Proton magnetic resonance spectroscopy of the hippocampus in patients with mild cognitive impairment: a pilot study.
To assess the brain metabolites in the hippocampus of patients with mild cognitive impairment (MCI) using proton magnetic resonance spectroscopy at 0.5 T. Absolute concentrations and ratios to creatine of N-acetyl aspartate, myoinositol, glutamate + glutamine, and choline were measured in the right and left hippocampus of 5 MCI patients and 5 control subjects. In MCI subjects, reduced N-acetyl aspartate was found in the right hippocampus (P = 0.01), and increased myoinositol was found in the left hippocampus (P = 0.02). Myoinositol/N-acetyl aspartate ratios were higher in the right (P = 0.03) and left (P = 0.01) hippocampus of MCI subjects. No significant difference in the concentration of glutamate + glutamine was observed between the control and MCI groups. An increase in myoinositol and a decrease in N-acetyl aspartate may be observed in the preclinical stages of dementia. Ratio measurements of these metabolites may serve as a biomarker for MCI.