神经白塞病中枢神经系统受累的MRI分析（1）（英）

CNS Involvement in Neuro-Beh?et Syndrome: An MR Study

神经白塞病中枢神经系统受累的MRI分析

Naci Ko?er, Civan Islak, Aksel Siva, Sabahattin Saip, Canan Akman, Orhun Kantarci and Vedat Hamuryudan

From the Departments of Radiology (N.K., C.I., C.A.), Neurology (A.S., S.S., O.K.), and Internal Medicine (V.H.), Cerrahpasa School of Medicine, Istanbul, Turkey.

Received August 27, 1998; accepted after revision February 8, 1999.

American Journal of Neuroradiology 20:1015-1024 (6 1999)

Abstract

BACKGROUND AND PURPOSE: Beh?et disease (BD) is a multisystem vasculitis of unknown origin in which neurologic involvement has been reported in the range of 5% to 10% in large series. Reports on clinical and radiologic aspects of neuro-Beh?et syndrome (NBS) are in general limited in number. Our purpose was to determine the MR patterns in patients with NBS who had neural parenchymal involvement and to correlate our findings with possible vascular pathophysiology.

研究背景和研究目的：白塞病（Beh?et disease, BD）是一种不明原因的累及多系统的血管炎，约5%~10%的患者神经系统受累。总的说来，神经白塞病（neuro-Beh?et syndrome, NBS）的临床和影像学研究报道的较少。本研究的目的在于对中枢神经系统实质受累的神经白塞病患者行相应的MR序列检查后分析其影像特点并与其可能的血管病理生理变化相联系。

METHODS: The MR images of 65 patients with NBS and neural parenchymal involvement were reviewed. In a subgroup of patients who had serial MR studies, we evaluated the anatomic-radiologic location and distribution of the lesions and whether they corresponded to any vascular territory, and studied their extension, enhancement patterns, and temporal course.

方法：回顾65例中枢神经系统实质受累的神经白塞病患者的MRI影像，评估病灶的分布、位置及是否符合血管分布，并分析病灶的延伸情况、增强后病灶的特点、不同病程时的病灶特点。

RESULTS: The most common imaging finding in NBS patients who had neural parenchymal involvement was a mesodiencephalic junction lesion with edema extending along certain long tracts in the brain stem and diencephalon in 46% of the patients. The next most common location of involvement was the pontobulbar region, seen in 40% of the cases. Three primary cervical spinal cord lesions and one case of isolated optic nerve involvement were observed.

结果：中枢神经系统实质受累的神经白塞病患者最常见的影像特点是病灶位于中脑-间脑接合处，周围水肿带延长轴向脑干、间脑延伸，约46%的患者可见此改变。次常见的病灶部位分布于脑桥延髓区，约40%的患者可见此改变。另外还发现3例患者主要为颈髓受累、1例患者视神经单独受累。

CONCLUSION: The parenchymal distribution of lesions in NBS appears to support the hypothesis of small-vessel vasculitis; mainly, venular involvement. The anatomic distribution of intraaxial veins of the CNS explains the predominant involvement of the brain stem structures observed in our patients. This pattern of lesion distribution might help to differentiate NBS from other vasculitides as well as from the inflammatory-demyelinating diseases of the CNS, such as multiple sclerosis.

结论：神经白塞病的病灶分布特点似乎支持小血管炎假说，主要为小静脉受累。中枢神经系统的intraaxial静脉解剖分布可以解释病变主要累及脑干结构。病灶分布特点有助于将神经白塞病与中枢神经系统其它血管炎疾病和炎性脱髓鞘性疾病（如多发性硬化）相鉴别。

Introduction

Beh?et's disease (BD) is a multisystem vasculitis of unknown origin. The classical triad of oral and genital ulcerations with uveitis was originally described by a Turkish dermatologist Hulusi Beh?et in 1937^[1]. Other structures reported to be involved through the course of the disease are the cardiovascular, CNS, pulmonary, and gastrointestinal systems^[2–4].

白塞病（Beh?et disease, BD）是一种不明原因的累及多系统的血管炎。1937年土耳其皮肤科医师Hulusi Beh?et首先描述了经典的三联症——眼葡萄膜炎/眼色素层炎、口腔溃疡、生殖器溃疡（眼-口-生殖器三联综合征）。病程中其它系统如心血管系统、中枢神经系统、肺部、胃肠道系统均可受累。

Early neuroimaging reports on neuro-Beh?et syndrome (NBS) were based on studies done with either CT or, rarely, cerebral angiography. To our knowledge, the largest series in which neuroimaging findings were based on CT studies were those reported by Inaba^[5], in which 63 patients were examined, and by Siva et al^[6], who described the findings in 42 patients with NBS examined at this institution. With the introduction of MR imaging in clinical practice, articles reporting the MR findings in NBS have appeared; however, most of these are limited to either single cases or to relatively small series^[7–11]. The most common CNS findings reported in these studies, including ours, were a preference for brain stem–diencephalic involvement and a tendency to resolve over time. Cerebral venous thrombosis is another common neuroimaging finding reported in NBS^[12].

早期关于神经白塞病的神经影像学研究主要是基于CT检查，Inaba在文献《Clinical features of neuro-Beh?et syndrome》中利用CT研究分析了63例神经白塞病患者的神经影像学特点，Siva等人在文献《Neuro-radiologic findings in neuro-Beh?et syndrome》中利用CT研究分析了42例神经白塞病患者的神经影像学特点；另外，也有利用脑血管造影技术研究分析神经白塞病的神经影像学特点的少量报道。随着MRI技术在临床应用中的普及出现了一些利用MRI研究神经白塞病影像学特点的报道，但大部分仅限于个案报道或病例数相对较少的病案报道。包括本研究在内的以上各研究均提示：脑干-间脑处是最常见的受累部位，且病灶会随时间推移而逐渐消散。脑静脉血栓形成也是神经白塞病中另一个较常见的影像学发现。

In this study, we included only NBS patients who had CNS parenchymal involvement on MR imaging studies in order to define the MR patterns of this form of the disease and to correlate those findings with the results of vascular anatomic-pathologic investigation.

在本研究中，我们只对中枢神经系统实质受累的神经白塞病患者行MRI检查，进而分析其MRI影像特点并与其血管解剖病理变化相联系。

Methods

Sixty-five consecutive patients with neurologic symptoms caused by BD and with CNS parenchymal involvement on MR images were included for evaluation. All patients were referred from the Beh?et's Disease Research Center of our university hospital. Criteria established by the International Study Group for Beh?et Disease^[13] were used for diagnosis. Neurologic involvement was evaluated and defined by the neurology consultants of the Research Center from the department of neurology, who referred the patients for MR examination. Sixty-three patients had fulfilled the criteria for BD before the onset of neurologic involvement and two at the time of neurologic involvement. The study period ranged from January 1, 1990, to December 31, 1997.

我们收集了大学附属医院白塞病研究中心自1990年1月1日至1997年12月31日收治的65例患者进行评估。所有患者均在白塞病的基础上出现了神经系统症状、均在MRI上表现出了中枢神经系统实质受累、均符合国际白塞病研究小组于1992年在文献《Evaluation of diagnostic ("classification") criteria in Beh?et's disease: towards internationally agreed criteria》中提出的诊断标准。研究中心的神经科会诊医师评估并明确了所有患者均有神经系统受累并建议行MRI检查。所有65例患者中，63例患者在神经系统受累症状出现之前便已符合了白塞病的诊断标准，2例在神经系统受累症状出现时符合了白塞病的诊断标准。

The patients included 18 women and 47 men, ages 19 to 51 years (mean age, 36 years). Patients with normal MR findings (21 cases) and with isolated dural sinus thrombosis (13 cases) were excluded from the study, because our primary goal was to evaluate parenchymal involvement. In 48 cases (74%), a 1.0-T MR imager was used, whereas the remaining patients were studied with different MR systems, ranging from 0.5 T to 1.5 T, as some patients had been examined prior to the time of consultation. The imaging was assumed to have been done in the acute stage if the patient was studied within a week of the onset of the neurologic episode or subacute if within a month. MR studies consisted of sagittal and axial T1-weighted spin-echo (SE) sequences and coronal and axial proton density–or T2-weighted fast SE sequences with 3- to 6-mm contiguous sections over the whole brain. Additional cervical spinal cord examinations with sagittal T1- and T2-weighted SE and axial T2-weighted fast SE sequences were performed in three patients, because their clinical picture suggested cervical spinal involvement. A section thickness of 3 mm was used for spinal cord examinations. Contrast material was used in 11 cases. Twenty-three patients underwent follow-up MR examinations (more than one follow-up in eight cases).

鉴于我们的目的在于评估中枢神经系统实质受累的情况，我们将MRI正常的另外21例患者和单纯硬脑膜静脉窦血栓形成的另外13例患者排除于本研究之外。在本研究收集的所有65例患者中，包括18位女性和47位男性，年龄19~51岁（平均年龄36岁）。其中，48例患者行1.0T MR扫描，余下17例患者则因在神经科医师会诊之前便已行MR检查，因此分别用0.5T~1.5T的不同的MR扫描。在神经系统症状出现的1个星期内即行MR检查的为急性期患者，在神经系统症状出现的1个月内行MR检查的为亚急性期患者。MR扫描序列包括矢位、轴位T1加权自旋回波序列（T1-weighted spin-echo sequences）和冠位、轴位质子密度或T2加权快速自旋回波序列（proton density- or T2-weighted fast SE sequences），均行全脑扫描，层厚3~6mm。此外，鉴于3例患者临床表现提示颈髓受累，因此加行颈髓矢位T1、T2加权自旋回波序列（T1- and T2-weighted SE sequences）和轴位T2加权快速自旋回波序列（T2-weighted fast SE sequences）扫描，层厚3mm。11例患者行对比增强扫描。23例患者行MR随访检查，其中8例患者MR随访检查次数不止1次。

The distribution of the lesions and whether they corresponded to any vascular territory, their extension and enhancement patterns, as well as the temporal course in the subgroup of 23 patients with serial MR examinations were studied and classified.

我们对病灶的分布、病灶部位是否符合血管分布、病灶的延伸情况、增强后病灶的特点、23例MR随访患者不同病程时的病灶特点均分别加以研究和分类。

Results

The mean age of onset of neurologic symptoms was 26.8 ± 7.6 (SD) in patients with BD and 30.2 ± 8.5 for those with NBS. The male to female ratio was 2.6 to 1.0, showing a clear male preponderance. Fifty-two (80%) of the patients were examined in the acute/subacute phase and 13 (20%) in the chronic phase. Six patients (9%) had a primary-progressive course and nine (14%) had converted to a secondary-progressive course at the time of their MR study. The remaining patients, who had either a single attack or a relapsing-remitting form of the disease (77%), were studied during such an episode. Symptoms at onset in the order of frequency were headache, 85%; weakness, 57%; brain stem and/or cerebellar involvement, 50%; cognitive and behavioral disorders, 16%; and disorders of consciousness, 7%.

白塞病患者中出现神经系统症状的平均年龄为26.8±7.6岁，而神经白塞病患者中出现神经系统症状的平均年龄则为30.2±8.5岁。男女比例为2.6：1.0，男性好发。52例（80%）患者于急性期/亚急性期性行MR检查，13例（20%）患者于慢性期行MR检查。6例（9%）患者在行MR检查时为原发进展型病程，9例（14%）患者在行MR检查时已转为继发进展型病程，其余（77%）均为单次发病患者或复发缓解型患者，均于发病时行MR检查。首发症状的出现频率为：头痛85%；无力57%；脑干和/或小脑症状50%；认知行为异常16%；意识障碍7%。

Distribution of Lesions

病灶的分布

A total of 94 lesions were identified in the 65 patients. The most commonly affected region was the mesodiencephalic junction (MDJ), seen in 30 patients (46%), followed by the pontobulbar region in 26 (40%), the hypothalamic-thalamic region in 15 (23%), the basal ganglia in 12, the telencephalon in five, the cerebellum in three, and the cervical cord in three (Table 1). There was no difference in the distribution of lesions between the acute/subacute or chronic phases.

所有65例患者中共发现94处病灶。最常见的受累部位为中脑-间脑接合处（mesodiencephalic junction, MDJ），共在30例（46%）患者中发现此处受累；其次为脑桥延髓区，共在26例（40%）患者中发现此处受累；再次为下丘脑-丘脑区，共在15例（23%）患者中发现此处受累；在12（18%）例患者中发现基底节区受累；5例（8%）患者端脑受累；3例（5%）患者小脑受累；3例（5%）患者颈髓受累（表1）。

Table 1: Lesion distribution in 65 patients with neuro-Beh?et syndrome

表1：65例神经白塞病患者的病灶分布

Of the 30 MDJ lesions, 11 showed a marked upward extension involving the diencephalic structures and 18 had a prominent downward extension involving the pontobulbar region. In six, the extension was both upward and downward (Fig 1). In a single case, studied in the chronic stage, the MDJ lesion was isolated, suggestive of a sequela.

在30处中脑-间脑接合处病灶中，11处病灶显著向上延伸累及间脑结构，18处病灶显著向下延伸累及脑桥延髓区域。6处病灶既向上延伸又向下延伸（图1）。仅1例患者在慢性期行MR检查时仅见中脑-间脑接合处单独受累，提示为后遗症。

FIG 1. A, Coronal T2-weighted image (4000/90/2 [TR/TE/excitations]) at the level of the crus cerebri nicely shows heterogeneous left MDJ lesion with extensive edema, sparing the red nucleus.

图1. A，冠位T2像示大脑脚水平可见左侧不均匀的中脑-间脑接合处病灶，周围有广泛的水肿带，但红核未受累。

B, Coronal noncontrast T1-weighted image (300/15/3) at the same level as A reveals a hemorrhagic focus in the lesion.

B，冠位T1像示与图A相同部位、相同水平的病灶处可见出血灶。

C, Coronal T2-weighted image (4000/90/2) posterior to A shows extension of perilesional edema caudally to the superior cerebellar peduncle and pontine tegmentum, and upward to the white matter of the temporal lobe, external capsule, and thalamus.

C，相对于图A偏后的层面的冠位T2像示广泛的水肿带上至丘脑、外囊、颞叶白质，下至小脑上脚/结合臂、脑桥被盖部。

D, Caudal extension of the edema toward the pontine tegmentum is seen on axial T2-weighted image (4000/90/1).

D，轴位T2像示水肿带向下已延伸至脑桥被盖部。

E, Two years later, after another relapse of the disease, coronal T2-weighted image (4000/90/1) reveals a contralateral MDJ lesion. The left-sided lesion now has shrunk to a small hypointense area.

E，2年后患者再次复发，冠位T2像示对侧（右侧）中脑-间脑接合处也出现病灶。原先病灶侧（左侧）的病灶缩小为一处小的低密度区。

F, Contrast-enhanced T1-weighted image (660/17/1) shows enhancement of the new right MDJ lesion.

F，对比增强T1像示右侧新发的中脑-间脑接合处病灶强化。

G and H, Similar extension of edema as observed in C and D is seen in the right mesencephalopontine region of the brain stem on T2-weighted images (4000/90/1).

G和H，轴位T2像上与C图、D图相似，右侧脑干的中脑脑桥区也见广泛的水肿带。

Of the 26 lesions with pontine and bulbar involvement, three had no association with other lesions (Fig 2). Twelve were associated with tegmental and superior cerebellar peduncular extension, and six showed corticospinal tract involvement in continuity with an MDJ lesion. In one patient with additional telencephalic lesions, the right side of the pons was hyperintense on long TR/TE images that did not cross the midline, suggestive of an arterial lesion (Fig 3). In two patients with pontine tegmental lesions, there was an associated middle cerebellar peduncle and deep cerebellar white matter involvement (Fig 4). Two others had associated cervical lesions.

在26处脑桥延髓区病灶中，3处病灶仅限于脑桥延髓区，其它部位无病灶（图2）；12处病灶还同时伴有背盖部和小脑上脚/结合臂处病灶；6处病灶为与中脑-间脑接合处病灶相连的皮质脊髓束受累；还有1例患者除端脑见病灶外，右侧脑桥于T2像也见高信号病灶，但未超越正中线，提示可能系动脉病变所致（图3）；2例脑桥背盖部病灶的患者同时伴有小脑中脚/小脑脑桥脚和小脑深部白质受累（图4）；还有2处脑桥延髓区病灶还同时伴有颈髓病灶。

FIG 2. Axial T2-weighted image (2400/110/2) shows inhomogeneous hyperintense lesion located in the mid pons.

图2. 轴位T2像示脑桥中部不均匀的高信号病灶。

FIG 3. Axial T2-weighted image (2400/110/2) at the pontine level shows a right-sided pontine lesion that does not cross the midline.

图3. 轴位T2像示右侧脑桥处高信号病灶，但未超越中线。

FIG 4. A and B, Axial (A) and coronal (B) T2-weighted images (4000/90/2) reveal hyperintense lesions bilaterally in the middle cerebellar peduncles and deep cerebellar white matter.

图4. 轴位（A）、冠位（B）T2像示双侧小脑中脚/小脑脑桥脚和小脑深部白质病灶。

Cervical cord lesions were seen in three patients. They were predominantly located in the posterolateral part of the cord, continuing over at least two vertebral segments, with a tendency to reach the inferior cerebellar peduncles superiorly (Fig 5). One of them also had concomitant MDJ and pontobulbar region lesions.

3例患者查见颈髓病灶，主要位于颈髓后外侧部，至少累计2个节段，并有向上延伸至小脑小脚/绳状体上份的趋势（图5）；其中1个病灶还同时伴有中脑-间脑结合处病灶和脑桥延髓区病灶。

FIG 5. A~C, Midsagittal cervical lateral T2-weighted image (2200/80/1) (A) and axial T2-weighted image (4000/90/2) through the cervical medullary junction (B) show posteriorly located paracentral hyperintense lesion with mild cervicomedullary enlargement. The pattern of extension up to the inferior cerebellar peduncle suggests involvement of the dorsal columns. Midsagittal cervical lateral T1-weighted image (300/15/3) (C) shows slight enlargement of cervical cord.

图5. A~C，颈髓正中矢状位T2像（A）、颈髓延髓结合处轴位T2像（B）示旁中央偏后的高信号病灶，伴颈髓、延髓轻度膨大，病灶向上延伸至小脑下脚/绳状体，提示脊髓后索受累；颈髓正中矢状位T1像（C）示颈髓轻度膨大。

Of the 12 patients with basal ganglia and/or capsular lesions, one patient had involvement of the caudate nucleus and the adjacent anterior limb of the internal capsule without any other parenchymal abnormality. In the other 11 cases, the posterior limb of the internal capsule alone (n = 4) or together with the external capsule and putamen (n = 3) or with the globus pallidus (n = 4) were affected. In all 11 of these patients, additional MDJ and/or thalamic-hypothalamic lesions were also found.

在12例基底节区和/或内囊受累的患者中，1例患者仅见尾状核及邻近的内囊前肢受累，其余部位均未见病灶；余下11例患者，内囊后肢单独受累4例；内囊后肢、壳核、外囊共同受累3例；内囊后肢同时伴苍白球受累4例；这11例患者除基底节区和/或内囊受累外，均还可见中脑-间脑结合处和/或丘脑-下丘脑区病灶。

Telencephalic lesions were seen in only five patients (8%) and had a wide asymmetric distribution within the brain, involving the optic nerves and the subcortical and deep periventricular white matter (Fig 6). In the patient with optic neuropathy, the only finding was right optic nerve enhancement. In the other four patients, the hemispheric lesions were located in the subcortical and deep periventricular white matter without cortical involvement. These patients also had concomitant MDJ lesions, and, in one, wallerian degeneration of the optic radiation was observed in association with primary MDJ involvement (Fig 7). Two patients had prominent periventricular central atrophy, and four patients had asymmetric brain stem atrophy. All these patients had long-standing NBS.

仅于5例（8%）患者见端脑广泛的、不对称分布的病灶，病变包括视神经、皮质下白质、脑室周围深部白质（图6）。在1例视神经病患者中，唯一的发现仅为右侧视神经强化；其余4例患者中，病灶均位于皮质下白质、脑室周围深部白质，皮层均未受累，且同时均伴有中脑-间脑结合处病灶，其中1例患者可见视辐射华勒变性伴中脑-间脑结合处病灶（图7）。2例患者可见脑室周围明显萎缩，4例患者可见脑干不对称萎缩，这些患者均长期罹患神经白塞病。

FIG 6. A, Axial T2-weighted image (3500/90/2) shows a well-defined deep right occipital white matter lesion (asterisk) and a subcortical linear hyperintensity (arrow).

图6. A，轴位T2像示右枕叶深部白质边界清楚的高信号病灶（星号处）及皮质下白质线状高密度病灶（箭头处）。

B, Coronal T2-weighted image (3500/90/1) in a different patient shows multiple subcortical white matter and right MDJ and pontine lesions (asterisk and arrowheads).

B，另一位患者冠位T2像示皮质下白质多发的病灶及右侧中脑-间脑结合处（箭头处）、脑桥（星号处）的病灶。

FIG 7. A, T2-weighted image (4000/90/2) shows chronic left MDJ lesion (double arrowhead) and ipsilateral lenticulostriatal lesions (arrow).

图7. A，冠位T2像示左侧中脑-间脑结合处病灶（双箭头处）及同侧豆状核、纹状体（箭头处）病灶。

B, Wallerian degeneration of the optic radiation is evident on paraatrial section of the same sequence (double arrowheads).

B，冠位T2像示明显的视辐射华勒变性病灶（双箭头处）。

Characteristics of the Lesions

病灶的特点

The lesions observed during an acute/subacute episode were surrounded by a more hyperintense rostral and caudal extension on long-TR sequences, which was directly related to the location of the lesion. When located posteriorly at the MDJ, lesions tended to continue downward along the pontine tegmentum and superior cerebellar peduncle, whereas the corticospinal tract was the structure affected in more anteriorly located lesions. In all these lesions with downward extension, the red nucleus was always spared. The upward extension seen with the acute lesions was characterized by involvement of the posterior limb of the internal capsulae, accompanied by involvement of the globus pallidus in four and the putamen and external capsule in three. In lesions of the cervical spinal cord, the bulbar involvement was through extension via sensory long fiber tracts (fasciculus gracilis and cuneatus). The cranial and caudal extensions were found to disappear or decrease in size, leaving a residual lesion on follow-up examinations, as discussed below. These residual lesions were iso- to hypointense on T1-weighted images and slightly hyperintense on proton density–and T2-weighted images, with or without atrophy (Table 2).

在长TR序列扫描（质子密度加权像和T2加权像）时，急性期/亚急性期病灶周围常可见向上或向下延伸的高密度病灶，至于是向上还是向下延伸主要取决于病灶的部位。当病灶位于中脑-间脑结合处的偏后方时，倾向于沿着脑桥背盖部和小脑上脚向下延伸；当病灶向下延伸时，红核常不受累。但当病灶位于中脑-间脑结合处的偏前方时，倾向于累及皮质脊髓束；急性期向上延伸的病灶常累及内囊后肢，伴苍白球受累（4例）和壳核、外囊受累（3例）。位于颈髓的病灶常经薄束和楔束向上延伸累及延髓。行MR随访检查发现，颅内病灶和低位病灶的大小常随时间推移而逐渐减小或消失，遗留下一个在T1加权像上呈等密度或低密度、在质子密度加权像和T2加权像上呈轻微高密度的后遗症病灶，可伴或不伴萎缩（表2）。

（PS：T1和T2是组织在一定时间间隔内接受一系列脉冲后的物理变化特性。不同组织有不同的T1和T2，它取决于组织内氢质子对磁场施加的射频脉冲的反应。通过设定MRI的成像参数TR和TE（TR是重复时间即射频脉冲的间隔时间，TE是回波时间即从施加射频脉冲到接受到信号的时间，TR和TE的单位均为毫秒/ms）可以做出分别代表组织T1或T2特性的图像/T1加权像或T2加权像，通过成像参数的设定也可以做出既有T1特性又有T2特性的图像，称为质子密度加权像。TE短可为20ms，长可为80ms；TR短可为600ms，长可为3000ms。短TE、短TR为T1加权像；而长TE、长TR为T2加权像；短TE、长TR为质子密度加权像。了解水和脂肪的信号特征有助于区分T1加权像和T2加权像，特别是在图像没有显示特征性的TE和TR值时更有价值。观察液体结构如脑室、脑脊液，若液体是亮的，很可能为T2加权像；若液体是暗的，则可能为T1加权像；若液体是亮的，而其他结构不像是T2加权像，且TR和TE均短，则可能是梯度回波图像。）

Table 2: MR findings in acute and chronic phase

表2：神经白塞病急性期和慢性期的MRI特点

Serial MR examinations were performed in 23 cases. Of those, 18 were for follow-up purposes, whereas in five the subsequent studies were done because of a relapse or worsening in neurologic status. These MR examinations revealed resolution or decrease in the size of the lesions, 17 of which had shrunk to small areas with nearly total disappearance of the perilesional extension.

我们对23例患者行MR随访检查，其中18例患者是为了随访的目的而行MR检查，另外5例则是因为神经系统症状复发或恶化而行MR检查。结果显示病灶的大小随时间推移而逐渐减小或消散，17例患者的病灶缩小至一小处区域且病灶周围的延伸几乎完全消失。

Sixty patients had nonhemorrhagic lesions while five had hemorrhage (Table 3). Nonhemorrhagic lesions showed prolonged T1 and T2 relaxation times. They were mostly heterogeneous and asymmetric. Of the five patients with hemorrhagic lesions, three were in the subacute phase, as they appeared hyperintense on T1-, proton density–, and T2-weighted sequences, whereas the other two, which were hypointense on all sequences owing to the existence of hemorrhagic degradation products, as previously described, were in the chronic stage^[14].

60例患者病灶内无出血，5例患者病灶内可见出血（表3）。无出血的病灶常为不对称的、不均匀的病灶，T1和T2弛豫时间均延长。5例出血病灶中，3例均为亚急性期，因为在T1加权像、质子密度加权像、T2加权像均表现为高密度；另外2例均为慢性期，因为在T1加权像、质子密度加权像、T2加权像上由于出血退化产物的存在而均表现为低密度。

（PS：用特定频率的射频脉冲（radionfrequency, RF）进行激发，作为小磁体的氢原子核吸收一定量的能而共振，即发生了磁共振现象。停止发射射频脉冲，被激发的氢原子核就会把所吸收的能逐步释放出来，其相位和能级都恢复到激发前的状态。这一恢复过程称为弛豫过程（relaxation process），而恢复到原来平衡状态所需的时间则称之为弛豫时间（relaxation time）。有两种弛豫时间，一种是自旋-晶格弛豫时间（spin-lattice relaxation time），又称纵向弛豫时间（longitudinal relaxation time），反映自旋核把吸收的能传给周围晶格所需要的时间，也就是90°射频脉冲质子由纵向磁化转到横向磁化之后再恢复到纵向磁化激发前状态所需时间，称T1。另一种是自旋-自旋弛豫时间（spin-spin relaxation time），又称横向弛豫时间（transverse relaxation time），反映横向磁化衰减、丧失的过程，也即是横向磁化所维持的时间，称T2。T2衰减是由共振质子之间相互磁化作用所引起，与T1不同，它引起相位的变化。）

Table 3: Distribution of hemorragic lesions

表3：出血病灶的分布

In the 11 patients who had contrast-enhanced studies during an acute or subacute phase, nine had nodular enhancement within lesions. Eight of the enhancing lesions were located at the MDJ, corresponding to subacute hemorrhagic foci in three. In one case, the enhancement was confined to the right optic nerve, extending to the prechiasmal border without any other parenchymal involvement (Fig 8).

在11例于急性期或亚急性期行对比增强扫描的患者中，9例可见病灶内呈结节状强化。8例强化病灶位于中脑-间脑结合处。其中1例患者，强化病灶局限于右侧视神经且延伸至视交叉前缘，其它部位均为受累（图8）。

FIG 8. A, Contrast-enhanced coronal T1-weighted image (600/15/1) shows bilateral optic nerve atrophy and marked enhancement of the prechiasmatic segment of the right optic nerve (arrow).

图8. A，对比增强冠位T1像示双侧视神经萎缩，右侧视神经在视交叉以前的节段明显强化（箭头处）。

B, Contrast enhancement of the nerve disappeared after treatment (asterisk).

B，治疗后，右侧视神经的强化病灶消失（星号处）。

Discussion

Currently, the most widely used diagnostic criteria of BD is the International Study Group's classification, which requires recurrent oral ulcerations plus two of the following in order to establish a definite diagnosis: recurrent genital ulcerations, skin or eye lesions, or a positive pathergy test^[13]. The epidemiology of disease shows geographic variation, encountered more commonly along the Silk Road, which extends from the Mediterranean region to Japan^[15]. This is coupled with a similar variation in HLA B51 (human leukocyte antigen), which has been reported to be strongly associated with the disease in the high prevalence areas^[16–19]. Despite broadened clinical understanding of this disease, the etiologic factors remain obscured and speculative: viral agents, immunologic factors, genetic causes, bacterial factors, and fibrinolytic defects have all been implicated^{[3, 20–25]}. Vessel wall and perivascular mononuclear cell infiltration, which is consistent with vasculitis involving both arterial and venous systems, has been shown in histopathologic studies^{[20, 21]}. It has been postulated that genetic susceptibility together with a possible trigger by an extrinsic factor, such as an infectious agent, is responsible for the observed vasculitis^{[24, 26]}.

目前，白塞病最常用的诊断标准是国际白塞病研究小组于1992年在文献《Evaluation of diagnostic ("classification") criteria in Beh?et's disease: towards internationally agreed criteria》中提出的诊断标准。确诊白塞病需要复发性口腔溃疡加上以下3项中的2项：复发性生殖器溃疡、皮损或眼部损害、针刺试验阳性。白塞病的流行病学研究显示该病具有地理变异性，由地中海地区沿丝绸之路延伸至日本的区域更为常见。在这些高发地区，与本病有关的HLA B51（HLA，human leukocyte antigen，人类白细胞抗原）也具有相似的变异性。尽管对白塞病的临床认识逐渐加深，但本病的致病因素仍不明确，推测可能与病毒感染因素、免疫学因素、遗传因素、细菌感染因素、纤溶蛋白缺陷等多因素有关。组织病理学研究可见既累及动脉又累及静脉的血管壁及血管周围单核细胞浸润的血管炎表现。推测导致血管炎的原因是遗传易感性和外源性因子如病原体共同触发的结果。

Neurologic involvement in BD, which is not included in the current International Study Group's classification, was first reported in 1941 by Knapp^[27], and the term neuro-Beh?et syndrome was introduced by Cavara and D'Ermo in 1954^[28]. The reported rate of development of neurologic involvement among BD patients ranges from 4% to 49%^{[9, 29]}. This rate was found to be 6.7% in our large nonselective series of patients referred from the Beh?et's Disease Research Center^[30].

虽然白塞病神经系统受累没有被包括在国际白塞病研究小组于1992年在文献《Evaluation of diagnostic ("classification") criteria in Beh?et's disease: towards internationally agreed criteria》中提出的诊断标准中，但在1941年便由Knapp首先报道。1954年Cavara和D'Ermo又提出了神经白塞病（neuro-Beh?et syndrome, NBS）这个术语名词。白塞病患者中神经系统受累的比率为4%~49%不等，但我们大学附属医院的白塞病研究中心统计的比率为6.7%。

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  最后修改于 2007-11-28 02:26    阅读(653)评论(0)

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