NCT07139756

Deciphering the Mechanisms of Central BP Regulation in Patients With PD Associated With Orthostatic Hypotension

Deciphering the Mechanisms of Central Blood Pressure Regulation in Patients With Parkinson Disease Associated With Orthostatic Hypotension: A 2-phase Observational Study With Healthy Participants and Patients With Parkinson's Disease

• Status: Not Yet Recruiting
• Phase: —
• Study type: Observational
• Enrollment: 130 (estimated)
• Sponsor: Centre Hospitalier Universitaire Vaudois · Academic / Other
• Sex: All
• Age: 18 Years – 75 Years
• Healthy volunteers: Accepted

Summary

Phase 1 objective: test the feasibility of using a 3Tesla MRI scanner instead of a 7Tesla MRI scanner to measure brainstem responses to LBNP in healthy participants. Phase 2 primary objective: compare the brainstem responses to LBNP in patients with PD associated with OH to PD patients without OH using BOLD fMRI

Detailed description

Phase 1 objective: test the feasibility of using a 3Tesla MRI scanner instead of a 7Tesla MRI scanner to measure brainstem responses to LBNP in healthy participants using BOLD fMRI Phase 2 primary objective: compare the brainstem responses to LBNP in patients with PD associated with OH to PD patients without OH using BOLD fMRI Phase 2 secondary objectives: * assess modulation of functional connectivity in response to LBNP (effective connectivity analysis by psycho-physiological interactions (PPI)) and determine differences between the two groups * assess functional connectivity in resting state and determine differences between the two groups * compare structural connectivity in both groups using tractography * compare renal response to LBNP in both groups using contrast-enhanced ultrasound * compare pre-cerebral flow response to LBNP in both groups

Conditions

• Parkinson Disease
• Orthostatic Hypotension

Interventions

Type	Name	Description
DIAGNOSTIC_TEST	Lower body negative pressure	LBNP is a technique that redistributes blood from the upper body to the dependent regions of the legs, thus reducing central venous pressure and venous return and thereby activating the sympathetic nervous system (SNS). The subject is placed in a cylindrical airtight tank, which is sealed at the level of the iliac crests, and sub-atmospheric pressure is produced using a vacuum pump. It can be used to characterize the cardiovascular responses to orthostatic stress

Timeline

• Start date: 2025-10-01
• Primary completion: 2027-09-30
• Completion: 2028-03-31
• First posted: 2025-08-24
• Last updated: 2025-08-24

Locations

1 site across 1 country: Switzerland