Brain imaging review found a smaller hypothalamus in Alzheimer's disease
People with mild to moderate Alzheimer's disease had a smaller hypothalamus than controls. Imaging differences were associated with sleep and hormone measures, without establishing causation.
Based on the published abstract. The full paper may contain additional methods, results and limitations.
The 30-second takeaway
The pooled imaging analysis found a smaller hypothalamus, a brain region, in people with mild to moderate Alzheimer's disease than in controls. Other imaging differences were associated with worse sleep and some hormone-related measures. These associations do not establish that changes in this region caused symptoms, and evidence for Lewy body dementia was more limited.
Only part of the reviewed imaging evidence could be pooled. Lewy body dementia findings came from few studies, and associations between brain measurements and symptoms cannot establish causation.
What the scans showed
The review examined imaging of hypothalamic size, metabolism, and connections in dementia. Its pooled volume finding concerned Alzheimer's disease. The Lewy body dementia studies reported different findings involving grey matter and a measure of serotonin transporters.
Symptoms and unresolved links
In Alzheimer's disease, hypothalamic differences were associated with worse sleep, lower bone mineral density, and sex hormone levels. Body mass index was not associated with hypothalamic volume, although the authors said more research was needed.
The original publication
Hypothalamic imaging in Alzheimer's disease and Lewy body dementia: A systematic review and meta-analysis.
Laurell AA, Shah SN, Rahmati M et al.
Neurobiol Aging · 2025
- PubMed ID
- 40737816
- Record checked
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