Balance Training With tDCS for CAI

Study Overview
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Brief Summary
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The purpose of this research study is to examine the efficacy of non-invasive brain stimulation in addition to balance exercise for chronic ankle instability (CAI), a condition that develops following an initial ankle sprain, usually because of loose or unstable ankle joints.

Official Title
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Balance Training With Transcranial Direct Current Stimulation (tDCS) for Chronic Ankle Instability (CAI)

Conditions
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Ankle Injuries and Disorders

Intervention / Treatment
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* Device: Anodal tDCS
* Device: Sham tDCS


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subjects should be neurologically sound Subjects should have abilities to maintain a single-leg stance at least for 10 seconds. A history of ankle sprain A history of ankle joint giving ways Current feelings of ankle joint instability Exclusion Criteria: Individuals with a clinically defined neurological disorder, with an increased risk of seizure for any reason, with a history of treatment with Transcranial Magnetic Stimulation (TMS), deep brain stimulation for any disorder will be excluded. Patients with cardiac pacemakers, implanted medication pumps, intracardiac lines, or acute, unstable cardiac disease, with intracranial implants (e.g. aneurysm clips, shunts, stimulators, cochlear implants, or electrodes) or any other metal object within or near the head, excluding the mouth, that cannot be safely removed will be excluded. A history of balance or vestibular disorder A history of previous surgeries to the musculoskeletal structures in either limb of the lower extremity A history of a fracture in either limb of the lower extremity requiring realignment A history of acute injuries to the lower extremity joints in the previous 3 months, which impacted joint integrity and function (i.e., sprains, fractures) resulting in at least 1 interrupted day of desired physical activity A history of herniated disc Poorly controlled headache Hypersensitivity to electrical or magnetic stimulation Adults unable to consent Individuals who are not yet adults (infants, children, teenagers) Pregnant women Prisoner

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Anodal tDCS and Balance Training (BT) Group<br>Participants will undergo 4 weeks of BT under anodal tDCS treatment. | Device: Anodal tDCS<br>* An anodal surface electrode will be attached to the contralateral motor cortex (M1) of the CAI-involved side and the reference electrode will be placed on the ipsilateral side of the supraorbital ridge. Anodal tDCS will deliver a low electrical current stimulation at 2 milliamps (mA). Participants will undergo 3 sessions per week for a total of 12 sessions and each session will last approximately 20 minutes.<br>|
| Sham Comparator: Sham tDCS and BT Group<br>Participants will undergo 4 weeks of BT under sham tDCS. | Device: Sham tDCS<br>* An anodal surface electrode will be attached to the contralateral motor cortex (M1) of the CAI-involved side and the reference electrode will be placed on the ipsilateral side of the supraorbital ridge. Sham tDCS will deliver a low electrical current stimulation at 2 mA and will be turned off 30 seconds following the application. Participants will undergo 3 sessions per week for a total of 12 sessions and each session will last approximately 20 minutes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Static postural balance as quantified by center of pressure parameters (COP) | Static postural balance will be assessed by the displacement from COP on the anteroposterior and mediolateral axes using a force platform during quite single and double leg standing. The average of three trials for each standing position will be reported. | 4 weeks | 
| Cortical excitability as evaluated by Active Motor Threshold (AMT) | The soleus active motor threshold will be measured by TMS using a computation program, Parameter Estimation by Sequential Testing (PEST). | 4 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Self-reported functional scores | The percentage score of the Foot and Ankle Ability Measure (FAAM) will be used for the self-reported function. The total percentage score will be ranging from 0-100. The higher score indicates a better ankle function. | 4 weeks | 
| Spinal reflex excitability as evaluated by H-reflex and M-wave ratio (Hmax/Mmax ratio) | H-reflex is a refractory muscle response which results from electrical stimulation over the peripheral nerve. M-wave is a compound muscle action potentials which results from supra-maximal electrical stimulation. Maximal H-reflex and M-wave ratios will be measured. | 4 weeks | 
| Corticospinal excitability as evaluated by the peak-to-peak amplitude of Motor Evoked Potential (MEP) | The soleus active muscle response, due to transcranial magnetic stimulation (TMS) pulses over the motor cortex, will be used for quantifying the motor evoked potential. | 4 weeks | 
| Dynamic postural control as measured by the reach distance | The reach distance (cm) will be measured by Star Excursion Balance Test (SEBT). | 4 weeks | 
| Dynamic postural balance as measured by the time to complete the lateral hop | The completion time (seconds) for the lateral hop will be measured. Each trial consists of 10 lateral hops. The average completion time of 3 trials will be reported. The completion time will be recorded using a stopwatch in seconds. | 4 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Chronic Ankle Instability