To review seizures that present with IA during VEEG monitoring, assess contributory risk factors, characteristics of the asystole event and its relationship with ictal episode and interventions performed. Additionally, we review practices to identify patients at risk, identify prevention methods and suggest mitigating factors and treatment processes.
Ictal arrhythmias are prevalent in epilepsy with the most common being ictal tachycardia. IA is a rare complication often presenting as syncope / loss of tone. IA is defined as epileptogenic activity accompanied by a cessation of ventricular complexes for >4 seconds. It’s been hypothesized that IA may lead to an interruption of ictal activity through an anoxic-ischemic mechanism providing a self-resolution to the event. Left temporal epilepsy is considered more likely to present with such seizures. The first-line treatment recommendation is antiseizure medication optimization and epilepsy surgery. Cardiac pacing is reserved for cases in which anticonvulsant drug optimization has not prevented asystole episodes >6 seconds in length.
We identified 7 seizures associated with IA and analyzed the semiology of the seizure associated with asystole, asystole latency, duration, and association of asystole offset to ictal offset. We analyzed intervention - cardiac or neurologic in these patients.
Overall incidence of IA was low with 7 seizures identified out of >1500 VEEG studies. Equal balance of left and right temporal onset seizures was noticed. Syncope / fall was prominent presentation with these temporal lobe epilepsy cases. Mean offset time did not show correlation between offset of IA with ictal activity as previously hypothesized.
Syncope / fall can be a primary presentation of epilepsy when ictal semiology is associated with IA. IA may start close to ictal onset but is not always associated with termination of seizure. Treatment options are varied, and cardiac interventions may be warranted if epilepsy remains uncontrolled.