Effects of tDCS in Elderly With Pain Due to Knee Osteoarthritis

Study Overview
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Brief Summary
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The purpose of this study is to evaluate if anodal tDCS stimulation over M1 may decrease chronic knee OA pain in elderly subjects with defective CPM. In addition, this trial will help to investigate the role of central sensitization in knee OA and evaluate how tDCS stimulation may affect it.

Official Title
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Effects of Transcranial Direct Current Stimulation (tDCS) on Knee Osteoarthritis Pain in Elderly Subjects With Defective Endogenous Pain-Inhibitory System: Protocol for a Randomized Clinical Trial

Conditions
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Osteoarthritis, Knee, Chronic Pain

Intervention / Treatment
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* Device: Active Transcranial Direct Current Stimulation (tDCS)
* Device: Sham Transcranial Direct Current Stimulation (tDCS)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Individuals > 60 years old, of both genders. Diagnosis of primary knee osteoarthritis with chronic pain self-reported. Be able to sign the informed consent to participate in the study. Chronic pain (over the past 6 months) of at least 4 on a 0-10 VAS scale on average. Reduction on VAS (visual analogic scale) during CPM (conditioned pain modulation) < 10% Exclusion Criteria: Contraindications to transcranial brain stimulation, i.e. implanted brain medical devices or implanted brain metallic devices. Severe acute or chronic decompensated disease. Cognitive and behavioral impairment. Epilepsy. History of fractures in the lower limbs and/or spine in the last 6 months. Use of carbamazepine within the past 6 months as self-reported. Severe depression (with a score of >30 in the Beck Depression Inventory) History of syncope. Traumatic brain injury with residual neurological deficits. History of alcohol abuse within the past 6 months as self-reported.

Ages Eligible for Study
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Minimum Age: 60 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Active tDCS<br>Subjects will undergo low-intensity transcranial electrical stimulation for 20 minutes. | Device: Active Transcranial Direct Current Stimulation (tDCS)<br>* Subjects will undergo 15 sessions of tDCS stimulation, 1x per day at 20 minutes per session, of up to 2mA. During active stimulation, the current will be active for the full 20 minutes.<br>|
| Sham Comparator: Sham tDCS<br>Subjects will undergo low-intensity transcranial electrical stimulation for 20 minutes. | Device: Sham Transcranial Direct Current Stimulation (tDCS)<br>* Subjects will undergo 15 sessions of tDCS stimulation, 1x per day at 20 minutes per session, of up to 2mA. However, during sham stimulation (placebo) the current will not be active for the full 20 minutes<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in Pain Scale | Determine whether anodal transcranial direct current stimulation is effective in reducing pain in subjects with chronic pain due to knee osteoarthritis, as measured by changes in the Brief Pain Inventory (BPI) | Measured at baseline and up to 60 days after the end of stimulation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in Quality of Life | The investigators will use the 12-Item Short Form Health Survey (SF-12) to assess changes in quality of life. | Measured at baseline, 15, 30 and 60 days after the of stimulation | 
| Changes in Physical Function as measured through Lequesne Index | The investigators will use the Lequesne Index to assess changes in functional capacity. | Measured at baseline, 15, 30, and 60 days after the end of stimulation | 
| Changes in Patient Global Assessment | Modifications in the patient global assessment will be evaluated by measuring changes in the Visual Analogue Scale (VAS). | Measured at baseline, 15, 30 and 60 after the end of stimulation | 
| Changes in Physical Function as measured through Western Ontário and McMaster Universities Osteoarthritis Index | The investigators will use the Western Ontário and McMaster Universities Osteoarthritis Index (WOMAC) to assess changes in functional capacity. | Measured at baseline, 15, 30 and 60 days after the end of stimulation | 
| Adverse Events | Subjects will complete a questionnaire, after each session, to assess potential adverse events of stimulation (headache, neck pain, mood alterations, and seizures) on a 5-point scale. | Up to 60 days after the end of stimulation | 
| Changes in Mood | The safety of tDCS will be monitored by measuring changes in the Visual Analog Mood Scale. | Up to 60 days after the end of stimulation | 
| Changes in cognition | The safety of tDCS will be monitored by measuring changes in the MMSE. | Up to 60 days after the end of stimulation | 
| One leg standing balance test | The investigators will analyse how long time the subject can stay stand on one foot to analise those balance. | Measured at baseline, 15, 30 and 60 days after the end of stimulation | 
| Timed Up and Go Test | The investigators will measure the walking speed of the subjects. | Measured at baseline, 15, 30 and 60 days after the end of stimulation | 
| Changes Pain Pressure Threshold (PPT) | Changes in the pain pressure threshold will be analyzed in order to determine whether anodal transcranial direct current stimulation is effective in increasing the pain pressure threshold in subjects with osteoarthritis knee pain. | Measured at baseline, 15, 30 and 60 days after the end of stimulation | 
| Changes in mechanical detection threshold as measured through Von-Frey monofilaments | Changes in the mechanical detection threshold (MDT) will be measured through calibrated Von-Frey monofilaments in order to determine whether anodal transcranial direct current stimulation is effective in increasing the mechanical detection threshold of subjects with osteoarthritis knee pain. | Measured at baseline, 15, 30 and 60 days after the end of stimulation | 
| Changes in mechanical pain threshold as measured through Von-Frey monofilaments | Changes in the mechanical pain threshold (MDT) will be measured through calibrated Von-Frey monofilaments in order to determine whether anodal transcranial direct current stimulation is effective in increasing the mechanical pain threshold of subjects with osteoarthritis knee pain. | Measured at baseline, 15, 30 and 60 days after the end of stimulation | 
| Descending Noxious Inhibitory Control (DNIC) | The investigators will monitore the central modulation of pain. | Measured at baseline, 15, 30 and 60 days after the end of stimulation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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osteoarthritis, elderly, musculoskeletal pain, transcranial direct current stimulation