Sudden Unexpected Death in the Epilepsy Monitoring Unit

Commentary Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death among persons with chronic refractory epilepsy (1). The current accepted definition is a sudden, unexpected, witnessed or unwitnessed, non-traumatic, and non-drowning death, occurring in benign circumstances in an individual with epilepsy, with or without evidence for a seizure and excluding documented status epilepticus (2). SUDEP typically affects patients with drug-resistant epilepsy. The average incidence is 4 deaths per 1,000 patient-years; for patients with uncontrolled childhood-onset epilepsy, there is a 12% cumulative risk over 40 years. Epidemiologic risk factors include generalized tonic-clonic seizures, particularly nocturnal; male sex; age of onset of epilepsy <16 years; duration of epilepsy >15 years; and polytherapy (3,4). Other than identifying risk factors, there has been limited progress in our understanding of SUDEP. Most cases are thought to be peri-ictal (1). Putative mechanisms fall into 1 of 3 camps: cardiac, pulmonary, or cerebral (“cerebral shutdown”) causes. Further study is difficult as SUDEP is relatively rare and inherent within the name itself, cases are unpredictable. Prior information comes from either witnessed reports, typically family members, or published reports (9 in the literature) of cases occurring within epilepsy monitoring units (EMUs). These cases are important as through careful analysis of video-EEG monitoring, a better understanding of pathophysiological mechanisms may be elucidated. Ryvlin and colleagues through the MORTality in Epilepsy Monitoring Unit Study (MORTEMUS) gathered an international cohort of such cases. They performed a systematic retrospective survey of EMUs located in Europe, Israel, Australia, and New Zealand; collected data of all cardiorespiratory arrests; estimated incidence of cardiorespiratory arrests in surveyed EMUs; analyzed patterns; and explored mechanisms to explain SUDEP. Previously published cases were included. Incidence and Mechanisms of Cardiorespiratory Arrests in Epilepsy Monitoring Units (MORTEMUS): A Retrospective Study.