Evaluation of Valsalva Maneuver in Alpha-Synucleinopathies.

Parkinson's disease (PD) and multiple system atrophy (MSA) are neurodegenerative diseases that not only cause motor symptoms but also impair the autonomic nervous system. This study aims to characterize the response to Valsalva maneuver (VM) in individuals affected by PD and MSA by analyzing the systolic arterial blood pressure (SBP) and heart rate (HR) signals. During the maneuver SBP and HR signals are highly nonstationary, therefore we decided to adopt a multi-level uniform phase empirical mode decomposition (UPEMD), a modification of empirical mode decomposition (EMD), together with standard indices like overshoot and recovery in the II and IV phase of VM response. Our results show an impaired autonomic response, especially in MSA and PD with orthostatic hypotension (OH), as suggested by the attenuated overshoot and the recovery indices. Additionally, both branches of the autonomic nervous system (ANS) showed reduced activity, as indicated by a lower amplitude of the IMF spectra, more pronounced in the group PD OH.