Proton spectroscopy in Alzheimer's disease and cognitive impairment no dementia: a community-based study.

Objective: To describe the findings of proton magnetic resonance spectroscopy ((1)H-MRS) in Alzheimer's disease (AD) and cognitive impairment, no dementia (CIND) elderly from a community-based sample.

Methods: Thirteen patients with AD, 12 with CIND and 15 normal individuals were evaluated. The (1)H-MRS was performed in the right temporal, left parietal and medial occipital regions studying the metabolites N-acetylaspartate (NAA), creatine (Cr), choline (Cho) and myoinositol (mI). The clinical diagnosis was based on standardized cognitive tests - MMSE and CAMDEX - and the results correlated with the (1)H-MRS.

Results: Parietal Cho was higher in control individuals and lower in CIND subjects. AD and control groups were better identified by temporal and parietal mI combined with the temporal NAA/Cr ratio. CIND was better identified by parietal Cho.

Conclusion: The (1)H-MRS findings confirmed the hypothesis that metabolic alterations are present since the first symptoms of cognitively impaired elderly subjects. These results suggest that combining MRS from different cerebral regions can help in the diagnosis and follow-up of community elderly individuals with memory complaints and AD.