Symptoms of orthostatic intolerance are not correlated with changes in Middle Cerebral Artery Velocity

Background: Vascular diseases are recognized as a modifiable risk factor for the development of cognitive impairment. One potential underlying mechanism for this may be due to chronic alterations to cerebral blood flow (CBF), which has been linked to downstream consequences. Global decreases in CBF following a change in position are often manifested clinically as orthostatic hypotension, with changes in systolic blood pressure (SBP). This study describes clinical symptoms of orthostasis, depression, and dysautonomia in older adults and correlates these symptoms with objective measures of CBF velocity and systolic blood pressure following a supine to stand transition. Methods: 88 adult participants were recruited from a longitudinal, observational study. Participants completed standardized questionnaires for orthostatic, depression and autonomic symptoms. Participants were fitted with standardized equipment to measure SBP and CBF at baseline, nadir, 1 minute standing, and 3 minutes standing, during a protocol defined supine to stand transition and subsequent 3-minute stand. Results: Changes in CBF were not associated with any of the collected symptom scales. Changes in SBP were negatively associated with orthostatic symptoms. Change in SBP from baseline to stand after 1 minute was negatively associated with depression symptoms. Discussion: Symptoms of orthostatic hypotension, dysautonomia, and depression are common in older adults. Participants reported more nonspecific symptoms of orthostasis such as fatigue, trouble concentrating, and head and neck discomfort than traditional symptoms such as dizziness or light-headedness. Our results suggest that changes in CBF may be asymptomatic, while changes in SBP are correlated with reported orthostatic hypotension symptoms.