Clinical Efficacy and Mechanism of tDCS for Dysphagia in PD

Condition(s) studied

Investigational drug(s) / intervention(s)

tDCS: The IS200 intelligent electrical stimulator, manufactured in Chengdu, Sichuan, will be used. The electrode pads are 4cm × 6cm in size. The anode of the electrode pad will be placed on the swallowing sensorimotor cortex (S1/M1). The specific positioning will follow the international 10-20 electroencephalographic system: the left S1/M1 area is located at the midpoint of the line connecting C3 and T3 in the left hemisphere; the right S1/M1 area is located at the midpoint of the line connecting C4 and T4 in the right hemisphere. The cathode will be placed on the contralateral supraorbital margin. The S1/M1 areas of the left and right hemispheres will be stimulated alternately, with a current intensity of 1.6mA. The treatment will be given once daily, 20 minutes per session, 5 times a week, for 2 consecutive weeks, totaling 10 sessions (5 sessions for each hemisphere).

Conventional Dysphagia Treatment: 1. Training for perioral muscles, tongue sensory and motor functions, including ice cotton swab stimulation, gustatory stimulation, tongue muscle movement training, etc.; 2. Airway protection training, including Mendelsohn maneuver, supraglottic swallow training, etc.;

sham tDCS: According to previous literature, the electrode positions and treatment frequency of sham tDCS will be the same as those of real tDCS. The current will be adjusted to 0.05mA.

Study summary

This 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.

Eligibility

Primary outcome measure(s)

• Rosenbek Penetration-Aspiration Scale (PAS): — at baseline, after the completion of 10 days of intervention, at the 3-month follow-up
  Scored 1-8, with higher scores indicating poorer swallowing safety. 1. Level 1: The bolus does not enter the airway; it remains entirely within the oral cavity or pharynx and is propelled normally. 2. Level 2: The bolus enters the supraglottic area (e.g., vallecula) but does not touch the vocal cords, and is completely cleared (e.g., via swallowing or coughing). 3. Level 3: The bolus enters the supraglottic area without touching the vocal cords, but residue remains (not fully cleared). 4. Level 4: The bolus touches the vocal cords but does not enter the subglottic airway, and is completely cleared. 5. Level 5: The bolus touches the vocal cords without entering the subglottic airway, but residue remains. 6. Level 6: The bolus enters the subglottic airway (into the trachea) but is completely cleared by the patient (e.g., via coughing). 7. Level 7: The bolus enters the subglottic airway; the patient exhibits protective responses (e.g., coughing) but cannot fully clear it, leaving
• Videofluoroscopic Dysphagia Scale (VDS) — at baseline, after the completion of 10 days of intervention, at the 3-month follow-up
  14 items in total, including 7 items for oral-phase swallowing function and 7 for pharyngeal-phase function, used to assess overall swallowing function;
• oral residue — at baseline, after the completion of 10 days of intervention, at the 3-month follow-up
  Post-swallow residue was scored 0-3, with higher scores indicating more food residue and lower swallowing efficiency
• Amplitude of Low Frequency Fluctuation (ALFF) — at baseline, after the completion of 10 days of intervention, at the 3-month follow-up
  ALFF focuses on the low-frequency components of these HbO/HbR time series. It is defined as the average amplitude of hemodynamic signal fluctuations within a specific low-frequency range (typically 0.01-0.1 Hz, though the exact band may vary by study). This range is chosen because it captures slow, spontaneous oscillations in cerebral blood flow and oxygenation, which are hypothesized to reflect synchronized neural activity across brain regions (e.g., default mode network, sensorimotor networks). Mathematically, ALFF quantifies the "strength" of these low-frequency oscillations: a higher ALFF value indicates more prominent or intense fluctuations in the target frequency band, suggesting greater spontaneous hemodynamic (and thus neural) activity in that brain region.
• Functional Connectivity (FC) — at baseline, after the completion of 10 days of intervention, at the 3-month follow-up
  Functional Connectivity (FC) refers to the statistical association or synchronization between spontaneous hemodynamic signals from different cortical regions, reflecting the coordinated activity of spatially distinct brain areas. It quantifies how closely the neural activity (inferred from blood oxygenation changes) in one brain region correlates with that in another, providing insights into the integration of brain networks.
• vellaculae residue — at baseline, after the completion of 10 days of intervention, at the 3-month follow-up
  The residue amount was rated on a scale from 0 to 3: 0 indicates that no residue was visible, 1 indicates mild residue(the level of contrasted material constituted less than 25% of the height of the structure), 2 indicates moderate residue (the level of contrasted material constituted between 25 and 50%of the height of the structure), and 3 indicates severe residue(the level was higher than 50% of the height of the structure).
• pyriform sinuses residue — at baseline, after the completion of 10 days of intervention, at the 3-month follow-up
  The residue amount was rated on a scale from 0 to 3: 0 indicates that no residue was visible, 1 indicates mild residue(the level of contrasted material constituted less than 25% of the height of the structure), 2 indicates moderate residue (the level of contrasted material constituted between 25 and 50%of the height of the structure), and 3 indicates severe residue(the level was higher than 50% of the height of the structure).

Trial sites (1)

Other trials for the same condition