颅内动脉夹层的发病机制、影像学特点和自然病程

颅内动脉夹层相比颅外动脉夹层较少见，且临床表现缺乏特异性，既可以表现为缺血性
事件，也可以表现为出血性事件，多发生于年轻人。由于夹层发生部位、形成时机以及病变严重程度
不同，临床表现各种各样，影像学对于确诊动脉夹层至关重要。颅内动脉夹层易复发，且死亡率较高，
除无症状或症状轻微的患者给予保守治疗或随访观察外，对于症状较重或进展性动脉夹层患者，应
给予积极治疗，包括血管内治疗。     

颅内动脉夹层动脉瘤

夹层动脉瘤又称动脉剥离,是指病理性夹层发生在动脉中膜层内或中膜和外膜之间的剥离,动脉壁膨出,发生动脉瘤样扩张。以上病理变化发生在颅内动脉者称之为颅内动脉夹层动脉瘤。夹层最初作为主动脉疾病而受关注,后来发现颈动脉、椎动脉及颅内动脉亦有发生。现将颅内夹层动脉瘤流行病学特征、好发部位、病因、发病机制、临床特征及其诊治综述如下。     

颅内外动脉夹层及夹层动脉瘤的发病机制研究进展

颅内外动脉夹层和夹层动脉瘤多见于青年,自发性多见,病因目前不甚明确。内膜和内弹力 板的不可逆损伤可能是脑动脉夹层形成的病理学基础。高分辨率磁共振成像的出现提高了颅内夹层 及夹层动脉瘤的检出率,为此类疾病的病因和病理生理机制提供了新的研究方向。本文综述了颅内 外动脉夹层及夹层动脉瘤的病因、发病机制、病理类型及目前现状与展望。     

颅内动脉夹层的影像学研究进展

颅内动脉夹层是青年卒中的常见原因,其发病形式主要表现为蛛网膜下腔出血或后循环 缺血,致残率和病死率都很高,因其缺乏特异性症状和体征,极易造成漏诊或误诊,亟须制定统一 的临床影像诊断和分类诊断标准。本文就颅内动脉夹层的影像学研究现状和相关进展加以探究。     

颅内动脉粥样硬化的自然病程

动脉粥样硬化是全身性疾病,颅内动脉也是动脉粥样硬化的好发部位。在所有的缺血性卒中患者中,8%～10%是由于颅内动脉粥样硬化性狭窄所致。颅内动脉粥样硬化性狭窄是一个炎症反应过程,近来认为氧化型低密度脂蛋白在动脉粥样硬化过程中的作用最强。颅内动脉粥样硬化的好发部位包括颈动脉海绵窦虹吸段、大脑中动脉主干、椎动脉邻近融合部和基底动脉。颅内动脉粥样硬化在流行病学、自然病程、病理生理及药物治疗、介入治疗等方面均有显著进展。本文对颅内动脉粥样硬化的自然病程做一综述。     

颅内动脉夹层与夹层动脉瘤的诊治探讨

目的探讨颅内动脉夹层与夹层动脉瘤的临床特点,评价血管内栓塞疗效及安全性。方法 2003年12月至2011年12月共收治67例颅内动脉夹层与夹层动脉瘤。50例采用血管内治疗,其中单纯支架置入32例,单纯微弹簧圈栓塞3例,支架辅助微弹簧圈栓塞14例,微弹簧圈加真丝线段栓塞1例;17例未行外科治疗。结果 CTA及MRA造影随访28例,DSA造影随访20例,42例病人恢复良好,1例术后3 d再次出血死亡,4例复查见椎动脉闭塞,1例遗留进食呛咳;未治疗17例中,4例住院期间又突然发生出血死亡。结论采用支架置入重建受累血管的真腔、闭塞假腔是血管内治疗颅内动脉夹层与夹层动脉瘤的主要方法。     

颅内动脉夹层与夹层动脉瘤的诊断与治疗

动脉夹层是指动脉血管壁的病理性夹层累及动脉的内膜、形成内膜下血肿并扩张到内膜和中膜之间。 夹层动脉瘤或动脉剥离是指病理性夹层发生在动脉中膜层内或中膜和外膜之间的剥离，动脉壁膨出，发生动脉瘤样扩张。     

颅内动脉夹层及夹层动脉瘤

目前颅内动脉夹层的相关报告甚少,有必要研究发生颅内动脉夹层的动脉壁部位及其合理的治疗和预后的判断。当颅内动脉的内膜和中膜之间发生夹层时,会发生血管闭塞造成缺血,在中膜和外膜之间发生动脉的夹层,将导致动脉膨起,形成动脉瘤样扩张,甚至发生血管破裂。本文综述文献并结合作者临床经验,论述颅内动脉夹层的病理、病因学及其相关的临床问题,为治疗提供参考。     

基底动脉巨长夹层动脉瘤的影像学分析1例

1病例介绍患者,男,50岁,主因"阵发性头痛1个月余"于2012年1月28日收入我院。患者1个月余前与他人争吵后突发头部胀痛,中度疼痛,以右侧枕部明显,可耐受,伴头晕,无头部外伤,无视物旋转,无视力下降,无吞咽困难,无口齿不清,无肢体活动障碍,无肢体抽搐,无意识丧失,无呼吸困难,无大汗淋漓,无恶心及呕吐,无发热,血压升高至220/110 mmHg,口服降压药物(卡托普利、阿替洛尔)后,症状缓解,     

高分辨MR血管壁成像在颅内动脉夹层中的应用进展

颅内动脉夹层(intracranial artery dissection,IAD)包括夹层与夹层动脉瘤,是中青年卒中的主要病因之一[1],IAD可导致严重的脑缺血或脑出血,早期诊断尤为重要.然而,目前IAD的诊断仍然是一个巨大的挑战,主要原因是患者缺乏特异性症状和体征,需要依靠影像学检查进行诊断,但由于颅内动脉管径细...     

MRI在颅内动脉狭窄、闭塞诊断中的应用

目的评价头颅三维增强磁共振血管造影（3DCE-MRA）结合MRI常规扫描诊断颅内动脉狭窄、闭塞的临床意义。方法3D CE-MRA及头颅MRI常规扫描发现颅内大动脉明显狭窄或闭塞116例，其中43例同期行DSA检查。常规扫描采用横断面T1W、T2W和冠状面T2W成像；3DCE-MRA用超快速三维梯度回波序列（3DFISP），钆对比剂（Gd-DTPA）0．2mmol／kg，注射速率3ml／秒，行增强前、增强后动脉期及静脉期3次扫描，每次扫描时间约10秒，图像减影后至工作站上三维重建。结果116例中由动脉粥样硬化引起的颅内动脉狭窄或闭塞占72．4％；狭窄或闭塞以颈内动脉系统为多，占总狭窄或闭塞的68．7％；颈内动脉系统闭塞或狭窄伴随的脑梗塞高于椎一基底动脉系统；脑梗塞的发生与侧支血管是否形成有关；43例同期行DSA检查者中，80．4％狭窄或闭塞的3DCE-MRA与DSA一致。结论头颅3DCE-MRA结合常规MRI扫描作为一种无创性影像检查技术，可快速而准确地显示颅内大动脉狭窄或闭塞及其相对应的脑梗塞，一次检查即能为临床提供较为全面的信息，可作为脑梗塞患者的首选诊断方法。     

Large middle cerebral artery dissecting aneurysm mimicking hemorrhagic stroke

Dissection of intracranial arteries is a rare cause of cerebrovascular diseases commonly presenting as an ischemic stroke. We report a patient with middle cerebral artery dissection who developed a large middle cerebral artery dissecting aneurysm mimicking a hemorrhagic stroke.     

缘于颈动脉夹层的头痛特征

目的 探讨缘于颈动脉夹层的头痛特征,以期正确识别有头痛症状的颈动脉夹层患者,及时进行相关干预,减少继发于颈动脉夹层的危险并发症,以及防止进行具有潜在危险性的治疗措施和动作。      

磁共振管壁成像在颅内动脉夹层中的应用价值

颅内动脉夹层即颅内血管壁内血肿,是导致中青年缺血性或出血性卒中的重要病因,因血管管径细小,走行迂曲,颅内动脉夹层诊断较困难。磁共振管壁成像作为一种无创性、无放射性检查手段,可直接观察到动脉夹层所致的特征性壁内血肿信号,因而对颅内动脉夹层的诊断、鉴别诊断及随访具有重要作用。本文将对磁共振管壁成像在颅内动脉夹层中的应用价值做一简要综述。     

Cervical artery dissection—clinical features,risk factors,therapy and outcome in 126 patients

Abstract. The highly variable clinical course of cervical artery dissections still poses a major challenge to the treating physician. This study was conducted (1) to describe the differences in clinical and angiographic presentation of patients with carotid and vertebral artery dissections (CAD, VAD), (2) to define the circumstances that are related to bilateral arterial dissections, and (3) to determine factors that predict a poor outcome. Retrospectively and by standardised interview, we studied 126 patients with cervical artery dissections. Preceding traumata, vascular risk factors, presenting local and ischemic symptoms, and patientoutcome were evaluated. Patients with CAD presented more often with a partial Horners syndrome and had a higher prevalence of fibromuscular dysplasia than patients with VAD. Patients with VAD complained more often of neck pain, more frequently reported a preceding chiropractic manipulation and had a higher incidence of bilateral dissections than patients with CAD. Bilateral VAD was significantly related to a preceding chiropractic manipulation. Multivariate analysis showed that the variables stroke and arterial occlusion were the only independent factors associated with a poor outcome. This study emphasises the potential dangers of chiropractic manipulation of the cervical spine. Probably owing to the systematic use of forceful neck-rotation to both sides, this treatment was significantly associated with bilateral VAD. Patients with dissection-related cervical artery occlusion had a significantly increased risk of suffering a disabling stroke.     

Prognosis of intracranial dissection relates to site and presenting features

Intracranial arterial dissection is relatively rare and generally considered to have a worse outcome than extracranial arterial dissection. It is a clinically significant entity that can cause severely disabling ischaemic stroke or subarachnoid haemorrhage (SAH). Only a few large case series of intracranial arterial dissection have been reported, particularly in the anterior circulation, but it is being increasingly recognized with advances in non-invasive angiographic diagnostic procedures. Patients with posterior circulation dissection appear to present more commonly with SAH and are traditionally said to have a worse outcome. Treatment options remain controversial and include medical therapy, as well as endovascular and surgical intervention. We reviewed the clinical features and outcome of 25 patients who had been treated for intracranial dissection at The Royal Melbourne Hospital over a period of 5 years. We recorded patient age, clinical presenting features, neuroimaging findings, treatment, and outcome assessment at 90 days using the modified Rankin Score (mRS). Eleven patients had anterior circulation dissection, while 14 had posterior circulation dissection; and overall 12 patients had cerebral ischaemia while 13 had subarachnoid haemorrhage (SAH). Almost all intracranial arterial dissections occurred spontaneously, without a history of trauma. Patients were relatively young, especially those in the group with ischaemia, with an average age of 39 years. Hypertension was the most commonly identified vascular risk factor. Eight out of 12 patients with ischaemia (66.7%) had anterior circulation dissection, while posterior circulation dissection occurred in 10 of 13 patients with SAH (76.9%). Location of anterior circulation dissection was variable, while the terminal vertebral artery segment was most commonly involved in the posterior circulation group. Most of the patients in the ischaemic group received medical therapy (n = 10/12), while 10 out of 13 (76.9%) patients with SAH underwent endovascular and/or surgical intervention. There was a trend towards more favourable outcome at 90 days (mRS ?3) in the ischaemic group (n = 10/12, 83.3%) compared to the SAH group (n = 6/13, 46.2%), but this did not reach statistical significance (p value = 0.097). The mortality rate was 16.7% (n = 2/12) in the ischaemia group, and 7.7% in the SAH group (n = 1/13), not significant. Among all the ischaemic group patients who received medical therapy, there were no deaths or development of secondary intracranial bleeding complications including SAH at 90 days. Our series suggest that it is possible to divide patients with intracranial dissection into two groups: (i) an ischaemia group, associated with a more favourable clinical outcome even when treated with antiplatelet or anticoagulation therapy; or (ii) a SAH group with a less favourable prognosis. The mortality rate, especially in patients with SAH who are generally treated with endovascular and/or surgical intervention, is less than previously reported. Anterior circulation involvement appears more common than traditionally perceived. The spontaneous occurrence of intracranial dissection in a relatively young age group, the predominant site of dissection in the artery at some distance from its tethered proximal segment, and the commonly observed hypertension, together raise the possibility of spontaneous dissection in arteries prematurely weakened by accelerated atherosclerosis.