Rationale:
Ictal asystole, is a rare condition often associated with temporal lobe epilepsy, that remains incompletely understood. Defined by an R-R interval exceeding three seconds, ictal asystole is associated with an elevated risk of SUDEP. Here, we report a unique case of pre-ictal asystole.
Methods:
A 22-year-old male with refractory epilepsy and VNS therapy presented for EMU evaluation. Medications included lacosamide and lamotrigine. Multiple seizures were captured with asymmetric tonic posturing, EEG onset was anteriorly-dominant spike and polyspike waves, often asymmetric with shifting laterality, followed by diffuse fast activity. There were mixed focal and generalized features interictally. During monitoring, EKG noted non-sustained tachycardia, bradycardia, and increased heart rate variability. During lab draws, he experienced a 9 second asystole then development of a 19 second asymmetric tonic seizure. Appearance of junctional rhythm and bradycardia preceded seizure by 19 seconds, with the pause occurring 9 seconds prior to EEG onset of the seizure, which was overall diffuse, however there was no slowing on the EEG prior to seizure. Asystole continued 5 seconds into the seizure. There were 4 further cardiac pauses ranging 6-20 seconds in the next 2 minutes. Another asymmetric tonic seizure occurred during this period. Results:
There were no changes in EEG with the final 3 cardiac pauses in this period. EP cardiology was consulted, and it was determined that the pauses were unrelated to his VNS or medications, and ultimately he received a pacemaker. The patient was discharged on Perampanel 4 mg daily, and according to the parent’s report on a follow up visit, there has been significant improvement, with no new seizures of any type observed.
Conclusions:
Our case is unique given a long pre-ictal asystole, as most literature regarding ictal asystole suggests it occurs at or following ictal onset. While the asystole in our case occurred during lab draws, the preceding junctional rhythms and pauses suggest a more complex interplay between autonomic instability and this seizure’s onset rather than vasovagal response. Also, lack of EEG changes prior to and during asystole suggest against hypoperfusion-induced seizure. Our case offers further exploration into pre-ictal cardiovascular events, which could potentially be informative for preventative cardiac interventions aimed at mitigating risk.
Funding: N/A