extratemporal epilepsy. There was no evidence of lateralizing preference. Asystole began on average roughly 30 s into the seizure and was in some cases preceded by roughly 10s a loss of tone. The article also provides a helpful discussion of the literature comparing convulsive asystole with epilepsy.