Young stroke survivors with seizures at higher risk for dementia

Onset of seizures after stroke more than doubled the risk for dementia in young patients, according to a study published in Neurology.

“Dementia is frequent after a stroke, affecting one in three stroke survivors,” Alain Lekoubou, MD, MSc, of the department of neurology at Penn State University and Hershey Medical Center, and colleagues wrote. “Dementia after stroke is associated with a 2 to 6 times higher adjusted mortality rate, a higher rate of stroke recurrence and a poor functional outcome.”

Lekoubou and fellow researchers sought to examine the association between new onset of seizures and dementia in a cohort of young stroke patients by conducting a population-based study using the IBM Watson Health MarketScan Commercial Claims and Encounters database. They identified 23,680 patients, aged 18 to 60 years, with ischemic stroke (IS; n = 20,642) and hemorrhagic stroke (HS; n = 3,038) from January 2006 to December 2009. All participants were free from dementia, brain tumors, toxin exposure, traumatic brain injury and neuro-infectious diseases at inclusion; had 1 year of continuous enrollment before index stroke diagnosis and 5 years after; and had no seizures within 1 year before index date.

The primary study outcome was dementia within the follow-up interval of January 2010 to December 2014. For each participant, researchers calculated the person-time from index data to the initial occurrence of dementia, death, end of enrollment or end of follow-up, whichever came first. Cox proportional hazards regression model was used to predict association of seizures with dementia occurrence.

Results showed that cumulative incidence of seizure was 6.7% (n = 1,574) for all strokes, 6.4% (n = 1,322) for IS and 8.3% (n = 252) for HS, with corresponding cumulative incidence of dementia of 1.3% for all strokes, 1.4% for IS and 0.9% for HS.

Further, after multivariable adjustment, patients with stroke who developed seizures had a greater risk for dementia compared with those without seizures (all strokes adjusted HR = 2.53, 95% CI, 1.84-3.48; IS aHR = 2.52, 95% CI, 1.79-3.53; HS aHR = 2.8, 95% CI, 1.05-7.43).

“This observation raises the possibility that systematically screening and treating young stroke survivors for seizures may reduce the onset of dementia and have important public health implications,” Lekoubou and colleagues wrote.