Thalamic abnormalities in patients with schizophrenia revealed by proton magnetic resonance spectroscopy.

ABSTRACT

Recent investigations suggest that thalamic abnormalities may underlie symptom formation in schizophrenia. We previously demonstrated reduced concentrations of N-acetylaspartate (NAA) in tissue from the thalamus of schizophrenic patients using in vitro proton magnetic resonance spectroscopy (1H-MRS). In the present study, in vivo 1H-MR spectra of the left thalamus and frontal lobe were investigated in 20 patients with schizophrenia and 16 age-matched control subjects to replicate our previous postmortem findings and support the hypothesis of thalamic abnormality in schizophrenia. Schizophrenic patients showed significantly lower NAA/total creatine (Cr) and choline-containing compounds (Cho)/Cr ratios in the thalamus than control subjects, while no significant difference was found in the frontal lobe. There was no significant correlation in the schizophrenic patients between the NAA/Cr or Cho/Cr ratio and other clinical data including clinical symptoms or neuroleptic dosage. These findings may further support other studies suggesting decreased thalamic volume or neuronal number and/or thalamic dysfunction, and reduction in size of white matter tracts adjacent to the thalamus in schizophrenia, as well as our previous postmortem MRS study.