[Is hippocampal atrophy a specific change for Alzheimer's disease?]

Although detection of hippocampal atrophy has been proposed for the diagnosis of Alzheimer's disease (AD), atrophic changes in MRI can be found in other dementia diseases. This study was undertaken to determine whether hippocampal atrophy was a specific change for AD. Coronal T 1-weighted images were performed in 36 patients with AD, 40 patients with non-AD including vascular dementia, frontemporal dementia, Parkinson's disease with dementia, dementia with Lewy bodies, progressive supranuclear palsy, and normal pressure hydrocephalus, 9 patients with age-associated memory impairment (AAMI), and 24 control subjects. Hippocampal atrophy was graded subjectively on a 5-point scale. Scores of hippocampal atrophy for AD (2.11 +/- 0.95) and non-AD (1.80 +/- 0.91) were significantly higher than those for controls (0.79 +/- 0.72). Scores for AD were also significantly higher than those for AAMI (1.11 +/- 0.160), but no difference was found between AD and non-AD. These results suggest that hippocampal atrophy is not a specific marker for AD and appears to be a common phenomenon in dementia syndromes.