The Relationship Between Sleep, Cognition, and Dementia Risk in People With Focal Epilepsy

BACKGROUND AND OBJECTIVES: Sleep disruption and cognitive impairment are important comorbidities of focal epilepsy. However, the nature to which sleep affects cognition and long-term dementia risk in focal epilepsy, compared with other brain conditions, remains unclear. We examined the relationship between sleep, cognition, and dementia risk in patients with focal epilepsy compared with healthy controls and stroke patients. METHODS: We conducted an analysis of the prospective UK Biobank cohort study, with baseline assessments performed between 2006 and 2010 and follow-up until 2021. Study groups were mutually exclusive participants with focal epilepsy and stroke at baseline assessment and healthy controls. Sleep characteristics included reports of sleep duration, obstructive sleep apnea, insomnia, napping, and dozing. Main outcomes were risk of incident all-cause dementia and Alzheimer disease from Cox proportional hazard modeling and comparison of executive function measures and brain total hippocampal and gray matter volumes using generalized linear modeling. RESULTS: = 0.991). DISCUSSION: Optimal sleep modified both cognitive performance and dementia risk in individuals with focal epilepsy compared with stroke patients and healthy controls. Based on self-reported sleep data, these findings suggest that improving sleep may be an impactful intervention to improve cognition and reduce dementia risk particularly in focal epilepsy.