Frontotemporal dementia and early Alzheimer disease: differentiation with frontal lobe H-1 MR spectroscopy.

Abstract

PURPOSE: To evaluate cerebral biochemical abnormalities in patients with frontotemporal dementia and Alzheimer disease and to determine whether proton (hydrogen-1) magnetic resonance (MR) spectroscopy can help differentiate among these two patient groups and healthy (control) subjects. MATERIALS AND METHODS: MR imaging and H-1 MR spectroscopy were performed in 14 patients with frontotemporal dementia, 12 with probable Alzheimer disease (Alzheimer), and 11 healthy (control) elderly subjects. Spectra were acquired from midfrontal and temporoparietal gray matter with a double spin-echo sequence (repetition time, 3,000 msec; echo time, 30 msec). Results were expressed in metabolite concentrations corrected for the presence of cerebrospinal fluid. RESULTS: In frontotemporal dementia patients, the frontal lobe showed reduced N-acetyl compounds (-28%) and glutamate plus glutamine (-16%), suggestive of neuron loss, and increased myo-inositol (MI) (+19%), suggestive of increased glial content. In three frontotempo...