Shimazaki Haruo
Department of Internal Medicine, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi 329 0498, Japan.
Brain Nerve. 2008 Oct;60(10):1125-33.
Fibromuscular dysplasia (FMD) is a noninflammatory, nonatheromatous segmental angiopathy. The renal arteries are affected most commonly, followed by the internal carotid and vertebral arteries. FMD of the internal carotid and vertebral arteries usually occurs in the extracranial portions and is mostly observed at the level of the second cervical vertebra. FMD of the intracranial arteries is rare, but tends to occur in children and young adults. FMD is more common in females than in males, and it is often observed in middle-aged women. Although the etiology of FMD is not well understood, several mechanisms have been proposed, such as genetic predisposition, hormonal factors, and arterial wall ischemia. The pathology of FMD is characterized by smooth muscle hyperplasia or thinning, elastic fiber destruction, fibrous tissue proliferation, and arterial wall disorganization. Cerebrovascular fibromuscular dysplasia (cFMD) is relatively rare in Japan but is regarded as one of the cardinal causes of stroke in the younger population. cFMD without complications causes nonspecific symptoms such as headache or vertigo, but when it results in an arterial dissection or aneurysm, it leads to cerebral infarction or subarachnoid hemorrhage. Conventional angiographic findings mostly reveal a pattern called the "string of beads", which is pathologically correlated to medial fibromuscular dysplasia. Doppler echography, computed tomography and magnetic resonance angiography (MRA) may be useful for detecting cFMD lesions in some cases. MRA should be performed to rule out the presence of intracranial aneurysms. Antiplatelet and anticoagulation agents are prophylactics against cFMD complications. Surgical treatments such as graduated intraluminal dilatation had previously been the mainstays for treating cFMD. Percutaneous transluminal angioplasty with or without stenting has now become the preferred invasive treatment for symptomatic cFMD.
纤维肌发育不良（FMD）是一种非炎性、非动脉粥样硬化性节段性血管病。肾动脉最常受累，其次是颈内动脉和椎动脉。颈内动脉和椎动脉的FMD通常发生在颅外段，多在第二颈椎水平观察到。颅内动脉的FMD罕见，但倾向于发生在儿童和年轻人中。FMD在女性中比男性更常见，且常出现在中年女性中。虽然FMD的病因尚不完全清楚，但已提出了几种机制，如遗传易感性、激素因素和动脉壁缺血。FMD的病理特征为平滑肌增生或变薄、弹性纤维破坏、纤维组织增生和动脉壁结构紊乱。脑血管纤维肌发育不良（cFMD）在日本相对少见，但被认为是年轻人群中风的主要原因之一。无并发症的cFMD会引起头痛或眩晕等非特异性症状，但当导致动脉夹层或动脉瘤时，则会引发脑梗死或蛛网膜下腔出血。传统血管造影结果大多显示一种称为“串珠样”的模式，其在病理上与中层纤维肌发育不良相关。在某些情况下，多普勒超声、计算机断层扫描和磁共振血管造影（MRA）可能有助于检测cFMD病变。应进行MRA以排除颅内动脉瘤的存在。抗血小板和抗凝药物可预防cFMD并发症。诸如逐步腔内扩张等手术治疗以前一直是治疗cFMD的主要方法。经皮腔内血管成形术加或不加支架置入术现已成为有症状cFMD的首选侵入性治疗方法。
