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. 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.