Abnormal functional connectivity of motor circuit in the schizophrenic patients with tardive dyskinesia: A resting-state fMRI study.

Background: Animal and neuroimaging studies suggest that the volume of the motor-circuit region decreases in tardive dyskinesia (TD). This study examined the differences in functional connectivity within the motor circuit of patients with schizophrenia with and without TD to further clarify how the dysfunction is related to the pathogenesis of TD.
Methods: Functional magnetic resonance images were taken of 56 schizophrenic patients with TD (TD group), 64 without TD (non-TD group), and 68 healthy controls (HC group). The motor-circuit area was selected as the seed region for a whole brain resting-state functional connectivity (rsFC) analysis. Psychopathological symptoms and TD severity were assessed with the Positive and Negative Syndrome Scale (PANSS) and Abnormal Involuntary Movement Scale (AIMS), respectively. Group differences and correlations among 18 brain regions of interest (e.g., the global strength of connectivity between two regions) were analyzed.
Results: The analysis of variance results were as follows: The three groups exhibited rsFC losses in the left primary motor cortex, bilateral parietal cortices, right postcentral gyrus, right putamen, right superior parietal lobule, right supplementary motor area and bilateral thalami (false discovery rate,p < 0.05). The TD group showed a significant rsFC loss between the right postcentral gyrus and the inferior frontal gyrus of the left triangular part when compared with the non-TD group (AlphaSim, p < 0.001), which was negatively correlated with the AIMS total score (r=-0.259, p = 0.03).
Conclusions: These findings may suggest dysfunction of the postcentral and inferior frontal gyri of the triangular part in patients with schizophrenia and TD.
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