Incidence and Risk Factors Epilepsy in Patients with Dementia: A Population-Based Study Using Regional Healthcare Databases in Umbria

Background: Dementia is prevalent among the elderly, also representing a risk for seizures/epilepsy. Estimations of epilepsy risk in dementia patients are not widely available. Objective: Our research aims to ascertain the incidence of epilepsy and its associated risk factors in subjects with dementia in the Umbria region, based on data from healthcare databases. Methods: In this retrospective study based on the healthcare administrative database of Umbria, we identified all patients diagnosed with dementia from 2013 to 2017, based on ICD-9-CM codes. For epilepsy ascertainment, we used a validated algorithm that required an EEG and the prescription of one or more anti-seizure medications post-dementia diagnosis. A case-control analysis was conducted, matching five non-dementia subjects by gender and age to each dementia patient. Cox proportional hazards models were then utilized in the analysis. Results: We identified 7,314 dementia cases, also including 35,280 age- and sex-matched control subjects. Out of patients with dementia, 148 individuals (2.02%) were diagnosed with epilepsy. We observed a progressive increase in the cumulative incidence of seizures over time, registering 1.45% in the first year following the diagnosis, and rising to 1.96% after three years. Analysis using Cox regression revealed a significant association between the development of epilepsy and dementia (HR = 4.58, 95% CI = 3.67-5.72). Additional risk factors were male gender (HR = 1.35, 95% CI = 1.07-1.69) and a younger age at dementia onset (HR = 1.03, 95% CI=1.02-1.04). Conclusions: Dementia increases epilepsy risk, especially with early onset and male gender. Clinicians should have a low threshold to suspect seizures in dementia cases.