COMPRESSION OF THE DEEP BRANCH OF THE ULNAR NERVE BY AN INTRANEURAL CYST - CASE-REPORT

A cystic ganglion-like tumor which involved the substance of the motor branch of the ulnar nerve obviously caused paresis by intrinsic compression, in the patient described. Non-traumatic lesions causing paralysis of the motor branch of the ulnar nerve are well recognized but the condition is uncommon. In a review of 136 cases of compression of the ulnar nerve at and below the wrist, nineteen causes were listed, and thirty-nine cases were attributed to extrinsic compression by carpal ganglia. A ganglion-like lesion arising from within the motor branch of the ulnar nerve and causing paralyis has not been reported previously.