A H-1 MRS study of probable Alzheimer's disease and normal aging: Implications for longitudinal monitoring of dementia progression

In order to evaluate the capability of H-1 MRS to monitor longitudinal chan ges in subjects with probable Alzheimer's disease (AD), the temporal stabil ity of the metabolite measures N-acetylaspartate and N-acetylas-partylgluta mate (NA), total Creatine (Cr), myo-Inositol (mI), total Choline (Chol), NA /Cr, mI/Cr, Chol/Cr and NA/mI were investigated in a cohort of normal older adults. Only the metabolite measures NA, mi, Cr, NA/Cr, mI/Cr, and NA/mI w ere found to be stable after a mean interval of 260 days. Relative and abso lute metabolite measures from a cohort of patients with probable AD were su bsequently compared with data from a sample of normal older adult control s ubjects, and correlated with mental status and the degree of atrophy in the localized voxel. Concentrations of NA, NA/Cr, and NA/mI were significantly reduced in the AD group with concomitant significant increases in mi and m I/Cr. There were no differences between the two groups in measures of Cr, C hol, or Chol/Cr. Significant correlations between mental status as measured by the Mini-Mental State Examination and NA/mI, mI/Cr and NA were found. T hese metabolite measures were also significantly correlated with the extent of atrophy (as measured by CSF and GM composition) in the spectroscopy vox el. (C) 1999 Elsevier Science Inc.