Abnormal cerebral metabolite concentrations in patients with probable alzheimer disease

Abstract To establish whether recently described abnormalities of peak ratios are the result of changes in metabolite concentrations, quaintitative 1 H magnetic resonance spectroscopy was performed in 10 patients with Alzheimer disease (AD) and seven normal elderly. CSF volumes, metabolite T 1 and T 2 relaxation rates, ratios and concentrations of Kacetyl residues, creatine, choline residues, myeinositol, glutamine plus glutamate (Glx), and glucose were obtained. Difference spectroscopy and quantitative assays showed a 50% increase in myo ‐inositol (6.4–9.8 m M ; P < 0.005) and a decrease in N ‐acetyl in occipital gray matter. A reduction in β,γ‐Glx and a significant increase in intracerebral [glucose], greater than attributable to CSF, were defined. Choline concentration increased with age, but was not elevated above normal in AD patients. These findings indicate the need for quantitative 1 H MRS to substantiate metabolite ratios. The increased myo ‐inositol concentration in AD is demonstrated by these studies.