Epileptic seizure induced by tilt-table testing: a case report

Objective: N/A Background: Clinically epilepsy and syncope can be difficult to distinguish, at times leading to incorrect diagnoses and unnecessary anti-seizure medications (ASDs). A couple studies have showed the utility of tilt-table testing with EEG in parsing these entities – where EEG shows diffuse slowing despite clinical jerking movements, with no evidence of epileptic discharges. No studies have reported epileptic seizures induced by tilt-table testing. Design/Methods: We report the case of a 60 year-old woman with episodes of lightheadedness, whose events evolved to include a scream and loss of consciousness (LOC). These increased in frequency to every 3 months and she was treated with ASDs. Subsequent workup included electroencephalogram (EEG) and MRI brain, which were normal. 21-day cardiac Holter monitor revealed significant sinus pauses associated with a typical event. A pacemaker was placed and her ASDs were tapered. Despite the pacemaker she continued to have episodes of dizziness associated with upright posture (though LOC resolved). She was re-trialed on another ASD. When further EEG was unremarkable, the ASD was weaned. The episodes increased to monthly after taper of the ASD. Given high suspicion for syncope, though unexplained cause of increased events with weaning of ASD, tilt with EEG and ambulatory EEG were completed. Results: During tilt-table testing with EEG, when patient was tilted to the head-up position, she stopped answering questions, and EEG revealed a focal left temporal seizure. Her systolic BP abruptly dropped to 89 mmHg (64 mmHg below baseline). Her HR did not change, but pacemaker showed increased firing (set to fire below 60 bpm). 72-hour ambulatory EEG revealed occasional left temporal sharp waves. Conclusions: While likely rare, focal epileptic seizures provoked by head-up tilt can occur, and should be considered when episodes continue despite treatment. Combined tilt-table and EEG evaluation may be needed to determine the true etiology. Disclosure: Dr. Toprani has nothing to disclose. Dr. Walter has nothing to disclose.