Cervical syringomyelia after multi-level zygapophyseal joint injections: a case report

Zygapophyseal (ZA) joint Injections are performed to diagnose and treat axial spine pain. Though generally well-tolerated, serious complications have been described. We report a case of a 34 year-old female with syringomyelia after multi-level cervical ZA joint injections. Her history was remarkable for cervical radiculopathy and degenerative disc disease that required surgical decompression and fusion two years prior. She presented to our interdisciplinary clinic with opioid dependency and upper extremity neuropathic pain. Previously, she had received multiple injections under general anesthesia by another practitioner. On a particular visit, her right C2-3, C3-4, C4-5, C5-6, C6-7, C7-T1 ZA joints, C1, C2, C3, C4, C5, C6, C7 spinous processes, right acromio-clavicular joint, and bilateral sacroiliac joints. For her ZA injections a 22 gauge 2 ½ inch Chiba needle was used to instill 0.2 mL of bupivacaine 0.25% plus 2mg/ml of triamcinolone solution at each level. Post procedure, the patient complained of right upper extremity pain and weakness. MRI demonstrated a thin syrinx in the right paramedian spinal cord extending from the C3 to C6 level that was not present on previous imaging. No surgical intervention was undertaken. A follow up MRI showed mild progression in cavitation. Many factors may have contributed to this injury. A needle entering the spinal cord may not cause persistent pain or injury unless medication is injected. In her case, general anesthesia prevented any reactive indications of intramedullary trespass. It is unclear whether utilization of contrast would have prevented this outcome. Additionally, multiple injections eliminate any diagnostic utility and potentiate risk for anesthetic toxicity. In her case, successful medial branch blockade followed by radiofrequency neurotomy may have been more appropriate in lieu of monthly intra-articular injections. Clinicians should minimize risk factors for catastrophic outcome, including injecting under general anesthesia, frequent and extensive injections, and sub-optimal use of fluoroscopy.