The therapeutic effects of theta burst stimulation on negative symptoms in chronic schizophrenia using functional near-infrared spectroscopy.

BACKGROUND

To explore the efficacy of theta burst stimulation (TBS) on the negative symptoms in patients with chronic schizophrenia, and to investigate the alterations of local brain activity using functional near-infrared spectroscopy (fNIRS).

METHODS

100 patients with chronic schizophrenia were enrolled and divided into the real group (50 subjects) and sham group (50 subjects). The real group was given real stimulation of TBS for 4 weeks, and the sham group was sham-stimulated with the same site. The Positive and Negative Symptom Scale (PANSS) and the Scale for Assessment of Negative Symptoms (SANS) were used to assess the clinical symptoms. fNIRS was used to detect the amplitude of low frequency fluctuation (ALFF) of cortical hemoglobin before and after TBS. Repeated analysis of variance (ANOVA) was used to compare the changes in clinical features between the two groups. Correlation analysis was used to explore the associations between altered ALFF and clinical features.

RESULTS

Repeated ANOVA revealed that the interaction effect of group∗time showed significant influence on the scores of PANSS-total, PANSS-negative, and SANS in the two groups of patients. Test of within-subjects effects showed that significant reductions in scores of PANSS-total, PANSS-negative, and SANS were found between the real group and sham group after TBS, as well as in the real group before and after TBS. fNIRS revealed that the normalized ALFF (zALFF) of deoxyhemoglobin in the left dorsolateral prefrontal cortex was decreased in the real group after TBS. Furthermore, the zALFF of oxyhemoglobin was increased in the right and left frontal pole regions, and decreased in the right superior temporal gyrus in the real group compared to the sham group after TBS. Correlation analysis showed that the alterations of zALFF in frontal regions after treatment were associated with the improvement of negative symptoms in chronic schizophrenia patients.

CONCLUSIONS

Short-term TBS is effective in the improvement of negative symptoms of chronic schizophrenia. fNIRS could reveal the changes in brain activity after TBS treatment, providing an effective technique for exploring the efficacy of TBS in schizophrenia.