Effect Of Transcranial Direct Current Stimulation (tDCS) On Cognition,Symptoms In Chronic Schizophrenia Patients With Tardive Dyskinesia

Objective:The aim of the study is to evaluate the efficacy,safety,and cognitive function of transcranial direct current stimulation?tDCS?in chronic schizophrenia patients with tardive dyskinesia?TD?.Methods:This study is a multicenter,randomized,double-blind,sham-controlled clinical trial.Fifty-two patients with TD were randomly allocated to active?n=28?or sham tDCS groups?n=24?.All patients received 2-mA anodal left dorsolateral prefrontal cortex/cathode right contralateral supraorbital area tDCS treatment?fifteen 30-minutes sessions:Monday to Friday once daily,every other week to do a group of treatment?.Abnormal Involuntary Movements Scale?AIMS?,Tardive Dyskinesia Rating Scale?TDRS?and the Pattern Recognition Memory?PRM?,Intra/Extradimensional Set Shift?IED?of the Cambridge Neuropsychological Test Automatic Battery?CANTAB?were assessed in patients.All evaluations were scored at baseline,the end of the 3rd week,5th week,and7 th week.Side effects of tDCS were assessed with an experimenter-administered open-ended questionnaire during the whole experiment.Results:Of the 52 patients who were randomly assigned,nine patients dropped out in the process of baseline cognitive assessment or after the beginning of tDCS series because they withdrew their informed consent?five patients from active group and four from sham group?.At baseline the gender,age,and educational level of the two groups were matched and the course of the disease was not matched and there was no statistical difference between the two treatment groups in the clinical variables?P>0.05??1?Active tDCS subjects compared to sham showed significant lower AIMS total scores after the assessment of the 3rd weeks,5th week,and 7th week?P<0.05?.The total score of TDRS was significantly lower in active stimulation group at the end of the 5th week and the 7th week?P<0.05?.While there was no statistically significant difference in TDRS scores between the two groups at the end of the 3rd week.?2?Multiple repeated measures showed that in active stimulation group,the AIMS total score of the 3rd week or 5th week,7^thweek were significantly lower than the baseline,also that of the end of 5th week was lower than the 3 weeks?P<0.05?.However,there were no significant differences in score changes on the AIMS in the sham group?P>0.05?.The TDRS total score of the active tDCS group at the end of the 3rd week or the 5th week or the 7th week decreased significantly,compared to the baseline?P<0.05?.And the total score of TDRS at the end of the 5th week was lower than that of the 3rd week,and the difference was statistically significant?P<0.05?.While the total score of TDRS at the end of the 7th week was significant higher than that of the 5th week?P<0.05?.But there were no significant differences in score changes on the TDRS in the sham group?P>0.05?.?3?Between the two groups,there were no significant difference in accuracy rate in the PRM test?immediate or delayed pattern?,the IED test of IED Pre-ED errors,IED EDS errors,IED Stages completed,and IED Total errors?adjusted??P>0.05?.?4?There were no significant difference in accuracy rate in the PRM test?immediate or delayed pattern?,the IED test of IED Pre-ED errors,IED EDS errors,IED Stages completed,and IED Total errors?adjusted?at different points in each group of patients?P>0.05?.?5?At baseline there were no significant associations between the total score of AIMS or TDRS and the accuracy rate in the PRM test?immediate or delayed pattern?,as well as IED test of IED Pre-ED errors,IED EDS errors,IED Stages completed,IED Total errors?adjusted??P>0.05?.For TD patients,correlation analysis showed a significant positive association between the total score of AIMS and TDRS.?6?During tDCS,the tingling sensation was the most commonly reported adverse effect,while the next was the itching sensation,then the burning sensation,pain and fatigue.There was significant difference in the adverse effects of the tingling sensation between the two groups?P<0.05?,but there was no significant difference in other side effects?P>0.05?.Conclusions:tDCS may be an effective and safe treatment for ameliorating the motor symptomatology related to TD.But the results failed in demonstrating that the tDCS was effective on visual short-term recognition memory,attention to the flexibility of the conversion and executive function.There was no correlation between the motor symptoms and visual short-term recognition memory,attention switching flexibility and executive function.