Population-based study of the incidence of sudden unexplained death in epilepsy
Ficker DM, So EL, Shen WK, Annegers JF, O’Brien PC, Cascino GD, and Belau PG (1998) Population-based study of the incidence of sudden unexplained death in epilepsy. Neurology 51:5 1270–4.
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Abstract: OBJECTIVE: To determine the population-based incidence of sudden unexplained death in epilepsy (SUDEP) and to determine the risk of SUDEP compared with the general population. BACKGROUND: Prior studies of SUDEP have described a wide range of incidence and have suffered from selection bias and other methodologic limitations. A population-based study of the incidence of SUDEP has never been performed. Furthermore, the risk of sudden death in the epilepsy population has not been compared with that of the general population. METHODS: All deaths in persons whose epilepsy was diagnosed between 1935 and 1994 in Rochester, MN, were reviewed. The rate of SUDEP was compared with the expected rate of sudden death in the general population for patients age 20 to 40 years to determine the standardized mortality ratio (SMR). RESULTS: We identified nine cases of SUDEP. SUDEP accounted for 8.6% (7 of 81) of the deaths in persons 15 to 44 years of age. The incidence of SUDEP was 0.35 per 1,000 person-years. SMR for SUDEP was 23.7 (95% confidence interval, 7.7 to 55.0) compared with the general population. CONCLUSIONS: The incidence of SUDEP in our study was 0.35 per 1,000 person-years. SUDEP was responsible for 1.7% of deaths in our cohort. SUDEP is a rare cause of death in the epilepsy population but exceeds the expected rate of sudden death in the general population by nearly 24 times.
- Review of data from 6 decades of patient records in Rochester, Minnesota to determine the degree to which epilepsy elevates the risk of sudden death. The study only considered patients aged 20 to 40, and found that the risk of sudden unexplained death in epilepsy-afflicted persons was very low, 0.35 per 1,000 person years. At the same time, because the risk of sudden unexplained death in this age group in the general population is so extremely low, the rate for epilepsy patients is in the range of 7.7 to 55 times higher. This highlights the importance of providing meaningful context for interpretation of statistics when presenting data to patients. Includes valuable discussion of many other incidence studies. AED levels were low/undetectable in those patients in whom it was twsted. GTCS was most common type.