Parasellar syndromes

The parasellar compartments are located lateral to and on either side of the sella turcica. The cavernous sinuses are the most prominent anatomic feature of the parasella. Each sinus consists of a plexus of veins through which runs the intracavernous portion of the internal carotid artery. Ocular motor nerves three and four travel within the dural covering of the cavernous sinus to the superior orbital fissure, and cranial nerve six travels through the carotid sinus itself, giving rise to parasellar syndromes, which have distinctive clinical features. Ophthalmoplegia occurs as a result of damage to these ocular motor nerves and variable involvement of oculosympathetic nerves. Facial pain, dysesthesia, and paraesthesia are caused by damage to one or more of the divisions of the fifth cranial nerve, travelling in the dural wall of the cavernous sinus. Tumors, such as meningiomas, frequently cause parasellar syndromes, as do aneurysms of the intracavernous portion of the internal carotid artery, carotid-cavernous fistulas, and cavernous sinus thrombosis. Inflammatory conditions such as Tolosa-Hunt syndrome, ischemia to small vessels supplying the cavernous portion of the cranial nerves, and infections can cause this syndrome. Magnetic resonance imaging is the investigation of choice and therapy is specific to the cause of the parasellar syndrome, but now includes more aggressive endoscopic and microsurgical intervention, and radiosurgery.     

海绵窦内颅神经血液供应显微外科解剖研究

目的 为减少海绵窦显微外科手术时损伤海绵窦内颅神经血供而研究这些颅神经的血液供应解剖。方法 50具成人尸体海绵窦标本,在解剖显微镜下解剖和分析。结果（１）９０侧（占90％）的标本示动眼神经由颈内动脉的下外侧动脉分支供血;（2）滑车神经近段有74例（占74％）的标本示其接受下外侧动脉的分支供血,有26例（占26％）标本示其接受脑膜垂体动脉分支天幕动脉的供血,滑车神经远段主要由下外侧动脉的分支供血;（3）在Dorellos管区域,外展神经近段接受脑膜背侧动脉的血供,中段及远段由下外侧动脉的分支供血;（4）三叉神经的眼支和上颌支由下外侧动脉的分支供血,三叉神经节的内侧部由下外侧动脉和天幕动脉的分支供血,中部由下外侧动脉的分支供血,外侧部由下外侧动脉的分支或由脑膜中动脉供血。结论 下外侧动脉在海绵窦内颅神经供血中起重要作用。术中我们应保护这些血供,就可减少术后颅神经功能障碍。     

Meningo-orbital fold (MOF) as a guiding point in extradural approach to the anterior clinoid process

BACKGROUND AND PURPOSE: The essential stage of Dolenc's approach to the cavernous sinus is the incision of the meningo-orbital fold (MOF) without damaging nervous structures in the superior orbital fissure. The goal of the research is to perform a topographic and morphometric study of the meningo-orbital fold. MATERIAL AND METHODS: Formalin preserved central cranial base specimens from twenty adults (40 sides) were dissected for this study. The dissection was based on Dolenc's epidural approach to the cavernous sinus. RESULTS: The average width of MOF is 8.4 mm on the right side and 8.3 mm on the left side. The meningo-orbital artery (MOA) is an important reference point in recognizing the superior orbital fissure. In 75% (15 specimens) of cases the meningo-orbital artery passes by the superior fissure at a distance of a few millimeters. In 25% (5 specimens) of cases the MOA passes through the lateral margin of the superior orbital fissure. CONCLUSIONS: The MOF is an inset of the external layer of the dura mater of the middle cranial fossa which passes through the superior orbital fissure and joins the periorbita at the level of the sphenoparietal sinus. The average width of the MOF is 8.4 mm on the right side and 8.3 mm on the left side. The new approach to the safe incision of the MOF relies on the medial margin identification by splitting both layers in the lateral wall of the cavernous sinus between V1 and V2. After identification of the medial margin, it is possible to separate the margin from the superficial layer of the cavernous sinus, from the side anterior and middle cranial fossae. It is then possible to perform a safe incision of the MOF without any danger of damaging the nerves.     

Superior divisional third cranial nerve paresis: clinical and anatomical observations of 2 unique cases

BACKGROUND: Within the midbrain, the third nerve nucleus is composed of a complex of subnuclei. The fascicular portion of the nerve courses through the red nucleus and exists in the midbrain just medial to the cerebral peduncle. The cisternal portion of the nerve is a single structure that divides into a superior branch and an inferior branch in the region of the cavernous sinus and superior orbital fissure. OBJECTIVE: To describe 2 patients with superior divisional third cranial nerve paresis resulting from a lesion involving the cisternal portion of the nerve prior to its anatomical bifurcation. PATIENTS: Case 1 was a 77-year-old man with a superior divisional third nerve palsy as the presenting manifestation of a posterior communicating artery aneurysm. Case 2 was a 41-year-old woman who developed a superior divisional third nerve palsy following anterior temporal lobectomy for epilepsy. RESULTS: In both cases, the presumed location of the lesion was the cisternal portion of the third cranial nerve. CONCLUSIONS: Although the anatomical division of the third cranial nerve occurs in the region of the anterior cavernous sinus or superior orbital fissure, there is a topographical arrangement of the motor fibers within the cisternal portion of the nerve. The clinical evaluation of a patient with a third cranial nerve paresis requires an understanding of the regional neuroanatomy and topographical organization of the nerve.     

Massive plexiform neurofibroma in the orbit in a child with von Recklinghausen's disease

We report a case of orbital plexiform neurofibroma presenting in a 10-year-old boy with von Recklinghausen's neurofibromatosis. The patient had shown a slow enlargement of exophthalmos of the right eye present since birth, together with multiple café au lait spots on the skin of the trunk. Magnetic resonance (MR) images revealed diffuse and irregular nodular involvement of the retrobulbar nerves within the muscle cone, which was confirmed at the surgery. The tumour extended into the ipsilateral cavernous sinus. We discuss the MR findings as pathognomonic signs of this rare orbital tumour, including its multinodular nature among dispersed intraconal fat tissue, location around the optic nerve, extension through the superior orbital fissure into the cavernous sinus and association with von Recklinghausen disease. Received: 31 January 1997     

Painful ophthalmoplegia: the Tolosa-Hunt syndrome.

Painful ophthalmoplegia is characterized by unilateral involvement of the IIIrd, IVth and VIth cranial nerves, as well as supra- and retro-orbital pain, i.e. participation of the Vth cranial nerve. The pain is relieved within 48-72 h with steroid therapy. The paresis of the eye muscles in various combinations usually subsides gradually from within a few weeks to several months. The etiology is unknown. The few pathological examinations reported in the literature showed an unspecific inflammatory granulation tissue around the intracavernous portion of the carotid artery and on the dura mater in the vicinity of the cavernous sinus. Carotid arteriography may show stationary waves of this artery and narrowing of its intracavernous portion. With orbital phlebography the occlusion of the supraorbital vein and obstruction of the cavernous sinus are sometimes demonstrable. The syndrome is well defined and its etiology still unknown.     

Meningiomas of the cavernous sinus: the surgical resectability and complications

The optimal management for patients with cavernous sinus meningiomas is to evacuate tumor without causing mortality or morbidity. The records of 16 patients, including 11 women and 5 men ranging in age from 31 to 63 years, underwent surgical treatment for this condition were reviewed. Completeness of tumor resection, cranial nerve morbidity, complications, mortality, the internal carotid artery encasement and outcome were studied. Total removal was achieved in six patients. Of ten patients who underwent subtotal resection there was one death and four were sent to radiotherapy. Morbidity was 24% for cranial nerves controlling extraocular motor function; trigeminal nerve function did not improve after surgical treatment. Symptomatic recurrence occurred in two patients who underwent subtotal tumor resection and in one who underwent complete tumor resection. The average follow-up period was of 26 months. According to our findings, we conclude: 1) the resectability of meningiomas of cavernous sinus depends on the degree of internal carotid artery involvement; 2) total resection of meningiomas confined in cavernous sinus is rare; 3) morbidity of the cranial nerves is significant; 4) subtotal resection is an effective mean to obtain control of the disease.     

海绵窦内侧壁的显微解剖与扩大经蝶窦入路治疗侵袭海绵窦的垂体腺瘤（附103例分析）

目的研究海绵窦内侧壁结构的解剖特点，并探讨采用扩大经蝶窦入路治疗侵袭海绵窦垂体腺瘤的方法。方法在10具成人新鲜尸头上模拟扩大经蝶窦手术入路，观察海绵窦内侧壁结构的解剖特点。根据解剖学研究结果，指导临床采用扩大经蝶窦手术入路治疗侵袭海绵窦的垂体腺瘤103例。结果垂体侧方的海绵窦内侧壁薄弱，仅有一层疏松的纤维组织结构。颈内动脉是扩大经蝶窦入路海绵窦内所见的主要结构，可分为5段，有3个主要分支。颈内动脉海绵窦段主要的分支有脑膜垂体干、海绵窦下动脉和被囊动脉。向内侧走行的脑膜垂体干和被囊动脉是经蝶窦入路中较易损伤的血管。手术显微镜下全切除肿瘤62例（60．2％），次全切除38例（36．9％），大部切除3例（2．9％）；无手术死亡；手术并发症包括短暂性脑脊液鼻漏5例，暂时性脑神经功能损伤4例，垂体功能低下3例，颈内动脉损伤2例，永久性尿崩症1例。术后行放射治疗17例，γ刀治疗15例，药物治疗13例。随访3个月～8年，2例出现肿瘤复发而予以γ刀治疗。无再手术病例。结论扩大经蝶窦入路是切除侵袭海绵窦垂体腺瘤理想的入路；了解颈内动脉海绵窦段及其分支在解剖形态上的变化，对于减少术中出血，确保术中安全，具有重要意义。     

扩大经鼻蝶入路海绵窦的内镜解剖研究

目的通过对扩大经鼻蝶窦入路的内镜解剖学研究,为临床应用提供形态学基础.方法在10具动脉灌注染料的成人尸头上模拟扩大经鼻蝶窦手术入路,测量海绵窦内重要结构与鞍底的距离.结果扩大经鼻蝶手术入路可清晰显示鞍底的骨膜、硬脑膜外层、海绵窦内侧壁,及海绵窦内的颈内动脉及其分支血管、动眼神经、滑车神经、展神经及视神经等结构.结论内镜下行扩大经鼻蝶手术入路可清晰显露海绵窦及其内的解剖结构,适用于鞍内病变侵犯海绵窦的外科治疗.     

Review of complications due to foramen ovale puncture.

We aim to evaluate the mechanisms responsible for complications during trigeminal rhizotomy via foramen ovale puncture. Ten dry skulls and 10 skull-base specimens were investigated in the present study. In cadaveric skull-base specimens, the anatomical relationships between the foramen ovale, mandibular nerve and Gasserian ganglion and the surrounding neurovascular structures were investigated intradurally. The distance between the foramen ovale and Gasserian ganglion was measured as 6 mm. The abducent nerve, adjacent to the anterior tail of the petrolingual ligament, was observed passing along the lateral wall of the cavernous sinus. Advancement of the catheter more than 10 mm from the foramen ovale is likely to damage the internal carotid artery and the abducent nerve at the medial side of the petrolingual ligament. Thermocoagulation of the lateral wall of the cavernous sinus may damage the cranial nerves by heat, giving rise to pareses.     

Cavernous sinus fistulas: Carotid cavernous fistulas and dural arteriovenous malformations

Direct and indirect carotid cavernous sinus fistulas are uncommon vascular anomalies that result in increased pressure in the cavernous sinus. The subsequent changes in blood flow lead to orbital venous congestion, cranial neuropathies, and glaucoma. The following review summarizes knowledge of the clinical features, natural history, diagnostic testing, and therapy for carotid cavernous sinus fistulas.     

上颌窦-翼腭窝-海绵窦手术入路的显微解剖学研究

目的对上颌窦-翼腭窝-海绵窦手术入路相关结构进行显微外科解剖学研究,为手术入路提供解剖学基础.方法利用10例经福尔马林固定的国人成人尸头共20侧,完全模拟该手术入路,对入路相关解剖标志进行了详细地显微解剖、观察、拍摄、测量和统计.结果上颌窦后壁与翼腭窝区结构复杂,有重要的神经和血管经过,是颅前、中窝与鼻腔、窦肿瘤互相蔓延的通道.该入路可较好地显露海绵窦前外侧相关的结构.结论该手术入路是海绵窦入路的一个特殊方法,拓展海绵窦手术入路的路径,为利用颅底硬膜外间隙进行入路提供了依据.     

Radioanatomy of the laterosellar veins. Value of dynamic computerized tomography.

Dynamic computerized tomography is a simple and rapid technique which can provide an accurate mapping of the vascular elements of the cavernous sinus. It is not very different from the technique used to visualize the capillary bed of the pituitary gland and its progressive contrast enhancement. From a series of 780 dynamic CT explorations, we were able to individualize 5 groups of veins: (1) the veins of the lateral wall of the cavernous sinus; (2) the veins of the infero-lateral group, located beneath the intracavernous segment of the internal carotid artery (ICA); (3) the vein of the carotid sulcus, located between the intracavernous ICA and the carotid sulcus; (4) the medial vein, situated between the intracavernous ICA and the pituitary gland, and (5) the pericarotid plexus. In some cases the anterior and inferior coronary sinuses and the basilar sinus can be visualized.     

Neural connections in and around the cavernous sinus in rat,with special reference to cerebrovascular innervation

There is a confluence in and around the cavernous sinus of neural pathways innervating the intracranial structures. To determine the patterns of innervation, particularly of the cerebral arteries, we stained whole-mount preparations of the cavernous sinus and adjacent regions of the rat for acetylcholinesterase. The cavernous nerve plexus, with several small ganglia, mainly occupied the lateral wall of the sinus and extended laterally above the ophthalmic and maxillary divisions of the trigeminal nerve, in relation to the oculomotor and trochlear nerves. The cavernous plexus was connected to the pterygopalatine ganglion, the trigeminal ganglion, and the abducens nerve. The elongated pterygopalatine ganglion consisted of an orbital part, from which parasympathetic fibers ran to the cerebral arteries, and a cavernous part. Nerves from the lateral extension of the cavernous plexus ran rostrally into the orbit along the oculomotor, trochlear, and ophthalmic nerves, and caudally to the pineal gland along the trochlear nerve. Several branches also ran over the dura mater. Caudal to the cavernous sinus, we found two large nerves and a number of small nerves that ran between the nerves surrounding the internal carotid artery and the abducens nerve. These nerves may represent additional parasympathetic and/or sensory pathways to the cerebral arteries. © 1996 Wiley-Liss, Inc.     

Experience in surgical management of tumours involving the cavernous sinus.

Potential injury to the neurovascular structures within the cavernous sinus often prohibits aggressive removal of tumours involving it, however, fully understanding the anatomy and selecting an appropriate surgical approach can often resolve this problem with acceptable morbidity. Moreover, a tumour may originate from different anatomical structures of the cavernous sinus which will influence the difficulty and outcome of the surgery. In general, tumours in this region can be classified as intradural, intracavernous and invasive types. The strategy of surgical treatment varies among these different anatomical types. Therefore, preoperative evaluation of tumours in the cavernous sinus is critical for the selection of an appropriate microsurgical approach. During the past 5 years, 12 tumours involving the cavernous sinus have been operated upon which included four neuromas, three meningiomas, three cavernous haemangiomas, one plasmacytoma and one chondroma. Nine of these twelve tumours were totally resected after one or two operations. There was no surgical mortality and the most common morbidity was transient cranial nerve palsy. At 2 months after surgery there was no additional postoperative cranial nerve deficit in all the patients; however, one patient developed a postoperative middle cerebral artery infarct due to accidental injury to the internal carotid artery during surgery. The respectability of the tumour mostly depends on its consistency and the involvement of the adjacent anatomy. The pathoanatomical features of the tumours and the clinicoradiological findings, as well as the selection of the microsurgical approach, are discussed.     

Surgical anatomy of the dural walls of the cavernous sinus

The external structure of each cavernous sinus (CS) is made of four dural walls. The aim of this study was to describe the anatomy of the dural walls of the CS. We studied 42 adult cadaveric heads, fixed with formalin and injected with coloured silicon. The main findings were: (i) the lateral wall of the CS has two layers – the external, which is thick and pearly grey, and the internal, which is semi-transparent and containing the cranial nerves (CNs); (ii) the medial wall of the CS has two areas – sellar and sphenoidal, both made up of one dural layer only; and (iii) the superior wall of the CS is formed by three triangles – oculomotor, clinoid and carotid – CN III may be found in a cisternal space of the oculomotor triangle; and (iv) the posterior wall of the CS is made up of two dural layers – meningeal dura and periostic dura – and this wall is close to the vertical segment of CN VI.     

Meningeal Layers Around Anterior Clinoid Process as a Delicate Area in Extradural Anterior Clinoidectomy : Anatomical and Clinical Study

Objective

Removal of the anterior clinoid process (ACP) is an essential process in the surgery of giant or complex aneurysms located near the proximal internal carotid artery or the distal basilar artery. An extradural clinoidectomy must be performed within the limits of the meningeal layers surrounding the ACP to prevent morbid complications. To identify the safest method of extradural exposure of the ACP, anatomical studies were done on cadaver heads.

Methods

Anatomical dissections for extradural exposure of the ACP were performed on both sides of seven cadavers. Before dividing the frontotemporal dural fold (FTDF), we measured its length from the superomedial apex attached to the periorbita to the posterolateral apex which connects to the anterosuperior end of the cavernous sinus.

Results

The average length of the FTDF on cadaver dissections was 7 mm on the right side and 7.14 mm on the left side. Cranial nerves were usually exposed when cutting FTDF more than 7 mm of the FTDF.

Conclusion

The most delicate area in an extradural anterior clinoidectomy is the junction of the FTDF and the anterior triangular apex of the cavernous sinus. The FTDF must be cut from the anterior side of the triangle at the periorbital side rather than from the dural side. The length of the FTDF incision must not exceed 7 mm to avoid cranial nerve injury.     

海绵窦显微解剖及颅眶颧入路研究

目的为海绵窦的颅眶颧入路提供解剖学依据。方法成人头颅湿标本15例，血管内灌注乳胶染料后进行至海绵窦的相关手术入路操作，手术显微镜下观测海绵窦的解剖结构，每侧测量了12个海绵窦各壁上解剖三角的有关数据，将颅眶颧入路与其他手术入路进行比较。结果通过Hakuba三角和Parkinson三角几乎能暴露海绵窦内所有结构。结论经海绵窦三角直接手术，既不损伤重要神经血管又能进入海绵窦内，充分认识有关解剖三角是手术顺利进行的前提。颅眶颧入路能充分暴露海绵窦侧壁各解剖三角。有利于进行海绵窦复杂病变的手术。     

内镜下经鼻蝶入路治疗鞍区病变的解剖学研究

目的研究内镜下蝶窦和鞍区的解剖结构。方法对8例成人头颅标本在内镜下模拟经鼻蝶手术入路,解剖观察蝶窦后壁和鞍区。结果将蝶窦后壁“井”字线划分为九个区,中间从上到下分别为视交叉区、鞍区和斜坡区,两侧从上到下分别为视神经管区、鞍旁海绵窦区和斜坡旁海绵窦区。鞍型蝶窦后壁中常见的解剖标志有斜坡凹陷、视神经管隆突、颈内动脉隆突和视神经颈内动脉隐窝;其中视神经颈内动脉隐窝是恒定的骨性解剖标志,毗邻视神经、海绵窦、海绵窦内颈内动脉、眶尖;两侧视神经颈内动脉隐窝的连线是鞍结节的投影。鞍旁海绵窦区是骨缺损好发的位置。结论对蝶窦后壁的九分区法适用于骨质层、硬膜层和颅内层,使复杂的鞍区及附近结构相对简化,易于识别和定位;视神经颈内动脉隐窝是重要的解剖标志。     

经耳前颧弓硬膜外入路切除海绵窦肿瘤60例分析

目的 总结回顾2002年至2009年经治的海绵窦病变60例的临床特点、手术人路及手术效果.方法 神经鞘瘤18例,海绵状血管瘤23例,皮样囊肿9例,脑膜瘤4例,脊索瘤3例,垂体瘤3例.均经耳前颧弓硬膜外入路切除.结果 神经鞘瘤18均全切,海绵状血管瘤23例,全切18例,5例有残留.皮样囊肿9例全切,脑膜瘤4例,全切3例,次全切1例.脊索瘤3例,结合经鼻蝶窦入路手术,均达到了全切.垂体瘤3例全切.结论 经耳前颧弓硬膜外入路切除海绵窦病变是一个理想的手术入路,可以充分显露病变,减少对脑组织的牵拉,也可以明确Ⅲ～Ⅵ脑神经和颈内动脉的位置,减少神经和血管损伤的概率.对与动脉或神经粘连无法彻底切除的病变可以辅以立体定向放射治疗.

Abstract：

Objective To review our experience of microsurgery for 60 cavernous sinus tumors from 2002 to 2009.The clinical features,surgical techniques and outcome of cavernous sinus tumor in 60 cases were investigated retrospectively.Methods The patients included 23 hemangiomas,18 shwannomas,9 dermoid cysts,4 meningiomas,3 chordomas,3 pituitary adenomas.AIl the tumors were removed with subtomperal preauricular extradural approach.Results The tumors were removed satisfactorily.The shwannomas were totally removed. The hemangiomas were totally removed in 18,near-totally removed in 5 cases.Nine dermoid cysts were removed totally.For the 4 meningiomas,3 were removed completely,neartotallv removed in 1 cases.The 3 Chordomas were resected near-totally and achieved a completely removal with combined approach.Conclusion The subtomperal preauricular extradural approach is a rational choice.It can reveal the cranial nerve branches and artery at an early stage so that cranial nerves Ⅲ～Ⅵ and internal carotid artery can be preserved during operation.The tumor exposure is ideal and brain traction and contusion are slightly.The adjunctive radiotherapy is demanded for residual tumors adhering to nerves and arteries severely.