Distal ulnar neuropathy. Clinical and electrophysiologic aspects.

Nine patients with distal ulnar neuropathy were studied. Weakness of the hand muscles was the only abnormality in six patients; abnormal sensation was present in two patients. The cause was known in seven patients: chronic "occupational" nerve compression occurred in three meat packers and two long-distance bicyclists--acute blunt trauma to the palm of the hand in two patients. Our study indicates that electromyographic abnormalities in distal ulnar neuropathy are more variable than reported. The electromyographic findings indicated predominant axonal degeneration of motor nerve fibers, contrasting also to electromyographic abnormalities seen in entrapment neuropathies. The reasons for these differences are discussed.