Incidence and risk factors in sudden unexpected death in epilepsy - A prospective cohort study

Objective: To determine incidence of and risk factors for sudden unexpected death in epilepsy (SUDEP). Methods: Three epilepsy centers enrolled 4,578 patients and prospectively followed these patients for 16,463 patient-years . The cohort was screened for death annually. Deaths were investigated to d etermine whether SUDEP occurred. Potential risk factors were compared in SU DEP cases and in controls enrolled contemporaneously at the same center. Re sults: Incidence of SUDEP was 1.21/1,000 patient-years and was higher among women (1.45/1,000) than men (0.98/1,000). SUDEP accounted for 18% of all d eaths. Occurrence of tonic-clonic seizures, treatment with more than two an ticonvulsant medications, and full-scale IQ less than 70 were independent r isk factors for SUDEP. The number of tonic-clonic seizures was a risk facto r only in women. The presence of cerebral structural lesions and use of psy chotropic drugs at the last visit were not risk factors for SUDEP in this c ohort. Subtherapeutic anticonvulsant levels at the last visit were equally common in the two groups. No particular anticonvulsant appeared to be assoc iated with SUDEP. Conclusions: These results support the idea that tonic-cl onic seizures are an important proximate cause of SUDEP. This information c reates a risk profile for SUDEP that may help direct preventative efforts.