Objective:

To study impact of seizures on clinical and mortality outcomes in dementia patients.

Background:

Dementia and seizures are both public health imperatives.Seizures occur in 10-64% of those with dementia and accelerate cognitive decline.However,the impact of seizures on clinical and mortality outcomes in dementia patients has not been studied. 

Design/Methods:

We analyzed longitudinal data from 39  Alzheimer’s disease Centers from 9/2005 –12/2021,maintained by National Alzheimer's Coordinating Center.We included patients with cognitive impairment at initial visit.We compared cognitive,functional and mortality outcomes among those with and without seizures.

Results:

 At the initial visit, among 26,425 cognitively impaired patients, 374(1.4% point prevalence) had  seizures. Seizure patients were significantly younger(62.91vs 68.4years,p<0.001) at onset of cognitive decline. In multivariate regression analysis,dominant Alzheimer’s disease(AD) mutation(OR:5.55,CI:2.39-12.89,p<0.001),stroke(OR:3.17,CI:2.35-4.27,p<0.001), transient ischemic attack[TIA](OR:1.72,CI:1.21-2.46,p=0.003), traumatic brain injury[TBI] (OR:1.92,CI:1.48-2.50,p<0.001), Parkinson’s disease [PD] (OR:1.79,CI:1.07-2.98,p=0.025), depression(OR:1.61,CI:1.30-1.99,p<0.001) and lower education(OR:0.97,CI:0.95-0.99,p=0.043) were associated with seizures.

Patients with seizures performed worse on mini-mental-status examination(18.50 vs 22.88,p<0.001) and Clinical-Dementia-Rating Sum-of-boxes(7.95 vs 4.28,p<0.001); and had more physical dependence(OR:2.52,CI:1.99-3.19,p<0.001) compared to those without seizures after adjusting for age and dementia duration using generalized linear model.

Analysis of longitudinal mortality data showed that a higher proportion of seizure patients had died (OR:1.56,CI:1.27-1.91,p<0.0001),and they were younger at death(72.99 vs 79.72years,p<0.001). Multivariate survival analysis using Cox regression was conducted to study age at death and seizure status.We adjusted the model for sex,disease duration, stroke,TIA,TBI, depression,education and dominant AD mutation.Despite adjustment,patients with seizures were at a higher risk of dying at a younger age(hazard ratio:1.76,CI:1.49-2.08,p<0.001).

Conclusions:

Our study shows that dementia patients with seizures have worse cognition and higher mortality rates at a younger age compared to dementia patients without seizures.Dementia patients with early onset of dementia, dominant AD mutation,stroke,TIA,TBI,PD,depression, and/or lower education are more likely to have seizures.Dementia patient with these risk factors may be routinely considered for EEG for early identification and treatment of seizures to improve outcomes.