• glutamine + glutamate;
  • exacerbation;
  • magnetic resonance spectroscopy;
  • schizophrenia

Ota M, Ishikawa M, Sato N, Hori H, Sasayama D, Hattori K, Teraishi T, Nakata Y, Kunugi H. Glutamatergic changes in the cerebral white matter associated with schizophrenic exacerbation.

Objective:  Glutamatergic dysfunction in the brain has been implicated in the pathophysiology of schizophrenia. This study was aimed to examine several brain chemical mediators, including Glx (glutamate + glutamine), using 1H magnetic resonance spectroscopy (MRS) in medicated patients with schizophrenia, with and without psychotic exacerbation.

Method:  1H MRS was acquired in 24 patients with schizophrenia, with psychotic exacerbation; 22 patients without exacerbation; and 27 age- and sex-matched healthy volunteers. The levels of metabolites were measured in the left frontal and inferior parietal white matter and compared across the three groups.

Results:  The Glx level was significantly elevated in the left inferior parietal white matter in the patients with psychotic exacerbation in comparison with that in the healthy volunteers and the patients without exacerbation (P < 0.05). We also detected that there was a significant correlation between Positive and Negative Syndrome Scale-positive scale and Glx level in the left parietal white matter (r = 0.51, P < 0.001).

Conclusion:  Higher than normal Glx levels indicate glutamatergic overactivity in the left inferior parietal white matter with schizophrenic exacerbation, a finding that is in accordance with the glutamatergic hypothesis in schizophrenia. The Glx level measured by 1H MRS could be a biomarker for exacerbation in schizophrenia.