Abstracts

Ictal asystole with focal epilepsy is a rare but potentially life-threatening event and is a likely contributor to sudden unexpected death in epilepsy (SUDEP). Risk factors allowing early detection and intervention are unknown and ictal asystole remains an incidental finding in large monitoring populations. While there have been some inconsistent correlations (such as more frequent accompaniment to left temporal lobe seizures) semiologic characteristics associated with ictal asystole have not been described, and may be helpful in screening for high risk patients. Electronic database search of all patients undergoing longterm Video-EEG monitoring between 1994 and 2005 with episodes of aystole during simultaneous ECG acquisition. Patients with asystole during non-epileptic events (e.g. syncopal events) were excluded. Ictal asystole was found in seven out of 5977 patients (0.12%) and occured in 12 out of 42 (29%) of their recorded events. Two of the patients were male and five female, mean age was 28 years (range 2 to 54 years). Asystole occured on average 41 seconds (s) after EEG onset (range 3-95 s) and was in all cases preceded by sinus bradycardia. Duration of asystole averaged 17 s (range 4-33 s). Sinus rhythm recurred spontaneously in all patients without requiring cardiac resusciation.
Temporal lobe epilepsy was diagnosed in five patients, in three on the right, in one on the left and in one bilateral. Asystole in this group lasted between 4.5s and 33 s. In all five patients, episodes of sudden unresponsiveness associated with manual or oral automatism were reported as typical events. During the Video-EEG monitoring in four of these five patients, the habitual semiology was followed by a pronounced sudden loss of tone and body posture coinciding with the asystole. In the one patient without noticeable loss of tone, a generalized tonic seizure lasting more than 20s occured within five seconds after onset of the asystole. All five patients underwent pacemaker implantation.
Two patients had extratemporal lobe epilepsy. One suffered from axial tonic seizures associated with a regional EEG seizure pattern over the vertex. The other one had episodes of unresponsiveness and staring associated with a left hemispheric focal epilepsy. Asystole lasted between 4s and 7s and no loss of tone was noted during Video-EEG monitoring. Ictal aystole is a rare but potentially life-threatening event. It is most commonly seen in patients with right or left temporal lobe epilepsy. Although a history of atonia and falls is often not obtained, loss of tone and posture can frequently be seen during Video-EEG-monitoring. Drop attacks at clinical onset have been reported in patients with temporal lobe epilepsy, however a delayed sudden loss of tone is distinctly uncommon and may be revealed by a detailed history. Further cardiac monitoring in patients with temporal lobe epilepsy and delayed atonia or drop attacks might be warranted.