Specificity of temporal amygdala atrophy in Alzheimer's disease: quantitative assessment with magnetic resonance imaging.

The aim of the study was to assess the specificity of temporal amygdala (TA) atrophy with magnetic resonance imaging (MRI) by comparing a group of early impaired patients with Alzheimer's disease (AD) with 'other types of dementia' and controls. In this prospective case-control study, 41 patients were selected: 12 with probable AD according to NINCDS-ADRDA and CERAD inclusion and exclusion criteria, 14 with other types of dementia and 15 age-matched control subjects. Two radiologists blindly measured the TA volumes on coronal oblique contiguous slices with a 1.5-tesla MRI scanner. TA volume measurements obtained by the 2 observers and right-left TA values were not significantly different. A significant TA atrophy was found in the AD group as compared to the other groups, with 39.7% (p < 0.001) difference in TA volumes between AD and other types of dementia groups and 41.4% (p < 0.0005) difference between AD and control groups. There was no significant difference between other types of dementia and control groups. There was an overlap between the three groups for 4 patients. TA atrophy assessed with MRI could be of diagnostic value in AD, especially in the early stage of the disease.