Snapshot A 36-year-old man presents to his primary care physician due to hand weakness. He reports that his symptoms are accompanied by "tingling" of the 4th and 5th digits. He says that his symptoms worsen when placing the phone to his ear for a long period of time or resting on his elbow. He does not recall any trauma to the wrist or elbow but reports elbow pain. His social history is significant for working as a construction worker. On physical exam, the patient has decreased grip strength on the right arm, as well as a decreased sensation on the 4th and 5th digit. Introduction Anatomy the ulnar nerve arises from the C8 and T1 anterior rami of the brachial plexus above the elbow login to view 1 more bullet at the elbow login to view 1 more bullet at the forearm login to view 7 more bullets at the wrist login to view 8 more bullets in the hand login to view 1 more bullet Ulnar Neuropathies Ulnar Neuropathies Location Etiology Presentation Elbow Injury to the medial epicondyle Compression in the cubital tunnel cubital tunnel syndrome Paralysis of the flexor carpi ulnaris flexor digitorum profundus (medial half) interossei impaired abduction and adduction lumbricals (medial two) weakened movement of the 4th and 5th digit Sensory impairment in all regions supplied by the ulnar nerve Unable to grip paper when placed between the fingers Wrist Laceration of the wrist Paralysis of the interossei impaired abduction and adduction lumbricals (medial two) weakened movement of the 4th and 5th digit Unable to grip paper when placed between the fingers Ulnar claw Sensory impairment of the palmar and superficial branches palmar side of the medial one and half fingers (5th and 1/2 of 4th digit) preservation of the dorsal branch