Epileptic patients are 24 times more at risk for sudden, unexpected death when compared to the general population, according to a recent report.
The research paper, “Sudden unexpected death in epilepsy: a silent killer,” published in The Ceylon Medical Journal, described the most common cause of sudden unexpected death in epilepsy (SUDEP), and identified risk factors and prevention strategies to lessen the chances.
After SUDEP, the next two most common causes of death for epilepsy patients are accidental deaths resulting from epileptic seizures, and status epilepticus, a condition in which seizures follow one another or a seizure lasts too long without recovery in between.
According to the report, SUDEP is defined as “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, in which post-mortem examination does not reveal a cause of death.” It is a mostly sleep-related, unwitnessed event, with most studies reporting that only 10% of SUDEP deaths are usually witnessed.
The reported incidence of SUDEP is highly variable, as research tools and diagnostic criteria also vary.
A clear understanding of the risk factors associated with SUDEP is essential for the design and establishment of prevention strategies. In the authors’ review of clinical studies, the frequency of generalised tonic-clonic seizures (GTCS), a convulsive seizure that involves the entire body, is the leading risk factor for SUDEP. Nocturnal seizures also appear to be an independent risk factor for SUDEP. The prone position, lying with the chest down, has been recently significantly associated with SUDEP.
Pathophysiology studies in humans and animal experiments have established that seizure-related respiratory dysfunction, cardiac abnormalities, dysfunction of the autonomic nervous system and postictal cerebral dysfunction (cerebral shutdown) are considered the most common mechanisms for SUDEP. Genetic susceptibility, lack of serotonin and deficiency at a cellular level, and poor compliance to anti-epileptic medication have also been found as factors.
Because full underlying physiological mechanisms have not been identified, prevention measures have not been fully established. But some suggestions include improvement of seizure control because GTCS is the most consistent risk factor; using a seizure alarm or monitoring system; and nocturnal supervision. Data also suggests that patients should talk about SUDEP with their doctors to broaden awareness of the risk.
The authors concluded: “Currently, modification of those risk factors remains the most practical intervention to reduce the risk of SUDEP. There is a need to increase awareness of SUDEP among the general public, patients, policy makers and health care providers.”