Abstracts

Rationale: Cardiac arrhythmia is thought to be one of the potential mechanisms of Sudden Unexplained Death in Epilepsy (SUDEP). Studies have established the importance of the insular cortex and temporal lobe in cardiovascular autonomic modulation. Ictal asystole (IA) is a rare event mostly seen in patients with temporal lobe epilepsy and is a potential contributor to SUDEP. In a large surgical epilepsy center, IA was reported in 5 out of 1244 monitored patients (0.4%). Event only occurred in focal epilepsies (frontal and temporal) with lateralization to the left side based on this study. Significant bradycardia/asystole was noted in 4 (21%) of 19 patients with intractable focal epilepsy monitored with implantable ECG loop recorder over several months and 2 of 4 patients with these events had seizures originating in the left temporal lobe. Based on another study, IA was recorded in 0.27% of 6825 patients on long term video EEG monitoring, 8 patients had temporal lobe epilepsy (TLE), 2 had extra temporal lobe epilepsy and none of the patients with generalized epilepsy had IA. We report another case of a patient with left TLE who presented with new transient loss of consciousness (TLOC).Methods: 18 channel video EEG monitoringResults: A 53 year old right-handed female with episodes of staring spell and speech arrest since 2012 and a diagnosis of complex partial epilepsy presented to our facility for a second opinion of new TLOC. There were no identifiable seizure risk factors. Prior EEG revealed ""localized spike and wave activity in the frontal and temporal areas” and MRI brain was normal. In November of 2014, while being on Trileptal and Keppra, she had her first episode of LOC and two more episodes in the following two months with reported right arm shaking. Patient was admitted to Epilepsy Monitoring Unit for event characterization. Her antiepileptic medications (OXC and LEV) were slowly tapered off. On day 4, the first electro-clinical event was captured lasting 10 sec. It was characterized by speech arrest correlating on EEG with appearance of rhythmic theta activity over the left temporal region. On day 7, a second electro-clinical event was captured. It was characterized clinically by behavioral arrest lasting for 17 seconds followed by LOC and lower extremities twitching lasting for 43 sec. Electrographically, the event started with left temporal rhythmic theta activity correlating with the beginning of sinus bradycardia approximately 7 seconds after electrographic onset followed by ictal asystole lasting 18 seconds. The finding of IA in this patient prompted subsequent cardiac pacemaker placement. Upon outpatient follow up, patient reported no further episodes of TLOC, but she continued to have her usual seizure of staring spells and speech arrest.Conclusions: Ictal bradycardia and ictal asystole are rare but potentially life-threatening complication predominantly seen in patients with TLE. It should be suspected in people with focal epilepsy who report new semiological features with sudden onset of atonia, TLOC and seizure-related falls, as in the case reported here.