Background. @entity551 ( @entity551 ) is an important nonmotor manifestation of @entity191 ( @entity191 ). 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 @entity1 with @entity551 . Methods. Twenty-two individuals were selected and divided into three groups: with and without @entity551 and controls. Transcranial Doppler was used to assess basal mean blood flow velocity, postapnea mean blood flow velocity, percentage increase in mean blood flow velocity, and cerebrovascular reactivity as measured by the breath-holding index. Results. @entity191 @entity1 had lower values of basal velocity (p = 0.019), postapnea velocity (p = 0.0015), percentage increase in velocity (p = 0.039), and breath-holding index (p = 0.04) than the controls. @entity1 with @entity551 had higher values of basal velocity (p = 0.09) and postapnea velocity (p = 0.19) but lower values of percentage increase in velocity (p = 0.22) and breath-holding index (p = 0.32) than @entity1 without @entity551 . Conclusions. @entity191 @entity1 present with abnormalities in a compensatory mechanism that regulates cerebral blood flow. @entity551 could be an indicator of these abnormalities.

Abnormal Cerebrovascular Reactivity in @entity1 with XXXX .

@entity1 :: ('9606', 'Species') :: ['Patients', 'patients'] @entity551 :: ('MESH:D007022', 'Disease') :: ['Orthostatic hypotension', 'OH'] @entity191 :: ('MESH:D010300', 'Disease') :: ["Parkinson's disease", 'PD']
@entity191 :: (MESH:D010300,Disease) :: ['Parkinson's Disease']
