835 Ictal Central Apneic Events Detected on Polysomnogram: An Educational Case Report

Abstract

Abstract Introduction Ictal central apneas (ICA) are frequently observed in focal epilepsy, mostly with temporal lobe seizures, and have been considered as potential biomarkers of sudden unexpected death in epilepsy (SUDEP), particularly when they are prolonged and associated with significant hypoxemia. We present an interesting educational case report of occurrence of such ictal apneic events as recorded during a nocturnal diagnostic polysomnogram (PSG). Report of case(s) A 39-year-old woman with history of left focal epilepsy, hypertension, and headaches was referred to the sleep clinic for loud snoring, witnessed apneic events, and excessive daytime sleepiness. She subsequently underwent a diagnostic (PSG) that demonstrated severe obstructive sleep apnea (apnea-hypopnea index of 63.1) associated with significant hypoxemia (nadir SpO2 of 58%). In addition, the patient had one ictal discharge detected on the PSG’s limited electroencephalogram that occurred in N2 sleep and lasted for almost three minutes with a focal onset and progression in the left hemisphere. The ictal discharge was briefly preceded by central apneic events that continued to occur during and shortly after the termination of the ictal discharge. These ICA events were associated with severe oxygen desaturations down to an SpO2 of 62%. The only time during the PSG recording that the patient had central apneic events was around the ictal event. There were no behavior changes on the video during the seizure, but the ictal discharge was associated with a sustained increase in the mentalis muscles activity and a brief tachycardia. The patient’s neurologist was alerted about the above findings on PSG. The patient was taking a lower dose then prescribed of her anti-epileptic medication (topiramate) that was adjusted, and the patient was counseled on the risks associated with the above findings and positive airway pressure therapy was recommended for her severe sleep apnea. Conclusion The above case report illustrates the importance of polysomnography (specifically the recording of respiratory variables rarely performed in epilepsy monitoring units) in the evaluation of patients with epilepsy given that central apneic events (ICA and post-convulsive central apneas) potentially underlie SUDEP, the most common cause of mortality in refractory epilepsy patients and usually occurring during sleep. Support (if any) None