A rare presentation of Horner's syndrome following cervical epidural steroid injection.

Horner's syndrome is a clinically significant condition caused by disruption of the oculosympathetic nerve pathway, typically presenting with ptosis, miosis, and facial anhidrosis. It can result from serious, life-threatening conditions such as trauma, carotid artery dissection, or malignancy; however, it may also arise from iatrogenic reasons, including stellate ganglion blocks, by other surgical interventions of the head and neck. While exceedingly rare, Horner's syndrome has been reported to occur after a cervical epidural steroid injection. Given the various potential etiologies of Horner's syndrome, prompt evaluation is required to rule out life-threatening conditions in the setting of an acute and unexpected presentation. This case study describes a presentation of Horner's syndrome following a cervical epidural steroid injection (ESI) for a cervical radiculopathy. Due to the unusual nature, a serious cerebrovascular event was initially considered and urgent evaluation was advised. Fortunately, all symptoms resolved fully within two hours without medical intervention. It has been suggested that local anesthetic diffusion to the preganglionic neurons caused pharmacologic disruption of the sympathetic fibers. This case provides additional evidence to the limited reports of Horner's syndrome after cervical epidurals. It also highlights the importance of minimizing or forgoing local anesthetics, considering non-particulate steroids, and conducting emergent evaluation for new onset of neurological deficits during or after cervical ESIs.