Morphological characteristics of the cranial root of the accessory nerve

There has been the controversy surrounding the cranial root (CR) of the accessory nerve. This study was performed to clarify the morphological characteristics of the CR in the cranial cavity. Fifty sides of 25 adult cadaver heads were used. The accessory nerve was easily distinguished from the vagus nerve by the dura mater in the jugular foramen in 80% of 50 specimens. The trunk of the accessory nerve from the spinal cord penetrated the dura mater at various distances before entering the jugular foramen. In 20% of the specimens there was no dural boundary. In these cases, the uppermost cranial rootlet of the accessory nerve could be identified by removing the dura mater around the jugular foramen where it joined to the trunk of the accessory nerve at the superior vagal ganglion. The cranial rootlet was formed by union of two to four short filaments emerging from the medulla oblongata (66%) and emerged single, without filament (34%), and usually joined the trunk of the accessory nerve directly before the jugular foramen. The mean number of rootlets of the CR was 4.9 (range 2–9) above the cervicomedullary junction. The CR of the accessory nerve was composed of two to nine rootlets, which were formed by the union of two to four short filaments and joined the spinal root of the accessory nerve. The CR is morphologically distinct from the vagus nerve, confirming its existence. Clin. Anat. 27:1167–1173, 2014. © 2014 Wiley Periodicals, Inc.     

胶原海绵人工硬脑膜结合臭氧修复颅脑损伤

背景：硬膜的完整性对于颅脑损伤患者手术的预后十分重要。人工硬脑膜是目前常见的硬脑膜修补材料,寻找理想的人工硬脑膜是神经外科探索的方向。 目的：观察并分析胶原海绵人工硬脑膜和臭氧治疗颅脑损伤患者的临床资料,探讨并评价其使用价值。 方法：回顾性分析60例颅脑损伤患者应用胶原海绵人工硬脑膜修补和臭氧治疗后的疗效及并发症随访结果。 结果与结论：患者中2例死于重型颅脑损伤术后弥漫性脑肿胀,1例死于脑损伤合并多器官衰竭,2例因广泛脑挫裂伤合并脑疝术后植物生存,其余55例患者进入结果分析。术后2例出现切口局部皮下积液,予穿刺抽吸及弹性绷带加压包扎后好转;1例术后出现术侧少量硬膜下积液,未行特殊处理,动态复查头颅CT显示积液逐步吸收减少。头颅CT 检查未见与人工脑膜有关的异常反应和表现。28例患者3-6个月进行颅骨修补时发现人工硬脑膜与正常硬脑膜融合恢复较好,无粘连及炎症反应发生。表明胶原海绵人工硬脑膜和臭氧在颅脑损伤患者治疗中充分发挥减压作用,维持脑功能,缩短手术时间,并发症少,相容性好,能够较好的与正常硬脑膜融合,保护脑皮质,为后期颅骨修补创造有利条件。     

Persistent hypoglossal artery

It is well known that the internal carotid artery has no branches in the neck during postfetal life (von Lanz & Wachsmuth, 1955), but during embryonic development there are anastomotic connections between the internal carotid and basilar artery that rarely persist after intrauterine life (Hassen-Khodja et al. 1992; Widmann & Sumpio, 1992; De Caro et al. 1995). The most common anomaly found incidentally on angiography is a persisting trigeminal artery, but persistent hypoglossal, otic and proatlantal arteries can also be found (Reynolds et al. 1980; Ouriel et al. 1988; Salas et al. 1998). We report a rare example of a persistent hypoglossal artery in a 64 y old female cadaver, cause of death unknown, embalmed by standard mortuary procedures for dissection during the routine anatomy course. The persistent hypoglossal artery originated from the anteromedial wall of the left internal carotid artery 2.5 cm above the bifurcation (Fig.). It extended towards the hypoglossal canal. The diameter of its lumen was 1.5 mm. During its course in the neck, it was positioned anterior to the internal carotid artery and medial to the facial and lingual arteries, the posterior belly of the digastric muscle and the convexity of the hypoglossal nerve in the neck. At 1 cm above the convexity of the hypoglossal nerve in the neck, the artery gave rise to a branch that entered the skull through the carotid canal anteromedial to the internal carotid artery (Fig. 1) and joined the basilar artery. The medial branch of the hypoglossal artery crossed the internal carotid artery on its medial side and entered the skull together with the hypoglossal nerve and joined the basilar artery. We found no other anomalies in the cerebral arterial system.     

Persistent hypoglossal artery

It is well known that the internal carotid artery has no branches in the neck during postfetal life (von Lanz & Wachsmuth, 1955), but during embryonic development there are anastomotic connections between the internal carotid and basilar artery that rarely persist after intrauterine life (Hassen‐Khodja et al. 1992; Widmann & Sumpio, 1992; De Caro et al. 1995). The most common anomaly found incidentally on angiography is a persisting trigeminal artery, but persistent hypoglossal, otic and proatlantal arteries can also be found (Reynolds et al. 1980; Ouriel et al. 1988; Salas et al. 1998). We report a rare example of a persistent hypoglossal artery in a 64 y old female cadaver, cause of death unknown, embalmed by standard mortuary procedures for dissection during the routine anatomy course. The persistent hypoglossal artery originated from the anteromedial wall of the left internal carotid artery 2.5 cm above the bifurcation (Fig.). It extended towards the hypoglossal canal. The diameter of its lumen was 1.5 mm. During its course in the neck, it was positioned anterior to the internal carotid artery and medial to the facial and lingual arteries, the posterior belly of the digastric muscle and the convexity of the hypoglossal nerve in the neck. At 1 cm above the convexity of the hypoglossal nerve in the neck, the artery gave rise to a branch that entered the skull through the carotid canal anteromedial to the internal carotid artery (Fig. 1) and joined the basilar artery. The medial branch of the hypoglossal artery crossed the internal carotid artery on its medial side and entered the skull together with the hypoglossal nerve and joined the basilar artery. We found no other anomalies in the cerebral arterial system.     

枢椎4层皮质骨椎弓根螺钉的影像学测量及置钉策略

目的　探讨枢椎经椎管4层皮质骨椎弓根螺钉置钉策略的可行性及技术方法。 方法　利用PACS系统调阅92例正常成人枢椎椎弓根水平横断面MRI图像,测量椎弓根内侧壁切线（tangent of pedicle medial wall,TPMW）与脊髓切线（tangent of spinal cord,TSC）、硬膜切线(tangent of dura mater,TDM)间距离及椎管内侧壁切线 (tangent of spinal canal medial wall,TSCMW)与TSC、TDM间距离,以及脊髓和椎管横径、矢状径等参数。 结果　同性别双侧参数差异无统计学意义。男性枢椎TPMW与TSC的距离为9.05 mm,女性为8.57 mm;男性TPMW与TDM的距离为5.04 mm,女性为4.76 mm。男性TSCMW与TSC的距离为7.14 mm,女性为6.70 mm;男性及女性TSCMW与TDM的距离均为3.28 mm。 结论　在枢椎椎弓根水平,经椎管行枢椎4层皮质骨椎弓根螺钉理论上可行,但需根据具体情况采用个性化的策略。     

The microsurgical anatomy of the hypoglossal canal

Background  The hypoglossal canal (HC) is a region of the skull base whose involvement in many pathological entities is often ignored. Adequate knowledge of the anatomy of the HC and its related bony, neural, and vascular structures is essential for surgery of lesions involving this area. Methods  Ten adult human cadaver heads from a US source fixed by formalin (20 sides) and 20 dry human skulls from Indian sources (40 sides) were used in this study. Various aspects of the anatomy of this region including the size, course and variation of the hypoglossal nerve and its relationship to the adjacent and canalicular course were recorded. Results  The left HC was located at 10 o’clock and the right HC at the 2 o’clock position with respect to the foramen magnum. The canal was surrounded superiorly by the jugular tubercle, superolaterally by the jugular foramen, laterally by the sigmoid sinus and inferiorly by the occipital condyle. All dry skulls were drilled in the horizontal plane at an axis of about 45° and directed slightly upwards. Conclusions  Detailed knowledge of the microsurgical anatomy of the region of the HC is crucial when performing surgery for lesions of the condylar region, the lower clivus, and ventral brain stem. This study provides the knowledge required to achieve accurate orientation and effective maneuvers during surgical procedures for treatment of the patient without injuring the vital neural and bony structures.     

经椎板间隙溶核术的CT解剖学探讨

目的：为经椎板间隙行胶原酶溶核术避免损伤硬膜囊提供解剖学依据。方法：CT测量54例成人腰椎管及相应节段硬膜囊的横径，并计算两者之间的间隙值。结果：椎管的横径逐渐增宽，而相同节段的硬膜囊横径却是逐渐减小，两者间的差值也是逐渐增大。除L3/4和L4／5节段的硬膜囊横径差异无显著性外，其余3个节段的3个观测指标均有显著的统计学意义。特别是在L5、S1节段显得更为明显，但并不是所有患者都符合这个规律。结论：经椎板间隙行胶原酶溶核术有其解剖学依据，但由于有些个体解剖结构的变异，使得仅以腰椎的X线片作为依据进行操作，就有可能伤及硬脊膜。     

Nerve fibres and their terminals of the dura mater encephali of the rat

Summary The dura mater encephali of the rat is richly supplied by myelinated (A-axons) and unmyelinated (C-axons) nerve fibres. For the supratentorial part the main nerve supply stems from all three branches of the trigeminal nerve. Finally, 250 myelinated and 800 unmyelinated nerve fibres innervate one side of the supratentorial part. The vascular bed of the dura mater exhibits long postcapillary venules up to 200 m in length with segments of endothelial fenestration. Lymphatic vessels occur within the dura mater. They leave the cranial cavity through the openings of the cribriform plate, rostral to the bulla tympani together with the transverse sinus, and the middle meningeal artery. The perineural sheath builds up a tube-like net containing the A- and C-axons. It is spacious in the parietal dura mater and dense at the sagittal sinus along its extension from rostral to caudal and at the confluence of sinuses. Terminals of both the A- and C-axons are of the unencapsulated type. Unencapsulated Ruffini-like receptors stemming from A-axons are found in the dural connective tissue at sites where superficial cerebral veins enter the sagittal sinus and at the confluence of sinuses. The terminations of single A-axons together with C-fibre bundles mix up in their final course in one Schwann cell to build up multiaxonal units or terminations (up to 15 axonal profiles). A morphological differentiation is made due to the topography of these terminations; firstly, in different segments of the vascular bed: postcapillary venule, venule, the sinus wall, lymphatic vessel wall, and secondly, within the dura mater: inner periosteal layer, collagenous fibre bundles of the meningeal layer and at the mesothelial cell layer of the subdural space.     

脊柱颈段椎间盘平面椎管内前部结构的解剖学研究

目的　探讨经脊柱颈段椎间盘入路椎管内减压的相关解剖。 方法　取18具正常成人颈段脊柱防腐标本,通过不同断层,观察硬脊膜、后纵韧带与硬膜外前隙的毗邻关系和结构特点;测量椎间盘平面的硬脊膜厚度、后纵韧带宽度、椎体矢状径长度。 结果　颈段后纵韧带分为深、浅层,两层在中线两侧4～5 mm处分开,浅层与硬脊膜形成潜在的硬膜外前隙,该隙内有Hofmann's韧带连于硬脊膜与后纵韧带之间。深、浅层在硬脊膜前外侧形成一梭形腔隙－后纵韧带间隙; 椎体后面矢状正中线到两侧后纵韧带间隙外侧角的距离约为10 mm。 结论　根据后纵韧带的宽度和毗邻关系,颈椎前路手术经椎间盘达后纵韧带,逐渐由外进入后纵韧带间隙减压,可减少硬膜囊、脊髓或神经根的损伤。     

Histological investigations on the dura mater vascular system of mice

The human dura mater encephali is a well innervated and vascularized membrane. Its vascular system plays a crucial role in disorders and pathological cases like dural hematoma, meningitis, and different headache types. To investigate these diseases mouse models are increasingly being used. However, the literature on the vascular system of the mouse dura mater is sparse and explicit studies concerned exclusively with its vasculature are lacking. Here we present a detailed light and scanning electron microscopic investigation of the supratentorial dura mater of the mouse species, with a focus on the largest part of it, the parietal dura mater. By utilizing different immunohistochemical and classical staining methods, a “cartography” of the vascular system was achieved. Additionally, the different blood vessel types with their mural cells were characterized. In contrast to humans, no arteries were found in the mouse parietal dura mater. Its supply is assured through frontolateral and occipital localized arteriolar branches. These arteriolar vessels exhibit in some specimens arteriolar anastomoses with one another. The venous blood is drained to the superior sagittal and transverse sinus through satellite venules accompanying the arterioles or through solitary venules. In all samples, large ruptured venules were identified in the frontolateral dural area. Scanning electron microscopy revealed that these vessels were ruptured on the dorsal side (skull bones-oriented side) of the dura. Our results contribute to the anatomical data on the mouse species and may set up a basis for fundamental investigation of disorders, for which the role of dural blood vessels is not yet clarified.     

Neuropeptide Y- and substance P-like immunoreactive nerve fibers in the rat dura mater encephali

Summary Density and pattern of nerve fibers with neuropeptide Y-like immunoreactivity (NPY-LI) and substance P-like immunoreactivity (SP-LI) in the rat dura mater encephali were investigated by light and electron microscopy using whole-mount preparations. NPY-LI fibers are observed throughout the encephalic dura mater. A remarkable net of NPY-LI nerve fibers is located in the walls of the sagittal and transverse sinuses. Beyond that NPY-LI network, distinct NPY-LI nerve fibers or plexus occur in the rostral falx, parietal dura mater of the olfactory bulb, supratentorial dura mater, parietal dura mater of the cerebellum, tentorium cerebelli and the ventral dura mater. Electron microscopic studies reveal that NPY-LI is exclusively located in unmyelinated axons of small and large nerve fiber bundles, with or without a perineural sheath. Immunopositive C-fibers are predominantly associated with the vascular bed. SP-LI nerve fibers have a moderate and more uniform distribution in the encephalic dura mater. A distinct plexus of SP-LI fibers follows the branches of the middle meningeal artery and the adjacent dura mater. SP-LI fibers are most prominent in the parietal dura mater of the cerebellum. Fine beaded SP-LI fibers, arising from larger SP-LI fiber bundles, are observed in close association to the capillary bed. SP-LI axons are all unmyelinated. They are found in larger nerve fiber bundles with a perineural sheath or in Schwann cells lacking any perineural sheath. The function of NPY-LI and SP-LI nerve fibers in the rat dura mater is discussed in relation to their topography, density and termination.     

舌下神经断层解剖与MRI

目的：研究舌下神经在不同断面上的位置、毗邻、走行及识别标志,为舌下神经病变的影像学诊断和外科手术提供形态学依据。方法：取用国人成年尸体头部标本69例,以冷冻切片法切制成连续横断层标本36例、矢状断层标本18例和冠状断层标本15例;招募成年志愿者10名,利用3．0TMRI扫描仪,以3D—CISS序列扫描,获取横、矢状、冠状断层图像;在上述断层标本对照下,于MR图像上观察舌下神经在断面上的形态、位置、毗邻和识别标志等。结果：在横断面上,可见枕骨基底部两侧呈倒“八”字形的舌下神经管,管内走行着舌下神经;在矢状断面上,舌下神经管呈椭圆形,位于小脑前下方,岩下窦与寰枕关节之间;在经舌下神经管外口的冠状断面上,舌下神经管外口位于寰枕关节外上方、颈内静脉内侧,其间容纳舌下神经;在经舌下神经管内口的冠状断面上,呈“鸟喙”状的舌下神经管内口居枕骨侧部内,其内侧为延髓,外侧为颈内静脉,上方为颈静脉孔,下方为寰枕关节。结论：在横、矢状和冠状断面上,均可清晰显示舌下神经的位置及毗邻结构,但以横断面和冠状面为佳。     

Pathophysiology of intracranial epidural haematoma following birth

Epidural haematoma in newborn infants is rare, and few specific obstetrical data related to its formation are available in the literature. The aim of this study is to discuss the pathophysiology of this condition. EDH is always a post traumatic lesion and it is only possible if the insult has produced a cleavage of the dura mater from bone. Therefore, EDH results from the mechanical forces exerted on the foetal head during birth, with or with no instrumental interference. Although it is still unclear whether the injury (and dura mater cleavage) was directly caused by the forceps or had already been inflicted by natural forces, or a combination of both however, in some patients (with neither dystocia nor skull fracture), there is no basis for explaining EDH formation, apart from propulsion of the fore coming head through the birth canal. Excessive moulding, whether or not associated with iatrogenic trauma, has been incriminated in most cases of EDH. As dystocia cannot always be anticipated, EDH will remain an ever-present cause of morbidity in the neonatal population, albeit a rare occurrence.     

乙状窦前入路迷路后区应用解剖学研究

目的：为临床乙状窦前入路迷路后区域手术操作提供解剖学资料。方法：经10％甲醛溶液固定成人尸头标本15具共30侧。在外耳道后上棘、乳突上嵴、乳突尖之间磨除骨质，暴露乙状窦、岩上窦、岩上窦-乙状窦交点、颅中窝硬膜、乙状窦前方的颅后窝硬膜。磨出后骨半规管、外骨半规管、上骨半规管及面神经垂直段、颈静脉球。测量相关数据。结果：乙状窦前入路迷路后区域的骨质可分为三层：表面骨皮质，乳突蜂房骨质，覆盖深部结构的坚硬骨质。外耳道后上棘至后骨半规管的最近距离为（17．88±1．27）mm；面神经垂直段在外半规管下方、后半规管的前方走向二腹肌嵴前缘的内侧，其长度为（7．58～14．02）mm；外耳道后上棘．乙状窦最短距离为（13．84±2．74）mm。结论：此区域骨质分层明显的解剖学特点及测量的数据可以指导手术操作，避免损伤重要结构，为乙状窦前入路迷路后锁孔入路提供了重要的解剖学资料。     

颈神经后支的解剖及其临床意义

目的为临床诊治椎孔外颈神经后支卡压提供解剖学基础。方法对20具(40侧)成人尸体的颈神经后支起源、走行、分支、分布及其与颈椎周围组织的解剖关系进行观测。结果C     

Pathogenesis of central nervous system infiltration in acute leukemia.

The distribution pattern of leukemic infiltrates was studied in 31 cases of acute leukemia with CNS involvement. Dura mater involvement was found in 93% (29/31) of the cases; arachnoid, 71% (22/31); perivascular cuffing, 37% (17/31); parenchymatous, 16% (5/31). Dura matter infiltrates were the sole manifestation in nine cases; Infiltration of the arachnoid in the absence of dural infiltration was rare (9%). The anatomic evidence supports the concept that leukemic cells infiltrate by way of perivenous adventitial tissue connecting the dura mater and subarachnoid space. It is likely that this pathway leads directly from the bones of the skull into the brain parenchyma.     

侧颅底手术中乙状窦应用解剖学研究

目的　探讨侧颅底手术中乙状窦相关解剖标志的位置，为进一步提高侧颅底手术安全性提供解剖学基础。 方法　选取成人头颅标本40个，采用耳后切口行标准乳突根治术。充分暴露颅中窝及颅后窝硬脑膜、外半规管、面神经膝部、乙状窦、颈静脉球、乳突、茎乳孔、二腹肌嵴、外耳道后壁等重要解剖结构。使用双脚规测径器或电子数显游标卡尺分别测量相关解剖结构之间的距离。 结果　乙状窦前缘至外耳道后壁的距离是(1.41±0.32)cm，乙状窦外侧壁至乳突外侧壁的距离是(1.02±0.38)cm，面神经乳突段的长度是(1.28±0.13)cm，面神经乳突段起点（即面神经膝部）到乙状窦的距离是(0.56±0.20)cm，面神经乳突段终点（即茎乳孔部）到乙状窦的距离是(0.62±0.22)cm，二腹肌嵴至乙状窦的距离是(0.52±0.18)　cm，茎乳孔至乙状窦的距离是(1.02±0.24)cm。 结论　面神经乳突段起点和终点至乙状窦的距离及乙状窦至二腹肌嵴和茎乳孔之间的距离均呈正相关；乙状沟的深浅、宽窄及骨壁的厚薄因乳突气化程度不同而各异。     

Aspects of the organization of neurons and dendritic bundles in primary somatosensory cortex of the rat

In order to analyze some aspects of the spatial organization in the primary somatosensory cortex of the rat, we have reconstructed the positions of bundles of apical dendrites and neurons in a cortical prisms measuring 0.5 mm x 0.4 mm x cortical thickness, with special reference to a hypothetical columnar organization. Complete series of semithin (0.65 microm) sections were cut, tangentially from the pial surface down to the white matter, stained and digitizalized into a computer and represented as a stack of 2D images. The mean neuron density (N(V)-value) was (60 x 10(3) +/- 15 x 10(3)) neurons/mm3. The mean number of neurons beneath 1 mm2 of cortical surface (NC-value) was (113 x 10(3) +/- 8 x 10(3)) neurons/mm2. Well-defined bundles of apical dendrites emanating from layer V pyramidal cells were observed. The bundles consisted of 3-12 (mean 5 +/- 2) dendrites. The dendrites within a bundle converged while ascending towards the pial surface and reached a maximal close packing in layer IV. Superficially, the packing density decreased again. The mutual positions of the dendrites within the bundles shifted only slightly along their course towards the pial surface. The occurrence of bundles in tangential sections through layer IV was about 190 bundles/mm2 and the average number of neurons per bundle was estimated at approximately 600. However, when calculating Voronoi-diagrams, the number of neurons, which with this mathematical technique, is ascribed to each of the reconstructed dendritic bundles, varied between 200 and 1000. The possibility that the dendritic bundles are centers in cortical cell modules is discussed.     

The extracranial to intracranial anastomotic channel through the parietal foramen: delineation with magnetic resonance imaging

Purpose

Parietal foramina (PFs) are openings of fine canals that perforate the parietal bone. However, few studies have investigated the entire canals and their emissary vessels (EVs). Here, we explore the EVs with magnetic resonance imaging.

Methods

A total of 104 patients who underwent contrast examinations and exhibited an intact scalp, skull, dura mater, and superior sagittal sinus were enrolled in this study. Imaging data were obtained as thin-sliced, seamless sagittal sections and were transferred to a workstation for analysis.

Results

A total of 116 EVs passing through the PF and inner canals (parietal canal) were identified in 78 patients (75 %). All the EVs were found to perforate each layer of the parietal bone. Of 104 patients, 68 % exhibited one EV, 30 % two EVs, and 2 % three EVs. In 85.3 %, the EV was entirely delineated in one sagittal slice, 10.3 % were covered by two slices, and 4.3 % by three slices. In 68 %, the EV connected to the upper surface of the superior sagittal sinus (SSS) with variable courses from near-vertical to horizontal inclinations.

Conclusions

EVs perforate the skull with variable inclinations, while showing a highly consistent course in the sagittal dimension. The PF and EV can be used as landmarks of the SSS lying immediately below.

     

Primary intracranial choriocarcinoma arising from the pituitary fossa. Report of an autopsy case with literature review

A 12-year-old Japanese girl with a primary intracranial choriocarcinoma arising from the pituitary fossa is reported. There was a markedly high level of serum human chorionic gonadotropin (HCG) throughout the clinical course. Postmortem examination revealed metastatic lesions found in the cerebellum, dura mater, skull (clivus, sphenoidal bone), and lungs. Immunohistochemical characteristics of the primary intracranial tumor and lung lesions disclosed positive stainings for HCG and HCG-beta in the neoplastic syncytiotrophoblastic cells.