Efficacy Of High-frequency Repetitive Transcranial Magnetic Stimulation(rTMS) On Negative Symptoms Of Schizophrenia: A Follow-up Trial

Objective: In this study, we assessed the therapeutic effects and safety of left dorsolateral prefrontal cortex(DLPFC) high-frequency repetitive transcranial magnetic stimulation(r TMS) on negative symptoms of schizophrenia. We evaluated the efficacy of r TMS on recognition in patients with chronic schizophrenia.Method: This is a randomized, sham-controlled, double-blinded trial. 47 patients diagnosed with schizophrenia on stable antipsychotic treatment were randomly assigned to active r TMS treatment group(n=25) or a sham r TMS treatment group(n=22). 25 patients in the active r TMS group received 10 Hz 110% MT r TMS, while 22 patients were subjected to sham r TMS, both being given 4-week treatment(5 days per week). Efficacy of negative symptom was assessed with the Scale for the Assessment of Negative Symptoms(SANS), the Positive and Negative symptom scale(PANSS) at baseline, the end of 4 weeks and 8 weeks. The cognitive function was assessed with CANTAB at baseline, the end of 4 weeks and 8 weeks.The side effects were assessed with TESS at baseline and the end of 4 weeks.Results: A total of 47 patients were enrolled at baseline, six patients dropped out after the beginning of the r TMS series because they refused to participate(three patients from each group). Three patients dropped out before the end of 8 weeks because discharge from the hospital(two patients from active group and one from sham group). The demographics data, course of disease, the main antipsychotics, PANSS, SANS and CANTAB score did not differ between the active and sham r TMS groups at baseline( P>0.05).(1) At the end of 4 weeks: PANSS, SANS and CANTAB testing did not differ between the active and sham r TMS groups.(2)At the end of 8 weeks: There was no statistically significant difference in improvement in negative symptoms between the two groups assessed by PANSS. A statistically significant reduction of severity of the negative of schizophrenia occurred in the active r TMS group, indicated by reductions in the SANS-total score, SANS-poverty of thought score, and PRM testing scores.(P<0.05)(3) Repeated measures ANOVA revealed a significant reduction of the PANSS-total score, PANSS-negative score, PANSS-general score, SANS-total score, SANS-affective flattening score, SANS-volitiona bulia score and SANS-attention dysfunction(P < 0.01) in both group at the end of 4 weeks and 8 weeks, compared with that of the baseline. There was a significant reduction of PANSS-total score, PANSS-general score, SANS-total score, SANS-poverty of thought score, SANS- affective flattening score and PRM-correct score in active group at the end of 8 weeks, compared with that of the end of 4 weeks(P < 0.05).Conclutions: These results indicate that there is a moderate and lasting beneficial effect of r TMS on negative symptoms assessed by SANS. Cognitive function is significantly improved after r TMS in chronic schizhoprenia.