The nerve of Henlé.

The nerve of Henlé, a branch of the ulnar nerve in the forearm, is thought to deliver sympathetic innervation to the ulnar artery. Forty cadaver forearms were dissected under magnification. Two distinct patterns of the nerve were found. In the typical pattern, 18 (45%) of 40 extremities, the nerve originates 16 cm proximal to the ulnar styloid, travels distally with the ulnar artery, and frequently, 13 (72%) of 18, branches to pierce the superficial fascia 6 cm proximal to the ulnar styloid and innervate the skin of the distal ulnar forearm. In the atypical pattern (12%), the nerve originates in the distal 8 cm of the forearm and travels briefly with the ulnar artery before branching to the skin. The palmar cutaneous branch of the ulnar nerve was absent in cadavers with the nerve of Henlé and may be a distal variant of that nerve.