PROBABLE ALZHEIMER-DISEASE - DIAGNOSIS WITH PROTON MR SPECTROSCOPY

PURPOSE: To distinguish probable Alzheimer disease (AD) from other dementias (ODs) and normality in the elderly. MATERIALS AND METHODS: A double-blind trial of proton magnetic resonance (MR) spectroscopy was performed, principally in gray matter, in the occipital cortex of 114 patients with dementia (AD [n = 65], OD [n = 39], or frontal lobe dementia [FLD] [n = 10]), 98 patients without dementia, and 32 healthy control subjects. RESULTS: Reduced levels of N-acetylaspartate (NAA) (P <.0005) and increased levels of myo-inositol (MI) (P <.0005) characterize AD. Patients with OD had significantly reduced levels of NAA (P <.01) but normal levels of MI (P [vs AD] <.0005). When MI/NAA was used, AD was distinguished from normality with 83% sensitivity and 98% specificity. When MI/creatine was used, OD was distinguished from AD and FLD with a negative predictive rate of 80%, sensitivity of 82%, and specificity of 64%. CONCLUSION: Hydrogen-1 MR spectroscopy enables identification of mild to moderate AD with a specificity and sensitivity that suggest clinical utility.