what is it called when the ulnar nerve takes over for the damaged median nerve
Back to TopCauses. Damage to one nerve group, such as the ulnar nerve, is called a mononeuropathy. Mononeuropathy means there is nerve damage to a single nerve. Both local and body-wide disorders may damage just one nerve. Ulnar neuropathy occurs when there is damage to the ulnar nerve, which travels down the arm. The ulnar nerve is near the surface of the body where it crosses the elbow. The damage destroys the nerve covering (myelin sheath) or part of the nerve (axon). This damage slows or prevents nerve signaling.