Ulnar nerve neuropathy at the wrist.

Thirteen cases of ulnar nerve neuropathy at the wrist are presented. They include four cases of pure motor paresis affecting the ulnar-innervated intrinsic muscles, one case of pure sensory deficit and eight cases of mixed motor and sensory deficiency. A cyst was revealed by preoperative ultrasonography in two cases and by computerized tomography in one of them. The cause of ulnar nerve neuropathy was a tumor or tumor-like mass in six cases, long-time cycling in three cases and unknown in three cases. Surgery was performed in ten cases. Recovery of the nerve palsy was obtained in all except one case.