Spectroscopic metabolomic abnormalities in the thalamus related to auditory hallucinations in patients with schizophrenia

Objective: previous studies have found neurochemical abnormalities in thalamic nuclei in patients with schizophrenia. These abnormalities have been associated with information processing deficiencies and symptom formation. There are no metabolic spectroscopy studies in patients with schizophrenia attending to auditory hallucinations. The aim of the present Study is to explore metabolic Magnetic Resonance Spectroscopy (MRS) ratio differences in the thalamus between schizophrenic patients with and without auditory hallucinations and control subjects. Methods: MRS studies (MRI 1.5 T unit) were performed in 49 patients with schizophrenia (30 with auditory hallucinations and 19 without auditory hallucinations) and 37 controls. H-1 MRS imaging was used to acquire 2 transverse slices (TR/TE 2700/272 ms, region of interest I 10 x 100 x 23 ram). In the quantitative analysis four elements of volume (9.2 x 9.2 x 23 x 4 mill), added into one spectrum representative of each thalamus, were chosen in the slice passing through the main body of the thalamus. The areas of metabolites were integrated with the jMRUI program. Results: The patients with schizophrenia had significantly lower bilateral NAA/Cho ratios when compared with healthy subjects. There was also a lower NAA/Cho ratio in the right thalamus in patients with auditory hallucinations compared to patients without auditor), hallucinations and control subjects. Significant correlations were found between metabolic ratios and BPRS, PANSS and PSYRATS scores, age of onset of auditory hallucinations, and age of subjects. Conclusions: Cholinc and NAA ratio abnormalities determined by thalamic spectroscopy may be related to the pathogenesis of auditory hallucinations in patients with schizophrenia. (C) 2009 Elsevier B.V. All rights reserved.