Effects of tDCS and tUS on Pain Perception in OA of the Knee

September 15, 2025 updated by: Felipe Fregni, MD, PhD, MPH, Spaulding Rehabilitation Hospital

Effects of Transcranial Direct Current Stimulation (tDCS) and Transcranial Ultrasound (TUS) on the Perception of Pain and Functional Limitations Due to Osteoarthritis of the Knee

The purpose of this study is to investigate the effects of transcranial direct current stimulation (tDCS) in conjunction with transcranial ultrasound (TUS) on pain perception and functional limitations in people with osteoarthritis of the knee. The investigators hypothesize that there will be a decrease in pain levels with active stimulation, when compared to sham stimulation.

Study Overview

Study Type

Interventional

Enrollment (Actual)

64

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Massachusetts
      • Charlestown, Massachusetts, United States, 02129
        • Spaulding Rehabilitation Network Research Institute

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 85 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Able to provide informed consent to participate in the study.
  2. Subjects between 18-85 years old.
  3. Diagnosis of chronic osteoarthritis with pain of either knee as self-reported.
  4. Existing knee pain of at least 3 on a 0-10 VAS scale on average over the past 6 months.
  5. Pain of at least 3 on a 0-10 VAS scale on average over the week prior to the first stimulation session.
  6. Pain resistant to common analgesics and medications for chronic pain used as initial pain management such as Tylenol, Aspirin, Ibuprofen, Soma, Parafon Forte DCS, Zanaflex, and Codeine.
  7. Having the ability to feel pain as self-reported.

Exclusion Criteria:

  1. Pregnancy or trying to become pregnant in the next 6 months.
  2. History of alcohol or drug abuse within the past 6 months as self-reported
  3. Contraindications to transcranial brain stimulation or TUS, i.e. implanted brain medical devices or implanted brain metallic devices.
  4. Unstable medical conditions (e.g. uncontrolled diabetes, uncompensated cardiac issues, heart failure or chronic obstructive pulmonary disease).
  5. Epilepsy.
  6. Use of carbamazepine within the past 6 months as self-reported.
  7. Suffering from severe depression (with a score of >30 in the Beck Depression Inventory)
  8. History of unexplained fainting spells as self-reported.
  9. Head injury resulting in more than a momentary loss of consciousness
  10. History of neurosurgery as self-reported.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Active Electrical Stim/Active Ultrasound
Subjects will undergo active low-intensity transcranial electrical stimulation in conjunction with active transcranial ultrasound for 20 minutes.

Subjects will undergo 20 minutes of low-intensity transcranial electrical stimulation of up to 2mA. During active stimulation, the current will be active for the full 20 minutes.

Subjects will also undergo 20 minutes of transcranial ultrasound. During active stimulation, the ultrasound will be active for the full 20 minutes.

Sham Comparator: Sham Electrical Stim/Sham Ultrasound
Subjects will undergo sham (placebo) low-intensity transcranial electrical stimulation in conjunction with sham transcranial ultrasound for 20 minutes.

Subjects will undergo 20 minutes of low-intensity transcranial electrical stimulation, as in the active condition; however, during sham stimulation (placebo) the current will not be active for the full 20 minutes.

Subjects will also undergo 20 minutes of transcranial ultrasound in the same par. During active stimulation, the ultrasound will be active for 20 minutes - however, during sham stimulation (placebo) the ultrasound will not be active for the full 20 minutes.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Changes in Pain Scale as Measured by VAS
Time Frame: Baseline and 8 weeks

Changes in the Visual Analogue Scale (VAS) for pain were measured in order to determine whether transcranial direct current stimulation in conjunction with transcranial ultrasound is effective in reducing pain in subjects with Osteoarthritis of the Knee.

The VAS scale goes from 0 up to 10, where 0 means no pain at all and 10 means the worst imaginable pain and is reported following the full course of therapy. Since we are using a difference, smaller values (negative) represent a better outcome

Baseline and 8 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Average Daily Dose of Acetaminophen Equivalent
Time Frame: 8 weeks
Analgesic use (average daily dose of acetaminophen equivalent)
8 weeks
Changes in Pain Scale as Measured by VAS
Time Frame: Baseline and 4 weeks post-stimulation

Changes in the Visual Analogue Scale (VAS) for pain were measured in order to determine whether transcranial direct current stimulation in conjunction with transcranial ultrasound is effective in reducing pain in subjects with Osteoarthritis of the Knee.

The VAS scale goes from 0 up to 10, where 0 means no pain at all and 10 means the worst imaginable pain. Since we are using a difference, smaller values (negative) represent a better outcome.

Baseline and 4 weeks post-stimulation
Percentage Change in Diffuse Noxious Inhibitory Controls (DNIC) From Baseline
Time Frame: Baseline and 8 weeks
This measures the endogenous pain modulatory pathway. This study will evaluate DNIC in pain patients using pressure as the test stimulus, and cold water as the conditioning stimulus. DNIC will be induced approximately 1-min later by having subjects immerse their hand into a water bath maintained at 10-12˚C for approximately 1 min. Parallel to the last 30s of DNIC conditioning (cold water immersion), the pressure test stimulus will be reapplied. DNIC response will be calculated as the difference between the average of pain ratings from the test stimulus minus the average of pain ratings during the conditioned stimulus. Larger percentage change means a better outcome.
Baseline and 8 weeks
Percentage Change From Baseline in the Single Leg Standing Balance Test
Time Frame: Baseline and 8 weeks
We will record the time (seconds) for which a subject is able to stand unsupported on one foot while looking straight ahead with hands on hips. Larger percentage change means a better outcome.
Baseline and 8 weeks
Percentage Change From Baseline in the Step Test
Time Frame: Baseline and 8 weeks
The subject was asked to stand unsupported with their feet parallel to each other in front of a step. We assessed the number of times the participant could place their foot up onto the step and return it to the floor over a 15-sec interval. Larger percentage change means a better outcome.
Baseline and 8 weeks
Percentage Change in Functional Reach Test From Baseline
Time Frame: Baseline and 8 weeks
Subject will be instructed to stand next to, but not touch the wall, and position the arm that is closer to the wall at 90 degrees of shoulder flexion with a closed fist. Smoothness of wrist movement is assessed as the subject was asked to outstretch their arm in a maximal forward reach, while maintaining a fixed base of support. Smoothness is dimensionless and is calculated as mean speed divided by peak speed. Larger percentage change means a better outcome.
Baseline and 8 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 1, 2016

Primary Completion (Actual)

August 15, 2019

Study Completion (Estimated)

December 7, 2026

Study Registration Dates

First Submitted

February 26, 2016

First Submitted That Met QC Criteria

March 24, 2016

First Posted (Estimated)

March 31, 2016

Study Record Updates

Last Update Posted (Estimated)

September 29, 2025

Last Update Submitted That Met QC Criteria

September 15, 2025

Last Verified

September 1, 2025

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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