The radial width of the temporal horn in mild cognitive impairment

Background and purpose. The diagnosis of preclinical Alzheimer's disease (AD) (or mild cognitive impairment [MCI]) is loaded with a high degree of uncertainty. The aim was to test the accuracy of a computed tomography-based (CT-based) marker of medial temporal lobe atrophy, the radial width of the temporal horn (rWTH), in MCI. Methods. Ten MCI and 42 AD patients and 29 nondemented controls underwent brain CT on the temporal lobe plane (slice thickness = 2 mm). The rWTH was taken on CT films with a precision caliper placed at the tip of the temporal horn radial to the curvature of the hippocampal head region. Results. When specificity was fixed at 95%, the sensitivity for the detection of AD was 39/42 (93%) and that for the detection of MCI was 8/10 (80%). Conclusion. The rWTH is a measure sensitive to the regional brain atrophy common in early AD.