Small vessels in the brain is susceptible especially for the effect of hypertension. Therefore, longstanding hypertension may induce cerebral small vessel disease (CSVD) which is designated as hypertensive CSVD. The patients with hypertensive CSVD may exhibit various types of lesions including lacunar infarction, white matter lesion, cerebral hemorrhage and microbleeds in brain magnetic resonance (MR) imaging. White matter lesions (WMLs) are one of the most representative lesions which are closely related to hypertension and aging. They are classified into periventricular hyperintensity (PVH) and deep white matter hyperintensity (DWMH), and the former is more closely involved in cognitive decline than the latter. In the SPRINT MIND trial which examined the significance of intensive blood pressure control, WML volume increased by 0.28 cm3 for 4years in the intensive treatment group whereas by 0.92 cm3 in the standard treatment group, indicating 70% suppression of WML expansion. We quantitatively assessed WML volume in patients with vascular dementia and Alzheimer disease, and as expected, both PVH DWMH were significantly larger in vascular dementia than in Alzheimer disease. The mechanisms for CMBs are not fully understood but may be secondary to blood-brain barrier damages from long-standing hypertension, or alternatively, amyloid deposition in the tissue. In our previous study, we investigated degree of SVD changes using hypertensive arteriopathy SVD (HA SVD) and cerebral amyloid angiopathy SVD (CAA SVD) scores. With the analysis of SVD scores in 53 subjects with CMBs admixed with lobar and deep distributions, mixed CMBs were mainly caused by HA.
These neuroimaging markers are crucial for management of hypertension. Small subcortical stroke (SPS3) trial which enrolled patients with symptomatic lacunar infarctions, were divided into two groups: those with a systolic blood pressure target between 130 and 149 mm Hg and those with less than 130 mm Hg. There was no significant difference in the frequency of all strokes, the rate of intracerebral hemorrhage was significantly lower in the group with intensive blood pressure control. This SPS3 trial revealed that a systolic blood pressure target of less than 130 mm Hg is beneficial in reducing risk in lacunar stroke patients. Thus, we overview brain imaging markers in hypertensive patients and their significance for the management of SVD.
