Recurrence Plots and Cross Recurrence Plots

Proceedings of the IEEE EMBS International Conference on Biomedical and Health Informatics (BHI 2021) (2021) DOI:10.1109/BHI50953.2021.9508550

Recurrence quantification analysis of gait rhythm in patients affected by Parkinson's disease

Gait and balance capabilities are heavily affected by neurodegenerative disorders. In particular, Parkinson's disease (PD) manifests itself with a series of symptoms, such as tremor, bradykinesia, and hypokinesia, which lead to a global degradation of motor skills. Gait rhythm disturbance is a common sign of a degraded mobility regulation, recognizable also in mild PD patients. In this work, we aimed to explore gait rhythm timeseries of PD patients through the recurrence quantification analysis (RQA), a multi-dimensional tool for investigating the dynamics of the system generating the data, in terms of recurrence of state space trajectories. We considered stride intervals timeseries from a group of five healthy elderly and five PD individuals. Outcomes showed that four out of the six RQA-based parameters, were able to discriminate between groups, providing also a clear clustering with a high separability and highlighting that different dynamics and recurrence patterns are present in PD gait rhythm. We believe that this study provides evidences about the suitability of using RQA and related measures for the analysis of stride-to-stride fluctuations in subjects affected by neurological disorders.