AIRWAY DYSFUNCTION IN PATIENTS WITH PARKINSONS-DISEASE

To investigate pulmonary function abnormalities in Parkinson's disease (PD), we obtained maximal inspiratory and expiratory flow-volume curv es in 63 patients (59 under treatment) with different stages of the di sease, not filtered for respiratory symptoms. PD severity was evaluate d by the Unified PD Rating Scale, the Webster's scale, and Hoehn and Y ahr staging. Patients with more severe PD had lower percentage forced vital capacity (FVC%), and peak inspiratory and expiratory flows. Thos e with fluctuations and/or dyskinesias had lower FVC% and percentage f orced expiratory flow volume in 1 sec (FEV(1)%), There were a number o f weak but significant correlations between PD scales and spirographic parameters. Thirty one patients (49.2%) had pathological flow-volume curves. The clinical profile and the duration of the disease did not i nfluence the pattern of the curve. Physiologic evidence of upper airwa y obstruction was observed in 3 cases. A spirometric restrictive venti latory defect (FEV(1)/FVC higher than or equal to 80%) was observed in 54 patients (85%), while generalized airway obstruction was present o nly in one nonsmoker. We conclude that abnormal flow-volume loop conto ur is a frequent finding in PD. This probably reflects involvement of the upper airway musculature, that in some patients can produce upper airway obstruction. Generalized airflow limitation is not an important characteristic of PD. By contrast, a restrictive spirometric defect, probably due to incoordinated expiratory effort or abnormally low ches t wall compliance, is the main spirometric finding in these patients.