Focal Cortical Dysplasia Type IIa and SCN5A-associated Genetic Arrhythmia: A Case Report.

We report the clinical course of a 13-year-old male patient with a history of focal structural epilepsy starting at the age of 18 months due to focal cortical dysplasia (FCD) IIa and undetected genetic arrhythmia syndrome due to a pathogenic variant in sodium voltage-gated channel alpha subunit 5 (SCN5A) gene at that time.High-resolution MRI detected FCD in the left suprabasal margin matching the EEG focus. At the age of 12 years, epileptological-surgical evaluation led to lesionectomy, which resulted in seizure freedom postoperatively. Months later, the patient experienced an episode of leg pain, increased tone of the upper body, and subsequent cardiac arrest. Resuscitation efforts were successful, leading to survival with hypoxic brain injury. Unexpected cardiac arrest not in line with the previous seizure semiology led to further cardiological examinations including electrophysiology and genetic testing, revealing a pathogenic SCN5A variant associated with arrhythmia syndromes. A two-chamber implantable cardioverter defibrillator (ICD) was implanted. To our knowledge, this combination of diseases has not been reported yet, a causal relationship stays speculatively. Nevertheless, it highlights the complexity of coexisting structural and genetic conditions that can only be detected in alertness to uncommon conditions and via an interdisciplinary approach.