Severe asthma complicated by bilateral diaphragmatic paralysis attributed to Parsonage-Turner syndrome.

Progressive dyspnea that developed in a 52-year-old woman with a lifelong history of asthma did not respond to high-dose orally administered glucocorticoids. Initially, a diagnosis of allergic bronchopulmonary aspergillosis or hypersensitivity pneumonia was suggested as the cause of the worsening dyspnea. Pulmonary function tests demonstrated severe airway obstruction; substantial improvement was noted after bronchodilator therapy. Maximal inspiratory pressure was decreased, and the diffusing capacity of the lungs was abnormal. Computed tomography of the chest showed no parenchymal or mediastinal abnormalities. During a sniff test, fluoroscopy of her diaphragm disclosed paradoxical motion of both hemidiaphragms during inspiration, consistent with bilateral hemidiaphragmatic paralysis. Parsonage-Turner syndrome was diagnosed. The dose of glucocorticoids was tapered. Follow-up of the patient by telephone contact in March 1994 (9 months after her initial examination at our clinic) revealed that the dyspnea was still severe.