Neurologic conditions and sudden death

The most important type of sudden death in neurology is sudden unexpected (or unexplained) death in epilepsy (SUDEP). It accounts for up to 17 % of deaths in persons with epilepsy, and it is the most frequent cause of epilepsy-related deaths. The most prominent risk factor for SUDEP is uncontrolled generalized tonic-clonic seizures, the higher frequency of which results in greater SUDEP risk. However, the exact mechanism by which the seizures predispose a person to SUDEP is unknown. Although the phenomenon of seizure-related asystole is well known, it is usually very transient and uncommon. There is increasing evidence to implicate respiratory compromise as a major postseizure event that leads to cardiorespiratory arrest, but further investigations are needed to fully understand the relevance of this observation to the phenomenon of SUDEP. Most other “sudden” deaths in neurologic conditions are more properly termed “rapid death,” in that death in most cases occurs in the setting of deteriorating neurologic and vital functions. More common neurologic conditions associated with rapid deaths are large strokes with increased intracranial pressure and, less commonly, smaller strokes that affect cerebral regions specifically linked to cardiorespiratory or autonomic functions, such as the brainstem and the insula. Death can also occur “suddenly” in advanced metabolic or congenital myopathies in which cardiomyopathy or channelopathy is a feature or in certain neurodegenerative disorders with compromise of the autonomic nervous system.