A child with an idiopathic arrhythmia disorder experiences a seizure-like episode; what is the most likely diagnosis?

• A. Febrile seizure
• B. Adam-Stokes attack
• C. Epilepsy with EEG confirmation
• D. Vasovagal syncope

Answer: (B)

A seizure-like episode in a child with an arrhythmia disorder is best explained by a transient drop in cerebral blood flow during a sudden cardiac rhythm disturbance. This is characteristic of an Adam-Stokes attack, where abrupt bradyarrhythmia or a high-grade block (or other rapid rhythm change) causes brief loss of consciousness with convulsive movements from cerebral hypoperfusion. The movements are due to the brain not getting enough blood, not because of epilepsy, and consciousness typically returns quickly once the rhythm is corrected.

Febrile seizures would require fever and are more common in younger children with convulsions tied to fever. Epilepsy with EEG confirmation implies a primary brain disorder, not a cardiac-triggered event. Vasovagal syncope can cause fainting but usually follows a recognizable prodrome and fainting episode without the abrupt rhythm disturbance and associated convulsions seen with an arrhythmia-induced syncope.