Risk factors for sudden unexpected death in epilepsy: a controlled prospective study based on coroners cases

Abstract

We performed a controlled prospective study of pathologically verified sudden unexpected death in epilepsy (SUDEP) in a coronial setting, to identify risk factors. We prospectively studied coronial deaths of people with epilepsy in Vic., Australia, during a 21-month period. Fifty SUDEP and 50 subjects with epilepsy who died of other causes (controls) were collected sequentially. Clinical data was obtained shortly after death from questionnaires completed by treating doctors, discussion with family members and coronial files, including police reports of death, autopsy and toxicology reports. Factors assessed were age, sex, duration of epilepsy, type of seizure(s), seizure frequency, symptomatic epilepsy, including post-traumatic epilepsy, presence of structural brain lesion, idiopathic epilepsy, mental retardation, psychiatric illness, including dementia, recent stressful life event, particular antiepileptic drugs (AEDs) and AED polytherapy, compliance with AED treatment, psychotropic drug prescription, alcohol and other substance abuse, place of death and evidence of terminal seizure. The SUDEP group was characterised by younger age and higher proportion found dead in bed and with evidence of terminal seizure compared to controls. The profile of patients at risk for SUDEP are young people with epilepsy. They are most likely to die in sleep and our data support the view that SUDEP is a seizure-related event. This, taken in conjunction with the finding that there was no increased risk associated with a particular AED in monotherapy or multiple AEDs suggests that attempts to better treat patients' epilepsy with AEDs might decrease the risk of SUDEP. Although the literature suggests that SUDEP is more frequent in patients with severe epilepsy, we did not find a correlation with seizure frequency suggesting that other clinical indices may be more important.