Peripheral dystonia.

We studied four patients with distal, action-induced involuntary postures of the hand that could be considered focal dystonia. All four patients had electrophysiologic findings consistent with peripheral nervous system lesions (pronator teres syndrome, radial nerve palsy, lower brachial plexus lesion, or median nerve lesion). With varying success, patients were treated with carbamazepine, trihexyphenidyl, methocarbamol, and wrist splinting. We wish to emphasize that peripheral entrapment and brachial plexopathy should be added to the causes of secondary dystonias.