Effect of Transcranial Direct Current Stimulation on Executive Function and TREM2 Relative Expression Level in Patients with Cerebral Small Vessel Disease and Its Correlation Study

ObjectiveTo investigate the effects of transcranial direct current stimulation (tDCS) on executive function (EF) and the relative expression level of triggering receptor expressed on myeloid cells 2 (TREM2) in patients with cerebral small vessel disease (CSVD), and to explore their correlation.MethodsA total of 43 CSVD patients from the outpatient and inpatient departments of Mental Health Center of Jiangnan University (Wuxi Mental Health Center) between May 2022 and December 2023 were enrolled. The patients were divided into control group with 21 cases and experimental group with 22 cases using the random number table method. During the treatment, one case dropped out from the control group and two from the experimental group, resulting in 20 cases included in each group for final analysis. Both groups received conventional medication and cognitive training (30 min per session, once daily, 5 days per week for 4 weeks). The experimental group additionally received tDCS treatment concurrent with cognitive training, with a current intensity of 2 mA, 30 min per session, once daily, 5 days per week for 4 weeks. The control group received sham tDCS during cognitive training, with identical equipment, procedures, duration, frequency, and period as the experimental group. To mimic the slight tingling sensation of real stimulation and ensure blinding, the control group received a 30-second current ramp-up (0→2 mA) at the beginning and a 30-second current ramp-down (2→0 mA) at the end, with 0 mA current for the remainder of the session. Before and after treatment, EF impairment was assessed using the Executive Interview-25 (EXIT25); global cognitive impairment was assessed using the Mini-Mental State Examination (MMSE); EF was assessed using the Stroop Color-Word Test (SCWT); the relative expression level of TREM2 was measured by enzyme-linked immunosorbent assay; and adverse reactions were recorded using a tDCS experience questionnaire.ResultsCompared with pre-treatment, EXIT25 scores decreased in both groups after treatment (P