Respiratory Dysfunction in Parkinson's Disease: Relation with Dysautonomia

BACKGROUND: Parkinson's disease (PD) is a neurodegenerative disease perceived as a motor disorder. It is most commonly associated with autonomic dysfunction, affecting multiple systems. This altered autonomic control might be reflected by a parallel change in the airway caliber of these patients. AIM: To correlate the pulmonary impairment in patients with Parkinson's disease with the underlying dysautonomia. MATERIALS AND METHODS: A total of 30 patients with Parkinson's disease participated in the study. Heart rate (HR) variability was recorded for 5 min to assess the autonomic dysfunction, followed by impulse oscillometry (IOS) and spirometry. IOS being an effort independent technique uses sound waves at different frequencies (5–25 Hz) to measure the airway impedance. RESULTS: There was a significant decrease in SDSD (6.60 (10.18–6.01) vs. 12.22 (13.95–11.30); P = 0.04), RMSSD (6.59 (10.17–5.50) vs. 12.20 (13.93–11.28); P = 0.04), and total power (315.8 (506.3–120.7) vs. 771.3 (799.0–643.6); P = 0.04) in stage II as compared to stage I. Resistance at 20 Hz (R20) was found to be positively correlated with SDSD (r = 0.40, P = 0.04), RMSSD (r = 0.40, P = 0.04), and HF (r = 0.41, P = 0.03). CONCLUSION: Amongst the PD population, any changes in the parasympathetic component (responsible for bronchoconstriction) due to the underlying dysautonomia might be reflected as increased airway resistance in the pulmonary system.