Daily profile of arterial pressure and brain microstructural changes in patients with hypertension-related cerebral small vessel disease

Abstract

Introduction. Application of modern antihypertensive medications has improved the course of arterial hypertension (AH), but has not led to the expected decrease in small vessel disease (SVD) incidence and its complications. This fact encourages further investigation of hypertension-related mechanisms of brain damage. Objective: to study the relation between daily profile of blood pressure and brain microstructure changes in patients with both SVD and AH. Material and methods. The study included 64 patients (38 – 59.4%) female, mean age 59.4±5.4 years) with both SVD and AH. Ambulatory blood pressure monitoring and diffusion-tensor MRI were obtained for all participants. The relation between studied parameters was estimated using the multivariate statistical analysis method – linear regression analysis. Results. Сhanges in daily profile of blood pressure according to ambulatory blood pressure monitoring data was associated with microstructure abnormalities of the juxtacortical white matter hyperintensities (jWMH) of anterior frontal lobes, temporal-parietal regions and left posterior cingulate cortex. An increase and variability of diastolic blood pressure were of primary importance in brain microstructural damage in mentioned areas leading to mean diffusivity and radial diffusivity increase. Conclusion. The revealed relation between daily profile of blood pressure and brain microstructural changes indicating increase of free water diffusivity and myelin damage in jWMH and posterior cingulate cortex corresponds to the experimental data on the breakdown of the autoregulation reaction in cortex arteries and further increase of brain-blood barrier permeability with descending vasogenic edema in brain damage in hypertensive patients. An increase and variability of diastolic blood pressure have primary importance to microstructural damage of white matter in patients with SVD receiving antihypertensive treatment.