Transcranial Direct Current Stimulation over the Motor or Frontal Cortex in Patients with Chronic Ankle Instability

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Sports Medicine

Background:

• Chronic ankle instability (CAI) affects motor function and quality of life.
• Anodal transcranial direct current stimulation (atDCS) shows promise when combined with motor interventions for CAI.
• Limited research compares different atDCS application sites for CAI.

Purpose of the Study:

• To compare the efficacy of atDCS over the motor cortex versus the frontal cortex, combined with motor planning, for improving neural function, performance, and patient-reported outcomes in CAI patients.
• To assess the impact of atDCS on dynamic balance, muscle activation, reaction times, and cognitive performance in individuals with CAI.
• To evaluate patient-reported outcomes, including foot and ankle function and perceived disablement, following the intervention.

Main Methods:

• A double-blind, sham-controlled, parallel randomized trial involving 44 participants with CAI.
• Participants received a four-week motor planning intervention with atDCS applied over the motor cortex, frontal cortex, or sham.
• Outcome measures included neural excitability, dynamic balance, muscle activation, reaction times, and patient-reported outcomes assessed at baseline, week 2, week 4, and week 6.

Main Results:

• No significant differences were found in neural excitability or muscle activation across the groups.
• All groups showed significant improvements in dynamic postural stability from baseline.
• Improvements in foot & ankle function, perceived disablement, and overall perceived improvement were significant post-intervention and at retention.

Conclusions:

• The motor planning intervention effectively improved function in patients with CAI, irrespective of atDCS application.
• The potential benefits of atDCS may depend on the precise pairing of electrode placement with specific rehabilitation exercises.
• Further research is needed to optimize atDCS protocols for CAI rehabilitation.