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NCT Number: NCT07791966

Effects of Non-invasive Brain Stimulation on Pain Avoidance Behavior in Chronic Pain Patients

Pain avoidance helps with survival. However, chronic pain patients often avoid valued life activities fearing onset or exacerbation of pain. Hence, pain avoidance no longer protects, but reduces quality of life. The goal of this clinical trial is to learn if non-invasive brain stimulation technique called transcranial alternating current stimulation (tACS) impact pain avoidance behavior in chronic pain patients. tACS is a way to gently stimulate the brain using a small, portable device. It sends an extremely weak, continuous alternating current through the scalp. Participants will either get real tACS or a fake (sham) version. Real tACS will stimulate the brain in the alpha frequency (8-12 Hz) which has been found to influence pain avoidance behavior, whereas sham tACS will stimulate the brain in a different frequency that is not known to influence avoidance behavior. The main questions it aims to answer are:

Does tACS alter the way chronic pain patients confront pain in terms of avoidance behavior? How does tACS impact brain signals related to pain avoidance behavior?

Participants will:

1. fill out self-administered questionnaires asking about their medication use, personality and temperament, mood, including anxiety and depression, current pain level, and any disability you have due to your pain. 2. perform of a pain avoidance task before, during and after 'real' tACS or 'sham' tACS. They may also be asked to stay quiet before, during and after tACS. During this period, we will scan the brain using a neuroimaging device called Magnetoencephalography (MEG). Additionally, Electroencephalography (EEG) brain signals will also be collected using electrodes affixed to the scalp. We may also measure Skin conductance response (SCR) and electrocardiography (EKG) using electrodes affixed to the skin. 3. also get a T1 MRI if they do not have an implanted SCS, DRG, intrathecal pump, or other similar device that are not MRI compatible.

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Key information

Conditions

Complex Regional Pain Syndrome (CRPS) Autonomic Nervous System Diseases Complex Regional Pain Syndromes Nervous System Diseases Neuromuscular Diseases Peripheral Nervous System Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Cleveland Clinic

Cleveland, Ohio, 44195, United States

Location status: Recruiting

Location contact

Raghavan Gopalakrishnan

CONTACT

[email protected]

800-223-2273

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age 18 years or older
  • Diagnosed with Complex Regional Pain Syndrome (CRPS) Type I or II, based on Budapest criteria
  • 6 months or more of medically refractory severe pain
  • Average daily pain for past 30 days >= 5 on 0-10 scale
  • Presence of allodynia and/or hyperalgesia
  • Lower extremity CRPS: bilateral or unilateral pain
  • Not concurrently treated with neurostimulation therapies such as spinal cord stimulators (SCS)
  • Absence of co-occurring severe psychiatric disorders (PHQ-9<19 and/or GAD-7<14)

Exclusion criteria

  • Age under 18 years, pregnant women of any age
  • Any co-occurring pain diagnosis that might confound with allodynia/hyperalgesia resulting from CRPS reflecting a malfunction in sensory processing within the CNS.
  • Less than six months of medically refractory pain
  • Average daily pain for past 30 days <5 on 0-10 scale
  • Absence of allodynia and/or hyperalgesia
  • Concurrent neurostimulation therapies such as SCS
  • Severe disorders or conditions (e.g., cardiovascular, liver issues), terminal illness
  • PHQ-9>19 and/or GAD-7>14 (severe depression/anxiety)

Treatment and study plan

transcranial alternating current stimulation (tACS)

Device

Real tACS will stimulate the brain in the individual alpha frequency (8-12 Hz) measured from baseline MEG

Primary outcomes

  1. magnitude of alpha frequency band power

    Time frame: Periprocedural

    measured using MEG/EEG from resting-state and during the performance of pain avoidance task. The MEG/EEG neural signals will be transformed to frequency domain to measure the magnitude of power in the alpha band.

Secondary outcomes

  1. standard deviation in R-R length

    Time frame: Periprocedural

    standard deviation in R-R length (SDNN), a measure of heart rate variability from RR interval tachogram derived from EKG.

  2. number of spontaneous skin conductance fluctuations

    Time frame: Periprocedural

    number of spontaneous skin conductance fluctuations will be measured from galvanic skin conductance response time-series data.

Study contacts

Contact information is provided by the study sponsor or research team.

Raghavan Gopalakrishnan

CONTACT

[email protected]

2164459322

Sponsors and collaborators

Lead sponsor

The Cleveland Clinic

Other

Collaborators

  • National Center for Complementary and Integrative Health (NCCIH)

Registry information

Official study title

Alpha tACS and Pain Avoidance Behavior in Chronic Pain Patients

Important dates

Study start
2026
Primary completion
2028
Study completion
2028
First posted
Aug 28, 2026
Registry last updated
Aug 28, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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