Clinical Study Of Transcranial Direct Current Stimulation On Post-stroke Aphasia Rehabilitation

Objective:To observe the rehabilitation effect of transcranial direct current stimulation(tDCS)on aphasic patients with acute cerebral infarction and its possible electrophysiological mechanism.Method:Fifty-four patients with acute cerebral infarction with motor aphasia were selected and randomly divided into tDCS treatment group and control group,with 27 cases in each group,There were no statistically significant differences in age,gender,education,duration of illness,and NIHSS scores between the two groups(P>0.05).The control group was given conventional medication,speech rehabilitation therapy and tDCS sham stimulation,while the tDCS treatment group was given tDCS real stimulation on top of conventional medication and speech rehabilitation therapy.The stimulation site was the somatotopic projection site of Broca’s area in the left hemisphere,and the stimulation intensity was 1.5 mA,with real stimulation for 20 min and automatic stop after 2 min of sham stimulation,5 times a week,10 days of treatment in total.Patients in both groups were assessed for language function before treatment and after 2 weeks of treatment using the Aphasia Battery of Chinese(ABC)and Boston Diagnostic Aphasia Severity Evaluation(BDAE),and quantitative electroencephalography(QEEG)was performed in parallel to calculate(α+β)/(δ+θ)values.Result:(1)ABC scores:There was no statistically significant difference in the total ABC score,information,fluency,comprehension,repetition,and naming scores between the two groups before the intervention(P>0.05),The total ABC score and the scores of fluency,information,comprehension,repetition,and naming after the intervention were greater than the scores before the intervention in both groups(P<0.05);the total ABC score and the scores of fluency,information,retelling and naming were higher in the tDCS group than in the control group after the intervention(P<0.05),and the differences of comprehension scores between the tDCS group and control group were not statistically significant(P>0.05).(2)BDAE scores:There was no statistically significant difference between the BDAE scores of patients in the two groups before the intervention(P>0.05);the BDAE scores of patients in the tDCS group were not greater than those in the control group after the intervention(P>0.05).(3)(α+β)/(δ+θ)values of Quantitative EEG:comparison between groups before intervention:no statistically significant difference in bilateral frontal area(α+β)/(δ+θ)values between the two groups(P>0.05);comparison within groups before intervention:the left frontal area(α+β)/(δ+θ)values were lower than the right frontal area in both groups(P<0.05).Comparison between groups after intervention:the(α+β)/(δ+θ)values of bilateral frontal areas in the tDCS group were greater than those in the control group(P<0.05);comparison within groups after intervention:the differences in(α+β)/(δ+θ)values of bilateral frontal areas in the two groups were not statistically significant(P>0.05).Conclusion:(1)tDCS anodal stimulation of the Broca area in the left hemisphere of the brain of aphasic patients with acute cerebral infarction can improve their speech function and promote the recovery of speech function.(2)The modulatory effect of tDCS on(α+β)/(δ+θ)values of EEG in aphasic patients with acute cerebral infarction may be one of its electrophysiological mechanisms to promote language rehabilitation.(3)The stimulation intensity of 1.5mA and the stimulation time of 20min for tDCS is safe.