Parsonage-Turner is a clinically defined syndrome that is easily confused with other neck and upper extremity abnormalities. Affected patients present with a characteristic pattern of sudden and acute pain across the top of the shoulder, lasting a few hours to a fortnight, followed by flaccid paralysis of some muscles of the shoulder girdle. Features supporting strongly diagnosis of Parsonage-Turner disease include:
-discrepancy for muscles wasting and denervation between muscles innervated by the same nerve;
-patchwork distribution of muscles denervation for muscles that are innervated by several nerves or nerve trunk arising from the brachial plexus;
-dissociation between sparing of the sensory nerve action potential and muscles denervation depending from the same mixed nerves.
The incidence has been estimated at approximately 1.64 in 100,000, with a peak rate between the third and fifth decades and a slight male predominance. Although different precipitating factors, such as infection, trauma, surgery, immunization, and autoimmune mechanisms, have been suspected and incriminated in the occurrence of Parsonage-Turner syndrome, the etiology remains unknown. Prognosis is generally favorable, with about 75% of complete recovery within 2 years. Treatment is symptomatic and is based on analgesic drugs and physical therapy. *Author: Dr I. Kolev (July 2004)*.