Discriminating Parkinson’s disease patients from healthy controls using nasal respiratory airflow

Background : Breathing patterns may inform on health. We note that the sites of earliest brain damage in Parkinson’s disease (PD) house the neural pace-makers of respiration. We therefore hypothesized that ongoing long-term temporal dynamics of respiration may be altered in PD. Methods : We applied a wearable device that precisely logs nasal airflow over time in 28 PD patients (mostly H&Y stage-II) and 33 matched healthy controls. Each participant wore the device for 24 h of otherwise routine daily living. Results : We observe significantly altered temporal patterns of nasal airflow in PD, where inhalations are longer and less variable than in matched controls (mean PD = −1.22 ± 1.9 (combined respiratory features score), Control = 1.04 ± 2.16, Wilcoxon rank-sum test, z = −4.1, effect size Cliff’s δ = −0.61, 95% confidence interval = −0.79 – (−0.34), P = 4.3 × 10⁻⁵). The extent of alteration is such that using only 30 min of recording we detect PD at 87% accuracy (AUC = 0.85, 79% sensitivity (22 of 28), 94% specificity (31 of 33), z = 5.7, p = 3.5 × 10⁻⁹), and also predict disease severity (correlation with UPDRS-Total score: r = 0.49; P = 0.008). Conclusions : We conclude that breathing patterns are altered by H&Y stage-II in the disease cascade, and our methods may be further refined in the future to provide an indication with diagnostic and prognostic value.