Lateral antebrachial cutaneous neuropathy after steroid injection at lateral epicondyle.

BACKGROUND AND OBJECTIVES: This report aimed to present a case of lateral antebrachial cutaneous neuropathy (LACNP) that occurred after a steroid injection in the lateral epicondyle to treat lateral epicondylitis in a 40-year-old woman.

MATERIAL AND METHOD: A 40-year-old woman presented with decreased sensation and paresthesia over her right lateral forearm; the paresthesia had occurred after a steroid injection in the right lateral epicondyle 3 months before. Her sensation of light touch and pain was diminished over the lateral side of the right forearm and wrist area.

RESULTS: The sensory action potential amplitude of the right lateral antebrachial cutaneous nerve (LACN) (6.2 μV) was lower than that of the left (13.1 μV). The difference of amplitude between both sides was significant because there was more than a 50% reduction. She was diagnosed with right LACNP (mainly axonal involvement) on the basis of the clinical manifestation and the electrodiagnostic findings. Her symptoms improved through physical therapy but persisted to some degree.

CONCLUSION: This report describes the case of a woman with LACNP that developed after a steroid injection for the treatment of lateral epicondylitis. An electrodiagnostic study, including a nerve conduction study of the LACN, was helpful to diagnose right LACNP and to find the passage of the LACN on the lateral epicondyle.