橄榄-桥脑-小脑萎缩的临床与MRI影像分析

橄榄-桥脑-小脑萎缩（OPCA）是一种神经系统变性病,是多系统萎缩（MSA）的三种不同临床亚型之一.分遗传性和散发性两种类型.以桥脑、小脑萎缩为特征,临床主要表现为小脑性共济失调.临床结合影像学改变可做出明确诊断.MRI可三维成像,清晰显示后颅窝解剖结构,目前已成为临床诊断OPCA的首选检查方法.     

橄榄-桥脑-小脑萎缩磁共振成像T2加权像“纵线”征

目的:本文收集47例橄榄-桥脑-小脑萎缩(OPCA)患者MR图像,除T1WI发现特征性形态改变外,在T2WI上发现桥脑有纵行线样高信号,我们称之为“纵线”征。材料与方法:47例OPCA患者,30例进行低场磁共振扫描,17例进行高场磁共振扫描;随机抽样因其他原因而进行头部磁共振检查的病例100例作为对照。结果:47例OPCA患者MR图像T2WI上可见位于桥脑至延髓上部贯穿于脑干前后径的连续性细线样高信号41例,高低场无显著性差异。结论:“纵线”征是OPCA的一种特征性异常信号,其病理基础尚不知,有待于进一步病理学或其他方法加以证实。     

脑干脑炎的MRI诊断

目的探讨脑干脑炎的ＭＲＩ表现特点及诊断价值。方法回顾分析２０例脑干脑炎ＭＲＩ表现。结果脑干脑炎ＭＲＩ表现为桥脑、中脑及延髓对称性长Ｔ１、长Ｔ２信号改变,脑干病变以桥脑和中脑多见,延髓少见。按病变部位可将脑干脑炎分为二类：一类为单纯脑干炎症（６例）,另一类为脑干炎症同时伴有大脑半球白质及深部核团（特别是丘脑）等部位病变（１４例）。结论ＭＲＩ可以准确而可靠地反映脑干脑炎的病变性质、部位及程度,是诊断脑干脑炎的首选检查法。     

手足口病合并脑脊髓炎的MRI特征及临床意义

目的：探讨MRI对婴幼儿手足口病合并脑脊髓炎的诊断价值及临床意义。方法：回顾性分析10例经临床诊断为手足口病合并脑脊髓炎患儿的头颅及颈髓MRI检查资料,分析其MRI表现特点。结果：10例中8例累及脑干（80%）,其中脑桥被盖5例,延髓4例,中脑2例;累及小脑齿状核4例,颈髓2例（分别为C2~C4,C4~C7水平）,小脑半球、半卵圆中心及侧脑室后角旁白质各1例;病变在T1WI上为稍低或低信号,T2WI上为稍高或高信号,FLAIR上为稍高或高信号,DWI上为等或稍高信号。结论：婴幼儿手足口病合并脑脊髓炎常累及脑桥被盖、延髓及小脑齿状核,MRI是手足口病合并脑脊髓炎早期诊断及随访的重要手段。     

桥脑及桥脑外髓鞘溶解症4例分析

目的 探讨桥脑中央髓鞘溶解症（CPM）的病因、诊断和康复治疗。方法 回顾性分析4例CPM的临床资料。结果 4例均表现为假性延髓麻痹、肌张力增高；3例有意识不清；2例发生在低钠血症被快速纠正之后；1例发生在高钠血症被快速纠正之后。4例均经头颅MRI检查显示桥脑脱髓鞘病灶，其中3例同时显示脑干外病灶。4例预后均良好。结论 低钠血症被快速纠正是CPM的常见原因，综合康复治疗可以改善预后，提高生活质量。     

Arnold-Chiari畸形MRI诊断

目的：探讨Ａｒｎｏｌｄ－Ｃｈｉａｒｉ畸形（ＡＣＭ）ＭＲＩ表现，并评价ＭＲＩ对其早期诊断及预测病情进展的临床价值；材料和方法：２７例ＡＣＭ均经ＭＲＩ诊断、手术及临床证实，其中男性１１例，女性１６例，年龄８～５６岁，平均３１岁；结果：小脑扁桃体疝至枕大孔平面下５～２６ｍｍ２０例，２～４ｍｍ７例；２５例扁桃体下极变尖，边缘锐直，２例生理曲度存在；２５例扁桃体前池变形，其中扁桃体前池消失和／或颈延髓扭曲成角１１例；伴脊髓空洞１３例，在Ｔ２加权像上脑脊液流空信号减弱３例，经手术证明均为多房空洞；颅颈部各种骨畸形１５例；结论：小脑扁桃体位于枕大孔下５ｍｍ即可诊断ＡＣＭ，对＜５ｍｍ者，在诊断ＡＣＭ前须注意正常扁桃体暂时低位；小脑扁桃体前池消失和／或颈延髓扭曲成角，表示延髓受压，患者病情将迅速恶化；根据Ｔ２加权像脊髓空洞内脑脊液流空信号变化可判断空洞是多房或单房，并能评价ＡＣＭ术后疗效。     

橄榄体桥脑小脑萎缩的MRI诊断

目的探讨OPCA的MRI的诊断价值。方法回顾总结22例OPCA典型的MRI表现。结果22例病例橄榄体桥脑、小脑半球及蚓部明显萎缩。周围脑室、脑池、脑沟明显扩大。11例桥脑下份“十字交叉”形长T2信号。4例小脑中脚长T2信号。3例合并轻度脑萎缩。结论OPCA的MRI表现具有特征性,能作出正确诊断。     

椎基底动脉供血不足患者脑干功能损害与经颅多普勒检测的相关性

目的 探讨椎基底动脉供血不足（VBI）患脑干功能与经颅多普勒（TCD）检测的相关性。方法 对68例临床诊断（VBI）的患进行瞬目反射（BR）、脑干听觉诱发电位（BAEP）和TCD检测。结果 VBI组脑干功能损害84．6％，TCD异常率为83．1％，X^2检验差异无显意义；非VBI组脑干功能损害8．3％，TCD为46．6％，X^2检验差异有显意义。VBI组脑干功能损害及TCD异常为98／136，皆正常为24／136，两占89．7％；非VBI皆异常为4／60，皆正常为32／60，两占60％。结论 根据临床表现，结合BR、BAEP及TCD检查结果可提高对VBI的诊断价值，而单独的TCD结果不足以作为诊断依据。     

病毒性脑干脑炎合并脑动脉炎的磁共振成像特征

目的探讨病毒性脑干脑炎合并脑动脉炎的磁共振成像（MRI）特征。方法回顾性分析经临床和MRI证实的脑干病毒性感染20例临床影像资料。所有患者均行常规T1WI、T2WI、液体衰减反转回复序列（FLAIR）检查,其中增强磁共振血管成像（MRA）检查11例。结果脑干病毒感染性病变位于延髓8例,脑桥13例,中脑5例;病灶单发7例,多发13例;病灶表现为长T1长T2信号。2例椎基底动脉FLAIR显示高信号,增强MRA显示椎基底动脉信号丢失或血管狭窄。结论 FLAIR与增强MRA相结合可以评估椎基底动脉的形态和血液动力学,可在一定程度上为临床的早期诊断脑血管炎及其鉴别诊断提供依据。     

脑干脑炎25例与脑干肿瘤20例MRI诊断及鉴别诊断分析

目的：探讨脑干脑炎与肿瘤的MRI鉴别诊断。方法：回顾分析25例脑干脑炎和20例脑干肿瘤患者的MRI资料，并进行比较。结果：脑干脑炎与脑干肿瘤患者在平均发病年龄（36．7岁、19．8岁）、缓慢起病（12．0％、70．0％）、脑桥双侧受累（92．0％、20％）、出现长T2信号（68％、95％）、边界清楚（12％、65％）、有增强表现（8．0％、90％）。结论：根据脑干脑炎MRI表现特点，结合临床及实验室检查，不难与脑干肿瘤作出鉴别诊断，对临床治疗起重要作用。     

颞下颌关节解剖及正常MRI表现

目的:研究颞下颌关节的影像解剖并观察其正常MR影像的特点来评价其诊断价值。材料与方法:筛选15例正常颞下颌关节,对其双侧颞下颌关节(Temporomandibular Joint)分别进行张及闭口位MR扫描,扫描方位包括斜冠状位、斜矢状位及横断位,序列包括T1WI、TWI、PDWI。结果:MRI可清晰显示关节盘前、中、后带,关节结节,关节腔,关节窝,髁状突,双板区等解剖结构及其相互关系。结论:多种序列及方位联合应用可更为真实的反映颞下颌关节运动状况的影像学表现并为诊断提供更为可靠的依据。     

MRI在侵袭性垂体腺瘤中的诊断价值

目的探讨MRI在侵袭性垂体腺瘤中的诊断价值,提高其术前正确诊断率。方法回顾性分析110例MR诊断并经手术病理结果证实的垂体腺瘤。结果MRI诊断52例侵袭性垂体腺瘤,表现为突破鞍隔向鞍上生长;侵入蝶窦;累及海绵窦、包绕颈内动脉。术中发现65例为侵袭性生长,MRI阳性预测值为86.5%。侵袭性垂体腺瘤以多功能腺瘤和泌乳素腺瘤多见,分别占33.8%、24.6%。结论MR诊断侵袭性垂体腺瘤具有较高的敏感性和阳性率,对治疗方案的选择有重要的指导意义。     

ADC mapping of neurodegeneration in the brainstem and cerebellum of patients with progressive ataxias

Analysis of the apparent diffusion coefficient (ADC) maps derived from diffusion-weighted MR imaging is emerging as a reproducible, sensitive, and quantitative tool to evaluate brain damage in diseases of the white and gray matter. To explore the potentials of ADC maps analysis in degenerative ataxias, we examined 28 patients and 26 age-matched controls with T1, T2, and diffusion (b values 0-1000 along the three main body axes)-weighted MR images. Twenty-four patients had inherited genetically proven diseases including spinocerebellar ataxia type 1 (SCA1) (n = 9), spinocerebellar ataxia type 2 (SCA2) (n = 8), and Friedreich's ataxia (FA) (n = 7), whereas four patients had sporadic adult onset pure cerebellar ataxia (three idiopathic, one gluten intolerance). Area and linear measurements of the CNS structures contained in the posterior cranial fossa (PCF) preliminary enabled classification of the patients in the three morphological categories reflecting the gross pathology findings, namely olivopontocerebellar atrophy (OPCA) (n = 10: six SCA2 and four SCA1), spinal atrophy (SA) (n = 7: all FA), and cortical cerebellar atrophy (CCA) (n = 4: three idiopathic and one gluten intolerance). Seven patients with SCA1 (n = 5) or SCA2 (n = 2) had morphologic changes reminiscent of OPCA, but their values were still in the lower normal range and were classified as undefined. Mean diffusivity (D) maps of the entire brain were generated and D was measured with regions of interest (ROI) in the medulla, pons, middle cerebellar peduncles, and the peridentate white matter. Moreover, after exclusion of the skull with manual segmentation and of the CSF with application of a threshold value, histograms were obtained for D of the brainstem and cerebellum and for D of the cerebral hemispheres. As compared to controls, a (P < 0.001) increase of D was observed in the medulla, middle cerebellar peduncles, and peridentate white matter in OPCA and undefined patients groups who had also significantly increased values of the 25th and 50th percentiles in the brainstem and cerebellum D histogram. In CCA (P = 0.01), an increase of the 25th and 50th percentile of the D value was observed in the brainstem and cerebellum histograms. The SA group showed (P < 0.001) an increased D in the medulla only. A correlation between clinical severity as assessed with the Inherited Ataxias Clinical Rating Scale (IACRS) and the 50th percentile of the D value in the brainstem and cerebellum histogram (r = 0.69) was observed in patients with SCA1 or SCA2. Diffusion MR imaging reveals variable patterns of increase of D in the brainstem, cerebellum, and cerebral hemispheres in degenerative ataxias that match the known distribution of the neuropathological changes.     

Two types of abnormal somatosensory evoked potentials in chronic cerebellar ataxias

To investigate subclinical sensory impairment in spinocerebellar degenerations, median nerve somatosensory evoked potentials (SEPs) were examined in 16 patients with chronic cerebellar ataxia who were originally diagnosed by clinical neurologists as having olivopontocerebellar atrophy (OPCA). Two types of abnormal SEP patterns were found in six patients. Two patients had the SEP pattern of peripheral neuropathy, which was also detected by peripheral sensory nerve conduction studies. Four patients had abnormal SEPs seen in patients with the lesions in the central nervous system (dorsal column, medial lemniscus). Magnetic resonance imaging (MRI) showed multiple sclerosis (MS). It is possible that clinically diagnosed OPCA sometimes includes a similar form of Friedreich's ataxia with subclinical sensory fiber neuropathy detected by SEPs and peripheral sensory conduction studies. In cases of lesions in the central nervous system demonstrated by both SEPs and MRI, there must be a follow-up in order to make a final diagnosis. In those cases, an alternative diagnosis of MS must be considered when the temporal profile of symptoms and signs characteristic of MS is observed.     

Epidemiological findings and clinical and magnetic resonance presentations in subacute sclerosing panencephalitis

Subacute sclerosing panencephalitis (SSPE) is a rare, progressive, inflammatory neurodegenerative disease. This study investigated the relationships of clinical stage with epidemiological and magnetic resonance imaging (MRI) findings in SSPE by retrospective review of 76 cases (57 male) diagnosed by typical periodic electroencephalographic features, clinical symptoms and elevated measles antibody titre in cerebrospinal fluid. Clinical stage at diagnosis was I or II in 48 patients, III in 25 and IV in three. Prominent findings at presentation were atonic/myoclonic seizures (57.9%) and mental deterioration with behaviour alteration (30.3%). Frequent MRI findings (13 - 32 patients) were subcortical, periventricular and cortical involvement and brain atrophy; the corpus callosum, basal ganglia, cerebellum and brainstem were less frequently involved. Five patients had pseudotumour cerebri. Cranial MRI at initial diagnosis was normal in 21 patients (19 stage I/II, two stage III/IV). Abnormal MRI findings were significantly more frequent in the later stages, thus a normal initial cranial MRI does not exclude SSPE, which should, therefore, be kept in mind in childhood demyelinating diseases even when the presentation is unusual.     

先天性遗传性蛛网膜囊肿引发对橄榄体脑桥小脑萎缩的临床研究

目的初步探讨橄榄体脑桥小脑萎缩（olivopontocerebellar atrophy，OPCA）的显微解剖结构、病因和发病机制。方法对近5年北京天坛医院神经外科28例OPCA的患者作临床、分子遗传学及影像学特征研究。结果OPCA是主要累及小脑、脑干和脊髓的进行性神经变性病。结论OPCA有遗传和散发两类，临床有多种类型和变异型。对OPCA所采用的基因诊断可以直接在DNA水平上鉴定突变基因。SCA1、SCA2、SCA7的CAG可作为基因诊断的标志。在临床上凡有小脑性共济失调，特别是以此为首发症状者，均应首选做MR检查，这对OPCA的诊断及鉴别诊断具有重要意义。     

脑基底异常血管网症的MRA诊断价值的探讨

目的:探讨MRA和MRI对脑基底异常血管网症诊断价值。材料与方法:回顾性分析14例脑基底异常血管网症的MRA和DSA表现,其中10例行MRA检查,5例行DSA(1例同时做MRA和DSA检查),采用2.0T超导高磁场MR扫描仪,MRA采用3D-TOF或3D-PC法。DSA采用美国GEAdvantx心血管造影系统。结果:MRA显示狭窄或闭塞的血管,表现为多支、双侧受累。MRI平扫表现脑基底部狭窄、闭塞血管的流空效应减弱甚至消失,侧支循环血管形成所致的点状、条状迂曲低信号影。5例颅内可见血肿。结论:MRA作为一种无创伤的血管成像技术,能准确诊断moyamoya病,可以与DSA媲美,结合MRI平扫可同时显示脑组织病变。     

MRI迷路水神经成像对三叉神经痛神经血管压迫的诊断价值

  目的  探究MRI迷路水神经成像诊断三叉神经痛和神经血管压迫的效果。  方法  回顾性分析我院168例三叉神经痛患者的临床资料,均行手术治疗证实,且进行MRI迷路水神经成像检查,分析患者神经血管压迫的影像学检查结果,与手术结果对比,并比较患者三叉神经池段形态学参数（三叉神经脑池段最大长度及面积、三叉神经-桥脑夹角、桥小脑角池截面）。  结果  168例三叉神经痛患者中MRI成像检测处左侧受压80例,与临床左侧三叉神经痛分布区的相符率为90.91%,右侧受压74例,与临床右侧三叉神经痛分布区的相符率为92.50%,未见压迫14例;患侧和健侧压迫位置的差异无统计学意义（P>0.05）;主要压迫动脉为中小脑上动脉,占70.83%（119/168）;患侧压迫程度较高（P < 0.05）;两侧三叉神经最大长度的差异无统计学意义（P>0.05）,患侧三叉神经横截面积、三叉神经桥脑夹角、桥小脑角池截面积较低（P < 0.05）。  结论  MRI迷路水神经成像能够有效诊断三叉神经痛,显示神经周围具体情况,判断三叉神经脑池段形态学改变,为临床三叉神经痛神经血管压迫的诊断提供依据。      

脑内囊虫病的磁共振诊断(附9例分析)

目的 描述脑内囊虫病的MRI的表现，探讨该病变的病理学改变特征及MRI的诊断价值。方法 对8例经临床及实验室检查证实及1例经手术病理证实的脑内囊虫病进行了MRI检查，对其MRI影像学表现特征进行了回顾性分析。结果 MR显示8例均为多发小病灶，1例为单发病灶，病灶位于四脑室。其中6例病灶位于脑实质，2例病灶位于脑实质及四叠体池。病灶在T1WI上圆形或卵圆形低信号，T2WI上呈高信号，部分囊壁上可见等信号的头节影。经钆喷替酸葡甲胺(GD-DTPA)增强后部分虫体有环形强化，其中有2例各有1个病灶呈结节状强化，病灶周围见明显水肿。结论 磁共振不仅能正确诊断和发现脑内囊虫病而且能正确描述囊虫病的病理特点。