Clinical Features and Diagnostics of Cerebrovascular Disorders in Patients with Arterial Hypotension: Experimental Verification

Abstract

Background: Chronic arterial hypotension and orthostatic blood pressure instability can cause repetitive cerebral hypoperfusion, yet the diagnostic expression
of these mechanisms is still not well defined for everyday cerebrovascular care. This study analyzed the clinical phenotype, multimodal diagnostic profile, and
experimental correlates of cerebrovascular disorders in hypotensive patients.
Methods: We prepared a prospective, single-center, observational clinical–experimental study model. The clinical arm included 92 adults with persistent arterial
hypotension and neurologic complaints suggestive of cerebrovascular insufficiency and 40 age-matched normotensive controls. Participants received
standardized orthostatic blood pressure testing, 24-hour ambulatory blood pressure monitoring, transcranial Doppler during tilt, duplex ultrasonography of neck
vessels, and 3-T brain MRI with fluid-attenuated inversion recovery and arterial spin labeling. In the experimental arm, 24 Wistar rats were allocated to chronic
hypotension or sham conditions for 4 weeks, followed by cortical perfusion and hippocampal histology assessment.
Results: Hypotensive subjects had more frequent reports of dizziness (71.7%), gait unsteadiness (44.6%), transient visual obscuration (34.8%), and cognitive
slowing (31.5%) than controls. 47.8% of hypotensive subjects exhibited MRI markers of cerebrovascular injury, in contrast to 15.0% of controls, predominantly
white matter hyperintensities and small lacunar lesions. Tilt-related decline in middle cerebral artery mean flow velocity was greater in the hypotension group
(24.6%±8.7% vs 11.2%±4.9%, p<0.001), and regional perfusion on arterial spin labeling was reduced in frontal–periventricular territories. Multivariable analysis
demonstrated orthostatic systolic blood pressure fall ≥20 mmHg (adjusted odds ratio [aOR] 3.41, 95% CI 1.58–7.34), nocturnal mean arterial pressure <65
mmHg (aOR 2.86, 95% CI 1.29–6.31), and impaired dynamic autoregulation on transcranial Doppler (aOR 4.08, 95% CI 1.84–9.03) independently predicted
MRI-detected cerebrovascular lesions. Chronic hypotension decreased cortical perfusion in rats by 26.2% and hippocampal neuronal density by 21.4% (both p<0.01).
Conclusion: Participants with arterial hypotension present with a reproducible syndrome of symptomatic cerebral hypoperfusion, impaired autoregulation, and
subclinical structural brain injury. A combination of orthostatic testing, ambulatory blood pressure monitoring, transcranial Doppler, and perfusion-sensitive MRI
appeared diagnostically superior to conventional imaging alone.