Paralysis of the ulnar nerve at the wrist associated with aneurysmal dilatation of the ulnar artery

The authors report a case of paralysis of the ulnar nerve at the wrist associated with causalgia due to aneurysmal dilatation of the ulnar artery. The most frequent cause is trauma or arteritis. Furthermore, arteriosclerosis may weaken the vascular wall, causing an aneurysmal dilatation of the vessel and damage to the ulnar nerve owing to tenacious adhesion existing between the vessel and the nerve. The authors recommend conservative treatment of the aneurysm and the accurate neurolysis of the adhesions.