Department of Neurology, Donders Institute for Brain, Cognition, and Behaviour, Center for Neuroscience, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands.
Stroke. 2010 Dec;41(12):2801-6. doi: 10.1161/STROKEAHA.110.597237. Epub 2010 Oct 28.
Hypertension is a risk factor for cerebral small vessel disease, which includes white matter lesions (WML) and lacunar infarcts. These lesions are frequently observed on MRI scans of elderly people and play a role in cognitive decline. Preferably, one would like to evaluate the effect of hypertension before fluid-attenuated inversion recovery visible macrostructural lesions occur, possibly by investigating its effect on the microstructural integrity of the white matter. Diffusion tensor imaging provides measures of structural integrity.
In 503 patients with small vessel disease, aged between 50 and 85 years, we cross-sectionally studied the relation between blood pressure, hypertension, and hypertension treatment status and diffusion tensor imaging parameters in both normal-appearing white matter (NAWM) and WMLs. All of the subjects underwent 1.5-T MRI and diffusion tensor imaging scanning. Fractional anisotropy and mean diffusivity were calculated in both NAWM and WMLs.
Increased blood pressure and hypertension were significantly related to lower fractional anisotropy in both NAWM and WMLs and to higher mean diffusivity in WMLs. For hypertensives, odds ratios for the risk of impaired microstructural integrity (fractional anisotropy) were 3.1 (95% CI: 1.8 to 5.7) and 2.1 (95% CI: 1.2 to 3.5) in NAWM and WMLs, respectively, compared with normotensives. Fractional anisotropy odds ratios for treated uncontrolled subjects were 6.5 (95% CI: 3.3 to 12.7) and 2.7 (95% CI: 1.5 to 5.1) in NAWM and WMLs, respectively, compared with normotensives.
Our data show that diffusion tensor imaging may be an appropriate tool to monitor the effect of blood pressure and the response to treatment on white matter integrity, probably even before the development of WMLs on fluid-attenuated inversion recovery.
高血压是脑小血管病的一个危险因素，包括脑白质病变（WML）和腔隙性梗死。这些病变在老年人的 MRI 扫描中经常被观察到，并且与认知能力下降有关。最好在液体衰减反转恢复可见的宏观结构病变发生之前评估高血压的影响，可能通过研究其对脑白质微观结构完整性的影响来实现。弥散张量成像提供了结构完整性的测量。
我们在 503 名年龄在 50 至 85 岁之间的小血管病患者中进行了横断面研究，研究了血压、高血压以及高血压治疗状态与正常表现的脑白质（NAWM）和 WML 中的弥散张量成像参数之间的关系。所有受试者均接受了 1.5-T MRI 和弥散张量成像扫描。在 NAWM 和 WML 中计算了各向异性分数和平均弥散系数。
血压升高和高血压与 NAWM 和 WML 中的各向异性分数降低以及 WML 中的平均弥散系数升高显著相关。对于高血压患者，与血压正常者相比，NAWM 和 WML 中微结构完整性（各向异性分数）受损的风险比分别为 3.1（95%CI：1.8 至 5.7）和 2.1（95%CI：1.2 至 3.5）。与血压正常者相比，治疗未控制的高血压患者的各向异性分数比值在 NAWM 和 WML 中分别为 6.5（95%CI：3.3 至 12.7）和 2.7（95%CI：1.5 至 5.1）。
我们的数据表明，弥散张量成像可能是监测血压和治疗反应对白质完整性影响的一种合适工具，甚至可能在液体衰减反转恢复可见的 WML 发生之前。
