SAN ANTONIO – A diagnosis of epilepsy increases the risk of death from any cause, and mortality risk is highest for those diagnosed with epilepsy in the first year of life, according to neurologist Dr. Jakob Christensen.
Adverse birth outcomes account for some of the increased mortality. Even after excluding those with adverse birth outcomes from analysis, however, the risk is still 10 times greater than the background mortality rate.
The conclusion is based on findings from a large cohort study of all-cause mortality in people with epilepsy born in Denmark from 1977 to 2006. Dr. Christensen, of Aarhus (Denmark) University Hospital, used linked information from Danish civil service, health, and cause of death registries to examine mortality rates of those with and without epilepsy.
Among the 1.5 million people in the cohort, there were 10,648 deaths, and 806 were in people diagnosed with epilepsy, Dr. Christensen said at the annual meeting of the American Epilepsy Society. Based on 26.2 million person-years of follow-up, overall mortality was approximately 40 times higher in the epilepsy group. Risk was highest among people diagnosed with epilepsy in the first year of life, "approximately 60 times that of the background mortality," he said.
Mortality risk declined with increasing age at diagnosis, but the mortality rate in epilepsy patients never reached the background value seen in those without epilepsy, he said. Even those diagnosed after age 15 had a 5-10 times greater mortality risk.
After excluding from the analysis epilepsy patients with adverse birth outcomes, such as low birth rate, asphyxia, early birth, or malformations, mortality risk decreased relative to the epilepsy population as a whole. However, mortality was still 10 times higher than the background rate.
Investigation into specific causes of death was not part of the study. "We did look at the data to see if any causes were highly increased, and there were no surprises. For example, mortality was higher in patients with brain tumors, which is not unexpected," Dr. Christensen said.
"What we hope to do next is to look more closely at the 8%-10% of the epilepsy patients in this study whose cause of death was listed as ‘epilepsy,’ to gain insight into factors associated specifically with sudden unexpected death in epilepsy."
Dr. Christensen reported having no financial conflicts of interest.