Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 24-30: Mononeuropathies + Key Features Download Section PDF Listen +++ ++ Occurs commonly in the elbow where the nerve runs behind the medial epicondyle and descends into the cubital tunnel In the condylar groove, the ulnar nerve is exposed to pressure or trauma Any increase in the carrying angle of the elbow, whether congenital, degenerative, or traumatic, may cause excessive stretching of the nerve when the elbow is flexed May also result from thickening or distortion of the anatomic structures forming the cubital tunnel, and the resulting symptoms may be aggravated by flexion of the elbow because the tunnel is then narrowed by tightening of its roof or inward bulging of its floor May also develop at the wrist or in the palm of the hand, usually owing to repetitive trauma or to compression from ganglia or benign tumors + Clinical Findings Download Section PDF Listen +++ ++ Sensory changes in the fifth and medial half of the fourth digits and along the medial border of the hand Weakness of the ulnar-innervated muscles in the forearm and hand With a cubital tunnel lesion, there may be relative sparing of the flexor carpi ulnaris muscle Lesions at the wrist or palm cause weakness, sensory deficits, or both, restricted to the hand + Diagnosis Download Section PDF Listen +++ ++ Electrophysiologic evaluation using nerve stimulation techniques allows precise localization of the lesion + Treatment Download Section PDF Listen +++ ++ Initial treatment Avoid pressure on the medial elbow (eg, avoid resting the elbows on arm rests; pad the elbow during sleep) Prevent prolonged elbow flexion, especially at night; splints are available to keep the elbow from flexing beyond 45 to 90 degrees If repetitive mechanical trauma is responsible, this is avoided by occupational adjustment or job retraining If conservative measures are unsuccessful in relieving symptoms and preventing further progression, surgical treatment consists of nerve transposition if the lesion is in the condylar groove or a release procedure if it is in the cubital tunnel