Using Cox proportional hazard modelling, researchers studied the occurrence and risk factors for epilepsy in the Swedish dementia registry (SveDem), a large cohort of patients with dementia. They collected data on epilepsy and seizure-related diagnoses, comorbidities and survival for all people in SveDem (n = 81,192) and three randomly chosen age- and gender-matched controls from the population register without a dementia diagnosis (n = 223,933).
In patients with dementia, a diagnosis of epilepsy was discovered more frequently than controls.
Data reported that the risk of incident epilepsy after dementia was 2.1% at 5 years and 4.0% at 10 years, compared to 0.8% and 1.6% for controls, respectively. Dementia was linked to a hazard ratio of 2.52 for epilepsy in multivariate analysis.
The authors concluded that dementia, especially young onset Alzheimer disease, raises the risk of subsequent epilepsy. They observed that the risk was significantly increased by young age, male sex, stroke, brain trauma, brain tumour and low Mini-Mental State Examination score.