Common brain feature linked to cellular damage in region vulnerable to Alzheimer’s disease

The entorhinal cortex is a brain region important for memory and navigation. It’s also one of the earliest regions affected by tau pathology in Alzheimer’s disease. In many people, an impression known as the tentorial notch can form on the surface of the entorhinal cortex.

Smriti Chadha, BS

A new study led by researchers from Mass General Brigham provides evidence that the tentorial notch is linked to neuronal damage in the region. But the authors show that tau pathology does not originate at this tentorial notch site, suggesting this phenomenon does not initiate Alzheimer’s disease. 

The study, led by senior author Jean Augustinack, PhD, with co-lead authors Smriti Chadha, BS, and Joshua Chase, BA, all of the Mass General Brigham Department of Radiology, evaluated the tentorial notch in postmortem brain samples from 55 cognitively healthy individuals and on MRIs from 22 young adults.

Joshua Chase, BA

They found that a tentorial notch was extremely common: 96% of the postmortem samples and 95% of young adults examined by MRI had one. Among samples with a notch, 74% showed localized cellular damage, including neuron loss, neuronal stretching and/or disruption of cortical layers. More severe notches correlated with greater cellular damage. 

Jean Augustinack, PhD

But the damage they saw was not associated with early tau pathology. Tentorial-notch severity was not associated with Braak stage (a method of classifying the degree of Alzheimer’s progression), and the researchers observed relatively little tau at the notch itself. They conclude that the cellular damage is independent of tau at this early stage.  

Published in Acta Neuropathologica Communications on August 28, 2026 | Read the paper: “Tentorial notch severity in the human brain: protocol, distribution and histology validation” 

Summary reviewed by: Joshua Chase, co-lead author; Jean Augustinack, PhD, senior author