Division of Clinical Neurosciences, Brain Research Imaging Centre, University of Edinburgh, Western General Hospital, Edinburgh, UK.
Cerebrovasc Dis. 2012;33(4):378-84. doi: 10.1159/000336762. Epub 2012 Mar 14.
White matter lesions (WML) are commonly seen on brain MRI and are generally considered a marker of tissue damage from cerebral small vessel disease. WML are associated with increasing age and vascular risk factors, but their precise cause is unknown. A role for carotid artery atherothromboemboli has been suggested. If this is the case, more WML would be expected ipsilateral to increasing degrees of carotid stenosis.
We recruited patients with ischaemic stroke from two large, separate prospective stroke studies, assessed with brain MRI and carotid Doppler ultrasound. We scored hemispheric WML visually in periventricular and deep locations. We assessed the association between carotid stenosis asymmetry and WML asymmetry, and vice versa. Further, we assessed the association between carotid stenosis and ipsilateral WML, before and after adjusting for vascular risk factors, and tested associations between ipsilateral and contralateral stenoses and WML.
We recruited 247 (Study 1) and 253 (Study 2) patients. In Study 1 and Study 2, 36 (15%) and 29 (11%) patients had ≥50% carotid stenosis, and 27 (11%) and 15 (6%) had ≥70% stenosis, respectively. Carotid stenosis was asymmetric in 28 (11%) and 26 (10%) patients and WML were asymmetric in 22 (9%) and 11 (4%) patients in Study 1 and Study 2, respectively. We found no association between carotid stenosis and ipsilateral WML score, before or after adjusting for vascular risk factors or sidedness, but WML were strongly associated with increasing age (p < 0.001).
In two large cohorts of ischaemic stroke patients, we found no association between carotid stenosis and ipsi- or contralateral WML. There is now substantial evidence that atherothromboemboli are unlikely to cause most WML or other forms of cerebral small vessel lesions. Future studies should focus on determining what causes the intrinsic small vessel pathological changes that appear to underlie most WML.
脑磁共振成像（MRI）常可见到脑白质病变（WML），一般认为其是脑小血管病导致组织损伤的标志物。WML 与年龄增长和血管危险因素相关，但确切病因尚不清楚。有人提出颈动脉粥样硬化血栓形成栓子起作用。如果是这样，随着颈动脉狭窄程度增加，预计同侧会出现更多的 WML。
我们从两项大型独立前瞻性卒中研究中招募了缺血性卒中患者，用脑部 MRI 和颈动脉多普勒超声进行评估。我们对侧脑室周围和深部位置的半球性 WML 进行视觉评分。我们评估了颈动脉狭窄不对称性与 WML 不对称性之间的关系，反之亦然。此外，我们在调整血管危险因素后，评估了颈动脉狭窄与同侧 WML 之间的关系，并测试了同侧和对侧狭窄与 WML 之间的关联。
我们招募了 247 例（研究 1）和 253 例（研究 2）患者。在研究 1 和研究 2 中，分别有 36 例（15%）和 29 例（11%）患者的颈动脉狭窄≥50%，分别有 27 例（11%）和 15 例（6%）患者的颈动脉狭窄≥70%。在研究 1 和研究 2 中，分别有 28 例（11%）和 26 例（10%）患者的颈动脉狭窄不对称，有 22 例（9%）和 11 例（4%）患者的 WML 不对称。我们发现，在调整血管危险因素或侧别后，颈动脉狭窄与同侧 WML 评分之间无关联，但 WML 与年龄增长显著相关（p<0.001）。
在两项大型缺血性卒中患者队列研究中，我们发现颈动脉狭窄与同侧或对侧 WML 之间无关联。目前有大量证据表明，动脉粥样硬化血栓形成栓子不太可能导致大多数 WML 或其他形式的脑小血管病变。未来的研究应集中于确定是什么导致了似乎是大多数 WML 基础的内在小血管病理变化。
