Imaging lesions of the cavernous sinus

Cavernous hemangioma within the cavernous sinus: illustrative case

BACKGROUND

Cerebral cavernous hemangiomas (CHs) are the most common vascular malformations and can be found in many locations in the brain. The most common extra-axial locations are the intrasellar and parasellar regions. Both locations are rare for CH.

OBSERVATIONS

A 41-year-old female who had experienced headaches for about a year presented to the authors' institution because of a mass located in the left cavernous sinus (CS). It was confirmed that it was not causing any loss in the visual field and that there was no pituitary irregularity. Surgery was planned with a preliminary diagnosis of CH. An endoscopic endonasal approach (EEA) was undertaken with the otorhinolaryngology team. The dura mater was opened following excision of the back wall of the sphenoid sinus. A blue-purple vascular lesion was observed, filling the left CS. Gross-total resection (GTR) was achieved. In the literature, there were 10 cases in which GTR had been performed using the EEA.

LESSONS

Patients with CHs located in the sellar region present with various complaints. The preference for endoscopic surgery over cranial surgery for such lesions requires more comprehensive studies, but it is thought that this approach can reduce surgical complications and the time to discharge for the patient. https://thejns.org/doi/abs/10.3171/CASE24227.

Diffusion-weighted imaging of the orbit

Orbital lesions compose a heterogeneous group of pathologies that often present with non-specific imaging findings on conventional magnetic resonance imaging (MRI) sequences (T1-and T2-weighted). Accordingly, the application of diffusion MRI offers an opportunity to further distinguish between lesions along this spectrum. Diffusion-weighted imaging (DWI) represents the simplest and most frequent clinically utilised diffusion imaging technique. Recent advances in DWI techniques have extended its application to the evaluation of a wider spectrum of neurological pathology, including orbital lesions. This review details the manifestations of select orbital pathology on DWI and underscores specific situations where diffusion imaging allows for increased diagnostic sensitivity compared to more conventional MRI techniques. These examples also describe preferred management for orbital lesions identified by DWI.

Endoscopic Endonasal Biopsy for Diagnosis of Undifferentiated Lesions of the Cavernous Sinus

BACKGROUND

Radiologically undifferentiated lesions of the cavernous sinus can pose a diagnostic challenge. Although radiotherapy is the mainstay for treatment of cavernous sinus lesions, histologic diagnosis allows access to a wide variety of alternative treatment modalities. The region is considered a high-risk area for open transcranial surgical access, and the endoscopic endonasal approach presents an alternative technique for biopsy.

METHODS

A retrospective case series was performed of all patients undergoing endoscopic endonasal biopsy of isolated cavernous sinus lesions at 2 tertiary institutions. The primary outcomes were the percentage of patients in whom a histologic diagnosis was achieved and the proportion of patients in whom therapy differed from radiotherapy alone. Secondary outcomes included preoperative and postoperative 22-item Sino-Nasal Outcome Test symptom scores, as well as perioperative adverse outcomes.

RESULTS

Eleven patients underwent endoscopic endonasal biopsy, with a diagnosis achieved in 10 patients. The most common diagnosis was perineural spread of squamous cell carcinoma, followed by perineuroma and single cases of metastatic melanoma, metastatic adenoid cystic carcinoma, mycobacterium lepri infection, neurofibroma, and lymphoma. Six patients had treatments other than radiotherapy, including immunotherapy, antibiotics, corticosteroids, chemotherapy, and observation alone. There was no significant difference in prebiopsy and postbiopsy 22-item Sino-Nasal Outcome Test scores. There was 1 case of epistaxis requiring return to theater for cautery of the sphenopalatine artery and there were no mortalities.

CONCLUSIONS

In a limited case series, endoscopic endonasal biopsy was safe and effective in obtaining diagnosis for cavernous sinus lesions and had a significant impact on therapeutic decision making.

Deadly Fungi: Invasive Fungal Rhinosinusitis in the Head and Neck

Invasive fungal rhinosinusitis (IFRS) is a serious infection that is associated with high morbidity and mortality rates. The incidence of IFRS has been increasing, mainly because of the increased use of antibiotics and immunosuppressive drugs. Rhino-orbital cerebral mucormycosis has recently reemerged among patients affected by COVID-19 and has become a global concern. The detection of extrasinus involvement in its early stage contributes to improved outcomes; therefore, imaging studies are essential in establishing the degree of involvement and managing the treatment properly, especially in immunocompromised patients. The common sites of extrasinus fungal invasion are the intraorbital, cavernous sinus, and intracranial regions. Fungi spread directly to these regions along the blood vessels or nerves, causing devastating complications such as optic nerve ischemia or compression, optic neuritis or perineuritis, orbital cellulitis, cavernous sinus thrombosis, mycotic aneurysm, vasculitis, internal carotid arterial occlusion, cerebral infarction, cerebritis, and brain abscess. IFRS has a broad imaging spectrum, and familiarity with intra- and extrasinonasal imaging features, such as loss of contrast enhancement of the affected region, which indicates tissue ischemia due to angioinvasion of fungi, and the surrounding anatomy is essential for prompt diagnosis and management. The authors summarize the epidemiology, etiology, risk factors, and complications of IFRS and review the anatomy and key diagnostic imaging features of IFRS beyond the sinonasal regions. ^©RSNA, 2022.

Radiological review of rhinocerebral mucormycosis cases during the COVID-19 Pandemic: A single-center experience

Mucormycosis is caused by the fungi belonging to the order Mucorales and class Zygomycetes. The incidence of mucormycosis has increased with the onset of the severe acute respiratory syndrome coronavirus 2 infections leading to the coronavirus disease 2019 (COVID-19) pandemic. This rise is attributed to the use of immunosuppressive medication to treat COVID-19 infections. Authors have retrospectively collected data of our cases of mucormycosis diagnosed from April 2020 to April 2021 at our institute. A total of 20 patients with rhinocerebral mucormycosis were studied. Most of the study subjects were male patients (90%) and were of the age group 41-50 years. Most patients in the review had comorbidities (85%) with diabetes being the most common comorbidity. Para nasal sinuses were involved in all the cases. Involvement of the neck spaces was present in 60% of the cases. Involvement of the central nervous system was present in 80% of the cases. Orbital involvement was present in 90% of the cases. The authors reviewed the various imaging findings of mucormycosis on computed tomography and magnetic resonance imaging in this article.

Spectrum of Surgically Resected Lesions of the Cavernous Sinus: A Neuropathologic Audit

Background  The cavernous sinus is a complex space composed of extradural venous plexus within dural folds. Several important structures like the carotid artery, cranial nerves, and sympathetic nerve fibers traverse through this space. Radiological diagnosis may not be definitive and in the context of discordance between clinical and neuroimaging diagnosis, histopathological evaluation becomes essential for diagnosis and management. Literature on the pathological spectrum of lesions is scarce as, with a shift in the treatment paradigm, most small lesions of cavernous sinus are treated with radiosurgery. However, surgical management still plays a role for larger lesions and in radiologically ambiguous cases for planning the definitive management.

Materials and Methods  We retrospectively reviewed all surgically resected lesions of the cavernous sinus over the last two decades (1998–2019). The clinical presentation, neuroimaging features, and histopathological findings were reviewed. Lesions extending from sella and other adjacent areas were excluded.

Results  Thirty-eight cases of isolated cavernous sinus mass lesions were diagnosed over the last two decades (1998–2019). Cavernous hemangiomas (19 cases, 50%) constituted the most frequent pathology, followed by aspergilloma, meningioma, schwannoma, metastatic adenocarcinoma, chondrosarcoma, and chordoma. Overall, 29.4% (10/34) could not be accurately diagnosed on neuroimaging. Of these, four cases of cavernous hemangiomas were mistaken for either meningioma (three cases) or schwannoma (one case). Neither chordoma nor chondrosarcoma was suspected.

Conclusion  This is the first study in literature, enumerating the pathological and imaging spectrum of surgically resected cavernous sinus lesions. Cavernous hemangiomas, metastases and chordomas, and chondrosarcoma posed the greatest difficulty in diagnosis on neuroimaging and the reasons for the same are analyzed. In the context of clinical and neuroimaging discordance in diagnosis, pathological characterization becomes essential for appropriate and timely management.

A Large Cavernous Sinus Giant Cell Tumor Invading Clivus and Sphenoid Sinus Masquerading as Meningioma: A Case Report and Literature Review

Giant cell tumor (GCT) of the bone is a rare benign, locally aggressive tumor that occurs in the epiphysis of long bones, especially the lower femur and the upper tibia. GCT of the bone of cranial origin is very rare, accounting for 1% of all GCT of the bone. We report the diagnosis, treatment, and immunohistochemistry of a rare case of intracranial GCT of the bone. We also review and summarize the imaging features, diagnostic markers, and current major treatment options for GCT of the bone. Our case and literature review emphasizes the importance of considering the full picture when making a diagnosis, rather than relying on imaging alone to make the diagnosis.

Volumetric growth rates of untreated cavernous sinus meningiomas

OBJECTIVE

Meningiomas that arise primarily within the cavernous sinus are often believed to be more indolent in their growth pattern. Despite this perceived growth pattern, disabling symptoms can arise even with small tumors. While research has been done on cavernous sinus meningiomas (CSMs) and their treatment, very little is known about their natural growth rates. With a better understanding of the growth rate of CSM, patient treatment and guidance can be can optimized and individualized. The goal of this study was to determine volumetric growth rates of untreated CSMs.

METHODS

Thirty-seven patients with 166 MR images obtained between May 2004 and September 2019 were reviewed, with a range of 2-13 MR images per patient (average of 4.5 MR images per patient). These scans were obtained over an average follow-up period of 45.9 months (median 33.8, range 2.8-136.9 months). All imaging prior to any intervention was included in this analysis. Volumetric measurements were performed and assessed over time.

RESULTS

The estimated volumetric growth rate was 23.3% per year (95% CI 10.2%-38.0%, p < 0.001), which is equivalent to an estimated volume doubling time (VDT) of 3.3 years (95% CI 2.1-7.1 years). There was no significant relationship between growth rate and patient age (p = 0.09) or between growth rate and patient sex (p = 0.78). The median absolute growth rate was 41% with a range of -1% to 1793%. With a definition of "growth" as an increase of greater than 20% during the observed period, 65% of tumors demonstrated growth within their observation interval. Growth rates for each tumor were calculated and tumors were segmented based on growth rate. Of 37 patients, 22% (8) demonstrated no growth (< 5% annual growth, equivalent to a VDT > 13.9 years), 32% (12) were designated as slow growth (annual growth rate 5%-20%, VDT 3.5-13.9 years), 38% (14) were found to have medium growth (annual growth rate 20%-100%, VDT 0.7-3.5 years), and 8% were considered fast growing (annual growth rate > 100%, VDT < 0.7 years).

CONCLUSIONS

This study evaluated CSM volumetric growth rates. A deeper understanding of the natural history of untreated CSMs allows for better counseling and management of patients.

Cavernous Sinus Vascular Venous Malformation

Vascular venous malformations of the cavernous sinus have multiple imaging features that can be used to distinguish them from other entities in the region. Accurate identification of these lesions is essential: Vascular venous malformation lesions carry considerable risk of intraoperative hemorrhage, so preoperative recognition of vascular venous malformations can greatly impact the treatment strategies used. Nevertheless, because of their scarcity, many radiologists are unfamiliar with the radiologic and clinical features of cavernous sinus vascular venous malformations. This article will describe a case of an asymptomatic vascular venous malformation; outline its imaging, clinical, and pathologic features; and review the relevant literature regarding this diagnosis.

MR vessel wall imaging in cerebral bacterial and fungal infections

Purpose

Central nervous system (CNS) bacterial and fungal infections can cause secondary vasculitis which worsens the prognosis due to development of complications like infarctions or hemorrhages. In this prospective study, we aim to study intracranial vessel wall imaging findings in bacterial and fungal infections.

Methods

We included 12 cases of nontubercular bacterial and fungal CNS infections each, in whom definitive microbiological diagnosis could be made. High-resolution vessel wall imaging (VWI) and time of flight MR angiography (TOF MRA) were incorporated in the routine imaging protocol. All cases were evaluated for the presence of vascular enhancement, pattern of enhancement, and stenosis on VWI. Statistical analysis was done to evaluate association between findings of vessel wall imaging and infarctions.

Results

We found infarctions in 5 out of 12 cases (41.7%) of the bacterial group and 7 out of 12 cases (58.3%) of the fungal group. Vessel wall enhancement was seen in 5 cases (41.7%) of the bacterial group and 9 cases (75%) of the fungal group. There was a significant association between infarctions and vessel wall enhancement in the fungal group. However, pattern of enhancement or stenosis on VWI was not significantly associated with presence of infarction. VWI detected more cases of vascular involvement than TOF MRA.

Conclusion

Secondary infectious vasculitis in bacterial and fungal infections can be detected by VWI, which can play an important role in better patient management as detection of vascular involvement can prompt early treatment to prevent complications like infarctions or hemorrhages.

Anatomical Basis of Clinical Manifestations Seen in Cavernous Sinus Syndrome: A Narrative Review

Pathology involving the Cavernous Sinus (CS), generally referred to as Cavernous Sinus Syndrome (CSS), can arise from vascular disorders, neoplasms, infections, and non-infectious inflammatory disorders. An acute understanding of the CS and its regional anatomical structures is therefore pertinent in expounding the highly variable clinical manifestations seen in CSS as well as laying the groundwork for surgical intervention. Though the neuroanatomy of the cavernous sinus has been substantially chronicled in literature, their correlation to clinical signs has only been minimally described. This narrative review serves to address this knowledge gap and aims to comprehensively correlate the clinical manifestations of CSS with the relevant neuroanatomy, thereby allowing medical practitioners to better navigate the diagnostic quandary. We conducted a scoping review of the literature concerning CS anatomy and CSS, complied through MEDLINE/OVID and cross-referencing of articles on PubMed and Google Scholar with the keywords cavernous sinus, cavernous sinus syndrome, clinical signs/manifestations, neuroanatomy, CS pathology, Cavernous Sinus Thrombus (CST) and cavernous sinus neoplasms/tumours.

Segmental Imaging of the Trochlear Nerve: Anatomic and Pathologic Considerations

BACKGROUND

The trochlear nerve (the fourth cranial nerve) is the only cranial nerve that arises from the dorsal aspect of the midbrain. The nerve has a lengthy course making it highly susceptible to injury. It is also the smallest cranial nerve and is often difficult to identify on neuroimaging.

EVIDENCE ACQUISITION

High-resolution 3-dimensional skull base MRI allows for submillimeter isotropic acquisition and is optimal for cranial nerve evaluation. In this text, the detailed anatomy of the fourth cranial nerve applicable to imaging will be reviewed.

RESULTS

Detailed anatomic knowledge of each segment of the trochlear nerve is necessary in patients with trochlear nerve palsy. A systematic approach to identification and assessment of each trochlear nerve segment is essential. Pathologic cases are provided for each segment.

CONCLUSIONS

A segmental approach to high-resolution 3-dimensional MRI for the study of the trochlear nerve is suggested.

Bilateral cavernous sinus thrombosis complicating acute unilateral pansinusitis in a 15-year-old boy

Cavernous sinus thrombosis (CST) is a rare and potentially fatal complication of acute sinusitis. Timely diagnosis and management is, therefore, essential in preventing death and neurological disability. Here, we describe the case of a paediatric patient with bilateral CST secondary to acute unilateral pansinusitis that presented with rapidly progressing bilateral periorbital oedema. Initial imaging was negative. This case serves to emphasise the importance of maintaining a high index of suspicion when managing paediatric patients with suspected CST with persistent symptoms. Expeditious investigation and management of our patient in this case resulted in a positive outcome, with resolution of symptoms and no residual neurological deficit.

Cavernous Sinus Hemangioma: Imaging Diagnosis and Surgical Considerations

BACKGROUND

Cavernous sinus hemangiomas (CSHs) are extraaxial vascular malformations that tend to bleed during surgery.

METHODS

We reviewed 12 magnetic resonance imaging scans with CSH, 5 of them biopsy proven.

RESULTS

In our review, CSH commonly presented as a lobulated mass with high, uniform signal intensity on T2-weighted images, a dumbbell shape, and a sellar extension. Two thirds presented a "filling-in" pattern of enhancement on dynamic imaging. These features should lead to a correct preoperative diagnosis, which is essential for surgical planning and avoiding hemorrhagic complications.

CONCLUSIONS

A combination of low signal on T1, high signal on T2 and fluid-attenuated inversion recovery, no diffusion restriction and homogenous enhancement should place CSH at the top of the list of differential diagnoses. This is especially true when there is a "filling-in" pattern on dynamic or delayed imaging. Doing so may alert surgeons to the possibility of copious intraoperative bleeding and therefore avoid complications of hemorrhage.

Cavernous sinus lesions

The cavernous sinus is a complex structure susceptible to a wide variety of vascular, neoplastic and inflammatory pathologies. Vascular pathologies include ICA aneurysms, carotid-cavernous fistulas, cavernous sinus thrombosis, and cavernous hemangioma. Neoplasms that involve the cavernous sinus include pituitary adenoma, meningioma, schwannoma, lymphoma, perineural tumor spread, metastases, and direct tumor invasion. Infectious and inflammatory diseases include Tolosa-Hunt syndrome, sarcoidosis, granulomatosis with polyangiitis, IgG-4 related disease and invasive fungal infections. In this article, we review the clinical and imaging findings of a number of pathologies involving the cavernous sinus, focusing on key features that can narrow the differential diagnosis and, in some cases, support a particular diagnosis.

The fifth cranial nerve in headaches

The fifth cranial nerve is the common denominator for many headaches and facial pain pathologies currently known. Projecting from the trigeminal ganglion, in a bipolar manner, it connects to the brainstem and supplies various parts of the head and face with sensory innervation. In this review, we describe the neuroanatomical structures and pathways implicated in the sensation of the trigeminal system. Furthermore, we present the current understanding of several primary headaches, painful neuropathies and their pharmacological treatments. We hope that this overview can elucidate the complex field of headache pathologies, and their link to the trigeminal nerve, to a broader field of young scientists.

Gone in the blink of an eye - A Tolosa-Hunt syndrome variant

Tolosa-Hunt syndrome is a rare disorder characterized by severe peri-orbital headache and ophthalmoplegia resulting from pseudotumour in the cavernous sinus compressing structures within it, namely cranial nerves III, IV, and VI and the superior divisions of cranial nerve V. We report the case of a 47 year old female who presented with painless left unilateral ptosis and complete external ophthalmoplegia. Magnetic Resonance Imaging (MRI) identified an enhancing heterogeneous mass filling the left cavernous sinus, following the course of the oculomotor nerve. After 2 weeks symptoms and signs resolved and there was a parallel resolution of the MRI findings, without the administration of corticosteroids. As far as we are aware this is one of the first reports of Tolosa-Hunt syndrome variant, with painless neurological involvement confined solely to the oculomotor nerve, and with complete resolution without pharmacological intervention.

Diagnosis and Outcome of Biopsies of Indeterminate Lesions of the Cavernous Sinus and Meckel's Cave: A Retrospective Case Series in 85 Patients

BACKGROUND

When clinical presentation, laboratory studies, or imaging cannot diagnose cavernous sinus (CS) and/or Meckel's cave (MC) lesions, biopsy may be necessary.

OBJECTIVE

To review our institutional series of biopsies of indeterminate CS and MC lesions.

METHODS

Records from January 1994 to June 2016 were searched for biopsied indeterminate CS and MC lesions. We defined indeterminate as having an atypical imaging appearance or a broad differential and the need for tissue for definitive diagnosis. We defined primary tumors as originating from cells inherent or near the CS and MC.

RESULTS

Eighty-five patients were included (median age 59 [2-85] yr); 22 (28%) had a cancer history. Approaches included frontotemporal craniotomy (n = 48, 56%), endoscopic endonasal (n = 20, 24%), percutaneous transforamen ovale (n = 12, 14%), or retrosigmoid craniotomy (n = 5, 6%). Final diagnosis was metastatic in 27 (32%), primary in 21 (25%), inflammatory in 13 (15%), hematologic in 11 (13%), fungal in 5 (5%), and nondefinitive or nondiagnostic in 8 (10%) patients. Thirteen (59%) patients with a cancer history (n = 22) had a diagnosis consistent with their prior cancer; the remaining had a second pathology (n = 6, 27%) or nondiagnostic biopsy (n = 3, 14%). Two patients had surgical complications resulting in death.

CONCLUSION

In this patient cohort, metastatic tumors were the most likely pathology. The biopsy threshold should be lower in patients with a cancer history if clinical or radiographic diagnosis is uncertain as 27% had a second disease. However, we consider biopsy as a last resort because the risk of major morbidity/mortality, while low, is not zero.

Immunological and vascular characteristics in cavernous sinus meningioma

OBJECTIVES

It is difficult to treat cavernous sinus (CS) meningiomas because of their complex vascular and neurological structures. Recently, immunotherapy has become an attractive therapeutic modality, but the role of tumor immune microenvironment is yet to be investigated for CS meningiomas. In the current study, these molecular and histopathological characteristics were examined in CS meningiomas.

METHODS

The present study used twenty-eight meningioma tissues arising in two different locations (8 CS and 20 convexity meningiomas). Immunohistochemical analyses were performed with CD3, CD4, CD8, Foxp3, CD163, PDGFR-β, VEGF receptors 1 & 2 (VEGFR-1, VEGFR-2), VEGF-A and HIF-1α. Quantitative polymerase chain reaction (qPCR) was performed to assess the expression of Foxp3, VEGF-A, CD163, VEGFRs-1 & 2 and HIF-1α.

RESULTS

The numbers of different tumor-infiltrating immune cells, such as immunosuppressive cells, were significantly lower in CS meningiomas compared with convexity meningiomas. Analysis of the vascular characteristics showed the vessels in the CS meningiomas were covered with PDGFR-β-positive pericytes and were negative or had only very low amounts of VEGFR-1 and VEGFR-2. However, most vessels in convexity meningiomas showed high VEGFRs expression and were not covered with pericytes. Immunohistochemical and qPCR analyses revealed that the expression of HIF-1α, VEGF-A and VEGFRs-1 & 2 was lower in CS meningiomas.

CONCLUSION

Fewer immunocompetent cells were observed in CS meningiomas compared with convexity meningiomas. Lower expression of VEGF-A, VEGFRs-1 and 2, and the vascular structure may contribute to this specific immune microenvironment.

Diplopia: a unique presentation of recurrence of a salivary gland carcinoma

A 79-year-old man with a history of radical excision of a left submandibular gland carcinoma ex-pleomorphic adenoma presented with a new 2 cm lump in his left submandibular region which proved to be recurrence on surgical excision. During work up for revision surgery he developed a right VI cranial nerve palsy, which was attributed to his microvascular status having had a history of three previous transient ischemic attacks (TIAs). 6 months later, his palsy had not resolved. MRI revealed new soft tissue by the cavernous segment of the internal carotid artery. The exact source of this was unclear as there was no evidence of local recurrence or nodal disease. A repeat MRI scan 16 months later revealed further growth of abnormal tissue in the cavernous sinus and the primary submandibular location, now involving multiple nerves including branches of cranial nerves IV, V, VI, VII and XII making surgical excision impossible.

Imaging of cranial nerves: a pictorial overview

The human body has 12 pairs of cranial nerves that control motor and sensory functions of the head and neck. The anatomy of cranial nerves is complex and its knowledge is crucial to detect pathological alterations in case of nervous disorders. Therefore, it is necessary to know the most frequent pathologies that may involve cranial nerves and recognize their typical characteristics of imaging. Cranial nerve dysfunctions may be the result of pathological processes of the cranial nerve itself or be related to tumors, inflammation, infectious processes, or traumatic injuries of adjacent structures. Magnetic resonance imaging (MRI) is considered the gold standard in the study of the cranial nerves. Computed tomography (CT) allows, usually, an indirect view of the nerve and is useful to demonstrate the intraosseous segments of cranial nerves, the foramina through which they exit skull base and their pathologic changes. The article is a complete pictorial overview of the imaging of cranial nerves, with anatomic and pathologic descriptions and great attention to illustrative depiction. We believe that it could be a useful guide for radiologists and neuroradiologists to review the anatomy and the most important pathologies that involve cranial nerves and their differential diagnosis.

Renal Cell Carcinoma with Primary Presentation via Metastasis to the Trigeminal Ganglion

BACKGROUND

Renal cell carcinoma (RCC) accounts for ∼8% of all brain metastatic disease; however, spread to the cranial nerves and their ganglia is uncommon. To the best of our knowledge, we report the first case of RCC metastatic to Meckel's cave, which was diagnosed secondary to new trigeminal sensory loss.

METHODS

A 45-year-old man had presented with acute-onset right V3 numbness. Magnetic resonance imaging demonstrated contrast enhancement of the ipsilateral V3, extending from its root at the Gasserian ganglion to the foramen ovale.

RESULTS

He elected for observation, and his symptoms resolved over several weeks. At the scheduled, routine 3-month follow-up examination, he reported symptomatic relapse with new concomitant hyperesthetic/neuropathic pain. Magnetic resonance imaging demonstrated interval enlargement of the enhancing lesion in an atypical pattern, potentially consistent with trigeminal schwannoma versus meningioma, and operative resection was recommended.

CONCLUSION

We have reported a case of RCC presenting with numbness via metastatic spread to Meckel's cave. Although uncommon, metastasis is an important diagnostic consideration for enhancing cranial nerve lesions. Our case has demonstrated that, although a history of malignancy, multiple lesions, or systemic/constitutional symptoms are typical, rare cases can demonstrate isolated central nervous system findings. Thus, short-term radiographic surveillance is indicated if the diagnosis of an intracranial or cranial nerve mass lesion is equivocal.

Asymmetric cavernous sinus enlargement: a novel finding in Sturge-Weber syndrome

PURPOSE

Enlargement of deep cerebral veins and choroid plexus engorgement are frequently reported in Sturge-Weber syndrome. We aim to describe cavernous sinus involvement in patients with this syndrome and to identify possible clinical-neuroimaging correlations.

METHODS

Sixty patients with Sturge-Weber syndrome (31 females, mean age 4.5 years) and 120 age/sex-matched controls were included in this retrospective study. We performed a visual analysis to identify patients with asymmetric cavernous sinus enlargement. Then, we measured on axial T2WI the left (A), right (B), and bilateral (LL) transverse diameters of the cavernous sinus. We calculated the module of the difference |A-B| and the cavernous sinus asymmetry index as the ratio |A-B|/LL. Differences among groups were assessed by Mann-Whitney U and Kruskal-Wallis tests. Clinicoradiological associations were evaluated by Fisher exact test.

RESULTS

We found seven subjects (11.6%) with asymmetric CS enlargement. The |A-B| and cavernous sinus asymmetry index were higher in patients with asymmetric CS enlargement compared with controls and patients without visible CS abnormalities (p_B < 0.05). Asymmetric CS enlargement was always ipsilateral to facial port-wine stains (7/7), and, when present, to leptomeningeal vascular malformations (4/7). It was significantly associated with ipsilateral bone marrow changes (p = 0.013) and dilated veins (p = 0.002). Together with brain atrophy and deep venous dilatation, this sign was associated with neurological deficits (p < 0.05).

CONCLUSIONS

We expanded the spectrum of venous abnormalities in SWS, showing the presence of asymmetric cavernous sinus enlargement in more than one tenth of patients, likely related to increased venous drainage.

Natural history of cavernous sinus meningiomas

OBJECTIVE

Meningiomas confined to the cavernous sinus (MCSs) are benign tumors. Due to the high risk of severe complications, the intracavernous surgical procedure was abandoned in favor of radiotherapy. However, the choice of treatment remains complicated due to the fact that the natural history of this lesion has not yet been described.

METHODS

The authors studied the natural history of this lesion using a prospective series of 53 consecutive patients suffering from MCSs. The median follow-up duration was 10.2 years (range 2-25 years), from 1990 to 2016.

RESULTS

Patients ranged in age from 30 to 72 years (mean 53 years). The meningiomas were diagnosed by major symptoms (mainly oculomotor palsy and neuralgia experienced in 28 patients), minor symptoms (headache, intermittent diplopia in 15 patients), or incidental findings (10 patients). Simple symptomatic treatment (short courses of corticosteroids and carbamazepine) allowed patients to become asymptomatic in 19 (67.9%) of 28 cases experiencing major symptoms, and for 12 (80%) of 15 patients with initial minor symptoms (p < 0.0001). All patients with incidental findings remained asymptomatic. Forty four (83%) of 53 MCSs did not show any significant growth and 42 (80%) of 53 patients were not symptomatic at the end of follow-up (p < 0.001). The radiographic progression-free survival rates (± SD) at 5, 10, and 20 years were 90% ± 4.2%, 82% ± 5.7%, and 70% ± 10.2%, respectively. Five patients (9.4%) with no evidence of any effect of the initial medical treatment desired additional conventional radiation therapy.

CONCLUSIONS

Because of the capricious, unpredictable, and slow growth of MCSs, together with high growth variability from one patient to the next, the symptomatic medical treatment of these tumors is a highly effective method. This series shows that these lesions are naturally, clinically, and radiologically indolent.

Nontraumatic emergencies of inflammatory paranasal sinus disease

Inflammatory disease of the paranasal sinuses is extremely common and the course is often innocuous. However, when extrasinus spread of disease occurs life-threatening complications can arise. Intraorbital and intracranial involvement can progress rapidly either by hematogenous spread or in the case of fungal sinusitis via angioinvasion. An understanding of anatomy and appropriate imaging protocols is critical when these complications arise. The knowledge of imaging features of the different disease processes and prompt diagnosis is essential to improve patient outcomes and positively impact patient care.

Hemangioma of the Cavernous Sinus: A Case Series

Introduction  Cavernous sinus hemangiomas (CSHs) are rare, vascular, extra-axial tumors that are diagnosed with a combination of imaging and biopsy. We describe the clinical presentations, imaging findings, and management of two male patients with CSHs. Case Report  Case 1 describes a 57-year-old man who presented with vision changes and cranial nerve palsies. Initial imaging and surgical biopsy were nondiagnostic. Follow-up Tc-99m tagged red blood cell (RBC) imaging supported CSH diagnosis. He was treated with surgical resection and radiotherapy. Case 2 describes a 57-year-old man who presented with chronic headache. Imaging findings were suggestive of CSH. He underwent endoscopic endonasal surgical resection and a final diagnosis of CSH was made via biopsy. Discussion  CSHs often present with headache, vision changes, and cranial nerve palsies. Characteristic findings of a T2 hyperintense lesion with homogeneous contrast enhancement has been described in the literature. There is also a role for tagged RBC imaging studies in the setting of nondiagnostic imaging and biopsy. Surgical resection can be difficult due to tumor vascularity and encasement of internal carotid arteries. Stereotactic radiosurgery and adjuvant radiotherapy can play a role in the treatment of patients who have inoperable lesions or subtotal resections.

A cavernous sinus lesion clinically responsive to steroids

Tolosa Hunt syndrome (THS) is characterized by painful ophthalmoplegia secondary to idiopathic granulomatous inflammation of the cavernous sinus. The characteristic finding on MRI is an enhancing T1 isointense and T2 hypo- or hyperintense cavernous sinus mass lesion, which may result in focal narrowing of the ipsilateral internal carotid artery. Although the incidence is quite rare, it is a common diagnostic consideration in cases that present with multiple cranial neuropathies. However, the differential diagnosis for a unilateral cavernous sinus lesion in adults is broad and includes neoplastic, inflammatory (such as sarcoidosis and immunoglobulin G4-related disease [IgG4-RD]), infectious etiologies (such as syphilis and leprosy), as well as vascular lesions. We describe a patient presenting with neurologic symptoms referable to a persistent unilateral cavernous sinus MRI abnormality, initially thought to be consistent with Tolosa-Hunt syndrome, that was clinically but not radiographically responsive to steroids. Following reevaluation due to the presence of new symptoms, pathology revealed that the abnormality was most consistent with chordoma, a rare skull based tumor. In patients with a presumed diagnosis of Tolosa-Hunt syndrome, close clinical and radiographic follow-up is imperative, with early consideration for biopsy in patients that fail to respond to treatment both clinically and radiographically.

Neuroimaging of Meckel's cave in normal and disease conditions

Abstract

Meckel’s cave is a dural recess in the posteromedial portion of the middle cranial fossa that acts as a conduit for the trigeminal nerve between the prepontine cistern and the cavernous sinus, and houses the Gasserian ganglion and proximal rootlets of the trigeminal nerve. It serves as a major pathway in perineural spread of pathologies such as head and neck neoplasms, automatically upstaging tumours, and is a key structure to assess in cases of trigeminal neuralgia. The purpose of this pictorial review is threefold: (1) to review the normal anatomy of Meckel’s cave; (2) to describe imaging findings that identify disease involving Meckel’s cave; (3) to present case examples of trigeminal and non-trigeminal processes affecting Meckel’s cave.

Teaching points

• Meckel’s cave contains the trigeminal nerve between prepontine cistern and cavernous sinus.

• Assessment is essential for perineural spread of disease and trigeminal neuralgia.

• Key imaging: neural enhancement, enlargement, perineural fat/CSF effacement, skull base foraminal changes.

Actinomyces cavernous sinus infection: a case and systematic literature review

A 63-year-old man presented with a 2-month history of progressive right-sided exophthalmos, painful ophthalmoplegia and fevers. As more features developed, he was diagnosed with giant cell arteritis, then Tolosa-Hunt syndrome, and transiently responded to corticosteroids. A bland cerebrospinal fluid and highly metabolically active brain (¹⁸F)-fluoro-D-glucose-positron emission tomography suggested lymphoma. Biopsy of the mass showed sulphur granules with Gram-positive filamentous bacteria with Actinomyces-like colonies. Actinomyces cavernous sinus infections are rare and indolent. They often mimic non-infective causes including other inflammatory and infiltrative conditions, vascular and neoplastic causes, particularly lymphoma. Clinicians should consider infective cavernous sinus syndromes in people with a fluctuating painful ophthalmoplegia that responds poorly to corticosteroids. The term Tolosa-Hunt syndrome is problematic and should be retired or used only with reservation.

Radiosurgery in trochlear and abducens nerve schwannomas: case series and systematic review

INTRODUCTION

Schwannomas involving the occulomotor cranial nerves  (CNs; III, IV and VI), can be disabling, due to the associated diplopia and decreased quality of life and are extremely rare. We evaluated the role of Gamma Knife surgery (GKS) in these cases.

METHODS

Five patients with CN IV and VI schwannomas (three and two, respectively) were treated in Lausanne University Hospital between 2010 and 2015. Four benefitted from upfront GKS and one from a combined approach (planned subtotal resection followed by GKS), due to a large preoperative tumour volume (size, 3 × 2 × 2.5 cm; volume, 7.9 ml), with symptomatic mass effect and oedema, as well as an entrapement cyst at the brainstem interface, in a young patient. Neuro-ophtalmological evaluation was performed at baseline and during each follow-up time-point. A systematic literature review is presented and compared to the present report.

RESULTS

The mean follow-up was 44.4 months (12-54). Initial clinical presentation was diplopia in four cases and cavernous sinus syndrome in one. The marginal dose was 12 Gy in all cases. The mean target volume was 1.51 cm³ (0.086-5.8). The mean prescription isodose volume (PIV) was 1.71 cm³ (0.131-6.7). At last follow-up, all patients presented with disappearance of the baseline symptoms. Tumour control was achieved in 100%, with decrease in volume in all cases. The systematic review analysed 11 peer-reviewed studies, with a total of 35 patients. For uniformly reported CN VI, the mean marginal radiation dose ranged between 12 and 12.5 Gy, with disappearance of symptoms in 12.5%, improvement in 31.25%, stabilisation in 6.25%, worsening in 12.5%. Tumour volume decreased in all cases.

CONCLUSIONS

Our data suggest that first intention GKS is a safe and effective option for patients with small to medium size oculomotor schwannomas, providing a high rate of clinical alleviation and tumour control. When the initial tumour volume is too large for first intention GKS, a combined approach with planned subtotal resection followed by GKS can be performed, with favourable and comparable outcomes as in upfront GKS.

Headache and Its Approach in Today's NeuroIntensive Care Unit

Headache is a very common symptom in the neurointensive care unit (neuroICU). While headache in the neuroICU can be caused by worsening of a pre-existing primary headache disorder, most are secondary to another condition. Additionally, headache can be the presenting symptom of a number of conditions requiring prompt recognition and treatment including subarachnoid hemorrhage, ischemic and hemorrhagic stroke, central nervous system infection, pituitary apoplexy, and cerebral vasoconstriction. The neuroICU also has a unique postoperative population in which postcraniectomy and postcraniotomy headache, postintravascular intervention headache, hyperperfusion syndrome, ventriculitis, medication overuse or withdrawal headache, and hypercapnia may be encountered. Management varies dramatically depending on the etiology of the headache. Overreliance on opiate analgesics may produce significant adverse effects and lengthen ICU stays. However, nonnarcotic medications are increasingly being recognized as helpful in reducing the pain among various postsurgical and headache patients. Taken together, a multimodal approach targeting the underlying pathology and choosing appropriate systemic and local analgesic medications may be the best way to manage headache in critically ill patients.

Moyamoya Disease Associated with Tuberculum Sellae Meningioma and Cavernous Sinus Hemangioma

BACKGROUND

Primary moyamoya disease associated with skull base tumors has been reported only rarely in the literature. Surgical treatment can be complicated due to the compensatory collateral circulation through meningeal and leptomeningeal anastomosis. A standard frontotemporal craniotomy may interrupt critical transdural anastomoses.

CASE DESCRIPTION

We report a case of primary moyamoya disease coexisting with tuberculum sellae meningioma and left cavernous sinus hemangioma. Simultaneous management of tuberculum sellae meningioma and moyamoya disease was performed using a left modified pterional incision. Two separate bone windows were opened to protect the transdural anastomosis via the middle meningeal artery. The tuberculum sellae meningioma was successfully removed through a small frontal craniotomy, and encephaloduromyosynangiosis was used to treat moyamoya disease through a temporoparietal craniotomy. Finally, CyberKnife radiotherapy was used to treat the left cavernous sinus hemangioma at 6 weeks after the initial operation. The patient recovered well without complications. This is the first report of moyamoya disease associated with tuberculum sellae meningioma and cavernous sinus hemangioma.

CONCLUSIONS

With careful bone flap design, moyamoya disease and skull base tumors can be treated simultaneously. Care should be taken to avoid interruption of critical dural-pial collaterals and injury to fragile moyamoya vessels.

Gamma Knife surgery for a hemangioma of the cavernous sinus in an adult: Case report and short review of the literature

Cavernous sinus hemangiomas (CSH) are rare benign extra-axial vascular lesions. Both radiological and clinical aspects are important, for deciding a therapeutic modality, including medical treatment, radiation therapy or microsurgery. In the particular case of CSH, a radical removal of the tumor often cannot be achieved and is associated with a considerable risk for intraoperative uncontrollable bleeding. An alternative treatment modality is radiosurgery. Here we report the case of a 45-year-old patient, who presented with diplopia due to left abducens nerve palsy. A left-sided cavernous sinus lesion was found, initially considered to be a meningioma. However, after serial MR acquisitions, a progressive and heterogeneous enhancement was observed. In order to clarify the diagnosis between meningioma and hemangioma, a diagnostic Tc-99m labeled red blood cells (RBC) scintigraphy (Tc-99m RBC scintigraphy) was performed and showed a typical perfusion blood pool mismatch, with accumulation of the RBC at the level of the left CS, which is typical for a hemangioma. The patient underwent Gamma Knife surgery. The CSH showed a significant reduction in size starting 6 months after treatment and a full regression of the left abducens nerve palsy was observed within 1 year. These clinical and radiological results persisted over the next 3 years.

Clinical-radiological-pathological correlation of cavernous sinus hemangioma: Incremental value of diffusion-weighted imaging

AIM

To elucidate the clinical, magnetic resonance imaging (MRI), pathological features of these lesions and asses the incremental value of diffusion-weighted imaging (DWI) in diagnosing them.

METHODS

Fifteen consecutive patients (11 females and 4 males; mean age 40.93 years; age range 13-63 years) with cavernous sinus hemangiomas (CSH) who underwent examination between November 2008 and May 2016 were included for the analysis. MRI, clinical and surgical findings of each patient was retrospectively reviewed. DWI were also analysed and mean-apparent diffusion coefficient (ADC) value was calculated. Eleven patients underwent surgical removal of the lesion and 2 patients had biopsy only. Diagnosis of CSH was confirmed histologically in 13 patients.

RESULTS

Eleven patients (73%) presented with headaches and 10 (66%) had cranial nerve involvement. Extra cavernous sinus extension was noted in 14 (94%). Surgery was performed in 13 (87%) and post-operative radiation was given to 4 (28%) patients. Thirteen patients remained asymptomatic on follow up. Three conspicuous imaging features were highly suggestive of the diagnosis: Lack of diffusion restriction (100%), homogeneous hyperintensity on T2 weighted image sequences (93.3%) and intense post-contrast enhancement (100%). The mean ADC was 1.82 × 10^-3 ± 0.2186 cm²/s.

CONCLUSION

T1-weighted hypointensity with homogeneous hyperintensity on T2-weighted sequences, intense enhancement and absence of hemosiderin within the lesion on GRE sequence favour the diagnosis. Facilitated diffusion on DWI differentiates CSH from other solid cavernous sinus lesions and significantly improves the diagnostic accuracy, a critical factor for planning surgery.

Bing-Neel syndrome - Bilateral cavernous sinus lymphoma causing visual failure

We report the case of a 68-year-old male with right eye vision loss secondary to a compressive optic neuropathy from Waldenstrom macroglobulinaemia relapse in both cavernous sinuses. Central nervous system involvement is extremely uncommon in lymphoplasmacytic lymphoma. Known as Bing-Neel syndrome, this has not been previously reported to present simultaneously in bilateral cavernous sinuses. We discuss the pathophysiology, diagnostic and neuroradiological features of Bing-Neel syndrome. In this case, there was marked clinical and radiological response to chemotherapy. As outcomes following treatment for Waldenstrom macroglobulinaemia improve, greater awareness of its less common manifestations becomes important. Neurosurgical intervention may be indicated to obtain histological diagnosis or decompress critical structures.

Microsurgical management of benign lesions interior to the cavernous sinus: A case series

Background:

Benign lesion interior to the cavernous sinus (CS) is very rare.

Objective:

In this series we found nonneoplastic lymphatic aggregation and osteoclastoma inside the CS which is very rare and probably not reported in literature. One interesting postoperative complaint of feeling of tickling down of warm water under the skin forehead was found in the patient of inflammatory disease of CS which is not reported in literature. Here we also describe our experiences of microsurgical management of series of benign lesions inside the CS.

Materials and Methods:

Benign mass originated from the content of CS or inner side of walls of CS, confirmed peroperatively were included in this series. Prospectively recorded data of microsurgical management was retrogradely studied.

Results:

Total number of patient was 12. Patient's age range was 30–60 years. Follow-up range was 60 months to 19 months. Three was nonneoplastic lesion (tuberculosis, inflammatory and nonneoplastic lymphoid infiltration). Among the 9 neoplastic lesions, two hemangiomas, two meningiomas, three 6^th nerve schwannomas, one osteoclastoma and one epidermoid tumor. Middle cranial fossa-subtemporal extradural approach was used in 9 cases and in two cases extended middle fossa zygomatic approach. New postoperative 3^rd nerve palsy developed in 5 cases all recovered completely except one. In seven patients 6^th nerve palsy developed after operation; only one recovered. Postoperatively simultaneous 3^rd, 4^th and 6^th nerve palsy developed in four cases. One interesting postoperative complaint of feeling of tickling down of warm water under the skin of left sided forehead was found in the patient of inflammatory disease of CS. Mortality was nil. Total resection was done in 9 cases. There was no recurrence till last follow-up.

Conclusion:

Though decision for microsurgical removal of such lesions is not straight forward. Probably microsurgery is the best option in treating such benign lesions though it may associate with some permanent cranial nerve palsy.

Imaging of the Sella and Parasellar Region in the Pediatric Population

Masses in the sella and parasellar region comprise about 10% of all pediatric brain tumors but type and frequency differs from those in adults. Imaging is critical for diagnosis and characterization of these lesions. By assessing the site of origin, signal and contrast enhancement characteristics, and the presence or absence of characteristic patterns, differential diagnosis can narrow the possibilities. The clinical presentation is often characteristic for lesion type and should be considered. This article summarizes the characteristic imaging features of the most frequent pediatric tumors and tumor-mimicking lesions in children in this region.

Sellar and Parasellar Imaging

The skull base is a complex anatomical region that harbors many important neurovascular structures in a relatively confined space. The pathology that can develop at this site is varied, and many disease processes may present with similar clinical and neuroimaging findings. While computed tomography maintains a role in the evaluation of many entities and can, for instance, delineate osseous erosion with great detail and characterize calcified tumor matrices, magnetic resonance imaging (MRI) is the mainstay in the neuroimaging assessment of most pathology occurring at the skull base. Various MRI sequences have proven to be robust tools for tissue characterization and can provide information on the presence of lipids, paramagnetic and diamagnetic elements, and tumor cellularity, among others. In addition, currently available MRI techniques are able to generate high spatial resolution images that allow visualization of cranial nerves and their involvement by adjacent pathology. The information obtained from such examinations may aid in the distinction of these disease processes and in the accurate delineation of their extent prior to biopsy or treatment planning.

[Giant inflammatory pseudotumor of the cranial base]

The inflammatory pseudotumour (IPT) is a non-neoplastic entity of unknown origin, and is characterised by a proliferation of connective tissue and a polyclonal inflammatory infiltrate. Central nervous system involvement is uncommon, and usually represents a diagnostic and therapeutic challenge even for the experienced clinician. This reports deals with the case of a 56year-old woman diagnosed with a giant, infiltrating mass centred in the left cavernous sinus, who had a rapid clinical and radiological response to steroid therapy. Biopsy specimens were diagnostic for IPT. The progression of a small orbital residual lesion was detected after steroid withdrawal. Treatment with cyclophosphamide induced a complete response that remains stable after six years of follow-up.

A singular case of cavernous internal carotid artery aneurysm in patient with cavernous sinus syndrome and bacterial meningitis

We report the uncommon case of an acute cavernous sinus syndrome in a patient who was consequently discovered to have both a cavernous internal carotid artery aneurysm and bacterial meningitis. Which came first, the chicken or the egg? Which of the two, the aneurysm or the meningitis, gave rise to the patient’s symptoms? We briefly reviewed the literature of similar cases and tried to analyze the possible pathophysiological relationship between these findings. Moreover, this case highlights the importance of a multidisciplinary management of these patients to better decide between a medical and a surgical and/or endovascular treatment.