Skip to main content
Premium Trial:

Request an Annual Quote

Epilepsy Linked to Alzheimer's Disease Risk Variants in New Analysis

NEW YORK – A new Mendelian randomization (MR) study supports the notion that some forms of epilepsy may stem from the same processes and genetic risk patterns as Alzheimer's disease (AD).

Based on their findings, the authors suggested that "[m]ore effort should be made to screen seizure in AD, unravel its clinical implications, and explore its role as a putative modifiable risk factor."

For a study appearing in Neurology on Wednesday, researchers at Zhejiang University School of Medicine in China analyzed data from a genome-wide association study meta-analysis on more than 111,000 AD cases and nearly 678,000 controls; 15,212 epilepsy cases and 29,677 controls; and cerebral spinal fluid (CSF) measurements on two AD biomarkers — amyloid beta 42 and phosphorylated Tau — in 13,116 individuals.

"This study used Mendelian randomization as a method to minimize several inherent limitations of conventional observational studies, including unobserved confounding [factors] and reverse causality," first author Yi Fang, a researcher at Zhejiang University School of Medicine, said in an email.

Consistent with prior studies, the team's results suggested that enhanced genetic risk for AD coincided with higher-than-usual rates of both generalized epilepsy and a form of epilepsy known as focal epilepsy with hippocampal sclerosis — results that were subsequently validated using genetic risk data from another AD-focused GWAS.

Likewise, individuals diagnosed with generalized epilepsy carried genetic variants linked to lower-than-usual levels of CSF amyloid beta 42 — a biomarker that accumulates in the brain and is consequently found at reduced levels in the CSF in individuals with AD.

Together, the results "show that there is a causal link between AD and generalized epilepsy and between lower CSF [amyloid beta 42] levels and generalized epilepsy," Fang explained, suggesting that AD and related amyloid pathology "increases [individuals'] propensity to generalized seizures."

Conversely, the researchers found that AD risk increased by nearly fourfold in individuals diagnosed with focal epilepsy with hippocampal sclerosis. Such results are consistent with earlier studies suggesting that the hippocampus contributes to AD-related hyperexcitability in the brain.

More generally, the authors suggested that these and other findings from their study may prove valuable in future efforts to understand and potentially treat AD and related forms of epilepsy.

"As our data suggested that seizure might be an integral part of AD, future studies and trials in AD may consider enrolling subjects with co-morbid seizure," Fang suggested, adding that it will also be important to explore which anti-epileptic medications, if any, might help in damping down AD disease progression.

The Scan

Machine Learning Helps ID Molecular Mechanisms of Pancreatic Islet Beta Cell Subtypes in Type 2 Diabetes

The approach helps overcome limitations of previous studies that had investigated the molecular mechanisms of pancreatic islet beta cells, the authors write in their Nature Genetics paper.

Culture-Based Methods, Shotgun Sequencing Reveal Transmission of Bifidobacterium Strains From Mothers to Infants

In a Nature Communications study, culture-based approaches along with shotgun sequencing give a better picture of the microbial strains transmitted from mothers to infants.

Microbial Communities Can Help Trees Adapt to Changing Climates

Tree seedlings that were inoculated with microbes from dry, warm, or cold sites could better survive drought, heat, and cold stress, according to a study in Science.

A Combination of Genetics and Environment Causes Cleft Lip

In a study published in Nature Communications, researchers investigate what combination of genetic and environmental factors come into play to cause cleft lip/palate.