Meningeal architecture of the cavernous sinus: clinical and surgical implications

OBJECTIVE: The meningeal structure of the cavernous sinus (lateral sellar compartment) was anatomically and histologically studied. We discuss the clinical and surgical significance and present clinical examples of cranial base tumors. METHODS: Ten adult cadaveric heads were used for microsurgical dissection or histological studies. Specimens of the cavernous sinus were continuously sectioned in three dimensions and stained by Masson's trichrome method. The findings are anatomically discussed as they pertain to presented clinical cases. RESULTS: The cavernous sinus, located in an interdural space between periosteal and meningeal dura, is properly accessed by detachment of the periosteal bridge between the superior orbital fissure and the middle fossa. The lateral meningeal dura is dissected under minimal hemorrhage from the sinus, with a surgically important cleaving plane between the "deep layer," a semitransparent meningeal sheath with which the cranial nerves are covered and protected. It has various degrees of meningeal pockets, of which Meckel's cave is the largest example. Adventitia of the carotid artery in the sinus, uncovered with protective meninges, is considered to contact directly with tumors of the sinus origin. The meningeal wall of the cavernous sinus anatomically has three weak points as far as tumor invasion and extension are concerned: the venous plexus around the superior orbital fissure, the loose texture of the medial wall around the pituitary body, and dural pockets of the IIIrd and Vth cranial nerves. The dural wall is extremely thin or missing at those points. CONCLUSION: A surgical technique based on the meningeal anatomy is important for cavernous sinus surgery. The cavernous apex and Meckel's cave, which are spaces of convergence of cranial nerves, however, are weak points for surgical dissection. The presence or absence of tumor invasion into those areas may influence the microsurgical results.     

Multiple myeloma presenting as parasellar syndrome and cranial nerve palsies

Cranial and intracranial locations have been rarely reported in multiple myeloma. Their occurrence as a harbinger of multiple myeloma seems to have a particular significance. In this report, we discuss a case of multiple myeloma presenting as parasellar syndrome and cranial nerve palsies. A 75-year-old woman was admitted to the hospital in June, 1994, with a 3-month history of headache and a 3-week history of diplopia and photophobia. Physical examination revealed right third, fourth and sixth cranial nerve palsies. MRI scan demonstrated a homogeneous, voluminous mass, isointense in T1-weighted images with the cerebral parenchyma and hyperintense in T2-weighted images, occupying the sphenoid sinus and extending within the sella turcica and right cavernous sinus. Lying above the mass and apparently separated from it by a thin rim of hypointensity was a normal pituitary gland. X rays revealed destructive changes of the sella turcica. A minimal disturbance of endocrine function together with a radiologically abnormal pituitary fossa indicated that the primary lesion might lie outside the pituitary fossa. A diagnosis of IgG-kappa type multiple myeloma was made by pertinent laboratory studies. She received local radiation to the intracranial mass (50 Gy) and conventional chemotherapy. Sixteen months after the therapy she is in good health.     

The suboccipital cavernous sinus

The authors studied the microsurgical anatomy of the suboccipital region, concentrating on the third segment (V3) of the vertebral artery (VA), which extends from the transverse foramen of the axis to the dural penetration of the VA, paying particular attention to its loops, branches, supporting fibrous rings, adjacent nerves, and surrounding venous structures. Ten cadaver heads (20 sides) were fixed in formalin, their blood vessels were perfused with colored silicone rubber, and they were dissected under magnification. The authors subdivided the V3 into two parts, the horizontal (V3h) and the vertical (V3v), and studied the anatomical structures topographically, from the superficial to the deep tissues. In two additional specimens, serial histological sections were acquired through the V3 and its encircling elements to elucidate their cross-sectional anatomy. Measurements of surgically and clinically important features were obtained with the aid of an operating microscope. This study reveals an astonishing anatomical resemblance between the suboccipital complex and the cavernous sinus, as follows: venous cushioning; anatomical properties of the V3 and those of the petrous-cavernous internal carotid artery (ICA), namely their loops, branches, supporting fibrous rings, and periarterial autonomic neural plexus; adjacent nerves; and skull base locations. Likewise, a review of the literature showed a related embryological development and functional and pathological features, as well as similar transitional patterns in the arterial walls of the V3 and the petrous-cavernous ICA. Hence, due to its similarity to the cavernous sinus, this suboccipital complex is here named the "suboccipital cavernous sinus." Its role in physiological and pathological conditions as they pertain to various clinical and surgical implications is also discussed.     

Non-Hodgkin lymphoma of the central skull base: MR manifestations

OBJECTIVE: The aim of this study was to demonstrate the MR characteristics of non-Hodgkin lymphoma of the skull base to help in the differential diagnosis of this neoplasm from other conditions. MATERIALS AND METHODS: MR of five patients, 7-64 years old, with pathologically proved lymphomas of the skull base were reviewed. Three cases had primary skull base lesions involving the sphenoid bone and the cavernous sinus. One case with a nasal cavity lesion involving the skull base and one with a relapsing skull base lesion of previously treated tonsillar lymphoma were included. RESULTS: The lesions had signal intensities that were similar to that of gray matter of brain on both T1- and T2-weighted imaging. Bilateral cavernous sinuses were involved with encasement of internal carotid arteries in every case. Postcontrast MR showed homogeneous enhancement of the tumor with dural infiltration along the planum sphenoidale, clivus, or tentorium. The clivus was destroyed or replaced by tumors in adult cases but in two children the clivus was preserved with intact sphenooccipital synchondrosis. In one case the tumor extended to the extracranial portion through the jugular foramen. CONCLUSION: The MR findings of a permeative lesion of the skull base, invasion of the cavernous sinus without arterial narrowing, infiltration along the dural surface, and an iso- or hypointensity with brain on T2-weighted imaging should suggest lymphoma.     

Nasopharyngeal carcinoma with intracranial spread: CT and MR characteristics

PURPOSE: Nasopharyngeal carcinoma (NPC) frequently spreads intracranially. We compare CT and MRI in identifying intracranial spread and reexamine the route of infiltration. METHOD: One hundred fourteen consecutive patients with proven NPC were evaluated prospectively with T1-, T2-weighted, contrast-enhanced MRI and CT. RESULTS: MRI showed 35 (31%) patients with middle cranial fossa involvement. Twenty-nine (25%) patients had cavernous sinus infiltration, while six (5%) showed only dural thickening. The most common route of spread is through the foramen ovale (FO) (12/35 patients, 34%), followed by skull base destruction (6/35 patients, 17%), foramen lacerum (FL) (6/35 patients, 17%), sphenoid sinus (6/35 patients, 17%), and combined FO and FL (5/35 patients, 14%). Using MRI as a standard, CT demonstrated the following involvement: cavernous sinus in 26 of 29 (90%) patients, FO in 9 of 12 patients, skull base in 6 of 6 patients, FO and FL in 3 of 5 patients, FL in 6 of 6 patients, sphenoid sinus in 6 of 6 patients and dura in 0 of 18 patients. CONCLUSION: It is believed that NPC most commonly spreads intracranially via the FL or by direct erosion. Perineural spread through the FO is an important route, which explains why with CT evidence of cavernous sinus involvement there may be no skull base erosion. These findings are best seen on MRI.     

Effects of oral treatment with sustained release morphine tablets on hypothalamic-pituitary-adrenal axis

A 31-year-old black male with sarcoidosis en-plaque of the dura mater, which is a rare morphological variant of neurosarcoidosis (NS), presented at our clinic. Magnetic resonance imaging (MRI) of the head with gadolinium showed non-specific enhancement of both tentorial leaves extending to the floor of right middle cranial fossa and cavernous sinus. The laboratory results were normal except for slightly increased serum angiotensin converting enzyme (SACE) (68 U/ml n = 4-56 U/ml) and cerebrospinal fluid (CSF) IgG index (0.57, n = 0.46). Biopsy of the intracranial dural lesion was consistent with sarcoidosis. Oral steroid therapy (Methylprednisolone 4 mg QID) was started and the patient became asymptomatic. However, MRI of the brain with gadolinium 2 months after biopsy showed progression and extension of the enhanced dural lesion. His SACE level was unchanged. We concluded that progression of the enhanced lesion seen in MRI could be recently formed scar tissue, new lesion or both. MRI findings should always be correlated with clinical findings for evaluation of NS during follow-up.     

Venous angiography is needed to interpret inferior petrosal sinus and cavernous sinus sampling data for lateralizing adrenocorticotropin-secreting adenomas

Bilateral simultaneous venous sampling of ACTH from the inferior petrosal sinus is a reliable test for diagnosing Cushing's disease, but is not reliable for lateralizing ACTH-secreting pituitary adenomas. We reviewed 23 consecutive patients with Cushing's disease who underwent venous angiography of the cavernous and inferior petrosal sinuses followed by bilateral simultaneous venous sampling of ACTH in the inferior petrosal and cavernous sinuses. Venous drainage was bilaterally symmetric in 14 patients (61%) and asymmetric in 9 (39%). The most common asymmetric pattern (6 patients) was for blood from both cavernous sinuses to drain into the right inferior petrosal sinus, with no significant drainage into the left. Cavernous sinus sampling in 21 patients correctly lateralized the tumor in 12 cases of symmetric venous drainage, but in only 3 cases of asymmetric drainage. Inferior petrosal sinus sampling in all 23 patients correctly lateralized the tumor in 12 cases of symmetric drainage, but in only four cases of asymmetric drainage. Overall, venous sampling correctly lateralized 70% of the tumors. Incorrect lateralization in cases of asymmetric venous drainage is probably attributable to shunting of blood toward the side of dominant venous drainage. Our findings illustrate the need for venography in all patients undergoing venous sampling of ACTH because an understanding of the venous drainage patterns is essential to correctly interpret venous sampling data and warn physicians that the lateralization data may be incorrect or unreliable.     

Investigations of anti-inflammatory activity of Jigrine

We report our experience with five lesions exclusively involving the entire cavernous sinus in which an essentially extradural surgical approach was used. There were two cases of cavernous haemangioma, two cases of meningioma and one case of fungal granuloma. The dural cover of the superior orbital fissure, and mandibular and maxillary divisions of the fifth nerve was dissected along with the dura of the lateral wall of the cavernous sinus. The presence of a relatively large intracavernous bulge due to the tumour assisted in this dissection. The contents of the cavernous sinus were exposed from an anterolateral, lateral and inferior approach. Through the corridor available between the splayed out cranial nerves, a radical resection of the tumour was accomplished in each case. The technical advantages of this approach are discussed in light of the anatomy of the dural configuration of the lateral wall of the cavernous sinus.     

Radical resection of meningiomas and arteriovenous fistulas involving critical dural sinus segments: experience with intraoperative sinus pressure monitoring and elective sinus reconstruction in 10 patients

OBJECTIVE: Radical resection of meningiomas and dural arteriovenous fistulas involving functional major dural sinuses entails the risk of intracranial hypertension and venous infarction. Surgical reconstruction of dural sinuses and bridging veins increases the spectrum of dural sinus conditions that can be treated by complete resection, but indications for venous reconstructions and associated risks are still not well defined. We report our experience with sinus reconstruction based on the intraoperative assessment of collateral venous flow. METHODS: Radical resection of meningiomas (n = 5) or dural arteriovenous fistulas (n = 5) involving critical segments of dural sinuses was performed in 10 patients. All but two patients were suffering from recurrent disease after incomplete treatment. Tolerance of sinus occlusion was assessed intraoperatively by measuring stump pressure in the superior sagittal sinus during test clamping of the involved sinus segment. RESULTS: In five patients, the results of pressure monitoring suggested that occlusion of the sinus might not be tolerated. In two other patients, major bridging veins entered the diseased segment. In these patients, the resected sinus segment was reconstructed and bridging veins were reinserted as far as possible. Postoperative graft occlusion occurred in two patients. One patient who was managed without reconstruction sustained a transient postoperative neurological deficit resulting from venous congestion in the vein of Labbé. Postoperative imaging confirmed total elimination of the pathological process in all 10 patients. There was no recurrence of disease during follow-up periods of up to 8 years. CONCLUSION: The monitoring of sinus pressure, together with the possible reconstruction of the diseased sinus, allows complete surgical treatment of dural sinus abnormalities and involves acceptable risk.     

Venous territories of the brain

The venous return of the cerebral hemispheres is ensured by two systems. The first, superficial system, reaches the peripheral dural sinuses, i.e. the superior sagittal sinus, the lateral sinus and the cavernous sinus. The second, deep system, corresponds to Galen's vein. Anatomical and angiographic data from the literature enable the usual drainage territory to be defined for each of these collecting vessels. However, the variability of the superficial sylvian vein and the importance of cortical anastomotic vessels make impossible to delimit precisely the territory of each peripheral sinus. The functional role played by numerous centro-peripheral anastomoses is more difficult to assert in each individual. It is therefore probable that in the cerebral hemispheres there is a deep territory balancing the superficial territories.     

Histopathological aspects of dural arteriovenous fistulas in the transverse-sigmoid sinus region in nine patients

OBJECTIVE: In recent years, dural arteriovenous fistulas (DAVFs) have been primarily thought to be acquired lesions, formed after sinus thrombosis. The pathogenesis of DAVF, however, is still controversial. We have studied histopathological aspects of DAVFs in resected specimens obtained from nine patients, to obtain clues to the pathogenesis of DAVFs. METHODS: Histological comparison was made among nine DAVF cases and five control cases without venous sinus disease. In addition, the relationship between the clinical course and histological aspects was investigated. RESULTS: The essential abnormality found was a connection between the dural arteries and the dural veins within the venous sinus wall, through small vessels averaging approximately 30 microns in diameter. By using several staining methods, we confirmed that the vessels were part of the venous system; we named these dilated venules "crack-like vessels." CONCLUSIONS: The development of abnormal communications between dural arteries and dural veins (crack-like vessels) is regarded as the essential part of the pathogenesis of DAVFs, and sinus thrombus is not thought to be an essential lesion of DAVFs. It might be postulated that sinus hypertension caused by stenocclusive disease of the venous sinuses triggers the development of fistulous connections between arteries and veins in the dural wall, which may result in increasingly dilated venules and the formation of DAVFs.     

Traumatic carotid cavernous sinus fistula: serial angiographic studies from the day of trauma

BACKGROUND AND PURPOSE: The purpose of this study was to ascertain the early angiographic features characteristic of traumatic carotid cavernous sinus fistulas (CCFs). METHODS: Eight patients with severe craniofacial injuries underwent emergency diagnostic and therapeutic angiography for intractable oronasal bleeding, starting on an average of 6.7 hours after trauma. Carotid angiograms and the clinical manifestation of traumatic CCFs were then reviewed retrospectively to determine characteristic angiographic features. RESULTS: In four of the eight patients, no arteriovenous fistulas were found in the cavernous sinuses and symptomatic CCF did not occur during the follow-up period. In the remaining four patients, dural CCFs (Barrow type B) were observed, unilaterally in three patients and bilaterally in one. One of these four patients subsequently became symptomatic and required transarterial coil embolization. CONCLUSION: Traumatic dural CCFs are frequently observed in the early stage of severe craniofacial trauma, if investigated. Although their spontaneous disappearance is known, some of these do become symptomatic and need treatment.     

Dural fistulae of the cavernous sinus and interventional neuroradiology. Apropos of 4 cases

PURPOSE: Our purpose was to show how difficult it is to diagnose a dural fistula of the cavernous sinus, which is an anomalous arteriovenous shunt within the dura mater extending from meningeal arteries to the cavernous sinus. CASE REPORT: A dural fistula was suspected in four female patients aged between 61 and 80, presenting with a red eye, dilated episcleral veins, exophthalmos and elevated intraocular pressure. A cerebral hyperselective angiography was performed in all cases. RESULTS: The cerebral angiography confirmed the diagnosis of a dural fistula in all cases, showing the early filling of the cavernous sinus followed by the draining vessel (posterior in case n. 4, anterior in cases n degrees 1, 2, 3). Case n degrees 2 was unilateral and cases n. 1, 3, 3 were bilateral. The blood flow was low in all cases. A successful embolization was performed in all patients with resolution of all symptoms. CONCLUSION: The diagnosis of dural fistulas is often difficult because of misleading clinical signs. It is documented by a cerebral angiography showing the feeding vessels and helping to choose either venous or arterial embolization which is the most suitable treatment.     

Combined pretemporal and endovascular approach to the cavernous sinus for the treatment of carotid-cavernous dural fistulae: technical case report

OBJECTIVE AND IMPORTANCE: The endovascular treatment of carotid-cavernous dural fistulae is becoming the prominent treatment modality for these lesions. The intractability of these lesions and their tendency to recur, especially after previous endovascular treatment sessions, exhausts the available routes and tends to present a difficulty in accessing the cavernous sinus. To avoid the risks associated with a direct surgical approach, an alternative, less invasive route to the cavernous sinus using a pretemporal extradural approach is combined with a direct endovascular approach. CLINICAL PRESENTATION: A 38-year-old woman presented with a history of right visual and ocular symptoms related to a Type D cavernous carotid dural fistula, which was fed by internal carotid and external carotid branches. The fistula was initially treated with embolization of the external carotid arterial supply. After a transient improvement, the patient's visual acuity worsened. A follow-up angiogram showed the major supply from the intracavernous internal carotid branches and draining through the inferior ophthalmic vein. The transvenous route was not accessible. An attempt to cannulate the intracavernous branches was not successful. The combined pretemporal and endovascular approach was then used. INTERVENTION: The pretemporal extradural region of the superior orbital fissure was exposed. Using microsurgical techniques and Doppler flow guidance, the anterior cavernous sinus was cannulated through the orbital venous drainage channels. Using intraoperative angiography, thrombogenic coils were deployed at the level of the fistula. Intraoperative angiography confirmed complete obliteration of the fistula. CONCLUSION: The combined pretemporal (extradural) and endovascular approach to the cavernous sinus is a less invasive alternative for the treatment of intractable carotid-cavernous dural fistulae.     

En bloc resection of the temporal bone for middle ear carcinoma extending to the cranial base

En bloc resection of the temporal bone for squamous cell carcinoma of the middle ear was performed by the postauricular transtemporal and retromastoid approaches. The patient was a 70-year-old woman whose tumor extended to the middle and posterior cranial fossae. Temporal and retromastoid craniotomies were carried out, then the temporal dura and the cerebellar dura, and the transverse and sigmoid sinuses were exposed. The temporal dura and the cerebellar dura were opened, and the transverse sinus was ligated at the junction with the sigmoid sinus. After that, the tentorial dura was incised, the incision extending anteriorly to the middle cranial fossa and transecting the superior petrosal sinus. Consequently, a wide view into the middle and the posterior cranial fossae was obtained. In the posterior fossa, cranial nerves VII and VIII were divided. On the other hand, nerves IX, X and XI were preserved at the dural incision on the posterior surface of the temporal bone. Subsequently, in the area of the carotid canal, the temporal bone was drilled toward the medial side of the internal auditory canal and also posteriorly down to the jugular bulb. At this stage, the temporal bone and the soft tissue attachments, such as the middle and posterior cranial fossa dura, and the sigmoid sinus, were separated from the pyramidal apex and the clivus. The dural defect was repaired with a free pericranial graft. A rectus abdominis muscle flap was transferred to reconstruct the defect of the skull base resulting from the temporal bone resection. Postoperative complications like CSF leakage, meningitis and lower cranial nerve damage, were not seen after the treatment. The patient has shown no evidence of recurrence for the 28 months since the surgical treatment, and has not complained of any problems with swallowing or conducting conversations in daily life. With the contribution of recent developments in skull base and reconstruction surgery, more aggressive en bloc resection of the temporal bone can be carried out on patients with advanced middle ear carcinoma. These developments will also make it possible for patients whose prognosis was previously thought to be poor to have a chance for a cure.     

Cavernous sinus syndrome caused by a primary paranasal sinus non-Hodgkin's lymphoma

Although uncommon, non-Hodgkin's lymphomas occasionally arise from the nose and paranasal sinuses. Rarely, they may invade into the cavernous sinus and produce signs and symptoms that characteristically include unilateral ophthalmoplegia, sensation loss in the distribution of the ophthalmic and other divisions of the trigeminal nerve, sympathetic nerve paralysis and proptosis. In this report, we present a case of cavernous sinus syndrome (CSS) caused by infiltration of non-Hodgkin's lymphoma from the adjacent paranasal sinuses and address issues regarding its diagnosis and treatment.     

Spontaneous dural carotid cavernous sinus fistula presenting isolated ophthalmoplegia: evaluation with MR angiography

We describe three patients with spontaneous dural carotid cavernous sinus fistula presenting an isolated ophthalmoplegia where magnetic resonance angiography demonstrated abnormal flow-related enhancements in the cavernous sinus with extension into the inferior petrosal sinus. Magnetic resonance angiography is of value in evaluation of patients with isolated ophthalmoplegia.     

The clinical assessment of attachment in children under five

Dural arteriovenous malformations (AVMs) are considered to be acquired lesions that develop secondary to venous obstruction, which sometimes happens in head trauma. However, there has been a report of an anterior cranial fossa dural AVM that occurred independently of a history of head trauma, and there has been speculation that these malformations are congenital. The authors recount their experience with a patient who had an anterior cranial fossa dural AVM that was discovered incidentally. The lesion was fed by the bilateral anterior ethmoidal arteries and drained into the superior sagittal sinus via frontal cortical veins. The patient had a history of severe head trauma that had occurred 30 years earlier. This is the first case report in which a previous head trauma is strongly believed to be the cause of an anterior cranial fossa dural AVM. The authors postulate that anterior cranial fossa dural AVMs can develop secondary to a head trauma.     

A case of cavernous dural arteriovenous fistula resulting in intracerebral extravasation during transvenous embolization

Cortical venous drainage has been described as one of the major risk factors for dural arteriovenous fistula, which may induce venous hypertension leading to venous ischemia or intracerebral hemorrhage. However, it is rather rare to observe cortical venous drainage manifesting in this way in the cavernous sinus region. We report a case of a 55-year-old gentleman with a right cavernous dural arteriovenous fistula, presenting with conjunctival chemosis, exophthalmus and ocular hypertension on the affected side. Magnetic resonance imaging showed a small intracerebral hemorrhage in the right frontal lobe. Cerebral angiography revealed a dural arteriovenous fistula in the right cavernous sinus draining into the right olfactory vein via the uncal vein, as well as into the superior and inferior ophthalmic veins. This unusual cortical venous reflux was thought to be consistent with the intracerebral hemorrhage found on the magnetic resonance imaging. The patient underwent transvenous embolization for the dural arteriovenous fistula using an inferior petrosal catheterization into the uncal vein was difficult, and the cortical venous reflux through the vein seemed to be slight. However, extravasation of the contrast material occurred in the right frontal lobe after obliteration of the ophthalmic veins during the procedure. The cause of the extravasation was suspected to be the same olfactory vein that had been involved in the previous intracerebral hemorrhage. The obliteration of the dural fistula was continued rapidly, and the fistula disappeared after the embolization. Neurologically, the patient had no noticeable troubles, except for a mild headache. The pretreatment symptoms were alleviated within several days, and the patient was discharged in a week. We emphasize the following points from this rare case in order to facilitate a safer procedure during transvenous embolization for cavernous dural arteriovenous fistula. It is important to obliterate the cortical venous drainage as early as possible, even if the reflux is small or the catheterization is difficult. Repeated, careful sinography is useful for the evaluation of the drainage pattern at certain stages during the transvenous embolization procedure.     

Hearing impairment in Thais due to sport shooting: a preliminary report

Frequency of intracavernous invasion by a pituitary adenoma varies from 9% to 40% depending on the publications. Without putting off the possibility of true intracavernous invasion, it seems less frequent than evocated on CT-Scan and/or MRI data. We studied 153 files of pituitary adenomas operated upon recently: 72 prolactinomas (47.3%), 30 GH-secreting adenomas (19.7%), 7 corticotrop adenomas (4.6%), 44 non secreting adenomas (28.3%). 108 patients (70.4%) harboured a macroadenoma (diameter > 10 mm). A suprasellar expansion was seen 90 times on CT-Scan and/or MRI views. 19 times (17.7% of macroadenomas, 12.5% of the whole series) MRI evocated an infiltration of one or both cavernous sinuses (CS). Such data were found 3 times before 1991, 16 times since 1991, i.e. since MRI is systematically performed preoperatively. Except in two patients who respectively presented with a large intraorbital or temporal expansion, we have not been able to confirm the reality of the intracavernous invasion. We think that most of CT-Scan or MRI data of so-called intracavernous invasion correspond in fact to a compression or to a fingerglove invagination of the medial wall of the CS. In fact, anatomical studies by Harris & Rhoton (1976) and by Taptas (1990) demonstrated that such an invagination of the medial wall exists in almost one third of normal pituitary glands. These data must bring up to much carefulness when considering a possible pathological CS invasion by a macroadenoma. Therefore, it should be thoroughly assessed with anatomoradiological and radio-surgical correlations.