Proton magnetic resonance spectroscopy in schizophrenia: investigation of the right and left hippocampus, thalamus, and prefrontal cortex

Single voxel proton magnetic resonance spectroscopy ('H MRS) was used to study the metabolites N-acetyl-aspartate (NAA), choline (CHO), and myo-inositol (ml) in order to test a neurodegenerative hypothesis in schizophrenia (decrease of NAA, increase of CHO, and increase of ml) and a cerebral asymmetry of these metabolites. 1H MRS was performed in 17 schizophre-nia patients and 14 healthy subjects in three cerebral areas highly involved in the pathophysiology of schizo-phrenia (the prefrontal cortex, the thalamus, and the hippocampus). The ratio amplitudes between metabo-lites and creatine plus phosphocreatine (Cr) were determined. No difference in the metabolites existed between patients and healthy subjects. However, rela-tionships were noted between NAA/Cr and age in the thalami of the schizophrenia patients (r =-0.37; p = 0.14) and healthy subjects (r =-0.52; p = 0.05). A sig-nificant correlation was observed between NAA/Cr and age of onset of illness in the hippocampi of schizo-phrenia patients (r =-0.59; p < 0.05). Moreover, NAA/Cr was lower in the right than in the left pre-frontal cortex in both schizophrenia patients and healthy subjects. There was no relationship between the metabolites and duration of illness or dose of antipsychotics. These findings might suggest a neu-rodegenerative process in the hippocampi of schizo-phrenia patients with late onset of illness, and the NAA/Cr ratio could be a marker of aging in the thai-ami