Left Hemi-Diaphragmatic Paralysis After Left Cervical Transforaminal Epidural Steroid Injection of the C5-C6 Level

Background: Cervical radiculopathy is a common cause of neck pain with radiation into the upper extremity in a dermatomal pattern. The age-adjusted incidence is 83.2 per 100,000 persons per year. The most common causes are vertebral spondylosis and intervertebral disc herniation. Corticosteroid injection is a conservative management option with a low risk of major adverse events. Adverse events could include epidural hematoma, infection, allergic reactions, seizures, nerve damage, or intravascular injections. No reviewed literature or case reports have indicated phrenic nerve injury secondary to cervical transforaminal epidural steroid injection (TFESI). Case Presentation: A 45-year-old male physician with severe left C6 radiculopathy secondary to a large left-sided C5-C6 herniated intervertebral disc presented to the neurosurgical clinic. The patient underwent a left side C6 TFESI. Immediately upon awakening from anesthesia, the patient experienced shortness of breath. A Sniff test demonstrated the patient had left diaphragmatic paralysis. Six weeks later, the patient underwent a C5-C6 anterior cervical discectomy and fusion with complete relief of his radicular symptoms. The left hemi-diaphragmatic paralysis remained at the one-year postoperative visit. Conclusion: A thorough literature review shows no indication of phrenic nerve injury with cervical TFESI. In the current study, we explore the suspected mechanisms of possible injury to the phrenic nerve. Epidural corticosteroid injection is a viable and safe option for conservative management of cervical radiculopathy. This report unveils a unique and important adverse event that should be held in consideration before undergoing a cervical TFESI.