The Effect of Risperidone on Metabolite Measures in the Frontal Lobe, Temporal Lobe, and Thalamus in Schizophrenic Patients. A Proton Magnetic Resonance Spectroscopy ( 1 H MRS) Study
Department of Psychiatry, Medical University in Bialystok, Bialystok, Poland. Pharmacopsychiatry
(Impact Factor: 1.85).
10/2005; 38(5):214-9. DOI: 10.1055/s-2005-873156
The aim of the study was the evaluation of risperidone effect on metabolite measures in the frontal lobe, temporal lobe and thalamus in schizophrenic patients on the basis of proton magnetic resonance spectroscopy ( (1)H MRS).
A group of 14 patients with the diagnosis of schizophrenia, according to DSM-IV, were examined in the study. The patients were examined twice, once after a period of at least 7 days without neuroleptics and for the second time at least 4 weeks after stable risperidone doses.
The significant differences in the metabolite levels before and after the treatment were observed only in thalamus: an increase in myoinositol (mI) and N-acetylaspartate (NAA) levels. Positive symptoms before the treatment correlated positively with NAA level in the frontal lobes and negatively in the temporal lobes. Negative symptoms before the treatment correlated positively with Glx (a common signal for GABA, glutamine and glutamate) level in the temporal lobes.
Our results seem to confirm the influence of risperidone on the brain metabolism, specifically in the region of thalamus.
Available from: journals.plos.org
- "The thalamus has been proposed as a site participating in neural circuits mediating the clinical effects of antipsychotic drugs due to its role in the integration and coordination of brain activity. Additional evidence has also been offered at the cellular and molecular levels, with increased expression of the Fos-like protein in the midline thalamic nuclei in response to antipsychotic drugs and an increased N-acetyl-aspartate (NAA) level in the thalamus in association with atypical antipsychotics. Therefore, our present results might suggest that thalamus volume could be a candidate biomarker to evaluate the efficiency of the antipsychotic response in terms of improvement in the positive symptoms of patients. "
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ABSTRACT: Both schizophrenia and antipsychotic treatment are known to modulate brain morphology. However, it is difficult to establish whether observed structural brain abnormalities are due to disease or the effects of treatment. The aim of this study was to investigate the effects of illness and antipsychotic treatment on brain structures in antipsychotic-naïve first-episode schizophrenia based on a longitudinal short-term design. Twenty antipsychotic-naïve subjects with first-episode schizophrenia and twenty-four age- and sex-matched healthy controls underwent 3T MRI scans. Voxel-based morphometry (VBM) was used to examine the brain structural abnormality in patients compared to healthy controls. Nine patients were included in the follow-up examination after 8 weeks of treatment. Tensor-based morphometry (TBM) was used to identify longitudinal brain structural changes. We observed significantly reduced grey matter volume in the right superior temporal gyrus in antipsychotic-naïve patients with schizophrenia compared with healthy controls. After 8 weeks of treatment, patients showed significantly increased grey matter volume primarily in the bilateral prefrontal cortex, insula, right thalamus, left superior occipital cortex and the bilateral cerebellum. In addition, a greater enlargement of the prefrontal cortex is associated with the improvement in negative symptoms, and a more enlarged thalamus is associated with greater improvement in positive symptoms. Our results suggest the following: (1) the abnormality in the right superior temporal gyrus is present in the early stages of schizophrenia, possibly representing the core region related to schizophrenia; and (2) atypical antipsychotics could modulate brain morphology involving the thalamus, cortical grey matter and cerebellum. In addition, examination of the prefrontal cortex and thalamus might facilitate an efficient response to atypical antipsychotics in terms of symptom improvement.
Available from: Lawrence S Kegeles
- "Several studies investigated the possible relationships between glutamatergic levels in the thalamus and clinical/behavioral symptoms as measured by the SANS and SAPS (Theberge et al., 2002, 2007; Bustillo et al., 2010; Aoyama et al., 2011), PANSS (Szulc et al., 2005, 2011, 2012; Yoo et al., 2009) and GAF scale (Egerton et al., 2012). No significant correlations were reported. "
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ABSTRACT: The last fifteen years have seen a great increase in our understanding of the role of glutamate in schizophrenia (SCZ). The glutamate hypothesis focuses on disturbances in brain glutamatergic pathways and impairment in signaling at glutamate receptors. Proton Magnetic Resonance Spectroscopy ((1)H-MRS) is an MR-based technique that affords investigators the ability to study glutamate function by measuring in vivo glutamatergic indices in the brains of individuals with SCZ. (1)H-MRS studies have been performed comparing glutamatergic levels of individuals with SCZ and healthy control subjects or studying the effect of antipsychotic medications on glutamatergic levels. In this article we summarize the results of these studies by brain region. We will review the contribution of (1)H-MRS studies to our knowledge about glutamatergic abnormalities in the brains of individuals with SCZ and discuss the implications for future research and clinical care.
Available from: Napoleon Waszkiewicz
- "According to our previous report, after at least 7 days without neuroleptic medication, a positive symptoms score correlated positively with NAA level in the frontal lobe and negatively with NAA level in the temporal lobe . Another report from our facility showed the following positive correlations: negative PANSS, general scale, total scale and choline level in the thalamus (on left side) in the group of patients in the course of neuroleptic therapy (chronic patients and first-episode patients) . "
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ABSTRACT: Proton magnetic resonance spectroscopy (1H MRS) allows for examining brain functions in vivo in schizophrenic patients. Correlations between N-acetylaspartate (NAA) level in the frontal lobe and cognitive functions and clinical symptoms have been observed. The aim of the present study was evaluation of relationship between clinical symptoms, cognitive outcomes and brain function in 1H MRS measures in schizophrenic patients.
The study included a group of 47 patients with chronic schizophrenia. Patients were assessed by means of PANSS, CGI, and a battery of cognitive tests: WCST, TMT, and verbal fluency test. MRI and MRS procedures were performed. Regions of interest were located in the left frontal lobe, temporal lobe and thalamus. Metabolite (NAA, choline, myoinositol and Glx complex) ratios to creatine were calculated.
We observed a significant negative correlation between myoinositol level in the frontal lobe and WSCT test performance. These data were confirmed by further analysis, which showed a significant correlation between WCST outcome, negative symptoms score, education level and myoinositol ratio in the frontal lobe. When analyzing negative symptoms as independent variables, the analysis of regression revealed a significant relationship between negative symptoms score and verbal fluency score, together with choline level in the thalamus.
The above data seem to confirm a significant role of the thalamus--a "transmission station" involved in connections with the prefrontal cortex--for psychopathology development (especially negative) in schizophrenia. Moreover, our results suggest that a neurodegenerative process may be involved in schizophrenia pathogenesis.
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