Event-related Potentials Of 40 Hz Transcranial Alternating Current Stimulation In Patients With Mild AD

The purpose of this study was to use 40 Hz transcranial alternating current(AC)stimulation to regulate patients with mild Alzheimer’s Disease(AD),and to observe whether the neural oscillation in Gamma band induced by electrical stimulation can improve the basic sensory and perceptual functions of patients.The changes of cognitive functions in patients with mild AD by 40 Hz transcranial AC stimulation were observed in the evidences of event-related potentials.These techniques could be used in the objective evaluation and early prevention of Alzheimer’s disease in the future.A total of 15 patients with mild AD were included in this study.The intervention period was three weeks,once a day,a total of 7 days every week,and the intervention duration was 1 hour each time.EEG data were recorded before and after the intervention using event-related potential technique.The EEG device was an EGI 128-lead highdensity EEG system.The task paradigm was the face comparison task,and E-prime 2.0tool was used for stimulus presentation.In the ERP results,we focused on the amplitude and latency of three ERP components before and after intervention,namely P1,N170(N1)and P300,which reflect the processing processes from sensory and perception to cognition.The default EEG acquisition parameters are set as follows: the sampling rate was 1000 Hz and the Cz electrode was set as the reference electrode.The band pass filter of 0.3-70 Hz and notch filter of 50 Hz.The whole experiment was carried out in a wellventilated indoor environment with bright and soft lighting and comfortable temperature.All patients completed the experiment under the guidance of the investigator himself.The results showed that there were significant differences in the amplitude of N1 in O1(t=-2.19,P<0.05)、O2(t= 3.16,P<0.05)、PO7(t=-3.35,P<0.05)of the cognitive components induced by the face perception task in patients before and after transcranial AC stimulation intervention.After faces were occluded,there was no significant differences in the above components.The results indicated that 40 Hz transcranial AC stimulation could change the ERP activities that may be related to the improvement of the cognitive functions in patients with mild Alzheimer’s disease,and the event-related potential technique had clinical value,which could provide objective indicators for the efficacy evaluation of Alzheimer’s disease.Figure 5;Table 4;Reference 72...