Disclosures: Justin X. Tu, MD: No financial relationships or conflicts of interest

Case Description: The patient presented to University Hand Center with persistent right hand numbness, tingling, and pain. His carpal tunnel releases, performed at a community hospital, had not provided any relief. On physical exam, the patient was noted to have decreased sensation to light touch in the median nerve distribution. The patient was referred for electrodiagnostic studies.

Setting: EMG clinic.

Patient: A 77-year old male with history of two right-sided carpal tunnel releases over the past year. Assessment/

Results: Nerve conduction studies of the right upper extremity were notable for partial motor conduction block of the median nerve in the forearm and absent right median sensory nerve action potentials. Electromyography was notable for enlarged polyphasic motor unit action potentials in the right abductor pollicis brevis, flexor digitorum superficialis, and flexor pollicis longus. These findings were indicative of a right median neuropathy in the proximal forearm, consistent with pronator teres syndrome. The patient deferred surgical decompression and was referred to occupational therapy, and treatment included deep tissue massage and nerve glides. The patient experienced improved sensation and reduced pain, resulting in an increased ability to perform leisure activities. He did not seek additional treatment or repeat electrodiagnostic testing.

Discussion: Pronator syndrome is a compression neuropathy of the median nerve at the elbow. It is rare compared to compression at the wrist and is often misdiagnosed clinically as carpal tunnel syndrome. Conservative management includes avoidance of provocative activity, splinting, and physical therapy. Surgical decompression can be pursued in refractory cases.

Conclusion: While focal entrapment neuropathy at the carpal tunnel is by far the most common cause of median nerve dysfunction, it is important to recognize the possibility of a more proximal median neuropathy. Electrodiagnostic testing is essential in making the diagnostic distinction and is indicated prior to initiating surgical treatment.

Level of Evidence: Level V

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PM&R Meeting Abstracts - https://pmrjabstracts.org/abstract/median-neuropathy-refractory-to-carpal-tunnel-release-a-case-report-of-pronator-teres-syndrome/