A Rare Triad of Lateral Rectus Palsy, Sylvain Fissure Bleed, and Bilateral SDH Shrouding a Benign Pathology.

Background: Arachnoid cysts are benign extra-cerebral congenital lesions that are thought to arise from the splitting of the arachnoid membrane. Although most arachnoid cysts remain static with advancing age, occasionally they can become symptomatic due to cyst enlargement or hemorrhage. Hemorrhage into the arachnoid cysts (intra-cystic hemorrhage) with or without associated subdural hematoma is of rare occurrence. Case Discussion: A 23-year-old male presented with a history of sudden onset severe headache while sleeping. The patient also noticed double vision, especially when looking towards the left side. Non-contrast computed tomography (NCCT) scan of the head showed left temporal pole hematoma with left Sylvian fissure bleed and bilateral fronto-temporoparietal (FTP) subacute SDH. Conclusion: Every patient with incidentally detected AC, especially in the middle cranial fossa, should be counseled regarding the risk of possible complications including hemorrhage and regular follow-up.

Fronto-orbito-zygomatic (FOZ) approach for infratemporal fossa lesions extending to middle cranial fossa: our experience and review of literature.

AIM OF THE STUDY: Tumours of the infratemporal fossa (ITF) are rare and include primary tumours, contiguity lesions and metastases. Surgical resection is the gold standard. The fronto-orbito-zygomatic (FOZ) approach is commonly used in order to obtain safe access to the lateral skull base and ITF to resect intra- and extra-cranial tumours. We here describe our series of ITF lesions extending to the middle cranial fossa and/or orbit, treated by single- or two piece FOZ. MATERIAL AND METHODS: All cases of single- or two-piece FOZ approach for an infratemporal fossa lesion extending to the middle cranial fossa operated at our Institution from January 2014 to January 2018 were retrospectively reviewed. The follow-up was for a minimum of four months and a maximum of 60 months. The inclusion criteria were lesions involving the ITF with an extension to the middle cranial fossa and/or orbit. Baseline characteristics of patients, tumour localisation, tumour extension, diffusion route, histology, extent of tumour resection, postoperative treatment, and post-operative complications were evaluated. RESULTS: Nine patients underwent a surgical procedure with a FOZ approach, two of them with a single-piece approach and the remainder with a two-piece one. All patients had an ITF localisation. Gross total removal (GTR) was achieved in 7/9 patients. Only one patient, with non-total removal (NTR), underwent radiotherapy. CONCLUSIONS: For the treatment of ITF fossa tumours extending to the orbit and or middle cranial fossa, we believe that both FOZ techniques are effective and allow a good medial extension toward the cavernous sinus and parasellar region. But a two-piece craniotomy may ensure a more medial extension and a wider angle of work compared to a one-piece craniotomy.

Endoscopic Subtemporal Epidural Key-Hole Approach: Quantitative Anatomic Analysis of Three Surgical Corridors.

BACKGROUND: The endoscope-assisted subtemporal key-hole epidural approach (ESKEA) has been recently described. The aim of this study was to measure working volumes and exposure of key areas of the middle cranial fossa provided by this approach. METHODS: Four fresh frozen cadaver heads were dissected to analyze 3 modular corridors (1A, 1B, and 2) harvested through ESKEA. A step-by-step dissection was performed, and key anatomic landmarks were recorded. A GTxEyesII-ApproachViewer was used to quantify the working volume and exposure of 4 different regions (sphenoorbital, parasellar, superior petrous apex, and squamopetrous). For each corridor, 3 incremental degrees of temporal dural retraction (5, 10, and 15 mm) were tested. RESULTS: The working volume of all corridors progressively increased with degree of retraction: Corridors 1A, 1B, and 2 showed a gain in working volume of 21%, 27%, and 19% from 5 mm to 10 mm retraction, respectively, and a gain of 40%, 45%, and 44% from 5 mm to 15 mm retraction, respectively. The sphenoorbital area was exposed (27%-45%) through corridor 1A, and exposure significantly increased with the degree of retraction. Corridor 1B provided optimal exposure of parasellar areas (86%-100%) and superior petrous apex (70%-87%) regardless of the degree of retraction. The squamopetrous area was satisfactorily addressed through corridor 2 (88%) only with the highest degree of retraction. CONCLUSIONS: ESKEA can be conceived as a modular approach: the 3 surgical corridors have specific working volumes, which are clearly influenced by the degree of temporal lobe retraction, and provide exposure of different middle cranial fossa areas.

Access to Meckel's cave for biopsies of indeterminate lesions: a systematic review.

Accessing Meckel's cave (MC) is surgically challenging. Open approaches are complex and often correlated with high morbidity. Endoscopic approaches emerged in the last decade as feasible alternatives to open approaches, especially for sampling indeterminate lesions. This article first analyses available routes to approach Meckel's cave and presents furthermore an illustrative case. We conducted a systematic review and reported according to the guidelines for preferred reporting items for systematic reviews and meta-analyses (PRISMA). Various surgical approaches identified through the search are evaluated and discussed in detail. Additionally, we report on a case of woman with a lesion in MC, which was accessed through an endoscopic transpterygoid approach subsequently diagnosed as a diffuse large B cell lymphoma. Our search delivered 75 articles that included case reports (n = 21), cadaveric studies (n = 32), clinical articles (n = 16), review of the literatures (n = 3), as well as technical notes (n = 2) and a radiological manuscript (n = 1). Open routes included lateral approaches with many variations, mainly intra- and extradural pterional approaches and anterior petrosal, as well as a retrosigmoid intradural suprameatal and a lateral transorbital approach. Endoscopically, MC was reached via approaches that included transpterygoid, transorbital or infraorbital fissure routes. Percutaneous approaches, e.g. through the foramen ovale, were also described. Multiple surgical approaches to MC are currently available. Their different characteristics as well as individual patient factors, such as clinical history and the localization of the disease, have to be considered when choosing a surgical corridor. Studies included in this review highlight the endonasal endoscopic transpterygoidal technique as an excellent corridor for biopsies in the ventral MC.

Same viewing angle, minimal craniotomy enlargement, extreme exposure increase: the extended supraorbital eyebrow approach.

The supraorbital eyebrow approach (SEa) has been commonly used as a straightforward route to reach lesions located in the anterior cranial fossa. The reduced surgical exposure provided by this approach limits its applicability. A modification of the SEa, the extended supraorbital eyebrow approach (X-SEa), allows use of the transylvian corridor to approach parasellar lesions, while maintaining most of the aesthetic advantages of the SEa. To quantify the surgical exposure and maneuverability provided by the X-SEa using a cadaveric study. Eleven heads were used to obtain all stereotactic measurements. Surgical exposure and maneuverability were measured by means of the area of exposure and the angles of attack along key representative points in the anterior circulation. The horizontal angle of attack at the middle cerebral artery provided by the X-SEa was larger than that provided by the SEa (32.6 vs 18.4°, p = 0.009). The X-SEa afforded broader vertical angles of attack at all targets in the anterior circulation (p < 0.05). The total area of exposure provided by the X-SEa was significantly larger than that provided by the SEa (1272 vs 978 ± 156 mm2, p = 0.003). The area of exposure in the ipsilateral trigon and in the midline quadrangle was also significantly larger for the X-SEa (paramedian 195 vs 121 mm2, p = 0.01; midline 1310 vs 778 mm2, p = 0.002). The X-SEa increases the exposure and surgical maneuverability along the anterior and middle cranial fossa when compared to the standard SEa.

The extradural extended eyebrow approach: A cadaveric feasibility study.

INTRODUCTION: Extradural anterior clinoidectomy (eAC) is key to expose the paraclinoid region. Several authors have pointed limitations of performing an eAC through a supraorbital craniotomy. In this article, we aim to provide educational material and discuss the technical nuances to successfully perform an eAC throughout a modification of the supraorbital approach, the extradural extended eyebrow approach (xEBA+eAC). METHODS: Four embalmed heads were used for anatomic dissection and perform the xEBA+eAC. Additionally, one head was used for a video demonstration of the surgical approach. RESULTS: The anterior clinoid process was successfully removed, and the ophthalmic artery and paraclinoid region were exposed in all specimens. Drilling the sphenoid wing until exposing the meningo-orbital band and further interdural dissection are vital steps to expose the anterior clinoid process. Removal of the anterior clinoid process can be simplified in 3 osteotomies, including the optic canal unroofing, detachment from the lateral pillar, and drilling of the optic strut. Sectioning of the distal dural ring facilitates the mobilization of the internal carotid artery and the surgical exposure of the ophthalmic artery. CONCLUSIONS: xEBA+eAC is a technically feasible approach that provides exposure to the paraclinoid region, along with anterior and middle cranial fossa.

MR Imaging Features of Middle Cranial Fossa Encephaloceles and Their Associations with Epilepsy.

BACKGROUND AND PURPOSE: Middle cranial fossa encephaloceles are an increasingly recognized cause of epilepsy; however, they are also often encountered on neuroimaging in patients with no history of seizure. We characterized the MR imaging features of middle cranial fossa encephaloceles in seizure and nonseizure groups with the hope of uncovering features predictive of epileptogenicity. MATERIALS AND METHODS: Seventy-seven patients with middle cranial fossa encephaloceles were prospectively identified during routine clinical practice of neuroradiology at a tertiary care hospital during an 18-month period. Thirty-five of 77 (45%) had a history of seizure, 20/77 (26%) had temporal lobe epilepsy, and 42/77 (55%) had no history of seizures. Middle cranial fossa encephalocele features on MR imaging were characterized, including depth, area, number, location, presence of adjacent encephalomalacia, and degree of associated parenchymal morphologic distortion. MR imaging features were compared between the seizure and nonseizure groups. RESULTS: No significant difference in MR imaging features of middle cranial fossa encephaloceles was seen when comparing the seizure and nonseizure groups. Comparison of just those patients with temporal lobe epilepsy (n = 20) with those with no history of seizure (n = 42) also found no significant difference in MR imaging features. CONCLUSIONS: Anatomic MR imaging features of middle cranial fossa encephaloceles such as size, number, adjacent encephalomalacia, and the degree of adjacent parenchymal morphologic distortion may not be useful in predicting likelihood of epileptogenicity.

Middle fossa meningiomas.

The middle cranial fossa is bounded anteriorly by the sphenoid ridge, medially by the lateral wall of the cavernous sinus and Meckel's cave, posteriorly by the sphenoid wing and petrous bone, and laterally by the greater wing of sphenoid and squamous temporal bone. In normal individuals, unnamed venous channels within the dura and arachnoid granulations can be seen on the floor of this fossa by the operating surgeon. Meningiomas arising mainly from the dura of the floor are uncommon, and middle fossa meningiomas have been arbitrarily named so based on an attachment of more than 75% to this location. They tend to present clinically at a large size and require special considerations for surgical treatment.

Pediatric clear cell meningioma involving the middle cranial fossa in the context of NF2 and SMARCE1 mutations.

Meningiomas are an uncommon entity in children and adolescents. <30 cases of pediatric clear cell meningioma (CCM), a World Health Organization (WHO) Grade II tumor, have been reported in the literature. These tumors are more likely to recur than the more common WHO Grade I meningiomas, especially with incomplete surgical resection. CCMs are most commonly found in the spine and posterior cranial fossa. Recently, SMARCE1 mutations have been linked to the development of CCM. To evaluate the progression of pediatric CCM in the context of emerging genetic knowledge, we reviewed all 45 cases of CCM at our institution for a 23 year period (1997-2019) to identify pediatric cases. Forty-four of the tumors arose in adults from age 34-81 years. The one pediatric case originally presented at age 4 years; the patient was found to have a CCM in the left cavernous sinus projecting into the posterior fossa, associated with a novel germline SMARCE1 mutation and somatic NF1 and DMD mutations. After two years, the patient had a recurrence of the tumor and underwent a second resection. This is the 5th reported case of CCM in the middle cranial fossa, and the only recurrent case, as well as the only reported case of recurrent pediatric CCM associated with a germline SMARCE1 mutation. Further study of the natural history of tumors associated with germline SMARCE1 loss could potentially inform prognosis.

Thinning or dehiscence of bone in structures of the middle cranial fossa floor in superior semicircular canal dehiscence.

BACKGROUND: Superior semicircular canal dehiscence (SSCD) is a rare inner ear disorder; currently, it is unknown whether the etiopathology underlying this structural irregularity affects neighboring structures. The goal is to investigate the prevalence of bone thinning in areas of the middle cranial fossa (MCF) floor in SSCD and non-SSCD patients. METHODS: This retrospective study analyzed 100 patients from March 2011 to June 2017 at a tertiary referral center. 100 patients undergoing 118 SSCD repair surgeries (18 bilateral) were identified. 12 SSCD ears were excluded due to lack of pre-operative computed tomography (CT) scans or history of prior SSCD repair at an outside facility. Non-SSCD ears were identified from routinely-obtained CT scans for temporal bone fracture (fractured sides excluded) for a total of 101 ears; 26 non-SSCD ears were excluded due to lack of high-resolution imaging. RESULTS: Univariate analyses reveal that SSCD diagnosis is associated with higher rates of geniculate ganglion (GG) dehiscence compared with non-SSCD controls (42.7 vs. 24%; χ2(1) = 9.69,P = 0.008). Individuals with SSCD depicted significantly thinner bone overlying the geniculate ganglion (GG) (0.23 ± 1.2 mm) compared to controls (0.28 ± 1.8 mm, (t(1 6 4)) = 2.1, P = 0.04). SSCD patients presented thinner bone overlying the internal auditory canal (IAC) (0.33 ± 1.3 mm) compared to patients without SSCD (0.46 ± 1.6 mm, (t(2 5 7) = 6.4, P < 0.001). CONCLUSIONS: The increased prevalence of dehiscence of the MCF in this cohort of SSCD patients compared to non-SSCD patients suggests that the etiology underlying SSCD affects surrounding structures.

[Temporal bone cholesterol granuloma penetrating into the middle cranial fossa]. / Középso skálába terjedo, temporalis csontból kiinduló koleszteringranuloma.

The authors present a case report of a patient who was treated conservatively for a non-specific headache for more than a decade, while an arachnoidal cyst in the middle cranial fossa, over the temporal bone tegmen was diagnosed, but ruled out as the cause of the headache. The patient was referred to our ENT department with left, purulent ear discharge. Besides a chronic purulent otitis media, a cholesterol granuloma occupying the antrum, eroding the tegmen of the pyramid bone and penetrating into the middle cranial fossa was diagnosed. Case presentation of a patient with cholesterol granuloma, surgical options, differential diagnostic problems, and a literature review are presented. Tympanoplasty with cortical mastoidectomy was carried out to treat the chronic purulent otitis media, and the cholesterol granuloma was removed during transmastoid craniotomy. The iatrogenic temporal meningo-encephalic tissue herniation was repaired and the bone defect of the tegmen was reconstructed with septal cartilage. The patient's headache diminished immediately after the surgery. The chronic ear discharge stopped, the cholesterol granuloma was excised completely and the cerebral herniation was repaired successfully. Neither CSF leak, nor further herniation or meningitis were noticed. Two years after the operation the patient is asymptomatic. A large cholesterol granuloma, eroding into the middle cranial fossa can cause serious complications, and needs a high level of attention besides individualized surgical treatment based on the surgeon's abilities and skills. Orv Hetil. 2019; 160(52): 2067-2072.

Synovial chondromatosis of the temporomandibular joint with glenoid fossa erosion: Disk preservation for spontaneous anatomical recovery.

Synovial chondromatosis (SC) of the temporomandibular joint is a pseudoneoplastic condition characterized by benign cartilaginous metaplasia of synovial tissue mesenchymal residues with intra-articular nodule formation. TMJ involvement is rare. Interposition of loose bodies in the articular space can generate pressure, leading to glenoid fossa erosion with intracranial extension. The aim of this study was to present six SC cases with intracranial extension treated using a surgical procedure. All the patients were treated with open surgery. The superior compartment of the TMJ was opened widely to carefully remove the metaplasic mass. Temporal synovectomy was then performed. Attention was paid to preserving the integrity of the articular disc. The exposed dura mater was also preserved. No material was used to reconstruct the gap in the glenoid fossa. A 1-year follow-up showed no swelling or pain. Patients demonstrated good recovery of mouth opening, with improvement over previous mouth limitations. Morphological studies, performed using MRI and CT, showed complete anatomical recovery of the TMJ and total bone reconstruction of the glenoid fossa. Simple removal of intra-articular nodules, with TMJ arthroplasty and articular disk preservation, represents an efficient treatment option for full anatomical and functional recovery in synovial chondromatosis of the temporomandibular joint with glenoid fossa erosion of less than 1 cm2.

Prevalence of Asymptomatic Middle Cranial Fossa Floor Pits and Encephaloceles on MR Imaging.

BACKGROUND AND PURPOSE: Temporal lobe encephaloceles are increasingly identified and treated as epileptogenic foci. However, there is relatively scant research on the prevalence of asymptomatic encephaloceles. This study set out to describe the frequency of incidental temporal lobe encephaloceles and middle cranial fossa pits. MATERIALS AND METHODS: A retrospective review was completed of high-resolution (≤0.5-mm section thickness) axial T2WI for internal auditory canal protocol imaging. The presence and laterality of middle cranial fossa pits (small bony defects containing CSF) and encephaloceles (brain parenchyma protrusion through osseous defects with or without bony remodeling) were recorded. Electronic medical records of patients with encephaloceles were searched for a history of seizure. RESULTS: A total of 203 patients were included in the final cohort; 106 (52.2%) women. Forty-five (22.2%) patients had middle cranial fossa pits: 14 (31.1%) unilateral on the right, 17 (37.8%) unilateral on the left, and 14 (31.1%) bilateral. Ten (5.0%) patients had ≥1 encephalocele, none of whom had a documented history of seizure in the electronic medical record. No significant difference was noted in the frequency of pits or encephaloceles based on sex (P = .332 and P = .383, respectively) or age (P = .497 and P = .914, respectively). CONCLUSIONS: Incidental middle cranial fossa pits are common findings, and their prevalence is not related to age or sex. Temporal lobe encephaloceles, though rarer, also exist occasionally among asymptomatic patients. Such findings have diagnostic implications for encephaloceles identified during imaging work-up for epilepsy.

Intracranial Multiple Pseudotumor Due to Immunoglobulin G4-Related Disease without Other Lesions: Case Report and Literature Review.

BACKGROUND: Immunoglobulin (Ig)G4-related disease (IgG4-RD) was defined only recently and can be found in many organs. As intracranial lesions, hypophysitis and pachymeningitis are well known, whereas intracranial pseudotumor is unusual. This case involved multiple intracranial pseudotumors without extracranial lesions, mimicking multiple meningioma. CASE DESCRIPTION: A 72-year-old woman was referred to our hospital with an incidental mass lesion at the craniocervical junction on magnetic resonance imaging (MRI). MRI showed diffuse enhanced extra-axial nodules around the medulla and middle cranial fossa. Surgery was performed for the gradually enlarging tumor. Intraoperative findings showed hard nodules around the vertebral artery. We performed subtotal resection. Neuropathological findings showed diffuse lymphoplasmacytic infiltration with lymphoid follicles. Immunohistochemical studies for IgG4 and IgG showed the histological criteria for IgG4-RD were met. Given the high IgG4 serum level, we diagnosed IgG4-RD. Steroid was administered initially but was then tapered, and nodules have since remained small. CONCLUSIONS: This case demonstrates IgG4-RD mimicking meningioma with multiple masses but without extracranial lesions. This case and previous descriptions suggest the possibility of pseudotumor due to IgG4-RD in the presence of multiple extra-axial lesions at the dura and supplying artery, hard nodules with thickening of the artery, and frozen section findings of lymphoplasmacytes surrounded by rich collagen fibers. In such cases, the pseudotumor due to IgG4-RD should be resected, and total resection might not be warranted.

Endoscopic Transcanal Approach to Geniculate Ganglion Hemangioma and Simultaneous Facial Nerve Reinnervation: A Case Report.

Hemangioma of the facial nerve (FN) is a very rare benign tumor whose origin is the vascular plexi that surround the nerve. The transpetrous, retrosigmoid, and middle cranial fossa (MCF) routes are the traditional and most widely used approaches to reach these lateral skull base neoformations. However, this very complex region can be reached through an exclusive transcanal endoscopic procedure in selected cases. One of these was a 42-year-old patient who had been presenting a worsening left FN paralysis (grade VI according to the House-Brackmann scale at the time of visit) for 22 months without a history of trauma or infection. Radiological studies showed a lesion in the region of the geniculate ganglion. A suprageniculate endoscopic approach was performed to remove the lesion, with the sacrifice of the FN and a simultaneous hypoglossal-facial anastomosis. The aim of this minimally invasive surgery is the complete excision of the disease, maintaining the hearing function intact and restoration of facial function, whenever possible, avoiding more invasive approaches.

Short Report on a Rare Presentation of Temporal Arachnoid Cyst and Lessons Learned.

BACKGROUND: Stiff neck or nuchal rigidity is a significant clinical sign of neurologic disease. It is commonly associated with meningitis, subarachnoid hemorrhage, and posterior fossa tumors. It may also occur as a result of tonsillar impaction following pressure in the infratentorial compartment from an expanding posterior fossa mass. It is, however, not commonly known to be associated with uncal herniation. CASE DESCRIPTION: We report a recent experience on this association. CONCLUSIONS: In the presence of stiff neck or nuchal rigidity in a patient with clinical signs of uncal herniation from a temporal arachnoid cyst, this unusual association could possibly be owing to the effect of increased pressure in the posterior fossa from massive shift of brain tissue posteriorly following a rapid rise in middle cranial fossa pressure consequent on an acute enlargement of the cyst. A false impression of acute meningeal irritation in such a situation could be quite misleading, resulting in late diagnosis and subsequently a delay in timely intervention.

Cognitive disorders in a patient with an arachnoid cyst of the sylvian fissure and improvement after surgical treatment: Case description.

Arachnoid cysts cause a wide spectrum of clinical symptoms. Often it is difficult to clearly establish the relation between the presence of an arachnoid cyst and problems reported by the patient, which may, although not necessarily, be due to chronically elevated intracranial pressure. In recent years, increasing attention is paid to cognitive disorders accompanying arachnoid cysts, such as memory disorders, attention disorders, or language function disorders. This article presents a case of an 11-year-old patient, treated at the University Children's Hospital in Cracow for an arachnoid cyst, located in the left middle cranial fossa. This analysis is focused on the description of cognitive and intellectual deficits of the child, as well as the discussion on their connection with the arachnoid cyst. Prior to the neurosurgical procedure, the boy presented significant deficits in cognitive functions, especially mnestic and attention functions and, also, a quite low level of intellectual functioning. Neuropsychological examination performed after the procedure indicated a significant improvement of cognitive functioning for all the functions, as well as a higher level of intellectual functioning. This analysis attempts to answer whether and to what extent the child still suffers from cognitive deficits from the organic lesions.