A short echo proton magnetic resonance spectroscopy study of the left mesial-temporal lobe in first-onset schizophrenic patients

Background: Past H-1 magnetic resonance spectroscopy (MRS) studies of the temporal lobe in schizophrenic patients have shown decreased levels of N-acetylaspartate (NAA) suggesting reduced neuronal density in this region. However, the measured volumes have been large and included contributions from mostly white matter. Methods: Short echo H-1 MRS was used to measure levels of NAA and other metabolites (i.e., glutamate and glutamine) from a 6 cm(3) volume in the left mesial-temporal lobe of II first-episode schizophrenic patients and II healthy control subjects of comparable age, gender, handedness, education, and parental education levels. Spectra were quantified without operator interaction using automated software developed in our laboratory. Metabolite levels were normalized to the internal water concentration of each volume studied. Images were also obtained to determine temporal lobe gray and white matter volumes. Results: No significant differences were found between levels of NAA or other metabolites or gray and white matter volumes, in first-episode schizophrenic patients and comparison subjects. Conclusions: Since the volume studied was small compared to previous studies and contained mostly gray matter, this result suggests consequential NAA decreases may be restricted to regions of white matter. (C) 1999 Society of Biological Psychiatry.