Consequences of Epilepsy on the Aging Brain

People with epilepsy face a number of related health challenges, including cognitive, physical, and psychological disorders. But new findings from international research presented at the American Epilepsy Society’s (AES) 69th Annual Meeting suggest other, less expected, consequences on the aging process.

In a new study¹ released by researchers from New York University (NYU) Langone Medical Center and Imperial College London, results indicated that patients with epilepsy who are unresponsive to medication have brains that appear older than would be expected for their age.

In the study, 58 participants were placed into 3 groups: 18 patients with intractable epilepsy were used in the study, along with 20 patients with new-onset focal epilepsy, and 20 healthy controls.

The authors used structural magnetic resonance imaging scans to predict the ages of participants with epilepsy and their healthy peers. A machine-learning algorithm was used to predict age based on data from healthy patients that had been gathered from large, publicly available imaging databases, including the Pattern Recognition for Neuroimaging Toolbox (commonly known as PRoNTo). Age prediction was carried out using the white matter and gray matter segmentation images separately, yielding two age estimates per subject.

The difference between predicted brain age and chronological age was, on average, 8.8 years older for patients with uncontrolled epilepsy than healthy participants, said Heath Pardoe, PhD, lead author and assistant professor of neurology at NYU Langone Medical Center. This finding, he stated during a press conference, “essentially highlights the importance of getting seizures under control.”

“The absence of similar changes in patients with new-onset epilepsy suggests that ongoing seizures may underlie the brain aging phenomenon observed in this study,” said Dr. Pardoe.

He further explained that this technique could potentially be used to diagnose patients with intractable epilepsy early in the course of their disease, and may also be useful for other applications, like measuring the protective effect of antiepileptic medication.

Related epilepsy and aging research was also presented by Matti Sillanpaa, MD, a professor and senior research scientist at the University of Turku, Finland.

Dr. Sillanpaa reported on a 50-year follow-up of 179 epilepsy patients (many of whom he treated throughout his career) who were diagnosed as children, using neuropsychological assessments and multimodality imaging techniques to gain insights into the aging process.

An analysis of the participants’ survival, seizure outcomes, social integration, and reproductive activity were deemed promising. At the 45-year follow-up,² most of the participants achieved 10-year remission without medications, and most of those without comorbid illnesses graduated from school, obtained driver's licenses, and achieved a socioeconomic status comparable with healthy controls.

“People with epilepsy today have a bright future,” said Dr. Sillanpaa during a press conference. Treatments have improved and the stigmas associated with epilepsy are not what they once were.

The subjects with epilepsy did have abnormal neurological signs – 23% had amyloid deposits, compared to 7% in the control group.

Although the researchers note that fewer participants with epilepsy live in partnership and have children compared with healthy participants, both groups appear to enjoy a high quality of life.

The AES 2015 Annual Meeting was held December 4-8 in Philadelphia.

Session: Epilepsy and Aging: Clinical, Cognitive and Basic Science Aspects of Aging and Epilepsy. Dec. 7, 2015.

References:

1. Pardoe HR, et al. Do seizures age the brain?: machine learning analysis of structural MRI. Abstract No 1.146, 2015. American Epilepsy Society Annual Meeting, www.aesnet.org.

2. Sillanpaa M, et al. Clinical conditions of long-term cure in childhood-onset epilepsy: a 45-year follow-up study. Epilespy Behav. 2014;37:49-53.