Reviewed by the Help Dementia Editorial Team — our editors review every article for accuracy against guidance from the National Institute on Aging, the Alzheimer’s Association, and peer-reviewed sources.
This guide is part of our pillar: Brain Mri Report Decoded Terms Families Misread.
Hippocampal atrophy is the single most studied imaging marker in Alzheimer’s disease. The hippocampus is the brain’s memory hub, and when it shrinks, memory falls first. Here is how doctors measure and interpret hippocampal atrophy.
Understanding hippocampal atrophy helps families ask better questions and make calmer decisions. The detail below covers what doctors usually skip when explaining hippocampal atrophy.
The Visual Rating Scale
Most radiologists use the Scheltens 0 to 4 scale. 0 is normal, 4 is severe atrophy. A score of 2 or higher at age 70 is concerning for early Alzheimer’s.
Quantitative Measurement
Software like NeuroQuant compares volume to age-matched norms and produces a percentile. Below the 10th percentile is significant.
Why the Hippocampus Falls First
Alzheimer’s tau pathology starts in the entorhinal cortex and spreads into the hippocampus before other regions, which is why memory loss is the first symptom.
Atrophy Rate Matters
Annual hippocampal shrinkage above 5 percent is far more predictive than absolute size at one timepoint.
Asymmetry Is a Clue
Markedly more atrophy on one side can point to other diagnoses like hippocampal sclerosis or limbic-predominant disease.
Frequently Asked Questions
Can hippocampal atrophy be reversed?
Not directly, but exercise, blood pressure control, and treating sleep apnea slow progression.
Is mild hippocampal atrophy at 75 normal?
Some is, but it should not be ignored. Pair it with a cognitive test for a full picture.
For more, see Alzheimer’s Association medical tests.
