Parkinson's Disease with Cerebrovascular Compensation of Orthostatic Hypotension

Author(s): Acree William*

Background: Orthostatic hypotension (OH) is an important non motor manifestation of Parkinson’s disease (PD). Changes in cerebrovascular reactivity may contribute to this manifestation and can be monitored using transcranial Doppler.

Objective: To identify possible changes in cerebrovascular reactivity in patients with OH.

Methods: Twenty-two individuals were selected and divided into three groups: with and without OH and controls. Transcranial Doppler was used to assess basal mean blood flow velocity, post apnea mean blood flow velocity, percentage increase in mean blood flow velocity, and cerebrovascular reactivity as measured by the breath-holding index.

Results: PD patients had lower values of basal velocity (p= 0.019), post apnea velocity (p = 0.0015), percentage increase in velocity (p = 0.039), and breath-holding index (p= 0.04) than the controls. Patients with OH had higher values of basal velocity (p = 0.09) and post apnea velocity (p = 0.19) but lower values of percentage increase in velocity (p= 0.22) and breath-holding index (p = 0.32) than patients without OH.

Conclusions: PD patients present with abnormalities in a compensatory mechanism that regulates cerebral blood flow. OH could be an indicator of these abnormalities.