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Electrodiagnostic testing, which includes electromyography and nerve conduction studies, can be used to confirm the diagnosis of ulnar neuropathy, locate the location of pathological ulnar nerve compression and differentiate between mononeuropathy, polyneuropathy, plexopathy, and radiculopathy. This activity describes the invaluable role of electrodiagnosis in ulnar neuropathy and highlights the role of an interprofessional team in evaluating and treating patients with ulnar neuropathy. Objectives: Identify the indications for electrodiagnostic testing in ulnar neuropathy. Assess the nerve conduction findings in a patient with ulnar neuropathy. Assess the electromyographic findings in a patient with ulnar neuropathy. Implement communications strategies among the interdisciplinary team to enhance care delivery for patients with ulnar neuropathy. Access free multiple choice questions on this topic.

The ulnar nerve is a sensorimotor nerve that arises from the lower trunk of the brachial plexus and converts into the medial cord, further diving into fibers of C8 and T1. It provides motor innervation to the intrinsic hand muscles, except the flexor carpi ulnaris, the flexor digitorum profundus medially, the thenar, and the lumbrical muscles. The ulnar nerve also provides sensory innervation to the medial aspect of the forearm, wrist, fourth digit, and the entire fifth digit. In the clinical setting, the typical patient presentation includes pain, numbness, paresthesia, and the fifth digit and medial aspect of the fourth digit. These symptoms can often be exacerbated by elbow flexion, especially while sleeping. If the neuropathy is more severe, patients may complain of hand weakness and frequent dropping of objects.[1] Intrinsic hand muscle atrophy may also be seen, especially of the first dorsal interosseus. A weak abductor digiti minimi and positive Froment sign indicate ulnar neuropathy. When testing for the Froment sign, the patient is asked to grasp a piece of paper between the first and second digits while the examiner attempts to pull the paper from the patient's grasp. The Froment sign is considered positive if there is noticeable hyperflexion at the interphalangeal joint of the flexor pollicis longus, which is a compensatory mechanism for a weakened adductor pollicis longus.[2] The Wartenberg sign is used to assess the motor weakness of the ulnar nerve. In this test, the patient is instructed to fully adduct their fingers with the metacarpophalangeal joint, proximal interphalangeal, and distal interphalangeal joints in full extension. If it is found that the small finger drifts away from the others into abduction, this is known as a positive Wartenberg sign.[3]

Ulnar neuropathy is a relatively common condition seen in the outpatient clinical setting. A thorough history and physical examination are vital in determining the diagnosis. Electrodiagnostic studies can be used by primary care physicians, physiatrists, and neurologists to aid in confirming the diagnosis. If conservative measures, such as anti-inflammatory medications and bracing or splinting, are unsuccessful, orthopedic surgical intervention may be indicated. Ultrasound-guided nerve blocks can also be performed in the ulnar nerve distribution, complete hand blocks, and brachial plexus blocks.[10] Physical and occupational therapists can also help patients perform daily living activities and improve functionality. Effective collaboration amongst the various disciplines is necessary to ensure the best possible outcome for patients.