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 t emporal lobe in schizophrenic patients have shown decreased levels of N-ace tylaspartate (NAA) suggesting reduced neuronal density in this region. Howe ver, the measured volumes have been large and included contributions from m ostly white matter. Methods: Short echo H-1 MRS was used to measure levels of NAA and other met abolites (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 heal thy control subjects of comparable age, gender, handedness, education, and parental education levels. Spectra were quantified without operator interac tion using automated software developed in our laboratory. Metabolite level s were normalized to the internal water concentration of each volume studie d. Images were also obtained to determine temporal lobe gray and white matt er volumes. Results: No significant differences were found between levels of NAA or oth er metabolites or gray and white matter volumes, in first-episode schizophr enic patients and comparison subjects. Conclusions: Since the volume studied was small compared to previous studie s 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.