Respiratory distress: an unrecognized non-motor phenomenon in patients with parkinsonism.

Although respiratory abnormalities are associated with parkinsonism, patients rarely complain of dyspnea. This study describes ten patients with parkinsonism and symptoms of dyspnea and respiratory distress that were unexplained by a pulmonary or cardiac abnormality or a psychological problem. Suggested underlying mechanisms are a central pathology affecting respiratory rhythm generation at the brainstem or lack of coordination of the respiratory muscles causing involuntary movements of the diaphragm. Dyspnea and respiratory distress should be included among the non-motor symptoms of parkinsonism.