Alzheimer Disease, Dementia Linked to Increased Seizure Risk

LOS ANGELES — Patients with dementia or Alzheimer disease (AD) have a significantly increased risk for seizures compared with patients without AD or dementia, according to results from two studies presented at the Annual Scientific Meeting of the Alzheimer’s Association International Conference 2019, held July 14-16 in Los Angeles, California.

The first study, presented by Ruby Castilla-Puentes, MD, DrPH, MBA, included patients aged ≥60 years with and without dementia from the Optum Insight Clinformatics^™ Data Mart database from 2005 to 2014 (n=2,885,336). The researchers used continuity adjusted-chi square to analyze group differences and logistic regression analysis to calculate hazard ratios [HRs] with 95% CIs.

Of all patients, 2.8% (n=79,561) had dementia; 56% were women.

The results indicated that patients with dementia had a 6.5 times higher risk for undifferentiated seizures, a 6-fold higher risk for partial seizures, and a 5.2 times higher risk for generalized/undifferentiated epilepsy compared with patients who did not have dementia. Patients with dementia also had a 4.75 times increased risk for both generalized seizures and partial epilepsy.

“The risk of new onset seizures associated with a diagnosis of dementia suggests the need for clinicians to monitor for seizures to ensure that patients with dementia receive an appropriate treatment,” said Dr. Castilla-Puentes.

The second study, presented by Jonathan Voglein, MD, included National Alzheimer’s Coordinating Center (NACC) data from 34 centers between 2005 and 2016 (n=20,745). Researchers analyzed the data for seizure prevalence in different stages of AD and for association of seizure risk with disease duration. They also analyzed the risk for seizure recurrence, as well as the associations between seizures and age at AD onset and cognitive and functional capability.

The results indicated that patients with AD dementia had a higher seizure prevalence compared with controls (active seizures: 1.51% vs. 0.35%; P <.0001; odds ratio [OR] 4.34; 95% CI, 3.01-6.27; seizure history: 3.14% vs. 1.57%; P <.0001; OR 2.03; 95% CI, 1.67-2.46). However, seizure prevalence was not increased in patients in pre-dementia stages.

The researchers found that as the duration of AD dementia increased, the prevalence of active seizures also increased (OR 1.55; 95% CI, 1.39-1.73; P <.0001). With 4.8 years of disease duration, the prevalence was 1.51%, which increased to 5.43% at 11 years.

After adjusting for age and disease duration, having a history of seizure was associated with both younger age at onset of cognitive symptoms (seizures vs no seizures: 64.7 vs 70.4 years; P <.0001) and worse cognitive and functional performance (mean Mini-Mental State Examination score: 16.6 vs 19.6; mean Clinical Dementia Rating Scale-Sum of Boxes score: 9.3 vs 6.8; P <.0001).

“Our findings emphasize a need for seizure history assessment in AD to inform individual therapeutic decisions and the necessity of systematic treatment studies of AD-associated epilepsy,” said Dr. Voglein.

References

1. Castilla-Puentes R. Dementia and the risk of new onset seizures: a cohort study of a national US managed care database. Abstract presented at: The Alzheimer’s Association International Conference 2019; July 14-17, 2019; Los Angeles, California.

2. Voglein J. Epilepsy in Alzheimer’s disease is frequent and characterized by high recurrence. Abstract presented at: The Alzheimer’s Association International Conference 2019; July 14-17, 2019; Los Angeles, California.