Highlights in clinical autonomic neurosciences: sudden unexpected death in epilepsy.

Sudden unexplained death in epilepsy (SUDEP) is an important unresolved problem affecting many patients with recurrent seizures. Amongst the mechanisms postulated are ictal or postictal cardiac arrhythmias, central hypoventilation or apnea, and neurogenic pulmonary edema. Across these categories, a common element appears to be some form of autonomic dysregulation. Accordingly, the search for biomarkers of SUDEP risk has focused increasingly on autonomic findings. Emerging models implicate attenuated cardiac vagal modulation coupled with surging cardiac sympathetic activity, neuronal dropout in the nucleus tractus solitarii, and in some cases genetic factors affecting ion channel behavior. Explicating the crucial links between brain and heart in epilepsy benefits from collaboration amongst neurologists, cardiologists, physiologists, and other specialists with an interest in the autonomic nervous system.