A 70 year old woman with a history of Epilepsy presented with recurrent seizures. At home she had become vacant, lost consciousness and experienced generalized seizures and urinary incontinence on multiple occasions. On admission further events of a similar phenotype were seen. She was initially administered lorazepam and phenytoin therapy and a CT head scan and electrolyte levels were normal.
A subtle prolongation of her QT interval was found on her admission ECG and she was placed on telemetry. On this monitoring frequent runs of ventricular tachycardia with profound hypotension were noted – at the same time as her seizures were occurring. Further work-up confirmed Long QT Syndrome provoking arrhythmic syncopal seizures. Review of her medical notes from the time of her epilepsy diagnosis revealed QT prolongation which had been missed. A pacemaker-defibrillator was implanted with resolution of her symptoms.
Long QT Syndrome most often presents with syncope or sudden cardiac death; initial presentation with seizures, particularly in late adulthood, is less well recognized. Failure to consider this diagnosis can cause delays in treatment, inappropriate anti-epileptic medication prescription, and an increased risk of sudden cardiac death. It is therefore an important differential diagnosis to consider in seizure presentations.