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.
Study Type
OBSERVATIONAL
Enrollment
90
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).
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.
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 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.
Asan Medical Center
Seoul, South Korea
Successful response
Successful response was defined as either a reduction of ≥4 points on the numerical rating scale or a ≥50% decrease in pain intensity at 3 months post-procedure.
Time frame: At 3 months post-procedure
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.