Proton magnetic resonance spectroscopy measures related to short-term symptomatic outcome in chronic schizophrenia.

Introduction: Proton magnetic resonance spectroscopy (¹H MRS) enables the evaluation of in vivo brain function. The purpose of the study was to compare ¹H MRS measurements in schizophrenic patients, who were clinical responders after short-term antipsychotic treatment, with non-responders and healthy controls.

Methods: We investigated a group of 47 patients diagnosed with schizophrenia. Patients were examined twice--once after a period of at least 7 days without neuroleptics and the second time at least 4 weeks after therapy with stable doses of medication. The follow-up was available in 42 patients. Baseline MRS measurements of clinical responders were compared with non-responders and the group of healthy controls (N=26). We assessed the following metabolite ratios: NAA (N-acetylaspartate), Glx (complex of GABA, glutamine and glutamate), Cho (choline) and mI (myo-inositol) to creatinine (Cr) in the left frontal and temporal lobes and the thalamus.

Results: Responders showed a significantly lower baseline frontal Glx/Cr level than non-responders. Both groups had a significantly lower NAA/Cr ratio in the frontal lobe than the controls, but only non-responders had a significantly lower NAA/Cr ratio in the thalamus.

Conclusions: Our results confirm the relationship between the glutamatergic system and pathophysiology of schizophrenia and suggest a significant value of ¹H MRS examination in the assessment of the future treatment effect.