Sierra Cristina, de la Sierra Alejandro, Chamorro Angel, Larrousse María, Domènech Mònica, Coca Antonio
Hypertension Unit, Department of Internal Medicine, IDIBAPS (Institut d'Investigacions Biomèdiques August Pi i Sunyer), Hospital Clínic, University of Barcelona, Spain.
Blood Press. 2004;13(5):304-9. doi: 10.1080/08037050410024448.
Cerebral white matter lesions (WML) represent a subclinical form of ischemic brain damage that have been associated with risk of future stroke. Studies have shown an association between WML and impaired cerebral autoregulation in hypertensives who had previously suffered a stroke. The aim of the study was to evaluate cerebral hemodynamics in asymptomatic hypertensives according to the presence or absence of WML. Fifty never-treated essential hypertensives (32 men, 18 women), aged 50-60 years, without clinical evidence of target organ damage were studied. All patients underwent 24-h ambulatory blood pressure monitoring, and brain-magnetic resonance imaging to establish the presence or absence of WML. Baseline cerebral blood flow velocity (CBF), pulsatility index (PI; differences between systolic and diastolic velocities), and CBF after acetazolamide infusion (vasomotor reactivity of cerebral vessels), were measured by transcranial Doppler ultrasonography in both left and right middle cerebral arteries, and averaged. Twenty hypertensive patients (40%) were found to have WML on brain resonance. No differences were observed on resting and stimulating CBF between hypertensives with and without WML. In contrast, patients with WML exhibited significantly higher PI compared with hypertensives without WML (0.79 +/- 0.13 vs 0.66 +/- 0.12; p = 0.003). Moreover, PI correlated with 24-h pulse pressure (r = 0.361; p = 0.015). We conclude that the presence of silent WML in middle-aged hypertensives is associated with increased cerebrovascular pulsatility. This increased pulsatility is also associated with higher pulse pressure values, suggesting a pathogenetic link between pulse pressure, pulsatility and the development of WML.
脑白质病变（WML）是缺血性脑损伤的一种亚临床形式，与未来中风风险相关。研究表明，在既往有中风病史的高血压患者中，WML与脑自动调节功能受损有关。本研究的目的是根据有无WML评估无症状高血压患者的脑血流动力学。研究了50例未经治疗的原发性高血压患者（32例男性，18例女性），年龄在50至60岁之间，无靶器官损害的临床证据。所有患者均接受24小时动态血压监测，并进行脑磁共振成像以确定是否存在WML。通过经颅多普勒超声测量左右大脑中动脉的基线脑血流速度（CBF）、搏动指数（PI；收缩期和舒张期速度之差）以及乙酰唑胺输注后的CBF（脑血管的血管运动反应性），并取平均值。20例高血压患者（40%）在脑磁共振检查中发现有WML。有WML和无WML的高血压患者在静息和刺激状态下的CBF未观察到差异。相比之下，有WML的患者与无WML的高血压患者相比，PI显著更高（0.79±0.13对0.66±0.12；p = 0.003）。此外，PI与24小时脉压相关（r = 0.361；p = 0.015）。我们得出结论：中年高血压患者中无症状WML的存在与脑血管搏动性增加有关。这种增加的搏动性也与较高的脉压值相关，提示脉压、搏动性与WML发生之间存在发病机制上的联系。
