THURSDAY, May 25, 2023 (HealthDay News) – People with a genetic predisposition to Alzheimer’s disease may have an increased risk of epilepsy, a new study says. And folks with a certain type of epilepsy may have higher odds of developing Alzheimer’s disease.
Having Alzheimer’s was linked to a 5.3% increased risk of generalized epilepsy, researchers report in the journal Neurology. This involves seizures that occur from both halves of the brain.
Researchers also found a 1.3% increased risk of a condition known as focal epilepsy with hippocampal sclerosis. In focal epilepsy, seizures affect one half of the brain.
“Our research found that not only are people with Alzheimer’s disease more likely to develop epilepsy, but also that those with focal epilepsy, which accounts for more than half of all cases of epilepsy, were more likely to develop Alzheimer’s disease,” said study co-author Jiali Pu, from Zhejiang University School of Medicine in Hangzhou, China.
“More effort should be made to screen for seizures in people with Alzheimer’s disease and to understand the impact of seizures on those facing these two challenging neurologic conditions,” Pu said in a journal news release.
Researchers studied this in a variety of directions, looking at gene variation throughout the human genomes of more than 111,300 people who had Alzheimer’s disease and more than 677,600 people without the disease.
These types of studies involve looking at long stretches of DNA to identify small differences in genetic sequences.
The team worked to determine if there was an association between the genetic variations and the risk of epilepsy.
In studying the genes of more than 15,000 people with epilepsy matched to the genes of more than 29,000 people without epilepsy, the researchers found that people who had focal epilepsy with hippocampal sclerosis had nearly four times the risk of developing Alzheimer’s disease compared to people without epilepsy.
They also analyzed the genes of more than 13,000 people who had data on the levels of a biomarker for Alzheimer’s disease called amyloid in their cerebrospinal fluid. Finding lower amounts of the biomarker suggests increased deposits of amyloid plaques in the brain, thought to be a hallmark of Alzheimer's disease.
Genes that predicted a lower amount of the biomarker were linked to an increased risk of generalized epilepsy, according to the study.
The study can't prove that one causes the other, only that there is an association. Aldo, participants were all of European ancestry, which is a study limitation.
The study results were published online May 24 in Neurology.
The Epilepsy Foundation has information on different types of seizures.
SOURCE: Neurology, news release, May 24, 2023