Changes in the MRI brain picture associated with newly diagnosed asymptomatic arterial hypertension

Abstract

ntroduction.Arterial hypertension (AH) is the major modified riskfactor for brain injury. Clarification of the brain changes and themechanisms of their development during the asymptomatic stagewill ensure better results in the prevention of AH complications. Objective. The study purpose was to evaluate specific changes inthe brain MRI picture, associated with AH of varying severity. Materials and methods. The study involved 82 patients with newlydiagnosed asymptomatic AH, aged 4559 years. The patients underwentMRI of the brain (T1 and T2 weighted images, FLAIR,diffusion weighted imaging with calculation of an apparent diffusioncoefficient (ADC) map). We evaluated the localization andseverity of white matter hyperintensity (WMH), lacunar infarcts,and dilated perivascular spaces as well as the white matter microstructurebased on ADC in a visually intact white matter in areasof its potential vulnerability. Results. The earliest and most typical change is the formationof hyperintensity lesions in the juxtacortical areas of the frontallobes. AH worsening is associated with an increase in the numberof hyperintensity lesions from the frontal to occipital areas of thewhite brain matter and from the surface to deep brain regionsas well as microstructural changes in the intact white matter inpotential vulnerability areas. Conclusion. The observed high correlations between WMH anddilated semioval perivascular spaces and increased diffusion inthe intact white matter as well as the absence of similar correlationsfor lacunar infarcts suggest that the pathophysiological basisof early brain changes in AH is increased vascular permeability,but not ischemia. The factors of a high risk of clinical symptomsinclude lesion extension to the posterior brain structures, multiplefoci of hyperintensity in the periventricular white matter ofthe frontal lobes, and an increasing number of lacunar infarcts.These findings are significant for evaluating potential risk of clinicalsymptoms and for understanding the mechanisms of earlybrain injury in AH.

Keywords

• asymptomatic hypertension
• white matter hyperintensity
• lacunar infarcts
• intact white matter apparent diffusion coefficient
• small vessel disease