EEG Prediction and Clinical Efficacy of tDCS in Fibromyalgia. (FM-TDCS-PREDIC)

May 7, 2026 updated by: Ionclinics & Deionic SL

Clinical Efficacy of tDCS in Fibromyalgia: A Controlled Clinical Trial and Analysis of Electrophysiological Biomarker Predictors.

The purpose of this randomized controlled trial is to investigate the non-inferiority, and possible superiority, of a high-dose home-based tDCS protocol compared with a conventional home-based protocol, and to assess its cost-effectiveness, in patients with fibromyalgia.

As complementary goals, we aim to assess the predictive value of baseline EEG for clinical response to high-dose home-based tDCS treatment; and to describe the effectiveness of a high-dose home-based protocol applied to the motor cortex (M1) versus the dorsolateral prefrontal cortex (DLFPC) in patients with fibromyalgia.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

250

Phase

  • Not Applicable

Contacts and Locations

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

Study Contact

Study Contact Backup

Study Locations

  • Spain
      • Valencia, Spain
        • Hospital Clinico Universitario de Valencia
        • Contact:

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients who meet the diagnostic criteria described by the American College of Rheumatology (Wolfe et al., 2016):
  • Widespread Pain Index (WPI) ≥7 and Symptom Severity Scale (SSS) score ≥5 or a WPI score of 4-6 and SSS ≥9
  • Presence of widespread pain, defined as pain in at least 4 of 5 regions. Jaw, chest, and abdominal pain are not included in the definition of widespread pain.
  • Symptoms have been generally present for at least 3 months.
  • The diagnosis of fibromyalgia (FM) is valid regardless of other diagnoses. The diagnosis of FM does not exclude the presence of other clinically significant diseases.
  • Patients with a stable prescription (or lack thereof) for antidepressant/pharmacological medication and who agree to continue it throughout the study.
  • Demonstrate the ability to properly administer home-based tDCS independently or with the assistance of a caregiver.
  • Have access to an electronic device with a camera (mobile phone or computer) to allow for monitoring of the intervention and communication with the participant.
  • Have the capacity and willingness to commit to the study team for the completion of all phases of the study.
  • Volunteer to participate and sign the specific informed consent form for this study.

Exclusion Criteria:

  • Presenting with immune system disorders or comorbidities that explain the main symptoms of fibromyalgia: rheumatoid arthritis, lupus, autoimmune, neurological, and oncological disorders.
  • Presenting with any uncompensated clinical condition such as ischemic heart disease, kidney disease, or liver disease.
  • Presenting with dermatological conditions, such as allergic skin reactions at the electrode sites, psoriasis, etc.
  • Any exclusion criteria established by clinical guidelines on non-invasive brain stimulation (Woods et al., 2016):
  • Metallic implants or head injuries, any electronic device such as cochlear implants or cardiac pacemakers.
  • Brain stimulation within the last 6 months.
  • A clinical or family history of epilepsy.
  • Having any structural lesion (for example, any structural neurological condition or more subcortical lesions than would be expected for their age, or having suffered a stroke affecting the stimulated area or connected areas) or any other clinically significant abnormality that could affect safety, participation in the study, or confound the interpretation of the study results, as determined by the investigator.
  • History of drug or alcohol abuse during the study or in the 3 months prior (except for nicotine).
  • Changes in drug treatment in the month prior to starting the trial.
  • Awaiting trial or litigation during the trial.
  • Pregnancy

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: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: High-dose home-tDCS M1
tDCS administered at home using a high-dose protocol targeting the primary motor cortex.
Device: High-dose home-tDCS M1

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique in which a weak direct current (2 mA) is applied to the scalp via electrodes.

The anode will be applied to C3 (primary motor cortex) and the cathode to Fp2 (contralateral anterior frontal region). The application of tDCS will be carried out at home in this group. Each session will consist of 20 minutes of stimulation.

Dose: 3 weeks, daily. (1) 1st week - 3 times per day; (2) 2nd Week - 2 times per day; (3) 3rd week - 1 time per day (total of 42 sessions).
Active Comparator: Conventional home-tDCS
tDCS administered at home using a conventional stimulation protocol targeting the primary motor cortex.
Device: Conventional home-tDCS

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique in which a weak direct current (2 mA) is applied to the scalp via electrodes.

The anode will be applied to C3 (primary motor cortex) and the cathode to Fp2 (contralateral anterior frontal region). The application of tDCS will be carried out at home in this group. Each session will consist of 20 minutes of stimulation.

Dose: 4 weeks, from Monday to Friday. 1 time per day (total of 20 sessions).
Experimental: High-Dose home-tDCS DLPFC
tDCS administered at home using a high-dose stimulation protocol targeting the dorsolateral prefrontal cortex.
Device: High-dose home-tDCS DLPFC

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique in which a weak direct current (2 mA) is applied to the scalp via electrodes.

The anode will be applied to F3 (left dorsolateral prefrontal cortex) and the cathode to F8 (right ventrolateral prefrontal cortex). The application of tDCS will be carried out at home in this group. Each session will consist of 20 minutes of stimulation.

Dose: 3 weeks, daily. (1) 1st week - 3 times per day; (2) 2nd Week - 2 times per day; (3) 3rd week - 1 time per day (total of 42 sessions).

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Fibromyalgia Impact Questionnaire
Time Frame: Baseline and end of treatment (week 3 for experimental; week 4 for active comparator).
Changes from baseline to the end of the treatment in the revised version of Fibromyalgia Impact Questionnaire (FIQ-R).
Baseline and end of treatment (week 3 for experimental; week 4 for active comparator).

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
WPI
Time Frame: Baseline; end of treatment (3 week experimental; 4 week active comparator)
Change from baseline to end of treatment in Widespread Pain Inventory (WPI).
Baseline; end of treatment (3 week experimental; 4 week active comparator)
SSS
Time Frame: Baseline; end of treatment (3 week experimental; 4 week active comparator)
Change from baseline to end of treatment in Symptom Severity Scale (SSS).
Baseline; end of treatment (3 week experimental; 4 week active comparator)
HADS
Time Frame: Baseline; end of treatment (3 week experimental; 4 week active comparator).
Change from baseline to end of treatment in Hospital Anxiety and Depression Scale (HADS).
Baseline; end of treatment (3 week experimental; 4 week active comparator).
PSQI
Time Frame: Baseline; end of treatment (3 week experimental; 4 week active comparator).
Change from baseline to end of treatment in Pittsburgh Sleep Quality Index (PSQI).
Baseline; end of treatment (3 week experimental; 4 week active comparator).
EQ-5D
Time Frame: Baseline; end of treatment (3 week experimental; 4 week active comparator).
Change from baseline to end of treatment in EuroQoL-5D (EQ-5D).
Baseline; end of treatment (3 week experimental; 4 week active comparator).
PGI-C
Time Frame: End of treatment (3 week experimental; 4 week active comparator).
Change at the end of treatment in Patient Global Impression of Change (PGI-C).
End of treatment (3 week experimental; 4 week active comparator).
BDI-II
Time Frame: Baseline and end of treatment (week 3 for experimental; week 4 for active comparator).
Changes from baseline to end of treatment in Beck Depression Inventory-II.
Baseline and end of treatment (week 3 for experimental; week 4 for active comparator).
Resting state EEG
Time Frame: Baseline
32-channel active-electrode EEG (impedances <5 kΩ) recordings in open and close eye conditions. The spectral density and spectral power of delta, theta, alpha, beta, and gamma will be analyzed, as well as the topographic distribution.
Baseline

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Patient Expectations
Time Frame: Baseline
Likert scale from 1 to 5 (where 1 is no expectation and 5 is the highest possible expectation) to study the influence of expectation on the effect of treatment.
Baseline
Responders to tDCS
Time Frame: Through study completion, an average of 2 years.

A subject is considered a responder if:

- Improvement of 50% or more in FIQ-R from baseline to immediate post-treatment.
Through study completion, an average of 2 years.
Adverse Effect
Time Frame: End-of-day application (Experimental: 7 days per week through 3 weeks; Active Comparator: 5 days per week, through 4 weeks).
A daily questionnaire about adverse effects will be completed at the end of the last intervention of the day.
End-of-day application (Experimental: 7 days per week through 3 weeks; Active Comparator: 5 days per week, through 4 weeks).
Success of blinding
Time Frame: Through study completion, an average of 2 years
A method 3 x 3 will be used to evaluate the success of the study's evaluator and statistician.
Through study completion, an average of 2 years
Incremental Cost Effectiveness Ratio
Time Frame: Through study completion, an average of 2 years.
Incremental Cost Effectiveness Ratio (ICER) will be derived from clinical effectiveness, utility and costs.
Through study completion, an average of 2 years.
Costs
Time Frame: Through study completion, an average of 2 years.
Direct and indirect medical and non-medical costs will be collected for the cost-effectiveness analysis.
Through study completion, an average of 2 years.
Utility
Time Frame: Through study completion, an average of 2 years.
Quality-adjusted life years (QALYs) will be calculated using the EQ-5D questionnaire for the cost-effectiveness analysis.
Through study completion, an average of 2 years.

Collaborators and Investigators

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

Sponsor

Ionclinics & Deionic SL

Collaborators

Hospital Clínico Universitario de Valencia

Investigators

  • Study Director: Ane Miren Gutiérrez Muto, PhD, Ionclinics & Deionics S.L.
  • Study Chair: Mar Hernández Secorún, PhD, Neuroscience in Physiotherapy independent research group; Ionclinics & Deionics S.L.
  • Study Chair: Gustavo Sarriá Córdoba, MSc, Neuroscience in Physiotherapy independent research group; Ionclinics & Deionics S.L.

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 (Estimated)

May 15, 2026

Primary Completion (Estimated)

December 31, 2027

Study Completion (Estimated)

June 30, 2028

Study Registration Dates

First Submitted

April 30, 2026

First Submitted That Met QC Criteria

May 7, 2026

First Posted (Actual)

May 13, 2026

Study Record Updates

Last Update Posted (Actual)

May 13, 2026

Last Update Submitted That Met QC Criteria

May 7, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • ION002_EEG_TDCS_FM

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

In accordance with the recommendations of the International Committee of Medical Journal Editors, the de-identified individual participant data (IPD) that underlie the results reported in this study will be shared. The data will become accessible one year after the publication of the primary results and will remain available for five years. Access will be provided to researchers who inquire and agree to a data-use agreement through Ionclinics (investigacion@ionclinics.com/ensayos@ionclinics.com). The data will be de-identified and shared in accordance with applicable regulations and the informed consent provided by the participants.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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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