A ten-year study reveals that epilepsy increases the risk of cognitive decline in older adults.
Dr. Evan Thacker, public health professor, wanted to know if having epilepsy increases the risk of cognitive decline in older adults. Understanding epilepsy, which is one of the three most common neurological diseases in older adults, and how it affects cognitive decline, could be the key to understanding how to manage and protect the brain health of older adults. Dr. Thacker explained, “We’re studying epilepsy because we are interested in overall brain health.”
Along with professors from Columbia University and the University of Washington, Dr. Thacker analyzed cognitive tests in a group of over 5,000 adults above the age of 65. The study participants took the cognitive tests once a year for up to ten years. As could be expected, the average scores on the test declined over time. The data also revealed that the 200 adults in the group who had epilepsy experienced a faster decline than the adults who did not have epilepsy.
Why do older adults with epilepsy experience faster cognitive decline? Dr. Thacker and his collaborators hypothesize it is because people who have epilepsy have a greater underlying burden of disease in the blood vessels of the brain.
The other important discovery that Dr. Thacker and his team made was that the fastest average cognitive decline occurred in people who had epilepsy and a certain gene, APOE-4. This gene is a known genetic risk factor for Alzheimer’s disease and related dementias. Adults who have the APOE-4 gene have a higher genetic predisposition toward cognitive decline. In the presence of epilepsy, the effect of the APOE-4 gene is greater.
Through these discoveries and future work, Dr. Thacker hopes that “epilepsy doctors will become more tuned into vascular health and aware that for people who have epilepsy, controlling seizures is not the only thing that matters, but other aspects of their brain health also matter.” He explained that both doctors and patients may benefit from considering how epilepsy can affect overall brain health. This research can also lay a foundation for future research about epilepsy prevention.
Dr. Thacker anticipates expanding the project in size and direction by increasing the number of people in the study from 5,000 to over 40,000 participants and testing additional variables. He explained, “We want to learn more about how having epilepsy is associated with a higher risk for stroke and higher risk for dementia or faster cognitive decline.” He also plans to study the effects of epilepsy combined with heart disease, high blood pressure, or smoking.
The most important thing that Dr. Thacker has learned through his research is that “The health of our brain matters.” He said, “Our research is aimed at trying to understand the connections between these different brain diseases.” With the understanding that comes from studying the connections, older adults with epilepsy and the APOE-4 gene and their doctors will be aware of their risk of cognitive decline and be prepared to face it.