Neuralgic amyotrophy with phrenic nerve involvement

Phrenic nerve involvement is a rare feature in patients with neuralgic amyo trophy (Parsonage-Turner syndrome). We report four patients who initially p resented with severe dyspnea in the absence of lung disease. All patients h ad a history of infectious disease or surgery and of pain of sudden onset i n the shoulder region. Weakness of the proximal arm was observed in only on e. Radiographic and pulmonary function studies, phrenic nerve conduction st udies, and needle electromyogram (EMG) of the diaphragm documented diaphrag matic paralysis which was unilateral in one patient, bilateral in two patie nts, and recurrent on alternating sides in another one. Follow-up studies r emained abnormal for up to 4 years. Neuralgic amyotrophy with phrenic nerve involvement should be considered in patients presenting with severe, unexp lained dyspnea of sudden onset. (C) 1999 John Wiley & Sons, Inc.