INVESTIGATING THE LINK BETWEEN LATE-ONSET EPILEPSY AND DEMENTIA: A SYSTEMATIC REVIEW OF CLINICAL EVIDENCE AND CONTRIBUTING FACTORS

The prevalence of late-onset epilepsy (LOE), defined as epilepsy that develops in adults aged 50 years or older, is increasing alongside global population aging. Emerging clinical evidence suggests an association between LOE and dementia. However, this relationship remains poorly understood due to the limited scope of existing clinical studies. We aimed to characterise associations between LOE and dementia by synthesising clinical evidence and identifying factors that may modulate disease onset and progression. A systematic search was conducted across PubMed, Scopus, and Web of Science. Articles were screened using predefined inclusion criteria, identifying those reporting clinical data on individuals diagnosed with both LOE and dementia. Extracted variables included demographic, clinical, treatment and vascular risk data. Initial analysis in 41 patients (mean age: 66.6±8.4 years) showed that age of LOE onset was not significantly associated with seizure type (p=0.44) nor treatment (p=0.26). However, individuals receiving levetiracetam monotherapy exhibited a later LOE onset age (p=0.01), potentially reflecting an association between anti-seizure medications and progression of cognitive decline. Hypertension was the most prevalent vascular risk factor (52.7%), and prevalence increased with age at LOE onset (p=0.01, n=74). In patients with comorbid Alzheimer’s disease, modest variability in the ages of LOE and dementia onset were observed (67.0±2.5 and 68.8±2.3, respectively, n=89). Our findings support a heterogenous, bidirectional association between LOE and dementia, with a potential role for shared vascular mechanisms. Current work is focused on expanding patient-level analyses of vascular risk factors and treatment-related effects to provide insights into underlying pathways.