Right hemidiaphragmatic paralysis after cervical transforaminal epidural steroid injection: illustrative case

BACKGROUND: Cervical radiculopathy is a common cause of neck pain, with radiation into the upper extremity in a dermatomal pattern. Corticosteroid injection is a conservative management option with a low risk of major adverse events. No reviewed literature or case reports have implicated phrenic nerve injury secondary to cervical transforaminal epidural steroid injection (CTFESI). OBSERVATIONS: A 45-year-old man with severe right C6 radiculopathy secondary to a large right-sided C5–6 herniated intervertebral disc presented to the pain management clinic, where he received a right-sided C6 CTFESI. An hour after injection, the patient experienced shortness of breath, which was found to be caused by right diaphragmatic paralysis. The patient underwent a C5–6 anterior cervical discectomy and fusion, which provided complete relief of his radicular symptoms. However, the right hemidiaphragmatic paralysis remained at the 1-year postoperative visit. LESSONS: Thorough literature review showed no established explanations for phrenic nerve injury after CTFESI. In this study, the authors explored the suspected mechanisms of possible injury to the phrenic nerve. Epidural corticosteroid injection is considered to be a safe option for conservative management of cervical radiculopathy. This study unveiled a unique and important adverse event that should be considered before a patient receives CTFESI.