Proton magnetic resonance spectroscopy (H-MRS) in chronic schizophrenia. A single-voxel study in three regions involved in a pathogenetic theory

Abstract

The cognitive dysmetria theory suggests a disconnectivity between the dorsolateral prefrontal cortex, thalami and vermis to explain the pathophysiology of schizophrenia. This study investigated the metabolic integrity of this neurologic circuit in patients with schizophrenia using proton magnetic resonance spectroscopy (H-MRS). Twenty-two patients with schizophrenia and twelve control subjects were studied. Metabolites concentrations were evaluated by a single-voxel technique in the prefrontal cortex, thalami and vermis. To our knowledge, this is the first H-MRS experience with concomitant evaluation of these regions in schizophrenic patients. We found no significant statistical difference in N-AA, Cho and Cr absolute concentrations and N-AA/Cho, N-AA/Cr and Cho/Cr ratios between the schizophrenic patients and control group. At the vermis, we found a constant spectrum with low levels of N-AA and higher levels of Cho and Cr. Our experience does not clearly support or refute the cognitive dysmetria theory. The consistency of metabolic findings in the cerebellar vermis could represent an important datum, highlighting the specificity of metabolic and functional activity in this region.

Figure 1

Axial, coronal and sagittal HASTE images showing the MR spectroscopy voxel placement.

Figure 2

Proton MR spectrum from a cerebellar vermis voxel: 1) N-AA peak at 2.01-2.03 ppm frequency. 2) Cr peak at 3.01-3.03 ppm frequency. 3) Cho peak at 3.21-3.23 ppm frequency.

Figure 3

Charts I-II-III. The box-plot graphs demonstrate the distribution of N-AA/Cho, N-AA/Cr and Cho/Cr ratios around the median values of control subjects (nor) and patients (pat).