Tentorium cerebelli notch severity in the human brain: protocol, distribution and histopathology validation

The dura forms an impression, the tentorial notch (TN), on the surface of the entorhinal cortex (EC). To characterize the potential injury to the EC, we evaluated the entorhinal surface in 55 postmortem samples. We developed a semi-quantitative protocol to rate the TN severity and evaluated the impact of the TN on the surrounding tissue. We rated the penumbral injury as: none, moderate or severe. We demonstrate that 96% of the samples showed a TN; specifically mild (33%), moderate (47%) and severe (16%). TN severity correlated positively with penumbra scores (Kendalls coefficient = 0.65, 95% CI [0.535, 0.735]). We found no association between TN severity levels and Braak and Braak stages (Fischers exact P value = .862). We established a robust protocol for assessing the tentorial notch, addressing a gap in understanding anatomical factors that may contribute to EC vulnerability in Alzheimers disease.