The posterior inferior cerebellar artery and its branches in relation to the cerebellomedullary fissure

The conventional approach to the fourth ventricle is by splitting the vermis on the suboccipital surface of the cerebellum. By a unilateral transcerebellomedullary fissure approach, it is possible to provide sufficient operative space from cerebral aqueduct to obex without splitting the vermis. This approach needs meticulous dissection of the cerebellomedullary fissure and preservation of the posterior inferior cerebellar artery (PICA) and its branches. The tonsillomedullary and telovelotonsillar segments of the PICA are the most important vessels encountered in the transcerebellomedullary fissure approach. The PICA was examined under a surgical microscope in a total of 40 specimens by perfusing with a mixture of 10% Indian ink and gelatin. The passing of the tonsillomedullary segment of the PICA through the cerebellomedullary fissure was observed superior to the tonsil in 5%, at the level of the upper pole of the tonsil in 17.5%, at the middle of the tonsil in 37.5% and at the level of the lower pole of the tonsil in 37.5% specimens. When the PICA arose from the lateral medullary (LM) segment of the vertebral artery (VA), a caudal loop was present in 90%, when the PICA originated from the premedullary segment of the VA, the loop was present in 87.5% specimens. When the PICA arose from the basilar artery (BA), the loop was absent, and the tonsillomedullary segment of the PICA showed a straight course (100%). A thorough understanding of the relationship of the branches of the PICA to the cerebellar tonsils are prerequisites for surgery in and around the fourth ventricle.     

The course of the posterior inferior cerebellar artery may be related to its level of origin

The course of the posterior inferior cerebellar artery (PICA) was analyzed with reference to its origin and relationships with the medullary and cerebellar surfaces and the adjacent cranial nerves in 40 brains after the injection with acrylic resins of the vertebrobasilar system. In 42.5% of instances, the PICA originated from the lateral medullary segment of the vertebral artery (VA), in 32.5% from its premedullary segment, in 22.5% from the basilar artery (BA), and in 2.5% it was absent. With reference to the level of origin, three patterns of course for the lateral medullary segment of the PICA can be outlined. (1) When it arises from the lateral medullary segment of the VA, it passes below the hypoglossal nerve, and the lateral medullary segment may form a loop with an anterosuperior convexity towards the pontomedullary sulcus (41%), or it may follow a rectilinear course (41%). It passes at the level of the accessory nerve. The tonsillomedullary (TM) segment shows a caudal loop and the telovelotonsillary (TVT) has a cranial loop. (2) When the PICA arises from the BA, it passes above the hypoglossal nerve. The lateral medullary segment forms a loop with lateral convexity (78%) and passes above or through the glossopharyngeal nerve, frequently showing a recurrent course among the roots of the IX, X, or XI cranial nerve. The TM and the TVT segments do not have loops. (3) When the PICA arises from the premedullary segment of the VA, it passes above, below, or through the rootlets of the hypoglossal nerve. In the lateral medullary segment, it follows a rectilinear course (54%) and passes the plane formed by the IX, X, and XI cranial nerves at an intermediate level with respect to the other two patterns. The TM and the TVT segments show caudal and cranial loops. The different origins and courses of the PICA derive from the selection of different branches of the primitive vertebrobasilar plexus during the development of the cerebellum. The existence of an embryologic correlation between the course of the PICA and its level of origin may be useful in the evaluation of its angiographic anatomy.     

小脑下后动脉在枕骨大孔区的解剖学研究

目的对颅后窝枕骨大孔区小脑下后动脉进行观察与测量,并探讨其临床意义。方法选取成人颅底标本15例,观察枕骨大孔区小脑下后动脉位置、走行、毗邻关系及其分布,测量相关数据并进行统计学处理。结果颅后窝枕骨大孔区小脑下后动脉左右两侧起始部外径:左侧为1.32~1.49 mm,平均(1.41±0.05)mm;右侧为1.27~1.49 mm,平均(1.39±0.07)mm,左右管径比较差异无统计学意义(P>0.05);小脑下后动脉走行呈“S”形,与第Ⅸ、Ⅹ、Ⅺ对脑神经的位置关系密切。结论小脑下后动脉在枕骨大孔区起点走行、分布具有特有的解剖特点,在临床中枕骨大孔区小脑下后动脉相关疾病的手术时应避免医源性损伤。     

Endovascular treatment of ruptured distal posterior inferior cerebellar artery aneurysms: report of 11 cases

Objective

To investigate the clinical characteristics and endovascular treatment of ruptured distal posterior inferior cerebellar artery (PICA) aneurysms.

Methods

11 consecutive patients (7 women, 4 men, mean age of 49.2 years) with ruptured distal PICA aneurysms were studied retrospectively. All had onset of acute intraventricular or cerebellar haemorrhage, and subarachnoid hemorrhage (SAH). Hunt-Hess (HH) grades were H-H I in 1 patient, H-H II in 5 patients, H-H 111 in 4 patients and H-H IV in 1 patient on admission.

Results

All patients were treated by endovascular treatment, seven cases got endosaccular coiling and four cases got parent artery occlusion at the same time. All the patients were followed up one to four years. Recurrences occurred in 1 patient two years post-treatment, and were successfully retreated by endosaccular coiling and parent artery occlusion. The occluded PICA was recanalized one year post-treatment but without any growth of the aneurysm in one case. One year post-treatment, 2 patients had a modified Rankin Scale (mRS) score of 0, 8 patients had a mRS score of 1 and 1 patient had a mRS score of 2.

Conclusions

Coiling of ruptured distal PICA aneury, with or without parent vessel occlusion, was feasible, relatively safe and effective in preventing early/medium-term rebleeding. A strict angiographic follow-up, however, was necessary to detect recurrence.     

小脑动脉与三叉神经根毗邻关系的应用解剖

目的观察小脑动脉的起始位置、行程特点及其与三叉神经根的毗邻关系,为三叉神经微血管减压术提供解剖学依据。方法采用12个福尔马林固定的成人头部标本,在手术显微镜下分别解剖小脑上动脉、小脑下前动脉、小脑下后动脉及三叉神经等结构。观察相关动脉、神经的位置、走行特点,测量上述动脉的起始段外径及其与三叉神经根最近距离等相关数据。结果共发现小脑上动脉27支,2支压迫三叉神经根,5支与神经根接触,其余无接触压迫者与三叉神经的最近距离为(3.87±1.58)mm(0.55～6.30 mm);小脑下前动脉23支,压迫神经根1例,与之接触者2例,其余20支小脑下前动脉与三叉神经根最近距离为(4.67±1.77)mm(2.65～9.50 mm);小脑下后动脉21支,与三叉神经根最近距离为(17.12±3.86)mm(10.45～25.70 mm),未发现与之接触或压迫者。结论小脑上动脉与三叉神经关系密切,常与三叉神经接触并压迫神经,成为三叉神经痛发生的主要结构。小脑下前动脉与三叉神经相距稍远,也可与三叉神经接触或压迫神经。小脑下后动脉与三叉神经相距较远,但偶尔也会压迫三叉神经根导致三叉神经痛。     

小脑动脉与三叉神经根毗邻关系的应用解剖

目的　观察小脑动脉的起始位置、行程特点及其与三叉神经根的毗邻关系,为三叉神经微血管减压术提供解剖学依据。 方法　采用12个福尔马林固定的成人头部标本,在手术显微镜下分别解剖小脑上动脉、小脑下前动脉、小脑下后动脉及三叉神经等结构。观察相关动脉、神经的位置、走行特点,测量上述动脉的起始段外径及其与三叉神经根最近距离等相关数据。 结果　共发现小脑上动脉27支,2支压迫三叉神经根,5支与神经根接触,其余无接触压迫者与三叉神经的最近距离为（3.87±1.58） mm（0.55~6.30 mm）;小脑下前动脉23支,压迫神经根1例,与之接触者2例,其余20支小脑下前动脉与三叉神经根最近距离为（4.67±1.77）mm（2.65~9.50 mm）;小脑下后动脉21支,与三叉神经根最近距离为（17.12±3.86） mm（10.45~25.70 mm）,未发现与之接触或压迫者。 结论　小脑上动脉与三叉神经关系密切,常与三叉神经接触并压迫神经,成为三叉神经痛发生的主要结构。小脑下前动脉与三叉神经相距稍远,也可与三叉神经接触或压迫神经。小脑下后动脉与三叉神经相距较远,但偶尔也会压迫三叉神经根导致三叉神经痛。     

Arterial relationships to the nerves and some rigid structures in the posterior cranial fossa

The close relationships between the cranial nerves and the arterial vessels in the posterior cranial fossa are one of the predisposing factors for artery-nerve compression. The aim of this study was to examine the relationships of the vertebral and basilar arteries to some skull and dural structures and the nerves in the posterior cranial fossa. For this purpose, the skull bases and brains of 70 cadavers were studied. The topographic relationships of the vertebral and basilar arteries to the cranial nerves in the posterior cranial fossa were studied and the distances between the arteries and some osseous formations were measured. The most significant variations in arterial position were registered in the lower half of the basilar artery. Direct contact with an artery was established for the hypoglossal canal, jugular tubercle, and jugular foramen. The results reveal additional information about the relationships of the nerves and arteries to the skull and dural formations in the posterior cranial fossa. New quantitative information is given to illustrate them. The conditions for possible artery-nerve compression due to arterial dislocation are discussed and two groups (lines) of compression points are suggested. The medial line comprises of the brain stem points, usually the nerve root entry/exit zone. The lateral line includes the skull eminences, on which the nerves lie, or skull and dural foramina through which they exit the cranial cavity.     

Magnetic resonance imaging based classification of anatomic relationship between the cochleovestibular nerve and anterior inferior cerebellar artery in patients with non-specific neuro-otologic symptoms

In this study, we aimed to assess anatomical relationship between the anterior inferior cerebellar artery (AICA) and cochleovestibular nerve (CNV) in patients with non-specific cochleovestibular symptoms using magnetic resonance imaging (MRI). One-hundred and forty patients with non-specific neuro-otologic symptoms were assessed using cranial and temporal MRI. Classification was performed according to four different types of anatomical relationship observed between the AICA and CVN. In type 1 (point compression), the AICA compresses only a limited portion of the CVN. In type 2 (longitudinal compression), the AICA approaches the CVN as both traverse parallel to each other. In type 3 (loop compression), the vascular loop of the AICA encircles the CVN. In type 4 (indentation), the AICA compresses the CVN so as to make an indentation in the nerve. The anatomical relationship between the CVN and AICA was encountered in 19 out of 140 (13.6%) patients (20 ears). The VCC was unilateral in 18 patients (94.7%) and bilateral in one patient (5.3%). There was no other vascular structure causing VCC to the CVN except for vertebral artery that was seen in 2 out of 140 patients (1.4%). These were unilateral cases. There were tinnitus, vertigo or dizziness, hearing loss, and both hearing loss and vertigo in 5 (25%), 13 (65%), 1 (5%) and 1 (5%) ears of 20 patients, respectively. There was no relationship between the cochleovestibular symptoms and type of compression (p>0.05). Neurovascular relationship between the CVN and AICA can be imaged properly using MR and MR based classification may help reporting this relationship in a standard way. Although, MR images can show the anatomical relationship accurately, diagnosis of vascular conflict should not be based on imaging findings alone.     

突发性聋与小脑下前动脉血管袢及颈静脉球形态学关系的研究

目的　探讨小脑下前动脉血管袢及颈静脉球的形态特点与突发性聋的关系。 方法　选取单侧起病突发性聋患者80例（80耳）,36例健康成人（72耳）,分别设为突聋组（80耳）和对照组（72耳）,回顾分析其内耳MRI扫描及三维重建图像,观察以下指标：（1）小脑下前动脉血管袢是否突入内听道;（2）小脑下前动脉血管袢与面神经及前庭蜗神经的位置关系;（3）颈静脉球与周围结构的位置关系。 结果 （1）小脑下前动脉血管袢突入内听道：突聋组35耳（43.8%）、对照组29耳（40.3%）,P=0.665,差异无统计学意义。（2）小脑下前动脉血管袢与面神经及前庭蜗神经的位置关系分型：突聋组上位型9耳（11.3%）、中间型53耳（66.3%）、下位型11耳（13.8%）、前位型7耳（8.8%）、后位型0耳,对照组上位型8耳（11.1%）、中间型46耳（63.9%）、下位型11耳（15.3%）、前位型7耳（9.7%）、后位型0耳。P=0.771,差异无统计学意义。（3）颈静脉球位置分型：突聋组I型2耳（2.5%）、Ⅱ型40耳（50.0%）、Ⅲ型36耳（45.0%）、Ⅳ型2耳（2.5%）,对照组I型0耳、Ⅱ型19耳（26.4%）、Ⅲ型46耳（63.9%）、Ⅳ型7耳（9.7%)。P<0.001,差异有统计学意义。 结论　突发性聋与颈静脉球的位置相关,与小脑下前动脉血管袢是否突入内听道无关,与面神经及前庭蜗神经的位置无关。颈静脉球Ⅱ型（后上型）较其它类型人群患突发性聋的比例更高。     

突发性聋与小脑下前动脉血管袢及颈静脉球形态学关系的研究

目的　探讨小脑下前动脉血管袢及颈静脉球的形态特点与突发性聋的关系。 方法　选取单侧起病突发性聋患者80例（80耳），36例健康成人（72耳），分别设为突聋组（80耳）和对照组（72耳），回顾分析其内耳MRI扫描及三维重建图像，观察以下指标：（1）小脑下前动脉血管袢是否突入内听道；（2）小脑下前动脉血管袢与面神经及前庭蜗神经的位置关系；（3）颈静脉球与周围结构的位置关系。 结果 （1）小脑下前动脉血管袢突入内听道：突聋组35耳（43.8%）、对照组29耳（40.3%），P=0.665，差异无统计学意义。（2）小脑下前动脉血管袢与面神经及前庭蜗神经的位置关系分型：突聋组上位型9耳（11.3%）、中间型53耳（66.3%）、下位型11耳（13.8%）、前位型7耳（8.8%）、后位型0耳，对照组上位型8耳（11.1%）、中间型46耳（63.9%）、下位型11耳（15.3%）、前位型7耳（9.7%）、后位型0耳。P=0.771，差异无统计学意义。（3）颈静脉球位置分型：突聋组I型2耳（2.5%）、Ⅱ型40耳（50.0%）、Ⅲ型36耳（45.0%）、Ⅳ型2耳（2.5%），对照组I型0耳、Ⅱ型19耳（26.4%）、Ⅲ型46耳（63.9%）、Ⅳ型7耳（9.7%)。P<0.001，差异有统计学意义。 结论　突发性聋与颈静脉球的位置相关，与小脑下前动脉血管袢是否突入内听道无关，与面神经及前庭蜗神经的位置无关。颈静脉球Ⅱ型（后上型）较其它类型人群患突发性聋的比例更高。     

Arterial supply of the upper cranial nerves: A comprehensive review

The arterial supply to the upper cranial nerves is derived from a complex network of branches derived from the anterior and posterior cerebral circulations. We performed a comprehensive literature review of the arterial supply of the upper cranial nerves with an emphasis on clinical considerations. Arteries coursing in close proximity to the cranial nerves regularly give rise to small vessels that supply the nerve. Knowledge of the arteries supplying the cranial nerves is of particular importance during surgical approaches to the skull base. Clin. Anat. 27:1159–1166, 2014. © 2014 Wiley Periodicals, Inc.     

Pathologic Reappraisal of Wallenberg Syndrome: A Pathologic Distribution Study and Analysis of Literature

Background

Wallenberg syndrome was first reported by Adolf Wallenberg as arising due to the obstruction of the posterior inferior cerebellar artery (PICA), which caused an infarct in the lateral medulla oblongata (MO).

Method

This study was carried out on brain tissue from 2 patients with typical Wallenberg syndrome and 10 autopsy cases without central nervous system disturbances.

Results

Patient 1 exhibited the 3 major neurological symptoms of right crossed sensory disturbance, right cerebellar ataxia and bulbar palsy. There was the pathological obstruction of the right vertebral artery (VA). Regarding the histopathlogical distribution, the infarct extended on the right side to the lateral spinothalamic tract, nucleus of the spinal tract of the trigeminal nerve, spinal tract of the trigeminal nerve, inferior cerebellar peduncle, spinocerebellar tract and nucleus ambiguous. Moreover, a clear infarct in the left lateral MO was pathologically identified, but pathological obstruction of the left PICA or left VA could not be found. The left cerebellar ataxia and bulbar palsy were observed among these 3 major symptoms. Patient 2 showed the 3 major symptoms of right crossed sensory disturbance, right cerebellar ataxia and bulbar palsy. A pathological luminal occlusion was identified in the right PICA. Regarding the histopathological lesion, the infarct disturbed on the right side the lateral spinothalamic tract, nucleus of the spinal tract of the trigeminal nerve, spinal tract of the trigeminal nerve, spinocerebellar tract, inferior cerebellar peduncle and nucleus ambiguus.

Conclusion

Based on our investigation of pathological lesions using our 2 autopsies, we suggest calling the cases that satisfy the following 3 criteria “definite pathologic Wallenberg syndrome”: i) identifiable pathological obstruction of the PICA or VA; ii) infarction in the lateral MO based on PICA or VA obstruction; and iii) a 1-to-1 correspondence between clinical symptoms and neuropathological lesions.     

颅后窝外侧入路术的应用解剖

目的 :为颅后窝手术入路提供避免损伤血管神经等的解剖学依据。方法 :解剖测量 16例成人头颅标本。结果 :乳突尖至茎突尖、寰椎横突外侧端和茎突尖至寰椎横突外侧端三者之间的距离分别为(3 0 .67± 6.3 8)mm ,(2 4.15± 4.46)mm和 (15 .2 0± 3 .5 0 )mm。乳突尖至面神经、颈静脉孔的外缘和颈动脉管外口的外缘、枕骨髁外侧缘中点的距离分别为 (10 .11± 3 .0 2 )mm ,(2 2 .93± 3 .5 9)mm ,(3 0 .40±3 .3 7)mm和 (3 1.43± 3 .11)mm。乳突尖至Ⅸ、Ⅹ、Ⅺ和Ⅻ对脑神经出颅处的距离分别为 (2 6.13± 5 .49)mm ,(2 4.2 7± 4.11)mm ,(2 1.17± 4.3 4)mm和 (2 4.64± 4.64 )mm。结论 :在颅后窝外侧入路的手术中 ,应重视乳突至茎突、寰椎横突外侧端和茎突至C1横突外侧端的间距 ,以及乳突至颈内静、动脉 ,Ⅸ、Ⅹ、Ⅺ和Ⅻ对脑神经的位置和距离等能有效地在手术时保护它们。     

面听神经血管压迫综合征患者小脑下前动脉血管袢与患者典型面听神经症状的MRI研究

目的 探讨小脑下前动脉前(AICA)血管袢的位置对面听神经血管压迫综合征患者典型面、听神经症状的影响。方法 回顾性研究。纳入兰州大学第二医院核磁共振科311例患者(622侧耳)内耳MR可变翻转角三维快速自旋回波(3D-SPACE)序列影像资料,其中男113例、女198例,年龄22~77(48±10.8)岁。统计AICA血管袢发生率及其Chavda分型占比。311例中,单侧面肌痉挛患者107例,比较其患侧(107侧)与健侧(107侧)AICA血管袢发生率、Chavda分型占比,以及AICA走行全程与神经有无接触。自血管袢阳性患者中选择90例(148侧)为血管袢组,比较不同Chavda分型AICA血管袢患者临床表现的差异;将ChavdaⅡ型及Ⅲ型的63侧耳纳入内耳道内血管袢组,将内耳道中的神经分布分为4个象限,观察AICA血管袢与面、听神经接触的位置象限不同的患者间典型面、听神经症状的差异。结果 本组311例622侧患者AICA血管袢的发生率为65.43%(407/622),其中双侧AICA血管袢形成144例、单侧119例,ChavdaⅠ型170侧(41.77%)、Ⅱ型189侧(46.44%)、Ⅲ型48侧(11.79%)。107例单侧面肌痉挛患者健侧AICA血管袢发生率为71.96%(77/107)、患侧70.09%(75/107),两侧比较差异无统计学意义(P＞0.05);健侧和患侧神经血管接触率分别为57.9%(62/107)、43.9%(47/107),差异有统计学意义(χ²=4.207, P＜0.05)。血管袢组90例(148侧)中,不同Chavda分型患者面肌痉挛、听力下降、耳鸣症状的发生率比较,差异均无统计学意义(P值均＞0.05);内耳道内血管袢组共63侧,内耳道内AICA血管袢所处象限不同患者的典型面、听神经症状比较,差异均无统计学意义(P值均＞0.05)。结论 内耳MR 3D-T₂-SPACE成像可清晰显示AICA血管袢及其与内耳道的位置关系,血管袢深度、位置对面听神经压迫综合征典型面、听神经症状无明显影响。     

Anatomy of the posterior inferior cerebellar artery

Lateral C1‐C2 puncture is associated with a number of complications including damage of aberrant posterior inferior cerebellar arteries (PICA). We propose to determine the frequency of cases in which the PICA originates or descends below C1, thus posing a risk to the patient undergoing lateral C1‐C2 puncture. Two hundred and eleven consecutive patients who received bilateral or unilateral vertebral angiography for evaluation of cerebrovascular lesions were included in this study. In total, 346 PICAs were studied. Lateral vertebral angiograms were analyzed for the location of the origin of the PICA and the inferior‐most portion of the PICA relative to three anatomical regions. Region 1 was defined as the region above the foramen magnum. Region 2 was defined as the region below the foramen magnum but above the inferior border of the posterior arch of C1. Region 3 was defined as the region below the inferior border of the posterior arch of C1. In 2 of 346 angiograms (0.6%) and 2 of 211 patients (0.9%), the caudal loop of the PICA descended to Region 3. The PICA did not originate in Region 3 in any cases. In ～1% of patients in our study, the caudal loop of the PICA descended into a region that may have placed it at risk for damage during C1‐C2 puncture. Our study suggests that it may be important for radiologists to assess the arterial anatomy of the C1‐C2 region before performing C1‐C2 puncture. Clin. Anat. 22:319–323, 2009. © 2009 Wiley‐Liss, Inc.     

颅后窝三角显微解剖及临床意义

目的：研究颅后窝三角的显微特征，为颅后窝手术提供快速辨认神经、血管的方法。方法：旁正中切口、乙状窦后入路，逐层开颅并切开硬脑膜，显微观察12具成人头部标本硬脑膜形成的三角。结果：颅后窝硬脑膜皱襞反光形成一个三角形：外上顶点即“光点”，位于横窦与乙状窦移行处的前方；内上顶点恰是岩静脉注入岩上窦的位置；颈静脉孔构成颅后窝三角内下顶点。结论：手术显微镜下，颅后窝硬脑膜形成的标志性三角，可以帮助迅速辨认三叉神经、岩静脉，经过内耳门的面神经、前庭蜗神经以及经过颈静脉孔的舌咽神经、迷走神经、副神经。     

肠系膜下动脉根部自主神经保护的解剖学基础

目的　观察肠系膜下动脉（IMA）根部与其周围自主神经的解剖学关系,为肠系膜下动脉根部自主神经保护提供解剖学证据。 方法　7例10%福尔马林固定标本进行大体解剖及显微解剖;2例新鲜标本模拟腹腔镜下直肠癌D3根治术中肠系膜下动脉根部自主神经的显露和保护。 结果　上腹下丛(SHP)的左、右侧束及束间交通支与肠系膜下动脉根部关系密切。右侧束距离肠系膜下动脉根部较远,位于肾前筋膜下。以左侧束降支为界,其近端,上腹下丛左侧束、肠系膜下丛、腹主动脉丛紧贴肠系膜下动脉根部左侧壁并相互延续,其远端左侧束走行于肾前筋膜下。左侧束降支距离IMA起点的距离不恒定。 结论　在肾前筋膜前平面分离可有效保护上腹下丛右侧束及侧束间交通支;以SHP左侧束降支作为肠系膜下动脉根部离断的解剖学标志可以有效保护左侧束。     

脑神经海绵窦段的显微解剖及其临床应用

目的　为海绵窦 (cavernoussinus,CS)直接手术提供解剖学基础。方法　在手术显微镜下对 15例 (30侧 )成人头颅标本CS内脑神经位置、行径以及与颈内动脉CS段的毗邻关系进行观测。结果　①动眼神经入窦点在前床突尖后方 (4 5 7± 1 0 5 )mm ,与滑车神经、眼神经垂直距离分别为 (2 2 0± 0 6 7)mm和 (4 37± 1 35 )mm。②滑车神经入窦点与眼神经垂直距离为 (5 5 2± 1 0 6 )mm。滑车神经CS段行程形状可分为三型。③颈内动脉后曲顶高出眼神经和展神经上缘分别为 (5 5 2± 1 84)mm和 (6 6 0± 1 94)mm。④经前床窦尖外侧或外下方时 ,动眼神经、滑车神经及眼神经与前床突尖垂直距离分别为 (1 85±0 75 )mm、(5 30± 1 0 4)mm和 (6 6 1± 1 6 3)mm。结论　掌握脑神经CS段的显微解剖对CS的直接手术具有重要意义。     

面肌痉挛与有关血管关系的显微外科解剖

目的：了解面听神经和有关血管的解剖关系;正确理解面肌痉挛的原因;为手术治疗提供解剖学参数。方法：手术显微镜下对１５例成人尸体头部标本进行面听神经和有关血管的观察,并测量有关数据。结果：面听神经和小脑前下动脉关系密切,８９．７％的小脑前下动脉在面听神经的不同部位穿过;１３．３％的面听神经起始部被血管压迫。结论：血管压迫可能是面肌痉挛的主要原因;显微血管减压术是面肌痉挛的首选治疗方法。