Clinical Outcomes of Magnesium Sulfate in Cervical Interlaminar Epidural Steroid Injection

This single-center, comparative retrospective observational cohort study will evaluate adults who underwent cervical interlaminar epidural steroid injection for chronic cervical radicular pain between January 1 and July 1, 2026. Participants will be classified according to the injection protocol received during routine clinical care: lidocaine, dexamethasone, and normal saline, or lidocaine, dexamethasone, and magnesium sulfate. The injection protocol was selected by the treating physician as part of routine clinical practice and was not assigned by the investigators.

Pain intensity will be evaluated using Numeric Rating Scale scores recorded before the procedure and at 1 hour, 3 weeks, and 3 months after the procedure. Neck-related disability and health-related quality of life will be evaluated using Neck Disability Index and Short Form-12 scores recorded before the procedure and at 3 weeks and 3 months.

All study data will be obtained retrospectively from existing electronic medical records, archived patient files, and routine clinical follow-up records. No prospective data collection, study-specific medication, treatment allocation, dose modification, procedure, test, or additional follow-up visit will be performed.

The study aims to determine whether the magnesium sulfate-containing protocol was associated with greater improvement in pain, neck-related disability, and health-related quality of life during the 3-month follow-up period compared with the standard protocol.

Inclusion criteria

• Adults aged 18 to 75 years
• Diagnosis of cervical disc herniation associated with chronic cervical radicular pain
• Underwent cervical interlaminar epidural steroid injection
• Availability of pre-procedure and 1-hour post-procedure Numeric Rating Scale scores
• Availability of baseline and 3-week Neck Disability Index and Short Form-12 assessments
• Availability of the 3-month routine follow-up assessment
• Documented injection protocol: standard protocol or magnesium sulfate-containing protocol

Exclusion criteria

• Cervical pain primarily attributable to a condition other than cervical radiculopathy
• Previous cervical spine surgery
• Cervical pain associated with malignancy, infection, trauma, or inflammatory disease
• Advanced neurological deficit or clinical findings of myelopathy
• Receipt of another interventional pain procedure during the same follow-up period
• Missing pre-procedure or 1-hour post-procedure Numeric Rating Scale data
• Missing baseline, 3-week, or 3-month Neck Disability Index or Short Form-12 data
• Unavailable or inadequately documented injection content or treatment protocol