Sudden unexpected death in epilepsy: from mechanisms to prevention.
OBJECTIVE
To discuss the pathophysiology and potential prevention of sudden unexpected death in epilepsy.


RESULTS
Long-term electrocardiogram monitoring over several months has detected ictal asystole in three out of 20 (15%) patients with refractory epilepsy, suggesting that high-risk ictal arrhythmias occur in a greater proportion of patients with refractory epilepsy than previously thought. In case-control studies, sudden unexpected death in epilepsy was found to be associated with frequent generalized tonic-clonic seizures and greater ictal maximal heart rate, especially during nocturnal attacks. Conversely, supervision at night was associated with a lower risk of occurrence. The impact of epilepsy surgery on the risk of death and sudden unexpected death in epilepsy remains unclear, with comparable long-term survival in an epilepsy surgery cohort compared with a matched population of patients with refractory epilepsy who did not undergo surgery. Previous results may have been partly confounded by the association observed between preoperative decreased heart rate variability and poor postoperative seizure outcome.


CONCLUSIONS
Ictal arrhythmias may represent a more prevalent cause of sudden unexpected death in epilepsy than previously thought. No clear recommendations have emerged from the literature regarding the most appropriate therapeutic strategies to prevent the event, apart from the supervision at night of patients with refractory epilepsy.
Department of Functional Neurology and Epileptology, Hospices Civils de Lyon and Université Claude Bernard Lyon 1, Unité 301, Hôpital Neurologique, 59 boulevard Pinel, 69003 Lyon, France. ryvlin@cermep.fr
Philippe
P
Ryvlin
Alexandra
A
Montavont
Philippe
P
Kahane
D002423:Cause of Death; D015897:Comorbidity; D003645:Death, Sudden / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control; D004562:Electrocardiography / Q000379:methods; D004827:Epilepsy / Q000150:complications* / Q000453:epidemiology / Q000601:surgery; D006801:Humans; D015994:Incidence; D009493:Neurosurgery / Q000379:methods; D012307:Risk Factors