Resting-state functional MRI results show that patients with schizophrenia and tardive dyskinesia have altered cerebral regional homogeneity.
“Neuronal degeneration and apoptosis may play an important role in the pathogenesis of tardive dyskinesia (TD),” Chiang-Shan Ray Li, MD, PhD, and colleagues wrote. “Previous studies suggested brain structural and functional abnormalities in patients with TD.”
For a study published in Psychiatry Research: Neuroimaging, Dr. Li and colleagues examined changes in cerebral regional homogeneity (ReHo) among patients with TD using resting-state functional MRI (rs-fMRI). They obtained data from patients with schizophrenia with and without TD, as well as healthy controls. The researchers evaluated psychopathology using the Positive and Negative Syndrome Scale (PANSS) and severity of TD with the Abnormal Involuntary Movement Scale (AIMS).
Cerebral Regional Homogeneity Impacted by TD
The study included 50 patients with schizophrenia and TD (33 men), 56 with schizophrenia alone (32 men), and 67 healthy controls (38 men). All participants were right-handed.
Dr. Li and colleagues reported no significant differences among the groups in age, sex, or education. Duration of both illness and antipsychotic use did not vary significantly between the TD and non-TD groups. Patients with schizophrenia and TD had significantly higher negative scores on the PANSS than the group with schizophrenia and no TD (P<0.001), but no other differences in PANSS scores were reported.
Compared with patients with schizophrenia without TD, the group with schizophrenia and TD had significantly higher ReHo in the left inferior semilunar lobule and right fusiform gyrus and lower ReHo in the left supramarginal gyrus, right inferior temporal gyrus, and left medial frontal gyrus. The ReHo value in the left inferior semilunar lobule was negatively correlated with AIMS upper limbs scores.
Association Between TD & Altered Neural Connectivity
The findings indicate that rs-fMRI plays a role in identifying functional connectivity across brain regions through the quantification of spontaneous functional activities, according to Dr. Li and colleagues.
“The findings suggest altered regional neural connectivities in association with TD and may inform research of the etiology and monitor the course of TD in patients with schizophrenia and potentially other psychotic disorders,” they wrote.