A Study Of Flow Volume Loops In Parkinson's Disease

The frequency of respiratory system involvement in Parkinson’s disease (PD) is more than what is perceived usually and pneumonia is one of the commonest causes of death in this disorder. In this study, 32 patients with PD (Age 59.4 ± 10.5 yr) of varying duration (47.4 ± 37.7 months) and severity of disease and on different therapeutic regimes have been assessed with detailed spirometric study including the study of patterns of flow-volume (FV) loops. Though none of the patients had any pulmonary complaints, 46.9% of cases revealed a restrictive ventilatory pattern. Study of FV loops revealed several types of abnormalities. Several patients had more than one abnormality. The restrictive defect has been explained on the basis of poor chest wall compliance related to muscular rigidity. The FV loop abnormalities have been explained on the basis of an unstable upper airway function or even upper airway obstruction in such patients. Exceptionally well preserved small airway performance as judged by forced expiratory flow between 25% and 75% of the vital capacity was observed in most patients. The relative risk of having a restrictive ventilatory defect seemed somewhat higher in early stages of the disease than in little advanced cases but subsequently there had been sharp rise with the progression of the disease. This may have important bearing on the development of respiratory complications even in moderately advanced cases of PD responding otherwise reasonably well to drug therapy.