Alternative ways of collateral venous flow in occlusion of superior sagittal sinus

The authors demonstrated alternative ways of bloodflow from occluded superior sagittal sinus through hypertrophic dural veins (middle meningeal veins) and sphenoparietal sinus. Parameters of bloodflow were evaluated using triplex ultrasonography. The possibility of venous drainage into anterior segment of superior sagittal sinus proximal to the site of occlusion with further retrograde flow towards dural venous anastomosis is verified. Possibilities of spiral CT-venography and standard time-of-flight MR-venography for assessment of collateral venous flow were estimated.     

大鼠上矢状窦闭塞后磁共振影像及病理研究

颅内静脉窦血栓为脑血管病的特殊类型,呈缓慢发病,临床表现不具特征性,极易延误诊断和治疗,病死率达5.5%～30.0%犤1犦。为了提高临床医师对颅内静脉窦和静脉闭塞性疾病的认识水平,笔者以上矢状窦为例,设计了大鼠脑静脉窦闭塞动物模型,以观察颅内静脉窦闭塞后局部脑血流量(re-gi     

Neuropathological changes following occlusion of the superior sagittal sinus and cerebral veins in the cat

Superior sagittal sinuses (SSS) of 36 mongrel cats were occluded by polymer injection. Immediately prior to the occlusion, Evans–blue (EB) was administered intravenously. The cats were killed 1, 3, 6, 12, 24, 72 and 120 h after sinus occlusion. Two sham–operated cats were killed 6 h and two 120 h after the operation. In 16 cats in which the occlusion was limited to the SSS, as well as in the sham–operated cats, no EB extravasation was present. However, ultrastructurally in two animals, the extracellular spaces were moderately enlarged, corresponding to increased permeability for water without opening of the BBB for proteins. In 20 cats in which cortical veins were occluded, in addition to the SSS, EB was extravasated. In nine of these cats, which had moderate oedema, EB–staining was present only in the cortex. In 11 cats with severe oedema, massive EB extravasation was observed also in the white matter. The U–fibre layer was free of EB, suggesting that the extension of oedema was blocked by this zone. Cats with severe edema showed extensive haemorrhagic cerebral infarction widely, but not completely, overlapping with ischaemic necrosis, and corresponding to the differences in the territories of arterial supply and of venous drainage. Seven animals displayed haematomas in the parasagittal white matter. Electron microscopy (EM) showed damage to the endothelium of capillaries and venules with extravasation of platelets. In cats which survived longer than 24 h, the extracellular spaces were filled with proteinaceous transudate. Gliosis of the affected grey and white matter was observed in cats examined 24, 72 and 120 h after occlusion. Notwithstanding the differences between this model and human cerebral sinus and vein thrombosis, the procedure represents an experimental approach to understanding the variability of the clinical course in patients with thrombosis of SSS. The results stress the role of the occlusion of the cortical veins in the extension of brain damage.     

国人上矢状窦窦腔内结构的内镜解剖

目的观察国人上矢状窦窦腔内结构，特别是纤维索和蛛网膜颗粒的完整解剖形态。方法成人头颅标本5具，去除颅盖，应用内镜观察研究上矢状窦窦腔内纤维索及蛛网膜颗粒的原始结构特征；并纵行剖开管腔，显微镜下观察纤维索、蛛网膜颗粒。结果内镜下观察上矢状窦管腔内纤维索大致分3种类型：瓣膜状（47．1％）、小梁状（30．6％）、板层状（22．3％）。蛛网膜颗粒多集中于上矢状窦中段侧壁及静脉隐窝处呈指状突起突入窦腔。结论内镜较常规解剖手段可以更直观地观察上矢状窦窦腔内结构的完整形态特征。     

Partial, non-thrombotic, superior sagittal sinus occlusion due to occipital skull tumours.

Two cases are described in which raised intracranial pressure occurred as a result of superior sagittal sinus (SSS) occlusion by an occipital skull tumour. One was a plasmacytoma, the other a metastatic deposit from a Ewing's sarcoma. The difficulties in diagnosis of this syndrome are illustrated together with the importance and success of appropriate treatment. From the literature it appears possible that these two tumours may be particularly likely to occlude the SSS and the reasons for this are discussed.     

Experimental study of rapid versus slow sagittal sinus occlusion in dogs

BACKGROUND: Clinical, radiological, postmortem and experimental studies are not enough for the definition of pathophysiological differences between rapid and slow-progressing cerebral venous system obstruction. AIMS: An experimental study was conducted to set some physiopathological differences between rapid and slow occlusion of the superior sagittal sinus. SETTINGS AND DESIGN: Eighteen dogs categorized into 3 groups were chosen as test subjects. The three groups were the rapid occlusion, slow occlusion and the control study groups and each group had six subjects. MATERIAL AND METHODS: Intracranial pressure values, histopathological findings, and the degree of cerebral edema formation, estimated by measuring the water content ratio of the brain and the angiographic results in the 2 different groups of subjects that underwent rapid and slow superior sagittal sinus obstruction were compared with that of the control subjects. STATISTICAL ANALYSIS: Statistical analysis was performed using GraphPad Prisma V.3 statistical software. Variables of the 3 groups were compared using non-parametric Kruskal Wallis ANOVA test and multiple comparisons were made using Dunn's multiple test. The comparison of initial and terminal intracranial pressure values obtained before and after the sinus occlusion, was made using the Wilcoxon test. A probability value of less than 0.05 was regarded as significant. RESULTS AND CONCLUSIONS: Comparison of the water content ratio of the brain in the 3 groups, the difference between the initial and terminal intracranial pressure values of the rapid occlusion study group, and the difference between the terminal intracranial pressure values of the 3 groups was statistically significant (P<0.05). Dunn's Multiple Comparison Test yielded significant differences in the water content ratio of the brain and in the intracranial pressure values between the rapid occlusion study group and the control group (P<0.05). Moreover, histopathological and radiological examination disclosed more prominent brain edema findings, and less apparent collateral venous flow in the rapid occlusion study group than in the slow occlusion one. To conclude, the clinical severity of sinus occlusion seems directly related to the quickness of the occlusion and the capacity of the collateral venous system.     

上矢状窦血栓的病因及诊断

目的 探讨上矢状窦血栓的病因及诊断方法。方法 分析34例上矢状窦血栓患者的病因、临床表现、影像学特征，其中3例无明确诱因所致上矢状窦血栓患者，利用化学分光法检测其血清中的雌二醇（E2）、睾酮（T）水平。结果 上矢状窦血栓最常见的病因是产褥期血液高凝状态。3例未查到明确诱因的青年男性患者，血清中E2↑、E2／T↑。上矢状窦血栓的临床表现以头痛最常见，在意识清楚的30例患者中发生率为100％。影像学检查：CT检出率仅为65．4％，磁共振成像（MRI）、磁共振静脉血管造影（MRV）检出率为100％。结论 各种原因造成的血液凝固性增高是上矢状窦血栓最常见的病因，男性高雌激素血症是其发病的一个重要的危险因素。MRI和MRV技术相结合是诊断上矢状窦血栓的最佳方法。     

Changes of visual evoked potentials in experimental occlusion of superior sagittal sinus in the cat.]

In the model of experimental occlusion of superior sagittal sinus (SSS) in 6 cats, the authors examined cerebral cortex activity by means of visual evoked potentials (VEP). They found shortening of latency of P2 wave potential in relation to the control by 5.5-13.3 msec, appearing after 4-6 hours following occlusion. Simultaneous cerebrospinal fluid pressure measurement indicated an increase in pressure following SSS occlusion from the control medium value 6.8 mmHg to 12-13 mmHg. Visual cortex in cat (area 17) is situated along the posterior portion of SSS. The occlusion of this vessel results in local haemostasis, which is likely to affect the physico-chemical properties of visual cortex cells, especially in the slow conducting system X (X cells can be found exclusively in area 17). The partial disappearance of this system activity results in reducing the signal and noticeable shortening of latency to peak P2 wave of VEP.     

外伤性上矢状窦损伤的救治体会

我院自1997年至2004年共收治18例外伤性上矢状窦损伤患者,通过积极抢救,取得了满意效果。一、资料与方法1.临床资料:18例患者中,男14例,女4例;年龄11￣64岁,平均(40±7)岁。车祸伤9例,坠落伤3例,他伤及砸伤6例。有昏迷史者15例,有神经损伤定位体征者12例,有胸腹四肢合并伤者4例。按GCS评分:3￣6分5例,7￣9分7例,10￣12分3例,13￣15分3例。开放性损伤9例,并发休克者5例。所有患者均行CT检查,全部伴有颅骨骨折及硬膜外血肿,其中凹陷骨折11例,骑跨型硬膜外血肿3例。14例伴有脑挫裂伤或硬膜下血肿。上矢状窦前1/3损伤者10例,中、后1/3损伤者8…     

First study on the peptidergic innervation of the brain superior sagittal sinus in humans

The superior sagittal sinus (SSS) of the mammalian brain is a pain-sensitive intracranial vessel thought to play a role in the pathogenesis of migraine headaches. Here, we aimed to investigate the presence and the potential co-localization of some neurotransmitters in the human SSS. Immunohistochemical and double-labeling immunofluorescence analyses were applied to paraformaldehyde-fixed, paraffin-embedded, coronal sections of the SSS. Protein extraction and Western blotting technique were performed on the same material to confirm the morphological data. Our results showed nerve fibers clustered mainly in large bundles tracking parallel to the longitudinal axis of the sinus, close in proximity to the vascular endothelium. Smaller fascicles of fibers encircled the vascular lumen in a spiral fashion, extending through the subendothelial connective tissue. Isolated nerve fibers were observed around the openings of bridging veins in the sinus or around small vessels extending into the perisinusal dura. The neurotransmitters calcitonin gene related peptide (CGRP), substance P (SP), neuronal nitric oxide synthase (nNOS), vasoactive intestinal polypeptide (VIP), tyrosine hydroxylase (TH), and neuropeptide Y (NPY) were found in parietal nerve structures, distributed all along the length of the SSS. Overall, CGRP- and TH-containing nerve fibers were the most abundant. Neurotransmitters co-localized in the same fibers in the following pairs: CGRP/SP, CGRP/NOS, CGRP/VIP, and TH/NPY. Western blotting analysis confirmed the presence of such neurosubstances in the SSS wall. Overall our data provide the first evidence of the presence and co-localization of critical neurotransmitters in the SSS of the human brain, thus contributing to a better understanding of the sinus functional role.     

Acetylsalicylic acid inhibits cerebral cortical vasodilatation caused by superior sagittal sinus stimulation in the cat*

Acetylsalicylic acid (ASA; aspirin) is one of the most widely used pain reliefs in the world and is certainly effective in the treatment of acute attacks of migraine of moderate severity. It has usually been considered that the action of ASA in migraine is related to peripheral inhibition of mediators of inflammation. Migraine involves episodic head pain that is thought generally to involve intracranial pain structures innervated by the ophthalmic (first) division of the trigeminal nerve, particularly vascular structures that have come to be known as the trigeminovascular system. In this study the effect of ASA on the cerebrovascular effects of the trigeminovascular system were assessed directly with measurements of cerebral blood flow. The trigeminovascular system was activated by stimulation of the superior sagittal sinus (SSS), a midline large venous sinus that is pain sensitive in humans. The SSS was stimulated electrically and cerebral blood flow measured using laser Doppler flowmetry (CBF_LDF). Stimulation of the SSS resulted in a stimulus-locked frequency-dependent increase in CBF_LDF that reached a mean maximum at 2 Hz with a 60 ± 6% reduction in calculated cerebrovascuiar resistance. Administration of ASA (30 mg/kg i.v.) resulted in a small non-sustained increase in blood pressure but no change in resting CBF_LDF. The CBF_LDF response to SSS stimulation was reduced at all but one frequency of stimulation to a maximum of a 43 ± 10% reduction in cerebrovascular resistance. Since electrical stimulation involves consecutive depolarization of trigeminovascular axons and bypasses the peripheral nerve vessel interaction it is likely that this effect of ASA is mediated in the central nervous system. Such a possibility draws attention to a possibly novel therapeutic locus of action for ASA and to the importance of central nervous system processing of trigeminovascular inputs that are integral to the clinical expression of migraine.     

上矢状窦血栓形成诊断和治疗进展

上矢状窦血栓形成(superior sagittal sinus thrombosis,SSST)是一种特殊类型的脑血管疾病,多因误诊漏诊而引起严重并发症甚至死亡。随着神经影像学和神经介入学发展以及新型抗栓药物的应用,其早期发现率和诊断率大大提高,预后明显改善,现对其诊断和治疗进展作一综述。一、病因     

Evolution of venous cerebral infarction and brain edema--an experimental study of sagittal sinus obstruction

Superior sagittal sinus with/without neighboring venous system of 36 mongrel cats were occluded by cyanoacrylate polymer after i.v. administration of Evans-blue (EB). Thereafter, the cats were sacrificed 1, 3, 6, 12, 24, 72 or 120 hours after sinus-vein occlusion. According to the degree of occluded region, the cats were divided into two groups; group A (GA) and B (GB). GA showed only superior sagittal sinus occlusion, while many cortical veins were also occluded in GB. No EB nor histological changes were found in 13 cats of GA and 4 sham operated cats, while EB distribution was observed in all 20 cats of GB. The other 3 cats of GA showed a little EB in gyrus lateralis. EB distribution of GB were divided into two types. Type 1 showed EB mainly in the cortical gray matter, while type 2 showed massive EB extravasation in the white matter as well. Edematous changes with gliosis in its resolution phase, were observed in type 1. In addition, EB free zone was formed along with U-fiber zone (cortico-medullary junction) in the cats of later phase (72 hours after occlusion). The findings of EB extension in the type 1 means the existence of blockage against edema evolution from cortex toward subcortical white matter. The cats of type 2 showed fulminant hemorrhagic changes which appeared depend on time interval. Although occurrence of pathological changes were rather earlier than that of cases of clinical cerebral sinus thrombosis, this pathological findings demonstrated the typical character of venous hemorrhagic infarction. In this paper, the similarity and difference between this model and clinical case of sinus-vein thrombosis were discussed. And the possible function of the U-fiber zone in the corticomedullary junction against edema evolution was suggested.     

上矢状窦中后部脑膜瘤导致静脉窦闭塞后静脉代偿特点及意义

目的 探讨中、后部矢状窦旁脑膜瘤导致静脉窦闭塞后静脉代偿特点以及全切除肿瘤的手术要点。方法 分析15例中、后部上矢状窦完全闭塞的窦旁脑膜瘤的脑血管造影表现，探讨其静脉回流代偿的形式对手术疗效的影响。结果 静脉回流代偿的形式有三种：(1)皮层浅静脉端-端吻合，主要流向侧裂、Labbe静脉；(2)脑膜静脉流向蝶顶窦、海绵窦；(3)板障静脉流向头皮。本组肿瘤全切除12例，无手术死亡，术后发生三肢瘫1例，双下肢瘫1例，高颅压、失明1例。结论 术前仔细研究血管造影上静脉回流代偿的形式，有助于术中加强对其保护，减少全切除肿瘤手术后的严重并发症的发生。     

Re-occlusion of the superior sagittal sinus after surgical recanalisation.

A 24-year-old woman was struck on the head by a hammer. Because of early signs and symptoms of intercranial hypertension, she underwent surgery for elevation of the depressed fragments which was compressing the superior sagittal sinus (SSS). After operation, the intracranial pressure (ICP) once decreased, but it gradually increased again. After hypothermia and barbiturate therapy, she recovered fully except for partial visual field defect due to brain contusion. A carotid angiogram 28 days after injury revealed complete occlusion of the whole SSS with good collateral circulation. After brain edema had subsided, a follow-up angiogram revealed normal blood flow through the SSS. Elevation of depressed bony fragments is required for a case presenting with early signs and symptoms of intracranial hypertension due to sinus compression. In a case with severe destruction of the SSS, one needs to know that re-occlusion of the dural sinus may occur after surgical recanalisation.     

The path of the superior sagittal sinus in unicoronal synostosis

Purpose

This study investigates the anatomic relationship between the superior sagittal sinus (SSS) and the sagittal suture in infants with uncorrected unicoronal synostosis. The morphology of the SSS is also evaluated postoperatively to assess whether normalization of intracranial structures occurs following reconstruction.

Methods

The study sample consisted of 20 computed tomography scans (10 preoperative, 6 postoperative, and 4 unaffected controls) obtained between 2001 and 2013. The SSS and the sagittal suture were outlined using Analyze imaging software. These data were used to measure the maximum lateral discrepancy between the SSS and the sagittal suture preoperatively and to assess for postoperative changes in the morphology of the SSS.

Results

In children with uncorrected unicoronal synostosis, the SSS deviates to the side of the patent coronal suture posteriorly and tends to follow the path of the sagittal and metopic sutures. The lateral discrepancy between the SSS and the sagittal suture ranged from 5.0 to 11.8 mm, with a 99.9 % upper prediction bound of 14.4 mm. Postoperatively, the curvature of the SSS was statistically decreased following surgical intervention, though it remained significantly greater than in unaffected controls.

Conclusions

The SSS follows a predictable course relative to surface landmarks in children with unicoronal synostosis. When creating burr holes for craniotomies, the SSS can be avoided in 99.9 % of cases by remaining at least 14.4 mm from the lateral edge of the sagittal suture. Postoperative changes in the path of the SSS provide indirect evidence for normalization of regional brain morphology following fronto-orbital advancement.     

A case of superior sagittal sinus thrombosis following long-term medication with carbamazepine]

A 55-year-old man, who had been medicated with carbamazepine, phenobarbital, and sodium valproate for 12 years' duration, presented with severe headache, nausea, and transient diplopia. The neurological examination revealed mild disturbance of consciousness and postural tremor. He also complained of severe continuous headache but no throbbing pain. Enhanced head CT showed empty delta sign and irregular pooling of contrast agent around the superior sagittal sinus. Head MRI did not show the flow void in the superior sagittal sinus. Cerebral angiography demonstrated incomplete occlusion of the superior sagittal sinus and well-developed colateral channels. He was diagnosed having superior sagittal sinus thrombosis, and was placed on anticoagulant and antiplatelet drugs. He did not have any other risk factors such as inflammatory disease, infection, malignancy, and oral contraceptives. However, he had been medicated with some anticonvulsants including carbamazepine, which is known to induce venous thrombosis in the leg. Therefore, the association between superior sagittal sinus thrombosis and long term medication with carbamazepine was suspected. This is the first case report of anticonvulsant-associated cerebral venous thrombosis. It suggests that long-term medication with carbamazepine should be considered to be one of the risk factors for cerebral venous thrombosis.