Ultrasound-Guided Stellate Ganglion Block in Fibromyalgia

Ultrasound-Guided Stellate Ganglion Block in Fibromyalgia: A Randomized, Single-Center, Single-Blind, Sham-Controlled Trial

This study evaluates the efficacy and safety of ultrasound-guided stellate ganglion block (SGB) as an adjunctive treatment for patients with treatment-resistant fibromyalgia. Patients who continue to experience significant symptoms despite stable duloxetine therapy (60 mg/day) were randomized to receive either ultrasound-guided SGB or a sham control procedure. The study aims to determine if SGB can provide clinically meaningful improvements in fibromyalgia impact and pain intensity compared to a sham injection.

Study Overview

• Status: Completed
• Conditions: Fibromyalgia
• Intervention / Treatment: Drug: Lidocaine and Dexamethasone; Other: Normal Saline

Detailed Description

This is a single-center, randomized, single-blind, sham-controlled trial conducted at Sanliurfa Education and Research Hospital.

Participants: Adults aged 18-65 years diagnosed with fibromyalgia (2016 ACR criteria) who have been receiving a stable dose of duloxetine 60 mg/day for at least 4 weeks but remain symptomatic.

Procedures: Participants were randomized 1:1 to either the SGB group or the sham control group.

SGB Group: Received ultrasound-guided stellate ganglion block at the C7 level using a mixture of 8 mg dexamethasone and 2 mL of 2% lidocaine (diluted to 7 mL with saline).

Sham Group: Received an intramuscular injection of 2 mL normal saline into the sternocleidomastoid muscle under ultrasound guidance.

Both groups received two procedures, performed one week apart. All patients continued their fixed-dose duloxetine throughout the study.

Assessments: The primary outcome is the change in the FIQR total score from baseline to 1 week. Secondary outcomes include FIQR changes at 1 month, pain intensity (NRS), and responder rates. This is a single-blind study where only the participants were blinded to the intervention.

• Study Type: Interventional
• Enrollment (Actual): 68
• Phase: Phase 2; Phase 3

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Şanlıurfa
    • Sanliurfa, Şanlıurfa, Turkey (Türkiye), 63290
      • Sanliurfa Education and Research Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Diagnosis of Fibromyalgia Syndrome (FMS) according to the 2016 American College of Rheumatology criteria.
• Followed for at least 1 year with insufficient benefit from previous pharmacological and/or non-pharmacological treatments.
• Receiving a stable dose of duloxetine 60 mg once daily for at least 4 weeks prior to inclusion.
• Willingness to continue the fixed dose of duloxetine throughout the study.
• Aged between 18 and 65 years.

Exclusion Criteria:

• Non-pharmacological treatments within the previous 6 months (e.g., acupuncture, ozone therapy, cognitive behavioral therapy).
• Local infection at the injection site.
• Pregnancy or suspected pregnancy.
• Known allergy to local anesthetics.
• History of malignancy.
• Bleeding or coagulation disorders or use of oral anticoagulants.
• Uncontrolled hypertension, diabetes mellitus, asthma, chronic obstructive pulmonary disease, or heart failure.
• Psychiatric or cognitive disorders that could interfere with treatment compliance (e.g., severe psychiatric illness, dementia).
• Refusal of interventional treatment.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Stellate Ganglion Block; Participants in this group received two ultrasound-guided stellate ganglion blocks at the C7 level, performed one week apart. Under real-time ultrasound guidance, a 22-gauge spinal needle was advanced to the stellate ganglion region. Following negative aspiration, a 7 mL mixture containing 8 mg of non-particulate dexamethasone and 2 mL of 2% lidocaine (diluted with normal saline) was injected. Success was clinically confirmed by the development of ipsilateral Horner syndrome.	Drug: Lidocaine and Dexamethasone; A mixture of 2 mL of 2% lidocaine and 8 mg of non-particulate dexamethasone, diluted with normal saline to a total volume of 7 mL. Administered via ultrasound-guided injection at the C7 level. Two doses in total, with a one-week interval.; Other Names: Lidocaine Hydrochloride, Dexamethasone Sodium Phosphate
Sham Comparator: Sham Control; Participants in this group underwent the same preparation, positioning, and ultrasound imaging as the intervention group to maintain blinding. They received two sham procedures, performed one week apart. In each procedure, 2 mL of normal saline was injected intramuscularly into the sternocleidomastoid muscle in a region distant from the stellate ganglion. This procedure replicated the needle insertion and ultrasound application without affecting the sympathetic nerves.	Other: Normal Saline; 2 mL of 0.9% normal saline administered via intramuscular injection into the sternocleidomastoid muscle. Two doses in total, with a one-week interval.; Other Names: 0.9% Sodium Chloride, Placebo

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Fibromyalgia Impact Questionnaire Revised (FIQR) Total Score	The FIQR is a 21-item validated instrument that assesses the overall impact of fibromyalgia on physical function, overall impact, and symptoms. Total score ranges from 0 to 100, with higher scores indicating greater disease impact. Change from baseline to 1 week is the primary endpoint.	Baseline to 1 week after the first injection

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in FIQR Total Score at 1 Month	Change in FIQR total score from baseline to 1 month (3 weeks after the second injection).	Baseline to 1 month
Change in Numerical Rating Scale (NRS) Pain Score	Pain intensity over the previous week assessed using an 11-point NRS (0 = no pain, 10 = worst pain imaginable). Change from baseline to 1 week and 1 month.	Baseline, 1 week, and 1 month
FIQR Responder Rates (≥30% and ≥50% Improvement)	Percentage of patients achieving at least 30% and at least 50% reduction in FIQR total score from baseline.	1 week and 1 month

Collaborators and Investigators

• Sponsor: Sanliurfa Education and Research Hospital
• Investigators: Principal Investigator: yagmur Dadakci, Sanliurfa Education and Research Hospital

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2025
• Primary Completion (Actual): December 25, 2025
• Study Completion (Actual): December 25, 2025

Study Registration Dates

• First Submitted: January 6, 2026
• First Submitted That Met QC Criteria: January 6, 2026
• First Posted (Estimated): January 15, 2026

Study Record Updates

• Last Update Posted (Estimated): January 16, 2026
• Last Update Submitted That Met QC Criteria: January 14, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Nervous System Diseases; Muscular Diseases; Neuromuscular Diseases; Rheumatic Diseases; Fibromyalgia; Organic Chemicals; Pharmaceutical Preparations; Polycyclic Compounds; Anilides; Amides; Aniline Compounds; Amines; Acetanilides; Inorganic Chemicals; Chlorine Compounds; Pregnadienes; Pregnanes; Steroids; Fused-Ring Compounds; Steroids, Fluorinated; Crystalloid Solutions; Isotonic Solutions; Solutions; Pregnadienetriols; Sodium Compounds; Chlorides; Hydrochloric Acid; Dexamethasone; Lidocaine; Saline Solution; dexamethasone 21-phosphate; Sodium Chloride
• Other Study ID Numbers: HRU-25-1-30

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be publicly shared to protect participant privacy. De-identified data may be made available from the corresponding author upon reasonable request and with appropriate institutional approvals.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No