Effects Of TDCS-rTMS Combined Stimulation On Cognitive Impairment After Strok

Stroke is a major disability in the global population.Within 6 months after stroke,about 52% of patients developed post-stroke cognitive impairment(PSCI).PSCI is often ignored by patients.Even after the recovery of physical function,PSCI will still affect patients’ independent life,and increase the risk of stroke,resulting in more cognitive deficits and higher mortality.So it is of great importance to search for a safe and effective treatment method for the patients with stroke patients.Repetitive transcranial magnetic stimulation(rTMS)and transcranial direct current stimulation(tDCS),as a non-invasive stimulation,have the characteristics of high safety,fewer side effects and quick effect compared with traditional rehabilitation therapy.Both rTMS and tDCS have been shown to have significant effects on cognitive function in stroke,but few studies have looked at the therapeutic effects of their combined stimulation.Previous studies have shown that the stimulation mode of rTMS combined with tDCS is safe and feasible,and the use of rTMS combined with tDCS may enhance the functional improvement to a greater extent.However,there are still different opinions on the selection of stimulation parameters and stimulation scheme between rTMS and tDCS,and further clinical research is needed.Objective:(1)The combined stimulation of rTMS and tDCS was used to intervene in the dorsolateral prefrontal cortex(DLPFC),posterior parietal cortex(PPC)and temporal lobe of patients with post-stroke cognitive impairment at the same time,aiming to promote the connection and interaction between cognitive-related brain regions,rebuild the cognitive network and improve the cognitive function of patients.(2)To analyze the difference of therapeutic effects and the possible mechanism of tDCS combined with left and right DLPFC rTMS,so as to provide the basis for clinical application and further research in the future.Methods: 36 patients who were eligible for inclusion and exclusion were randomized into a control group,left combination group and right combination group.Finally,a total of 33 subjects(10 in the control group,11 in the left combined group and 12 in the right combined group)completed all the tests and treatments.Subjects in control group received conventional treatment for post-stroke cognitive impairment during the study period,including post-stroke secondary prophylaxis and individualized routine rehabilitation.Combined stimulation of rTMS and tDCS was added to the conventional treatment in the left and right combination groups.Among them,the rTMS stimulation site of the left combination group was the left DLPFC,and the rTMS stimulation site of the right combination group was the right DLPFC,and the remaining rTMS parameters were the same(5Hz,80%-120% resting movement threshold,1200 pulses,20 minutes/time,once/day,5 times/week for 4weeks).The tDCS treatment regimen was also identical between the two groups(anode placed in temporal lobe and cathode placed in PPC,1.2m A,20 min/time,once/day,5 times/week for 4 weeks).The subjects were assessed on the montreal cognitive assessment(Mo CA),the mini-mental state examination(MMSE),the event-related potential MMN and P300,the modified Barthel index(MBI),and the stroke-specific quality oflife scale(SS-QOL)1 day before and 4 weeks after treatment began.Results:(1)Mo CA score:(1)Total scores of Mo CA scale: compared before and after intervention,the total scores of Mo CA in the control group,the left combined group,and the right combined group were significantly increased(P<0.05),and the improvement was superior to the control group in the left and right combined groups.(P<0.05).(2)Scores of each item by Mo CA: compared before and after intervention,the directional scores were increased in the control group;the naming,attention,language,delayed memory,and directional scores were increased in the left combined group;the visual space and executive function,naming,attention,delayed memory,and directional scores were increased in the right combined group with statistical significance(P<0.05).Moreover,the improvement in naming and attention scores of the left combined group was better than that of the control group,and the improvement in naming,attention and delayed memory scores of the right combined group was better than that of the control group.All the results had significant statistical significance(P<0.05).(2)MMSE score:(1)MMSE total score: compared before and after the intervention,the scores of the control group,the left combined group and the right combined group were all significantly increased(P<0.05).The improvement of the subjects’ MMSE total score in the left combined group and the right combined group was superior to that in the control group(P<0.05).(2)Score of each item in MMSE:compared before and after intervention,the scores of directional ability were increased in the control group;the scores of directional ability,memory,recall ability and language ability were increased in the left combined group;the scores of directional ability,memory,recall ability,language ability,attention and calculation ability were increased in the right combined group.Besides,the improvement in the directional force score of the left and right combined groups was better than that of the control group,and the results were statistically significant(P < 0.05).(3)MMN latency:before and after intervention,control group,left combination group and right combination group could significantly reduce the MMN latency of subjects(P<0.05),and the improvement effect was as follows: right combination group > left combination group > control group(P<0.05).(4)P300 latency and amplitude: before and after intervention,control group,left combination group and right combination group could reduce P300 latency and increase P300 amplitude(P<0.05).The left and right combined groups were better than the control group in improving the P300 latency,and the improvement effect of P300 amplitude was as follows: left combined group > right combined group >control group(P<0.05)(5)MBI score: before and after intervention,the control group,the left combined group and the right combined group can significantly improve the MBI score(P<0.05),but no significant difference was found among the 3 groups(P>0.05).(6)SS-QOL score: before and after intervention,SS-QOL score was significantly improved in control group,left combination group and right combination group(P<0.05),and the improvement of the SS-QOL score of the subjects in the left combined group and the right combined group is better than that in the control group(P<0.05).Conclusions: This study used tDCS-rTMS combined with stimulation for 4weeks in patients with cognitive impairment after stroke.The main results of the analysis are as follows:(1)tDCS-rTMS combined stimulation can effectively treat cognitive impairment after stroke.Both tDCS combined with rTMS of left and right DLPFC could improve the cognitive function of patients,as well as their activities of daily living and quality of life.(2)In improving electrophysiological indexes,tDCS combined with rTMS of left and right DLFC respectively has its own emphasis: when the stimulation site of rTMS is left DLFC,the effect is more significant in improving P300 amplitude;When the stimulation site of rTMS is the right DLPFC,the effect is more significant in shortening the latency of MMN.Based on this,corresponding treatment schemes can be given according to different neuroelectrophysiological manifestations of patients in clinic.(3)The combined treatment of tDCS-rTMS is safe and effective,and both regimens could be used for clinical treatment.