RecruitingDevice studyClinical Efficacy and Mechanism of tDCS for Dysphagia in PDThis study aims to verify transcranial direct current stimulation(tDCS) efficacy for Parkinson's disease (PD)-related dysphagia and its mechanism. Subjects are randomly split into two groups: control (sham tDCS + conventional dysphagia treatment) and experimental (real tDCS + conventional treatment). Assessments will be conducted at baseline, after the completion of intervention, and at the 3-month follow-up. Swallowing function will be evaluated via gold-standard videofluoroscopic swallowing study (VFSS) and scales. Resting-state functional magnetic resonance imaging (rs-fMRI) or functional near-infrared spectroscopy (fNIRS) will be measures for tracking changes in abnormal brain regions/networks. Correlations between swallowing recovery and brain function changes, plus group imaging differences, will reveal tDCS's neurophysiological mechanism.