Ictal asystole with convulsive syncope mimicking secondary generalisation: a depth electrode study

Area of Science:

• Neurology
• Cardiology
• Epileptology

Background:

• Ictal bradycardia is a rare phenomenon with debated localizing value in epilepsy.
• Bradyarrhythmias are clinically significant due to their association with sudden death and influence on seizure presentation.
• Differentiating seizure-induced cerebral hypoperfusion from generalized convulsive seizures can be challenging.

Observation:

• A case study analyzed seven seizures in a 51-year-old female with post-traumatic epilepsy and seizure-triggered asystole.
• All seizures originated from the left temporal lobe, with intracranial recordings showing onset in the left anterior hippocampus/amygdala.
• Seizures were associated with rapid onset asystole, cerebral electrical activity suppression, and myoclonic twitches.

Findings:

• Left temporal lobe seizures initiated a pattern of ictal asystole, leading to a generalized convulsive syncope.
• Intertemporal lobe seizure spread appears necessary, though not solely sufficient, for inducing bradycardia and asystole.
• The polyspike suppression pattern persisted in the hippocampi despite generalized cerebral suppression.

Implications:

• Pacemaker implantation effectively reduced seizure frequency and severity in this patient.
• Pacemakers may offer protection against malignant bradyarrhythmias associated with epileptic seizures.
• This case highlights the complex interplay between temporal lobe epilepsy and cardiac autonomic dysfunction.