Dementia Risk increases With Focal Epilepsy and Modifiable Cardiovascular Risk Factors

Focal epilepsy was associated with a significant risk of developing dementia, to a greater extent than stroke, in a recent study published online in JAMA Neurology. This was magnified substantially in individuals with a high cardiovascular risk.

Epilepsy is a common neurological condition characterized by unprovoked seizures. The incidence of epilepsy is highest in older life and progressively increases after 55 years of age. As individuals with epilepsy age, studies suggest an increased risk of cognitive impairment and potentially dementia. However, the extent to which epilepsy affects dementia risk and potential underlying mechanisms remains unclear. In addition, there are no specific clinical guidelines around mitigating the risk of dementia in epilepsy.

In this study by Tai et al, the researchers from UK analyzed the risk associated with developing dementia across a range of neurological conditions in the UK Biobank prospective cohort, with the aim to determine the extent to which focal-onset epilepsy is associated with risk of developing dementia compared with individuals with stroke or migraine, other nondegenerative neurological conditions, as well as healthy controls.

Their results showed that having focal epilepsy was associated with worse cognitive function in mid- to late-life individuals compared with controls. Furthermore, by leveraging a large epilepsy cohort with longitudinal data on dementia outcomes, they found a higher dementia risk in individuals with focal epilepsy compared with those with stroke, which was substantially worse in those with greater cardiovascular risk burden. Focal epilepsy was associated with widespread structural brain change reflected by lower total hippocampal and total gray matter volume.

Their investigation also identified worse cognitive function throughout mid- to late-life individuals with focal epilepsy compared with healthy controls, which was comparable with individuals who had a history of stroke. Taking more antiseizure agents was associated with worse cognition in those with focal epilepsy, which may reflect severity of disease in addition to potential for medication adverse effects.

The authors found more than a 13-fold increased risk of dementia in individuals who had high cardiovascular risk and epilepsy compared with those with no epilepsy and low cardiovascular risk. This increased dementia risk was greater than that of stroke.

“The association between epilepsy and dementia may represent shared risk factors between epilepsy and a vascular dementia-like process or an interplay between mixed underlying pathology, which is increasingly reported in dementia.In either event, our findings highlight a key clinical message that cardiovascular risk factor modification may be critical for managing cognitive outcomes in focal epilepsy”, they said.

Cardiovascular risk was associated with a substantially increased risk of dementia in people with focal epilepsy. Interventions targeting modifiable risk factors may offer an effective management strategy in preventing dementia in individuals with epilepsy.

Reference:

Tai XY, Torzillo E, Lyall DM, Manohar S, Husain M, Sen A. Association of Dementia Risk With Focal Epilepsy and Modifiable Cardiovascular Risk Factors. JAMA Neurol. Published online March 27, 2023. doi:10.1001/jamaneurol.2023.0339