Increased risk of epilepsy in older patients with neurodegenerative disease

Leah Blank is an Assistant Professor in the Departments of Neurology and Population Health, Science and Policy at the Icahn School of Medicine at Mount Sinai. Allison Willis, Associate Professor in the Departments of Neurology and Epidemiology is the director of the Department of Neurology’s Center for Translational Neuroepidemiology in the Perelman School of Medicine at the University of Pennsylvania.

Geriatricians frequently care for people with neurodegenerative diseases and are often the first point of contact when new neurologic symptoms occur. In patients with neurodegenerative disease, distinguishing between non-epileptic confusional episodes and seizures may be difficult but important, as there are potential harms from missing a treatable seizure as well as from inappropriately prescribing anti-seizure medication.

We have long known that the cell death and disorganisation that occurs in diseases such as Alzheimer’s Disease and Parkinson’s increases the risk of developing seizures, but we do not have good population-level data on the burden of epilepsy in these conditions. In our Age and Ageing paper, we used a large national U.S. dataset (Medicare) to report the rate of developing epilepsy after a new Parkinson’s or Alzheimer’s diagnosis. We also explored other sociodemographic factors and comorbid neurologic disease that might be associated with an increased risk of epilepsy in the older adult, neurodegenerative population.

The five-year epilepsy incidence rates among Medicare beneficiaries with Alzheimer’s and Parkinson’s disease are almost double the rate in those without a neurodegenerative diagnosis (approximately 4.5% in both Parkinson’s and Alzheimer’s Diseases and about 2.5% in controls). Sociodemographic factors including race/ethnicity or sex were not associated with new epilepsy; but, as one might expect, additional neurologic disease including traumatic brain injury and stroke were associated with increased risk of developing epilepsy within five years.

Depression, which is not uncommon, was independently associated with developing epilepsy within 5 years. This may be a marker of a high burden of global brain disease, but also suggests that clinically there should be increased consideration of the diagnosis of seizures in depressed patients who report events consistent with seizures. 

Overall, this population-level data demonstrates that the burden of epilepsy should be expected to continue to rise as the population continues to age. In particular, persons with neurogenerative disease will be disproportionately affected. Especially at the current time, with new telehealth practice modalities being quickly adopted, we should continue to give thoughtful attention to the integration between medical and neurologic care in order to best advocate for resources and planning for seizure and epilepsy treatment in older adults.

Read the Age and Ageing paper Neurodegenerative Disease Is Associated with Increased Incidence of Epilepsy- A Population Based Study of Older Adults.