Rationale:
Events associated with altered consciousness and unresponsiveness are commonly attributed to epilepsy until proven otherwise. We report on a case of an adolescent with prolonged ictal asystole and compare our case to those in the literature.
Methods:
A case report and a systematic literature review for ictal asystole using full articles, published in English from 2000, were reviewed.
Results:
All reported cases of ictal asystole occur with focal seizure, the majority localized to the temporal lobe. These patients are given a pacemaker and AED1, 2. Cases typically occur in adults (mean age =25 years), in those with focal, medically-resistant epilepsy of the insula, orbito-frontal, and temporal regions with 80-82% left-sided lateralization. Eighty-five percent of the studied cases did not have preexisting heart condition. Epileptic focus near the insula or limbic system has been hypothesized to increase vagal tone on the heart.
Our case is a healthy 16 year-old with a presumptive diagnosis of focal epilepsy with a strong family history of vasovagal syncope and no personal cardiac history. Previous history included events of receptive aphasia with possible late convulsions triggered by illness and sleep deprivation starting at age 11 years, and multiple vasovagal events. She presented to EMU for characterization of new “brain fog” semiology that began with the introduction of ASMs (LEV and LCT). Physical exam notes marfanoid features: long slender fingers, joint elasticity, mild scoliosis, without pectus excavatum or conjunctival hue.
Outpatient EEGs reported rare left midtemporal discharges in sleep, suggestive of benign transients. Prior MRI was normal. Repeat MRI found nonspecific FLAIR signal abnormality of bilateral temporal lobes. Ictal VEEG captured a 60 second vasovagal event with sinus slowing and asystole. During the event, there was flat EEG activity with rapid spontaneous recovery from Delta slow wave to normal awake pattern. She underwent cardiac pacemaker implantation and ASMs were changed due to side effects. Channelopathy genetic studies were negative. No further events have been reported on LCS monotherapy.
Conclusions:
Ictal syncope is a rare complication of focal epilepsy. However, altered consciousness and unresponsiveness are not exclusively epileptic in nature, even in patients with prior diagnoses of epilepsy. Our case emphasizes the importance of reconsidering previous diagnoses, especially for pediatric patients. In addition to ictal electrographic evidence, workups necessitate cardiac telemetry especially with a strong personal or family history of syncope. Ictal capture on Video-EEG with ECG remains the gold standard for the determination of diagnosis and whether treatment requires cardiac pacemaker. Perhaps this may shed light on sudden unexplained death in epilepsy (SUDEP)2.
1. Dalma, T, et al, Ictal asystole: A systematic review. Epilepsia. 2017 Mar;58(3):356-362.
2. Sowden N, Booth C, Kaye G. Syncope, Epilepsy and Ictal Asystole: A Case Series and Narrative Review. Heart Lung Circ. 2022;31(1):25-31. doi:10.1016/j.hlc.2021.07.003
Funding: Institutional