Predictors of Treatment Response to Stellate Ganglion Block in Cervical Radicular Pain

Summary

Purpose: Stellate ganglion block (SGB) is a procedure that uses ultrasound to guide a needle near a group of nerves in the neck called the stellate ganglion. A local anesthetic is then injected to block pain signals. This procedure has recently shown promise as a treatment for cervical radicular pain - pain that travels from the neck down into the arm, usually caused by a pinched nerve in the spine.

While SGB appears to be effective for many patients, not all patients respond equally well. Currently, there is no way to predict before the procedure which patients are likely to benefit and which are not. Identifying such predictors would help doctors select the right patients for this treatment and avoid unnecessary procedures.

Study Question: This study aimed to determine whether specific clinical characteristics or imaging findings on MRI could predict whether a patient would have a successful pain response after receiving SGB for cervical radicular pain.

Methods: This was a retrospective study that reviewed the medical records of patients who received ultrasound-guided SGB at a single medical center between October 2018 and April 2023. Patients were included if they had one-sided arm pain caused by a pinched nerve confirmed on MRI and had not improved after at least one month of standard treatments such as medication and physical therapy.

Information collected from medical records included patient age, sex, body mass index, presence of diabetes or hypertension, pain severity (measured on a 0-to-10 scale), duration of symptoms, and neck disability scores. Imaging findings from cervical MRI were also evaluated, including the degree of nerve compression, the cause of the compression (soft disc herniation versus bony overgrowth), the condition of the spinal canal, disc degeneration, and the amount of fatty changes in the small muscles along the back of the neck (called the multifidus muscles).

Hypothesis: The study hypothesized that certain imaging-based factors - specifically, significant fatty degeneration of the cervical multifidus muscles and bony overgrowth as the main cause of nerve compression - would be associated with a poorer response to SGB at 3 months after the procedure.

Conditions

• Radiculopathy, Cervical Region

Interventions

OTHER

Cervical multifidus fatty degeneration

Cervical multifidus fatty degeneration was assessed by evaluating the degree of fatty infiltration in the bilateral multifidus muscles at the C5-C6 level, which is a region noted for its high mechanical load and flexibility, rendering it susceptible to degenerative changes.T2-weighted axial MRI images were analyzed, and fatty infiltration of the cervical multifidus muscle was graded using the Goutallier classification as follows: grade 0 (no fat signal), grade 1 (minimal fat signal), grade 2 (more muscle than fat), grade 3 (equal amounts of fat and muscle), and grade 4 (more fat than muscle) (Fig. 1). For the analysis, cervical multifidus fatty degeneration was defined as minimal (Goutallier grades 0-1) or substantial (Goutallier grades 2-4).

OTHER

Primary etiology of foraminal stenosis

The primary etiology of foraminal stenosis was determined by differentiating between disc herniation and bony hypertrophy at the uncovertebral or facet joint, based on the more prominent lesion.

DRUG

Steroid use during stellate ganglion block

Use of dexamethasone 5 mg added to 6 mL of 1% lidocaine versus 1% lidocaine alone during ultrasound-guided stellate ganglion block, based on the treating physician's clinical decision.

OTHER

Other collected data

Other collected data included patient demographics, such as age, sex, body mass index, and comorbidities, including diabetes and hypertension, pre-procedural symptoms such as radicular pain with or without neck pain, neck disability index, pain duration, cervical curvature types, central stenosis grade, foraminal stenosis grade, and disc degeneration.

Sponsors & Collaborators

• Asan Medical Center

  lead OTHER

Eligibility

Min Age

19 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2024-10-08

Primary Completion

2025-09-15

Completion

2025-09-15

Countries

• South Korea

Study Locations