- The aim of the study is to investigate the correlation between orthostatic hypotension (OH), mean flow velocity (MFV) as measured by transcranial Doppler (TCD) in middle cerebral artery (MCA) bilaterally during tilt table test (TTT) and functional and neurological parameters in acute ischemic stroke patients, undergoing rehabilitation. Thirteen patients after first ischemic stroke in the MCA territory and 13 healthy volunteers were examined. TTT was performed with elevating the subject from supine to 80 masculine standing position and back to supine within 10 min. Peripheral blood pressure was measured and monitoring of MFV in MCA of damaged and healthy hemisphere by TCD was performed during the TTT. Patients underwent the test few days after admission to rehabilitation department and were classified into 2 subgroups: those with decrease of systolic blood pressure of at least 20 mm/Hg during the test and those without the OH. Among patients without OH, MFV indexes were almost the same in damaged and healthy MCA and did not changed during the test. Patients with OH symptoms showed significant differences between blood flow velocities in 2 hemispheres in favor of nondamaged size. No association was found between the OH and the severity of functional and neurological status after stroke. These findings suggest that the appearance of OH after ischemic stroke may be associated with decreased blood flow velocity in damaged MCA at the beginning of rehabilitation treatment, but not with functional and neurological status of the patient.