Compared with patients without epilepsy, those with late-onset epilepsy may be at increased risk for death, even after adjusting for comorbidities, according to study findings published in Neurology. In addition, the researchers found that adults with late-onset epilepsy (starting at ≥65 years) had a higher mortality risk due to stroke and dementia.
Although epilepsy has been shown to increase the mortality risk relative to the general population, less is known regarding the association between late-onset epilepsy and the risk for death.
To explore this association, the researchers of the current study analyzed data from the prospective Atherosclerosis Risk in Communities (ARIC) study, the Cohort Component of which began in 1987.
The ARIC study included a total of 15,792 individuals, a majority of whom were Black and White men and women aged between 45 and 65 years in 4 communities in the US. Participants were followed up with 7 in-person visits through 2018 and were contacted annually by telephone.
Researchers of the ARIC study collected hospital discharge records and information on death certificates of all participants. Participant data were linked to Centers for Medicare and Medicaid Services (CMS) Medicare claims data.
A total of 678 patients of the 9090 participants with sufficient CMS data developed late-onset epilepsy during follow-up (29 per 1000 person-years). Patients with late-onset epilepsy were diagnosed at 67 years.
At the end of 2018, a significantly greater percentage of patients with late-onset epilepsy had died compared with the ARIC participants without epilepsy (54% vs 34.9%, respectively; P <.005). In patients with late-onset epilepsy, the median duration of survival following the first seizure code was 4.79 years.
After the age of 67 years, the mortality rates in those with vs without late-onset epilepsy were 49.76 per 1000 person-years vs 33.68 per 1000 person-years, respectively (incident rate ratio [IRR], 1.48; 95% CI, 1.35-1.62).
An analysis of ARIC participants with late-onset epilepsy who did not have stroke or dementia showed an increased IRR for mortality of 1.57 (95% CI, 1.36-1.81), as well as an adjusted hazard ratio of mortality of 3.11 (95% CI, 2.69-3.62). Among individuals with stroke and dementia, there was no significant difference between participants with vs without late-onset epilepsy with regard to mortality (IRR, 1.09; 95% CI, 0.81-1.45).
Compared with ARIC participants without late-onset epilepsy, those with late-onset epilepsy had higher rates of deaths caused by stroke (4.3% vs 9.3%, respectively; P <.005) and dementia (8.9% vs 15.8%, respectively; P <.005).
A limitation of this study was the reliance on CMS Medicare claims data for identifying cases of late-onset epilepsy and the lack of information about the severity of epilepsy, a potentially crucial metric in determining risk for mortality and stroke.
The researchers concluded that the observed “mortality risks suggest that clinicians should address modifiable vascular risk factors with lifestyle and medication changes as appropriate” in patients with late-onset epilepsy.
Johnson EL, Krauss GL, Kucharska-Newton A, et al. Mortality in patients with late-onset epilepsy: Results from the atherosclerosis risk in communities study. Neurology. Published online July 19, 2021. doi:10.1212/WNL.0000000000012483