Conference Coverage

Alzheimer’s disease raises risk for recurrent seizures



– Seizures are not uncommon among patients with Alzheimer’s disease – particularly as patients live longer with the disease – and are often associated with worse cognitive and functional performance, according to research findings presented at the Alzheimer’s Association International Conference.

Jonathan Vöglein, MD, of the German Center for Neurodegenerative Diseases and Ludwig-Maximilian University in Munich presented results from a cohort of 9,127 patients with Alzheimer’s disease (AD), of whom 287 had experienced a seizure, and more than 10,000 non-AD control subjects recruited at clinics during 2005-2016.

Dr. Vöglein and colleagues found that seizure risk increased with duration of disease, from 1.5% of patients at 4.8 years with the disease to 5.4% at 11 years, with likelihood of a seizure increasing steadily over time.

Moreover, 70% of AD patients who experienced a seizure had a second one within 7.5 months. People who had seizures fared worse on cognitive and functional tests: a mean 16.6 on the Mini Mental State Examination, compared with 19.6 for patients without seizures. On a severity rating scale, the Clinical Dementia Rating Sum of Boxes, patients with seizures also fared worse, with scores of 9.3, compared with 6.8 for patients without seizures (P less than .0001 for all, with results adjusted for age and disease duration).

“The data of our study show that there’s an association of seizures with worse cognitive and functional performance,” Dr. Vöglein said in an interview.

“It’s important for clinicians to know that Alzheimer’s patients are at an increased risk for seizures,” Dr. Vöglein said. “In my clinical care experience, seizures are rarely the main complaint of patients with Alzheimer’s disease.” Detailed interviews with the patient and a proxy are important, he added, because patients with Alzheimer’s disease may not always remember events that could be a seizure.

Dr. Vöglein noted that, to his knowledge, there are no reliable data showing that treating seizures with antiepileptic drugs slows cognitive decline. “The results of our study suggest that an antiepileptic treatment after a first seizure in patients with Alzheimer’s dementia may be considered,” he said.

Also at the conference, researcher Ruby Castilla-Puentes, MD, DrPH, of Janssen Pharmaceuticals in Hopewell, N.J., along with Miguel Habeych, MD, MPH, of the University of Cincinnati presented findings on dementia and seizure risk from a large U.S. national managed care database of nearly 3 million people aged 60 years and older, of whom 56% were women.

The researchers analyzed this cohort during 2005-2014 and identified 80,000 people (2.8% of the cohort) as having any dementia diagnosis. The overall incidence of new-onset seizures in patients with dementia was 12.3% per year. In general, all subtypes of seizures and epileptic disorders (partial, generalized, or undifferentiated) occurred more frequently in patients with dementia, compared against patients without dementia (P less than .0001).

People with dementia had more than six times greater risk for experiencing recurring epileptic seizures than did people without dementia (95% confidence interval, 4.4-9.5). They were at six times higher risk for partial seizures (95% CI, 5.5-6.6); fivefold higher risk for generalized (95% CI, 4.9-5.5) and undifferentiated epilepsy (95% CI, 4.8-5.2); and 4.75 times higher risk for generalized seizures (95% CI, 4.5-5.0) and partial epilepsy (95% CI, 4.4-5.1).

“Although there are limitations with the use of administrative claims databases to calculate incidence rates, this analysis suggests that patients of 60 years of age or older have higher risks of new-onset seizures associated with a dementia diagnosis,” Dr. Castilla-Puentes commented.

The findings, she said, reinforce the need for clinicians to monitor for seizures to ensure that patients with dementia receive appropriate treatment.

Dr. Vöglein disclosed no financial conflicts of interest. Dr. Castilla-Puentes disclosed being an employee of Janssen, which funded her study.

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