Yakushiji Yusuke, Hara Hideo
Division of Neurology, Department of Internal Medicine, Saga University Faculty of Medicine.
Rinsho Shinkeigaku. 2012;52(11):1106-9. doi: 10.5692/clinicalneurol.52.1106.
Cerebral microbleeds (CMBs) on gradient-echo T(2) weighted MRI, which are characterized histologically by the presence of hemosiderin around small vessels, are now accepted as a manifestation of cerebral small vessel disease (SVD) pathologies, including hypertensive small vessel disease and cerebral amyloid angiopathy (CAA). CMBs are often detected in patients with stroke, Alzheimer's disease, and mild cognitive impairment. The pathological differences in MBs according to distribution is now well known, with MBs in deep regions considered to be associated with hypertensive arteriopathy, whereas strictly lobar MBs share risk factors with CAA. Evidence suggests that CMBs should not be considered to be clinically "silent". When CMBs are detected in healthy adults, physicians should recognize that subclinical SVD might have begun in their brain. Chronic hypertension can affect HA-related CMBs, as well as CAA-related CMBs. Furthermore, both types of CMBs are risk factor for intracranial hemorrhage under the antithrombotic drug use. Thus, CMBs should be considered as "warning sign" for inappropriate blood pressure control and antithrombotic drug use. It seems clear that CMBs should be an important component of future studies to investigate how SVD influence neurodegeneration via neurovascular units in elderly populations.
梯度回波T2加权磁共振成像（MRI）上的脑微出血（CMBs），在组织学上表现为小血管周围存在含铁血黄素，现在被认为是脑小血管疾病（SVD）病理的一种表现，包括高血压性小血管疾病和脑淀粉样血管病（CAA）。CMBs常在中风、阿尔茨海默病和轻度认知障碍患者中被检测到。根据分布情况，CMBs的病理差异现在已广为人知，深部区域的CMBs被认为与高血压性动脉病变有关，而严格局限于脑叶的CMBs与CAA有共同的危险因素。有证据表明，CMBs不应被视为临床上“无症状”。当在健康成年人中检测到CMBs时，医生应认识到其大脑可能已经开始出现亚临床SVD。慢性高血压可影响与高血压性动脉病变相关的CMBs以及与CAA相关的CMBs。此外，在使用抗血栓药物的情况下，这两种类型的CMBs都是颅内出血的危险因素。因此，CMBs应被视为血压控制不当和使用抗血栓药物的“警示信号”。很明显，CMBs应该成为未来研究的一个重要组成部分，以探讨SVD如何通过老年人群中的神经血管单元影响神经退行性变。
