Evaluation of the screening power of Cognitive Abilities Screening Instrument for probable Alzheimer's disease using voxel-based morphometry.

OBJECTIVE The aim of this study was to compare two screening methods, total score of the Cognitive Abilities Screening Instrument (CASI(T)) and the combined score for the short-term memory and orientation domains (CASI(R)) for screening and grading probable Alzheimer's disease (AD), based on their correlations with voxel-based morphometry (VBM). MATERIALS AND METHODS Forty-five subjects with probable AD and normal controls underwent magnetic resonance imaging and CASI testing. Their corresponding T1-weighted magnetic resonance images were analyzed using VBM. RESULTS VBM results showed that in moderate-to-severe AD subgroups, significant whole-brain gray matter loss was detected using both CASI(T) and CASI(R). Significantly more voxels were detected using the CASI(T) compared with the CASI(R) system in mild AD subjects (P<.05). CONCLUSIONS Based on their correlations with VBM results, there is no significant difference for CASI(R) and CASI(T) for grading moderate-to-severe AD subgroups, and CASI(R) scoring system may be more accurate and effective than the CASI(T) for screening mild AD.