部位診断が困難であった尺骨神経麻痺の一例

抄録

We report a case of ulnar nerve palsy with multiple lesions. A fifty-six-year-old man was admitted due to intrinsic muscle atrophy of the right hand and hypesthesia of the ulnar two fingers. Preoperative examination revealed three lesions; cervical spine, cubital tunnel and the canal of Guyon. We found marked degeneration of the ulnar nerve at the elbow, and furthermore, an anomalous muscle in the canal of Guyon. The ulnar nerve was compressed by this muscle in this canal. This muscle originated from palmaris longus tendon and attached to hypothenar muscle.
Preoperatively, it was difficult to determine the main lesion of the ulnar nerve, In EMG examination, there were delayed terminal latency at the canal of Guyon and decreased MCV at the elbow joint. Electrophysiological examination was very useful to decide an operation field.