Hyperbaric Oxygen Compared to Pharmaceutical Therapies for Fibromyalgia Syndrome (FMSRCT)

April 19, 2026 updated by: Shay Efrati, Assaf-Harofeh Medical Center

Hyperbaric Oxygen vs. Standard Pharmaceutical Therapies for Fibromyalgia Syndrome - Prospective, Randomized Crossover Clinical Trial

The investigators have previously studied the efficacy of hyperbaric oxygen therapy (HBOT) as a treatment for Fibromyalgia syndrome (FMS) in a prospective, active control, crossover clinical trial. The results demonstrated significant amelioration of all FMS symptoms, with significant improvement in life quality; furthermore, the investigators were able to demonstrate significant neuroplasticity on SPECT imaging, with a decrease of the hyperactivity in posterior regions and elevation of the reduced activity in frontal areas.

In the proposed study, the investigators intend to both repeat and expand our previous findings, treating FMS patients with HBOT while performing an extensive of evaluation both before and after treatment.

In the current study, the investigators plan to compare HBOT to current standard of care of FMS (pharmacological and non - pharmacological).

Study Overview

Detailed Description

The study will include 70 fibromyalgia patients in whom physical trauma, such mild traumatic brain injury (mTBI), could be considered as the trigger for FMS. Each participant will be examined at the time of recruitment and a diagnosis of FMS will be verified, based on the updated 2016 diagnostic criteria In the current study the investigators will recruit patients not currently being treated with medications specific for FMS, including anti-depression drugs, gabapentanoids and tricyclics, opiods and medical cannabis. Patients who are on such treatment will be required to discontinue treatment 2 weeks before recruitment.

Patients will undergo randomization upon recruitment to one of the two study groups. One group will proceed to a course of HBOT treatment while the second group will commence with standard treatment for FMS, as outlined in the Israeli guidelines for the diagnosis and treatment of FMS [41]. These patients will be given detailed education regarding the nature of FMS as well as recommendations regarding non - pharmacological interventions recommended for FMS, including graded physical exercise, hydrotherapy, movement-meditative treatments (e.g. Tai Chi) and cognitive behavioral treatment (CBT).

HBOT protocol: a total of 60 daily hyperbaric oxygen treatment sessions will be administrated 5 days per week. 60 sessions will include exposure of 90 minutes to 100% at 2 Absolute atmospheres (ATA), with 5 minutes air breaks every 20 minutes.

Pharmaceutical protocol: patients will be offered pharmacological treatment with one of the two medications currently licensed for the treatment of FMS in Israel, i.e. Cymbalta and Lyrica. Treatment with Lyrica will start at a dose of 75 mg at bedtime while treatment with Cymbalta will start at a dose of 30 mg a day (in the morning). After a period of 6 weeks patients will be evaluated and dose will be adjusted as necessary. Patients may also be switched from one medication to the other based according to clinical judgment.

Crossover: After 3 months of either pharmaceuitical or HBOT, once the 2nd evaluation is completed, all patients in both groups will be offered to switch to the alternative treatment group.

Study Type

Interventional

Enrollment (Actual)

76

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 Locations

      • Ẕerifin, Israel, 70300
        • Assaf-Harofeh Medical Center

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 and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • FMS diagnosis, based on the updated 2016 diagnostic criteria
  • previous physical trauma (such as traumatic brain injury)

Exclusion Criteria:

  • the presence of systemic inflammatory disorders including inflammatory rheumatological and autoimmune disorders.
  • active malignancy,
  • chronic ongoing infection
  • major psychiatric disorders (excluding anxiety)
  • Patients currently or previously treated with Duloxetine (Cymbalta) or Pregabalin (Lyrica) will also be excluded
  • previous HBOT for any other reason prior to their inclusion;
  • Chest pathology incompatible with pressure changes (including active asthma);
  • Inner ear disease
  • Claustrophobia;
  • Inability to perform awake brain MRI test;
  • Previous neurologic conditions (eg. Epilepsy, neuromuscular diseases, metabolic diseases, etc.);
  • Brain tumors;
  • Skull base fractures;
  • s/p neurosurgery that included: ventricular drainage, subdural hematomas drainage, epidural hematomas drainage, intracerebral hemorrhage evacuation. Depressed fracture surgery, (Patients suffering from Encephalomalacia per MRI imaging will not be excluded).
  • Inability to provide informed consent

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: Crossover Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Hyperbaric oxygen therapy
60 daily hyperbaric oxygen treatment sessions will be administrated 5 days per week. Each session will include exposure of 90 minutes to 100% at 2 ATA, with 5 minutes air breaks every 20 minutes Crossover: After 3 months of either pharmaceuitical or HBOT, once the 2nd evaluation is completed, all patients in both groups will be offered to switch to the alternative treatment group.
60 HBOT sessions at 2 ATA 100% oxygen
Active Comparator: Pharmacotherapy

patients will be offered pharmacological treatment with one of the two medications currently licensed for the treatment of FMS in Israel, i.e. Cymbalta and Lyrica. Treatment with Lyrica will start at a dose of 75 mg at bedtime while treatment with Cymbalta will start at a dose of 30 mg a day (in the morning). After a period of 6 weeks patients will be evaluated and dose will be adjusted as necessary. Patients may also be switched from one medication to the other based according to clinical judgment.

Crossover: After 3 months of either pharmaceuitical or HBOT, once the 2nd evaluation is completed, all patients in both groups will be offered to switch to the alternative treatment group.

60 HBOT sessions at 2 ATA 100% oxygen after crossover
one of the two medications currently licensed for the treatment of FMS in Israel, i.e. Cymbalta and Lyrica.
Other Names:
  • Cymbalta / Lyrica

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Visual analogue Scale (VAS)
Time Frame: at 3 months
The primary end point of the study will be the measurement of daily pain on a (0-10) Visual analogue Scale
at 3 months
Visual analogue Scale (VAS)
Time Frame: at 6 months
The primary end point of the study will be the measurement of daily pain on a (0-10 scale) Visual analogue Scale
at 6 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Global Pain Scale (GPS)
Time Frame: baseline, at 3 months, at 6 months
Fibromyalgia syndrome symptoms questionnaire named Global Pain Scale (GPS) questionnaire (0-100 scale)
baseline, at 3 months, at 6 months
Patient global impression of change
Time Frame: baseline, at 3 months, at 6 months
Fibromyalgia syndrome symptoms questionnaire named: Patient global impression of change (yes/no)
baseline, at 3 months, at 6 months
Fibromyalgia Impact Questionnaire
Time Frame: baseline, at 3 months, at 6 months
Fibromyalgia syndrome symptoms questionnaire named: Fibromyalgia Impact Questionnaire - FIQ (Hebrew version) (0-100 scale)
baseline, at 3 months, at 6 months
Wide Spread Pain Index
Time Frame: baseline, at 3 months, at 6 months
Fibromyalgia syndrome symptoms questionnaire named:Wide Spread Pain Index (WPI) Fibromyalgia syndrome symptoms questionnaire named:Wide Spread Pain Index (scale 0-19)
baseline, at 3 months, at 6 months
Symptom Severity Scale
Time Frame: baseline, at 3 months, at 6 months
Fibromyalgia syndrome symptoms questionnaire named:Symptom Severity Scale (SSS) (scale 0-12)
baseline, at 3 months, at 6 months
SF-36 questionnaire
Time Frame: baseline, at 3 months, at 6 months
Quality of life questionnaire named short-form 36 (SF-36) (scale 0-100)
baseline, at 3 months, at 6 months
Medical Outcome Sleep Scale
Time Frame: baseline, at 3 months, at 6 months
Sleep qualtiy questionnaire named: Medical Outcome Sleep Scale (MOS) questionnaire (0-100 scale)
baseline, at 3 months, at 6 months
Beck Depression Inventory
Time Frame: baseline, at 3 months, at 6 months
Depression questionnaire named Beck Depression Inventory (BDI-II) (scale 0-63)
baseline, at 3 months, at 6 months
EQ-5D
Time Frame: baseline, at 3 months, at 6 months
Quality of life questionnaire named EQ-5D (scale 0-25)
baseline, at 3 months, at 6 months
Cognitive function
Time Frame: baseline, at 3 months, at 6 months
The Mindstreams battery includes several cognitive tests devised to check various aspects of brain capabilities. In the current study we will evaluate the cognitive indices based on the scores of the 6 cognitive tests listed below, which are expected to be relevant for mild TBI. For detailed description of all cognitive tests in Mindstreams battery
baseline, at 3 months, at 6 months
Cerebral blood volume
Time Frame: baseline, at 3 months, at 6 months

Cerebral blood volume (in mililiter) will be measured using perfusion MRI protocol Dynamic susceptibility contrast (DSC).

• DSC: 50 T2*-weighted gradient-echo echo planar imaging (EPI) volumes will be acquired, 2 repetitions before a bolus injection of Gadolinium-DTPA (Gd-DTPA), 48 repetitions after injection of Gd-DTPA.

baseline, at 3 months, at 6 months
Cerebral blood flow
Time Frame: baseline, at 3 months, at 6 months

Cerebral blood volume (in mililiter/min) will be measured using perfusion MRI protocol Dynamic susceptibility contrast (DSC).

• DSC: 50 T2*-weighted gradient-echo echo planar imaging (EPI) volumes will be acquired, 2 repetitions before a bolus injection of Gadolinium-DTPA (Gd-DTPA), 48 repetitions after injection of Gd-DTPA.

baseline, at 3 months, at 6 months
Fractional anistropy
Time Frame: baseline, at 3 months, at 6 months

Brain microstructure imaging will evalute fractional anistropy (FA , scale 0-1 in each region of interest. The MRI protocol will include diffusion tensor imaging (DTI).

MRI sequence parameters:

• DTI: 30 diffusion weighted images will be scanned with different gradient directions (b=1000) and one volume without diffusion weighting

baseline, at 3 months, at 6 months
Mean diffusivity
Time Frame: baseline, at 3 months, at 6 months

Brain microstructure imaging will evalute mean diffusivity (MD, scale 0-1 in each region of interest. The MRI protocol will include diffusion tensor imaging (DTI).

MRI sequence parameters:

• DTI: 30 diffusion weighted images will be scanned with different gradient directions (b=1000) and one volume without diffusion weighting

baseline, at 3 months, at 6 months
Brain function imaging
Time Frame: baseline, at 3 months, at 6 months
Resting state fMRI(rsfMRI or R-fMRI)- a method of functional brain imaging that can be used to evaluate regional interactions that occur when a subject is not performing an explicit task. This resting brain activity is observed through changes in blood flow in the brain which creates what is referred to as a blood-oxygen-level dependent (BOLD) signal that can be measured using functional Magnetic Resonance Imaging (fMRI).
baseline, at 3 months, at 6 months
brain function imaging
Time Frame: baseline, at 3 months, at 6 months
Brain photon emission computed tomography (PET-CT) will be conducted using FDG.
baseline, at 3 months, at 6 months
Brain network analysis
Time Frame: baseline, at 3 months, at 6 months
EEG activity will be recorded at resting state , during performing cognitive tasks and following a trans-magnetic stimulation. EEG recording will be performed using a 64 electrodes cap.
baseline, at 3 months, at 6 months
Heat/Cold Pain threshold evaluation
Time Frame: baseline, at 3 months, at 6 months
Thermal pain is induced with thermal electrode (thermode). Thermode temperature will initially be set at 32.0°C and gradually increase at a rate of 0.3°C/sec. Participants will be instructed to report when the sensation produced by the thermode changed from heat sensation to pain (heat pain threshold) and when the pain became unbearable (heat pain tolerance). This procedure will be conducted twice for every subject and the mean of the two trials will be calculated. The thermode will be placed on adjacent areas of the forearm for every trial to avoid primary skin hyperalgesia.
baseline, at 3 months, at 6 months
Conditioned pain modulation
Time Frame: baseline, at 3 months, at 6 months
In the current study CPM efficiency will be evaluated by computing the difference in mean pain intensity induced by the Heat test-stimulus (HTS) before and during immersion of non-dominant hand to 10 degrees cold water (the Cold pressor test) (i.e., pain during pre-immersion HTS - pain during post-immersion HTS). Thus, effective pain inhibitory mechanisms are represented by higher (positive) values.
baseline, at 3 months, at 6 months
Physical activity
Time Frame: baseline, at 3 months, at 6 months
The daily physical activity will be objectively tracked by FitBit watch technology. The FitBit watch will be also wired during night for measurements of the time asleep, restless and awake, Fitbit trackers help you understand each night to make the most of each day
baseline, at 3 months, at 6 months
Exercise capacity
Time Frame: baseline, at 3 months, at 6 months
Participants will undergo exercise testing using a modified Balke treadmill protocol and continuous expired gas analysis. Resting and exercise vital signs will monitored continuously. The exercise duration and exercise-limiting symptoms will be recorded. The peak VO2, VCO2 and respiratory exchange ratio (RER) will be averaged over the last 15 seconds of the exercise test. The ventilatory equivalent (VE/VCO2 slope) will be calculated from start of exercise to the end of exercise.
baseline, at 3 months, at 6 months
Inflammatory cytokines
Time Frame: baseline, at 3 months, at 6 months
Blood Tests will include: IL-1, IL-6, Tumor necrosis factor-alpha, CRP.
baseline, at 3 months, at 6 months
CD4 number
Time Frame: baseline, at 3 months, at 6 months

CD4 number (cells per ml) .Using a 4-color FACS CD4 number will be evaluated. Isolation of peripheral blood mononuclear cells (PBMC) will be isolated using density gradient centrifugation and will behed 3 times in 1640 RPMI medium. Cells will be frozen in freezing medium and kept in liquid nitrogen until thawed for analysis.

PBMCs will be will behed twice in PBS with 3% FCS. 1X10^5 cells will be resuspended in 100 microliter PBS contatining CD4,CD8, CD25,CD28, CD56, CD16, CD3 conjugated colored antibodies.

baseline, at 3 months, at 6 months
CD8 number
Time Frame: baseline, at 3 months, at 6 months

CD8 number (cells per ml) .Using a 4-color FACS CD8 number will be evaluated. Isolation of peripheral blood mononuclear cells (PBMC) will be isolated using density gradient centrifugation and will behed 3 times in 1640 RPMI medium. Cells will be frozen in freezing medium and kept in liquid nitrogen until thawed for analysis.

PBMCs will be will behed twice in PBS with 3% FCS. 1X10^5 cells will be resuspended in 100 microliter PBS contatining CD4,CD8, CD25,CD28, CD56, CD16, CD3 conjugated colored antibodies.

baseline, at 3 months, at 6 months
CD4:CD8 ratio
Time Frame: baseline, at 3 months, at 6 months

CD4:CD8 number (ratio) .Using a 4-color FACS CD4:CD8 number will be evaluated. Isolation of peripheral blood mononuclear cells (PBMC) will be isolated using density gradient centrifugation and will behed 3 times in 1640 RPMI medium. Cells will be frozen in freezing medium and kept in liquid nitrogen until thawed for analysis.

PBMCs will be will behed twice in PBS with 3% FCS. 1X10^5 cells will be resuspended in 100 microliter PBS contatining CD4,CD8, CD25,CD28, CD56, CD16, CD3 conjugated colored antibodies.

baseline, at 3 months, at 6 months
CD8+CD28null
Time Frame: baseline, at 3 months, at 6 months

CD8+CD28null number (cells/ml) .Using a 4-color FACS CD8+CD28null number will be evaluated.

Isolation of peripheral blood mononuclear cells (PBMC) will be isolated using density gradient centrifugation and will behed 3 times in 1640 RPMI medium. Cells will be frozen in freezing medium and kept in liquid nitrogen until thawed for analysis.

PBMCs will be will behed twice in PBS with 3% FCS. 1X10^5 cells will be resuspended in 100 microliter PBS contatining CD4,CD8, CD25,CD28, CD56, CD16, CD3 conjugated colored antibodies.

baseline, at 3 months, at 6 months
Naïve B-Cells number
Time Frame: baseline, at 3 months, at 6 months

B cell number (cells/ml) .Using a 4-color FACS B cells number will be evaluated.

Isolation of peripheral blood mononuclear cells (PBMC) will be isolated using density gradient centrifugation and will behed 3 times in 1640 RPMI medium. Cells will be frozen in freezing medium and kept in liquid nitrogen until thawed for analysis.

PBMCs will be will behed twice in PBS with 3% FCS. 1X10^5 cells will be resuspended in 100 microliter PBS contatining CD4,CD8, CD25,CD28, CD56, CD16, CD3 conjugated colored antibodies.

baseline, at 3 months, at 6 months
CD4CD25 positive number
Time Frame: baseline, at 3 months, at 6 months

CD4CD25 cell number (cells/ml) .Using a 4-color FACS CD4CD25 number will be evaluated.

Isolation of peripheral blood mononuclear cells (PBMC) will be isolated using density gradient centrifugation and will behed 3 times in 1640 RPMI medium. Cells will be frozen in freezing medium and kept in liquid nitrogen until thawed for analysis.

PBMCs will be will behed twice in PBS with 3% FCS. 1X10^5 cells will be resuspended in 100 microliter PBS contatining CD4,CD8, CD25,CD28, CD56, CD16, CD3 conjugated colored antibodies.

baseline, at 3 months, at 6 months
Microbiome
Time Frame: baseline, at 3 months, at 6 months
Microbiome evaluation method: Using our cutting-edge facilities, 16S ribosomal RNA (rRNA) next-generation sequencing of fecal samples will be performed to identify bacteria present in the gut. 16S rRNA gene sequencing is a well-established method for studying phylogeny and taxonomy (the description, identification and evolutionary classification) of samples from complex microbial environments that are difficult to study.
baseline, at 3 months, at 6 months
Cognitive function - CANTAB
Time Frame: baseline, at 3 months, at 6 months
Patients' cognitive functions will be assessed by CANTAB computerized cognitive tests (Cambrdige cognition , England) [52]. The CANTAB is a semiautomated test battery which can be administered on a laptop PC and more recently has been modified for administration on a handheld tablet. The current release of CANTAB Eclipse comprises 25 tests designed to assess components of cognitive function which fall into 7 broad groups of tests: visual memory, executive function, working memory and planning, attention, semantic/verbal memory, decision making and response control, social cognition, and screening/familiarization.
baseline, at 3 months, at 6 months

Collaborators and Investigators

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

Investigators

  • Principal Investigator: Shai a Efrati, MD, Asaf-Harofhe MC

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)

March 1, 2017

Primary Completion (Actual)

June 1, 2022

Study Completion (Actual)

June 1, 2022

Study Registration Dates

First Submitted

October 19, 2017

First Submitted That Met QC Criteria

October 25, 2017

First Posted (Actual)

October 30, 2017

Study Record Updates

Last Update Posted (Actual)

April 22, 2026

Last Update Submitted That Met QC Criteria

April 19, 2026

Last Verified

April 1, 2026

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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