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BACKGROUND: Superior Semicircular Canal Dehiscence (SSCD) is a dehiscence of the otic capsule which normally lies over the superior semicircular canal. This database constitutes the largest series of SSCD patients to date. OBJECTIVE: To determine what preoperative factors, if any, contribute to postoperative outcomes and evaluate symptom resolution in a large SSCD patient cohort. METHODS: A single-institution, retrospective chart review collected patient demographics, intraoperative findings, and pre-and postoperative symptoms. Fishers exact t-test was performed for unpaired categorical variables, with a significance level of p

A 42-year-old male presented to the Department of Oral and Maxillofacial Surgery with the chief complaint of pain and stiffness in the right temporomandibular joint (TMJ). The patient's height was 174 cm and his body weight was 65 kg. The patient's occupation was heavy equipment operator. According to the patient, the pain had initiated a week prior to his first visit and was exacerbated during mastication. Evaluation of the range of motion revealed extensive crepitus along the right TMJ. The active and passive range of motion were measured at 45 mm and 42 mm, respectively, indicating adequate mouth-opening capacity. Occlusion was also favorable, and no other clinical symptoms were shown intraorally. [ABSTRACT FROM AUTHOR]

Objective Spontaneous temporal encephaloceles (STEs) are increasingly recognized as sequelae of idiopathic intracranial hypertension (IIH), which in turn may further complicate their management. We endeavored to review the University of Pennsylvania institutional experience on operative management of STEs, with a focus on factors which may influence surgical outcomes, particularly IIH. Design Retrospective chart review over 9 years from 2013 to 2022. Setting Single-center, two-hospital, tertiary care, academic setting. Participants Patients undergoing middle cranial fossa (43.9%), transmastoid (44.9%), or combined (11.2%) approaches for repair of STEs during the study period (n = 107). Main Outcome Measures Postoperative complication rates, recurrence, and diagnosis of IIH. Results The majority of patients were female (64.5%), with a mean body mass index (BMI) of 37 kg/m 2 and mean age of 57 years. Twelve patients (9%) represented reoperations after failed primary repairs. Fourteen percent of patients undergoing primary surgical repair of STE were diagnosed with IIH, compared with 42% of patients undergoing reoperations (p = 0.015). In addition, there was a significant difference in the average BMI of patients undergoing primary (36.4 kg/m 2) versus revision surgery (40.9 kg/m 2 , p = 0.04). Half of those undergoing reoperation were placed on postoperative acetazolamide compared with 11% of patients undergoing primary operations. No patient experienced recurrent leak after reoperation. Conclusion Based on our institutional experience, elevated BMI and the presence of IIH are significant predictors of reoperation for STE. In our experience, acetazolamide is a common adjunct management strategy in addition to reoperation for patients with recurrent cerebrospinal fluid leak in the setting of STE. [ABSTRACT FROM AUTHOR]

Objective: Compare outcomes for subjects who underwent middle cranial fossa (MCF) or transmastoid (TM) repair of superior semicircular canal dehiscence (SSCD). Study Design: Retrospective cohort study. Setting: Quaternary‐care, academic neurotology practice. Methods: Subjects who underwent MCF or TM repair of SSCD between December 1999 and April 2023 were identified. Main outcome measures included demographic data, length of surgery and hospital stay, clinical presentation, and audiometric testing. Results: Ninety‐three subjects (97 ears) who underwent surgery for SSCD met inclusion criteria: 58.8% (57) via MCF, 39.2% (38) via TM, and 2.0% (2) via TM + MCF. Median operative time was shorter for the TM (35) compared to the MCF (29) approach (118 vs 151 minutes, P <.001). Additionally, median hospital stays were shorter for TM (36) compared to the MCF (56) approach (15.3 vs 67.7 hours, P <.001). Overall, 92% (49/53) of MCF and 92% (33/36) of TM surgeries resulted in an improvement or resolution of one or more symptoms (P =.84). There was no significant preoperative to postoperative change in the median air conduction pure‐tone average (PTA), air‐bone gap, or word recognition score in both the MCF and TM groups (P >.05). Improvements of >10 dB in the pre‐ to postoperative absolute change in bone conduction PTA were noted in 3 subjects in the MCF group and 4 subjects in the TM group (P =.49). Conclusion: The TM approach for SSCD demonstrates shorter operative times and length of hospital stay. The TM and MCF approaches have comparable audiometric and clinical outcomes. [ABSTRACT FROM AUTHOR]

Endovascular treatment for isolated dural arteriovenous fistula (DAVF) in the middle cranial fossa (MCF) with pure cortical venous drainage poses challenges, including the absence of a safe access route for transvenous embolization (TVE) and the risk of ischemia to neuro feeding vessels and dangerous anastomosis at the sphenoid wing. Therefore, surgical treatment involving direct blockage of venous reflux via craniotomy is typically preferred. We describe the case of a 63-year-old woman presented with generalized seizures and was diagnosed with a Borden III left MCF-DAVF. Initial TVE was unsuccessful due to an occluded inferior petrosal sinus and a lack of connection between the cavernous sinus and the shunt point. After reducing the shunt flow with transarterial embolization, retrograde TVE through cortical drainage enabled successful treatment for the DAVF. We used a triple coaxial system (4-French guiding sheath, 3.2-French intermediate distal access catheter, and 1.5-French microcatheter) to retrogradely navigate a microcathter from the right jugular vein through the superior sagittal sinus, the vein of Trolard, and into the superficial middle cerebral vein, ultimately achieving shunt occlusion using several coils. This case demonstrates that TVE for MCF-DAVFs with pure cortical venous drainage is feasible when a safe anatomical route is established using appropriate strategies and instruments and provides a safe and effective treatment option for similar cases.

Eosinophilic angiocentric fibrosis (EAF) is a rare, benign fibroinflammatory condition primarily affecting the sinonasal and upper respiratory tract, with a few cases reported beyond these regions. Primary intracranial EAF is rare. To date, only one case of intracranial EAF has been reported; ours is the second. This case report presents a case of EAF in a 55‐year‐old man, initially misdiagnosed as meningioma based on clinical and radiological features. The patient complained of a persistent dull headache for six months without associated neurological symptoms. Brain magnetic resonance imaging revealed a dural‐based lesion with characteristics suggestive of meningioma. However, histopathological examination post‐surgical resection revealed a nodular vascular lesion with concentric angiocentric fibrosis, a distinctive onion skin pattern, and an inflammatory infiltrate rich in eosinophils, plasma cells, and histiocytes. Immunohistochemistry ruled out IgG4‐related disease, and other systemic disorders were ruled out based on combined clinical and histological features. This case underscores the need for considering EAF in the differential diagnosis of dural‐based lesions. Awareness of its potential mimicking of meningioma is crucial for accurate diagnosis and appropriate management, emphasizing the importance of histopathological examination in challenging cases. [ABSTRACT FROM AUTHOR]

Objective To study the microanatomic structure of the subtemporal transtentorial approach to the lateral side of the brainstem, and to provide anatomical information that will assist clinicians to perform surgeries on the lateral, circumferential, and petroclival regions of the brainstem. Methods Anatomical investigations were conducted on 8 cadaveric head specimens (16 sides) using the infratemporal transtentorial approach. The heads were tilted to one side, with the zygomatic arch at its highest point. Then, a horseshoe incision was made above the auricle. The incision extended from the midpoint of the zygomatic arch to one third of the mesolateral length of the transverse sinus, with the flap turned towards the temporal part. After removing the bone, the arachnoid and the soft meninges were carefully stripped under the microscope. The exposure range of the surgical approach was observed and the positional relationships of relevant nerves and blood vessels in the approach were clarified. Important structures were photographed and the relevant parameters were measured. Results The upper edge of the zygomatic arch root could be used to accurately locate the base of the middle cranial fossa. The average distances of the star point to the apex of mastoid, the star point to the superior ridge of external auditory canal, the anterior angle of parietomastoid suture to the superior ridge of external auditory canal, and the anterior angle of parietomastoid suture to the star point of the 10 adult skull specimens were 47.23 mm, 45.27 mm, 26.16 mm, and 23.08 mm, respectively. The subtemporal approach could fully expose the area from as high as the posterior clinoid process to as low as the petrous ridge and the arcuate protuberance after cutting through the cerebellar tentorium. The approach makes it possible to handle lesions on the ventral or lateral sides of the middle clivus, the cistern ambiens, the midbrain, midbrain, and pons. In addition, the approach can significantly expand the exposure area of the upper part of the tentorium cerebelli through cheekbone excision and expand the exposure range of the lower part of the tentorium cerebelli through rock bone grinding technology. The total length of the trochlear nerve, distance of the trochlear nerve to the tentorial edge of cerebellum, length of its shape in the tentorial mezzanine, and its lower part of entering into the tentorium cerebelli to the petrosal ridge were (16.95±4.74) mm, (1.27±0.73) mm, (5.72±1.37) mm, and (4.51±0.39) mm, respectively. The cerebellar tentorium could be safely opened through the posterior clinoid process or arcuate protrusion for localization. The oculomotor nerve could serve as an anatomical landmark to locate the posterior cerebral artery and superior cerebellar artery. Conclusion Through microanatomic investigation, the exposure range and intraoperative difficulties of the infratemporal transtentorial approach can be clarified, which facilitates clinicians to accurately and safely plan surgical methods and reduce surgical complications. [ABSTRACT FROM AUTHOR]

Meckel’s cave tumour, a rare benign tumour originating from the Schwann cells surrounding the trigeminal nerve within the Meckel’s cave region, can present with a variety of clinical manifestations. We report a case of a 44-year-old male patient who presented with symptoms of tear deficiency, including dryness, ocular discomfort, and blurred vision. Diagnostic evaluation revealed the presence of a Meckel’s cave tumour harming the trigeminal nerve, leading to alacrimia. This case highlights the association between Meckel’s cave tumour and tear deficiency disorders.

A 42-year-old male presented to the Department of Oral and Maxillofacial Surgery with the chief complaint of pain and stiffness in the right temporomandibular joint (TMJ). The patient’s height was 174 cm and his body weight was 65 kg. The patient’s occupation was heavy equipment operator. According to the patient, the pain had initiated a week prior to his first visit and was exacerbated during mastication. Evaluation of the range of motion revealed extensive crepitus along the right TMJ. The active and passive range of motion were measured at 45 mm and 42 mm, respectively, indicating adequate mouth-opening capacity. Occlusion was also favorable, and no other clinical symptoms were shown intraorally.

Background and Objectives: The adult superficial middle cerebral vein (SMCV) commonly drains into the middle cranial fossa. However, different embryonic types persist, in which the SMCV drains into the lateral sinus. The basal type of SMCV coursing on the middle fossa floor is a scarce variant. Materials and Methods: During a retrospective study of archived computed tomography angiography (CTA) and magnetic resonance angiography (MRA) files, three rare adult cases of the basal or sphenopetrosal type of SMCV were found and further documented. Results: In the first case, which was evaluated via CTA, the basal type of SMCV formed a sagittal loop. It continued on the middle fossa floor, over a dehiscent tegmen tympani, to drain into the lateral sinus. In the second case, documented via MRA, the basal type of SMCV's anterior loop was in the coronal plane and closely related to the internal carotid artery and the cavernous sinus. It continued with the basal segment over a dehiscent glenoid fossa of the temporomandibular joint (TMJ). In the third case, documented via CTA, the initial cerebral part of the SMCV had a large fenestration. The middle fossa floor coursed within a well-configured sulcus of the SMCV and received a tributary through the tympanic roof. Its terminal had a tentorial course. Conclusions: Beyond the fact that such rare variants of the SMCV can unexpectedly interfere with specific approaches via the middle fossa, dehiscences of the middle fossa floor beneath such variants can determine otic or TMJ symptoms. Possible loops and fenestrations of the SMCV should be considered and documented preoperatively. [ABSTRACT FROM AUTHOR]

The arcuate eminence (AE) is an anatomically consistent bony protrusion located on the upper surface of the petrous bone that has been previously studied as a reference for lateral skull base approaches. There is a paucity of information in the neurosurgical literature seeking to improve the safety of the extended middle cranial fossa (MCF) approach using detailed morphometric analysis of the AE. To evaluate the use of the AE as an anatomical landmark to help with early identification of the internal acoustic canal (IAC) in MCF approaches by means of a cadaveric study, using a new morphometric reference termed the "M-point." A total of 40 dry temporal bones and 2 formalin-preserved, latex-injected cadaveric heads were used. The M-point was established as a new anatomic reference by identifying the intersection of a line perpendicular to the alignment of the petrous ridge (PR), originating from the midpoint of the AE, with the PR itself. Subsequent anatomical measurements were performed to measure the distance between M-point and IAC. Additional distances, including PR length and the anteroposterior and lateral AE surfaces, were also measured. The mean distance between the M-point and the center of the IAC was 14.9 mm (SD ± 2.09), offering a safe drilling area during an MCF approach. This study provides novel information on identification of a new anatomic reference point known as the M-point that that can be used to improve early surgical identification of the IAC. [ABSTRACT FROM AUTHOR]

Background: The anterolateral triangle around the cavernous sinus is a surgical skull base triangle used as a neurosurgical landmark essential to skull-based surgeries. There are few reports of its measurements with little attention paid to anatomical variations. Methodology: A total of 15 adult human cadaveric skulls were dissected to expose the anterolateral triangle on both sides. The triangle was defined and measurements of the three borders were taken precisely and the area of each triangle was calculated using Heron's formula. Results: On an average, the length of the anteromedial border is 11.4 (+ 2.2 mm); the length of the posteromedial border is 8.7 (+ 2.6 mm); the length of the lateral border is 13.06 (+ 2.6 mm) and the area of the anterolateral triangle is 48.05 (+ 17.5 mm2). Conclusion: Concise understanding of anterolateral triangle is essential to skull-based surgeries; comprehending its anatomy helps with better surgical planning and provides insight into local pathology. [ABSTRACT FROM AUTHOR]

Different materials and techniques have been proposed for surgical repair of spontaneous middle cranial fossa (MCF) defects. However, conclusive evidence supporting their selection and impact on clinical outcomes is lacking. The study aims to conduct a systematic review and meta-analysis on materials and techniques employed to repair MCF defects and evaluate complications and rates of recurrent cerebrospinal fluid (CSF) leaks. A PRISMA-guided systematic review and meta-analysis were performed using MESH terms and specific keywords including studies published before May 2022. Primary outcomes included recurrence of CSF leak and complication rates by type of reconstructive material and technique utilized. Meta-analyses of proportions were performed using random effects and confidence intervals for individual proportions were calculated using the Clopper-Pearson method. Twenty-nine studies were included (n = 471 cases). Materials employed for repair were categorized according to defect size: 65% of defects were of unknown size, 24% were small (< 1 cm), and 11% were large (≥ 1 cm). Rigid reconstruction (RR) was significantly favored over soft reconstruction (SR) for larger defects (94% of cases, p < 0.05). Complications and recurrent CSF leak rates of SR and RR techniques were comparable for defects of all sizes (p > 0.05). Complication rates reported for these procedures are low regardless of technique and material. RR was universally preferred for larger defects and analysis of complication and recurrence rates did not reveal differences regardless of defect size. While RR was more frequently reported in smaller defects, SR was used by several centers, particularly for smaller MCF floor defects. [ABSTRACT FROM AUTHOR]

The pneumatization of the articular portion of the temporal bone is an anatomical variant that can modify the barrier between the articular space and the middle cranial fossa. Thus, this study aimed to identify the presence and degree of pneumatization, as well as the existence of pneumatic cell dehiscence towards the extradural or articular space determining whether it could lead to direct communication between the articular and extradural spaces. Hence, One-hundred skull computed tomography images were selected. The presence and extension of pneumatization were classified according to scores 0, 1, 2, and 3. Dehiscence towards extradural and articular spaces was recorded. In total, 200 TMJ from 100 patients were assessed and 40.5% of pneumatization cases were observed. The most prevalent score was 0 (restricted to the mastoid process), while the least prevalent score was 3 (extending beyond the crest of articular eminence). Dehiscence of the pneumatic cells towards the extradural space is more common than towards the articular space. One complete communication between the extradural and articular spaces was observed. Considering the results, it was concluded that to avoid neurological and ontological complications, awareness of the potential anatomical communications between articular and extradural spaces, particularly in patients with extensive pneumatisation, is necessary. [ABSTRACT FROM AUTHOR]

Abstract Background Juvenile nasopharyngeal angiofibroma (JNA) is an infrequent, highly vascular tumor that predominantly affects male adolescents. Although benign, it rarely may exhibit invasive growth, leading to significant morbidity, as in our case presentation. Diagnosis relies on clinical evaluation and imaging, with MR and CT playing vital roles in confirming the tumor's presence, determining its extent, and aiding in treatment planning. MR shows a mass with signal voids at T2-weighted images and intense contrast enhancement at T1-weighted images, while CT shows bone remodeling and destruction. A biopsy is usually avoided due to bleeding risks. Case presentation We present a case of a 16-year-old male with nasal obstruction and recurrent epistaxis from the right nostril, headache, and mucopurulent rhinorrhea. Furthermore, he had vision impairment in the right eye for one week associated with proptosis and periorbital swelling. MR and CT imaging evidenced the presence of JNA with extensive involvement in the nasal cavity, nasopharynx, pterygopalatine fossa, and infratemporal fossa. Moreover, the mass invaded the orbital apex and middle cranial fossa contacting the cavernous sinus and internal carotid artery. Preoperative embolization and complete surgical resection were performed. No complications occurred in the postoperative period and histopathological analysis confirmed the diagnosis of JNA. No recurrences were found at 12 months MR follow-up. Conclusions Early detection and accurate imaging evaluation are essential for the effective management of JNA. Regular post-treatment MR follow-ups are crucial to detect recurrences or assess fibrosis stability. MR and CT continue to be indispensable tools in the diagnosis and follow-up of JNA.

Background: The soft tissue dissection for the middle fossa approach requires adequate management of the neuro, vascular, and muscular structures in order to maximize exposure and diminish morbidities. Methods: An incision anterior to the tragus is performed, extending from the zygomatic process to the superior temporal line. The superior temporal artery is exposed, followed by a subfascial dissection of the frontalis nerve. The temporal muscle is dissected and released from the zygoma. All cranial landmarks are exposed for the 5 × 5 cm temporal fossa craniotomy. Conclusion: This novel approach provides a safe and adequate access to perform an extended middle fossa craniotomy. [ABSTRACT FROM AUTHOR]

Background: Juvenile nasopharyngeal angiofibroma (JNA) is an infrequent, highly vascular tumor that predominantly affects male adolescents. Although benign, it rarely may exhibit invasive growth, leading to significant morbidity, as in our case presentation. Diagnosis relies on clinical evaluation and imaging, with MR and CT playing vital roles in confirming the tumor's presence, determining its extent, and aiding in treatment planning. MR shows a mass with signal voids at T2-weighted images and intense contrast enhancement at T1-weighted images, while CT shows bone remodeling and destruction. A biopsy is usually avoided due to bleeding risks. Case presentation: We present a case of a 16-year-old male with nasal obstruction and recurrent epistaxis from the right nostril, headache, and mucopurulent rhinorrhea. Furthermore, he had vision impairment in the right eye for one week associated with proptosis and periorbital swelling. MR and CT imaging evidenced the presence of JNA with extensive involvement in the nasal cavity, nasopharynx, pterygopalatine fossa, and infratemporal fossa. Moreover, the mass invaded the orbital apex and middle cranial fossa contacting the cavernous sinus and internal carotid artery. Preoperative embolization and complete surgical resection were performed. No complications occurred in the postoperative period and histopathological analysis confirmed the diagnosis of JNA. No recurrences were found at 12 months MR follow-up. Conclusions: Early detection and accurate imaging evaluation are essential for the effective management of JNA. Regular post-treatment MR follow-ups are crucial to detect recurrences or assess fibrosis stability. MR and CT continue to be indispensable tools in the diagnosis and follow-up of JNA. [ABSTRACT FROM AUTHOR]

Simple Summary: The popularity that transorbital approaches (TOAs) gained in recent years has allowed their diffusion into skull base surgery. However, for their correct application, it is essential to know the potential and the limits of this group of transorbital routes, as well as the knowledge of anatomy from this relatively new surgical perspective. In this paper, the authors illustrate step-by-step the superior eyelid transorbital approach from a macroscopic and endoscopic perspective, highlighting the main anatomical relationships to understand the application of this surgical route for the treatment of skull base pathologies. Surgical cases are provided to illustrate indications for this approach. Background: The transorbital approaches (TOAs) have acquired growing notoriety, thanks to their ability to offer alternative corridors to the skull base. However, the limited access and the unfamiliarity with this surgical perspective make recognition of key landmarks difficult, especially for less experienced surgeons. The study wants to offer a detailed description of the anatomy to comprehend the potential and limitations of TOAs. Methods: Measurements of the orbit region and the surrounding areas were performed on two hundred high-resolution CT scans and thirty-nine dry skulls. Five specimens were dissected to illustrate the TOA, and one was used to perform the extradural clinoidectomy. Three clinical cases highlighted the surgical applications. Results: A step-by-step description of the key steps of the TOA was proposed and a comparison with the transcranial anterior clinoidectomy was discussed. The mean work distance was 6.1 ± 0.4 cm, and the lateral working angle increased 20 ± 5.4° after removing the lateral orbital rim. Conclusions: TOAs are indicated in selected cases when tumor involves the lateral portion of the cavernous sinus or the middle skull base, obtaining a direct decompression of the optic nerve and avoiding excessive manipulation of the neurovascular structures. Comprehension of surgical anatomy of the orbit and its surrounding structures is essential to safely perform these approaches. [ABSTRACT FROM AUTHOR]

Introduction: The foramen lacerum is located in the middle cranial fossa and transmits a number of nerves and blood vessels. Occlusion can result in the compression of the neurovascular bundle, and the foramen has been reported to be involved in the spread of tumours into the cranium. Aim: The aims of the present study was to describe the morphology of the foramen lacerum and to compare the anatomical parameters on the left and right sides of the skull. Also, the significance of the anatomical parameters in male versus female skulls and right side versus left side of the skull where studied. Materials and Methods: This cross-sectional study was conducted in May and June 2023 using 62 dry skulls (124 foramen lacerum) available in the Department of Anatomy at Gautam Buddha Chikitsa Mahavidyalay, a tertiary care teaching institute in Dehradun, Uttarakhand, India. The anatomical parameters, including the Anteroposterior (AP) and transverse diameters, were recorded using a calibrated digital Vernier caliper. The shape of the foramen was also observed. The mean and standard deviation of the recorded parameters were obtained. Results: Out of the 62 skulls, 41 were males and 21 were females, resulting in a male-to-female ratio of 1.8:1. The mean AP diameter on the Right Side (RT) and Left Side (LT) in males was 6.26 mm and 6.24 mm, respectively, while in females, the mean diameter was 4.97 mm (RT) and 5.4 mm (LT). The mean transverse diameter recorded in the present study was 6.14 mm (RT) and 6.2 mm (LT) in males, while in females, this measurement was 5.88 mm on both sides. The most common shape of the foramen lacerum observed in the study was bilaterally round, in both males and females. Conclusion: There are morphological differences in the AP diameter between male and female skulls, with males having a larger AP diameter on their right side and females having larger AP diameter on their right side. The overall size of the foramen lacerum was smaller in the present study, indicating a higher likelihood of neurovascular bundle compression with age. The recent advances in skull base surgery warrant further and larger studies on this neglected yet important foramen to gather more data on its morphometric variations in different geographical regions.

Adequate epidural procedures and anatomical knowledge are essential for the technical success of skull base surgery. We evaluated the usefulness of our three-dimensional (3D) model of the anterior and middle cranial fossa as a learning tool in improving knowledge of anatomy and surgical approaches, including skull base drilling and dura matter peeling techniques. Using a 3D printer, a bone model of the anterior and middle cranial fossa was created based on multi-detector row computed tomography data, incorporating artificial cranial nerves, blood vessels, and dura mater. The artificial dura mater was painted using different colors, with 2 pieces glued together to allow for the simulation of peeling the temporal dura propria from the lateral wall of the cavernous sinus. Two experts in skull base surgery and 1 trainee surgeon operated on this model and 12 expert skull base surgeons watched the operation video to evaluate this model subtlety on a scale of 1 to 5. A total of 15 neurosurgeons, 14 of whom were skull base surgery expert, evaluated, scoring 4 or higher on most of the items. The experience of dural dissection and 3D positioning of important structures, including cranial nerves and blood vessels, was similar to that in actual surgery. This model was designed to facilitate teaching anatomical knowledge and essential epidural procedure-related skills. It was shown to be useful for teaching essential elements of skull-base surgery. [ABSTRACT FROM AUTHOR]

Introduction The wide range of anatomical variability of the structures of the middle cranial fossa (MCF) and the lack of reliable surgical landmarks contribute to a high level of complications in the surgical treatment of vestibular schwannomas. We hypothesized that the cranial phenotype influences the shape of the MCF, the orientation of the pyramid of the temporal bone, and the relative topography of the internal acoustic canal (IAC). Methods The skull base structures were studied on 54 embalmed cadavers and 60 magnetic resonance images of the head and neck by photo modeling, dissection, and three-dimensional analysis techniques. By the value of the cranial index, all specimens were subdivided into dolichocephalic, mesocephalic, and brachycephalic groups for comparison of variables. Results The length of the superior border of the temporal pyramid (SB), the apex to squama distance, and the width of the MCF all peaked in the brachycephalic group. The value of the angle between the SB and the axis of the acoustic canal varied from 33 to 58 degrees; it peaked in the dolichocephalic group and showed its smaller value in the brachycephalic one. The pyramid to squama angle had reversed distribution and dominated in the brachycephalic group. Conclusion The cranial phenotype influences the shape of the MCF, temporal pyramid, and IAC. Presented in this article data help specialists operating on the vestibular schwannoma to localize the IAC based on the individual shape of a skull. [ABSTRACT FROM AUTHOR]

The superior dislocation of the condyle into the cranium occasionally requires invasive procedures due to the absence of a timely diagnosis. This review analyzed the available clinical data to provide information on treatment decisions. The reports were assessed using electronic medical databases from inception to 31 October 2022. A total of 116 cases from 104 studies were assessed; among the patients, 60% and 87.5% of the affected women and men required open reduction, respectively. The ratio of closed to open procedures within 7 days after injury was maintained; however, closed reduction decreased over time, and all cases required open reduction after 22 days. Eighty percent of the patients with a total intrusion of the condyle required open reduction, whereas the frequency for both procedures was comparable in the remaining patients. Open reduction was significantly more frequently performed for men (p = 0.026, odds ratio; 4.959, 95% confidence interval; 1.208–20.365) and less frequently performed in cases with partial intrusion (p = 0.011; odds ratio: 0.186; 95% confidence interval: 0.051–0.684); the frequency varied according to the time until treatment (p = 0.027, odds ratio; 1.124, 95% confidence interval; 1.013–1.246). Appropriate diagnostic imaging and prompt diagnosis are indispensable for minimally invasive treatment of this condition. [ABSTRACT FROM AUTHOR]

Abstract Background Facial nerve schwannomas account for about 0.8% of all petrous mass lesions. Schwannomas of the greater superficial petrosal nerve (GSPN) are a rare subtype with few case-reports up to date. Case presentations A retrospective analysis of clinical outcomes, radiographic findings and postoperative complication between June 2007 and December 2020 was performed. Four cases of GSPN schwannomas were reported. The presenting symptoms were facial nerve palsy and hearing loss. Imaging studies showed a subtemporal mass on the anterosuperior aspect of the petrous bone, in one case with extraordinary petrous bone and mastoid infiltration and destruction. Three cases were removed through a subtemporal extra- or intradural approach, one case via a combined pre- and retrosigmoid approach. Improvement of facial nerve palsy occurred in one case; new hearing loss was observed in another case. Xeropthalmia was a short-term temporary deficit in three cases. Short- to mid-term follow-up of the patients has not shown any tumor recurrence. Conclusions GSPN schwannomas are rare entities presenting with heterogenous symptoms. Our surgical findings emphasize safe resection. Complete remission is possible by GTR. Since the small data set limits the expressiveness of statements regarding standard of care and alternative therapy options, additional data is needed.

Background For endoscopic fenestration of middle cranial fossa arachnoid cysts (MCFACs), the decisions on the location and number of stomas are key issues. However, research on this particular topic has been limited. Thus, this study aimed to compare single- versus multiple-stoma endoscopic fenestration for treating Galassi type III MCFACs. Methods This retrospective study included 86 patients with Galassi type III MCFACs treated with endoscopic fenestration. Single-stoma fenestration to the basal cistern was performed in 37 cases, whereas multiple-stoma fenestration to the basal cistern and the carotid cistern was performed in 49 cases. Clinicoradiologic profiles and follow-up data were analyzed. Results The rate of symptom relief was 83.7% (72/86), and the rate of cyst shrinkage was 96.5% (83/86). Postoperative ipsilateral subdural effusion, which was significant (p = 0.042), and noninfectious fever were the two most common complications in the single- and multiple-stoma groups. No significant differences in intraoperative nerve injury, vascular injury, proportion of cases with cyst reduction, and symptom remission rate were observed between the two groups. The rates of cyst recurrence and secondary surgery in the single-stoma group were higher than those in the multiple-stoma group, although the difference was not significant. Conclusion Endoscopic fenestration is an effective and minimally invasive approach for treating Galassi type III MCFACs. Single- and multiple-stoma endoscopic fenestrations have the same curative effect. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the study is to evaluate MRI findings of middle fossa arachnoid cysts in children according to Galassi classification and determine the differences between types and to assess the morphological changes in cysts during follow-up imaging. Methods: MR images of 266 middle fossa arachnoid cysts of 255 pediatric patients were evaluated by two experienced radiologists retrospectively. MRI features including the sidedness of the cyst, Galassi type, parenchymal compression findings (cortical flattening and white matter compression), bone remodeling, and midline shift were evaluated on axial T2- and T1-weighted images. Follow-up MRI and available CSF flow MR imaging data were evaluated for change in cyst size and cisternal connections, respectively. Results: The most common type was type 1 according to Galassi classification. The accompanying bone remodeling and white matter compression had a higher incidence in Galassi type 2 and 3 groups than Galassi type 1. Mean age of patients with bone remodeling and white matter compression was significantly higher in patients with Galassi type 1. All patients with cyst enlargement were younger than 2 years of age, and all of them were Galassi type 1. Cisternal connection was demonstrated in 7 patients. Conclusion: While parenchymal compression and bone remodeling are expected findings in Galassi type 2 and 3 cysts, these features can also be seen in smaller Galassi type 1 cysts, regardless of size. Most of the middle fossa arachnoid cysts remain stable on follow-up imaging, and the increase in size is not an expected finding, especially in older children. [ABSTRACT FROM AUTHOR]

Background: Facial nerve schwannomas account for about 0.8% of all petrous mass lesions. Schwannomas of the greater superficial petrosal nerve (GSPN) are a rare subtype with few case-reports up to date. Case presentations: A retrospective analysis of clinical outcomes, radiographic findings and postoperative complication between June 2007 and December 2020 was performed. Four cases of GSPN schwannomas were reported. The presenting symptoms were facial nerve palsy and hearing loss. Imaging studies showed a subtemporal mass on the anterosuperior aspect of the petrous bone, in one case with extraordinary petrous bone and mastoid infiltration and destruction. Three cases were removed through a subtemporal extra- or intradural approach, one case via a combined pre- and retrosigmoid approach. Improvement of facial nerve palsy occurred in one case; new hearing loss was observed in another case. Xeropthalmia was a short-term temporary deficit in three cases. Short- to mid-term follow-up of the patients has not shown any tumor recurrence. Conclusions: GSPN schwannomas are rare entities presenting with heterogenous symptoms. Our surgical findings emphasize safe resection. Complete remission is possible by GTR. Since the small data set limits the expressiveness of statements regarding standard of care and alternative therapy options, additional data is needed. [ABSTRACT FROM AUTHOR]

The superficial middle cerebral vein (SMCV) commonly drains in the cavernous sinus. Its different drainage variants include preserved segments of the primitive tentorial sinus. In any of these variants, the terminal venous segment of SMCV passes on the base of the skull. The archived computed tomography angiograms of a 58-year-old female case were documented anatomically. On the left side was found the sinus of the lesser sphenoidal wing converging with the middle meningeal vein to form a venous channel located within the Sylvian fissure at 4 mm laterally to the cavernous sinus and trigeminal cavum. That venous channel was thus termed the 'laterocavernous vein'. It drained posteriorly within the superior petrosal sinus. This aberrant vein could interfere unpleasantly with pterional neurosurgical approaches for the Sylvian fissure, cavernous sinus or trigeminal ganglion. [ABSTRACT FROM AUTHOR]

Management of vestibular schwannoma (VS) is a complex process aimed at identifying a clinical indication for fractionated stereotactic radiotherapy (sRT) or microsurgical resection or wait and scan (WS). The aim of the review was to clarify which patient and tumor parameters may lead to different therapeutic choices, with a view to a personalized VS approach. A systematic review according to Preferred Reporting Items for Systematic Review and Meta-Analysis criteria was conducted between February and March 2022. The authors defined six parameters that seemed to influence decision-making in VS management: 1-incidental VS; 2-tumor size; 3-tumor regrowth after sRT; 4-subtotal resection; 5-patients' age; 6-symptoms. The initial search yielded 3532 articles, and finally, 812 articles were included. Through a qualitative synthesis of the included studies, management strategies were evaluated and discussed. An individualized proposal of procedures is preferable as compared to a single gold-standard approach in VS decision-making. The most significant factors that need to be considered when dealing with a VS diagnosis are age, tumor size and hearing preservation issues. [ABSTRACT FROM AUTHOR]

Background: Otitis media (OM) can uncommonly lead to intracranial complications. Epidural abscesses represent a large proportion of cases; however, literature regarding the optimal surgical management of otogenic epidural abscesses is sparse. Favorably located epidural abscesses may be amenable to drainage through a transmastoid approach because the tegmen mastoideum lies immediately inferior to the middle cranial fossa (MCF)., Case Description: We report 3 pediatric patients with OM complicated by epidural abscesses of the MCF. The ages ranged from 3 to 6 years old, with 2 females and 1 male. All 3 patients had acute mastoiditis with an abscess of the MCF ranging from 1.6 cm to 6.3 cm at the largest dimension. All patients underwent canal wall-up mastoidectomy with the evacuation of the MCF abscess through a small window, 0.7 × 0.7 cm or less, created in the tegmen mastoideum. All patients were successfully treated through this approach and had complete resolution of their infection on follow-up imaging. There were no postoperative temporal lobe encephaloceles., Conclusion: This is one of the few descriptions of the treatment of an otogenic epidural abscess of the MCF through a transmastoid approach. Collaboration with neurosurgery is vital because their familiarity with the intracranial space helped to guide the accurate direction of dissection. This highlights the importance of a multidisciplinary approach in the treatment of epidural intracranial abscess of the MCF through this approach. The risk of postoperative temporal lobe encephalocele was minimized due to the small tegmen defect size., Competing Interests: There are no conflicts of interest., (Copyright: © 2024 Surgical Neurology International.)

Background The petrous part of the temporal bone plays a crucial role in various cranial surgical approaches, particularly those involving the middle cranial fossa. Understanding the morphometry of this region is essential for minimizing intraoperative risks and enhancing surgical outcomes. This study aims to provide a detailed morphometric analysis of the petrous bone and its anatomical landmarks in an Indian population, addressing a gap in the literature. Methods The study was conducted in the Department of Anatomy and Forensic Medicine and Toxicology and involved 100 heads of unclaimed adult bodies that underwent post-mortem examination. Detailed morphometric measurements were taken using ImageJ software (National Institutes of Health, Bethesda, MD), focusing on landmarks critical for surgical approaches: the width of the trigeminal ganglion (TG), distances from the medial surface of the posterior root of the zygoma to TG (A), the lateral end of the petrous ridge to TG (B), the arcuate eminence to TG (C), the facial nerve hiatus to TG (D), the foramen spinosum to TG (E), the foramen ovale to TG (F), the superior margin of the internal acoustic meatus to the petrous ridge (G), the lateral end of the petrous ridge to the hiatus for the greater superficial petrosal nerve (GSPN) (H), the foramen spinosum to the foramen ovale (I), and the foramen spinosum to the lateral wall of the middle cranial fossa (J). Data were statistically analyzed using paired sample t-tests and Wilcoxon rank-sum tests. Results Significant differences were observed between the left and right sides for several measurements. The width of the TG averaged 13.57 ± 1.53 mm on the left and 14.20 ± 2.09 mm on the right (p = 0.029). Distances from the medial surface of the posterior root of the zygoma to TG (A) were 33.30 ± 6.26 mm (left) and 33.40 ± 5.52 mm (right) (p = 0.001). The lateral end of the petrous ridge to TG (B) measured 37.90 ± 5.72 mm (left) and 40.30 ± 3.35 mm (right) (p = 0.000). Other significant differences included distances from the arcuate eminence to TG (C), which were 28.50 ± 4.20 mm on the left and 29.60 ± 4.31 mm on the right (p = 0.001); the hiatus for the GSPN to TG (D), which were 11.00 ± 1.00 mm on the left and 10.70 ± 0.81 mm on the right (p = 0.003); and the foramen spinosum to TG (E), which were 12.60 ± 2.24 mm on the left and 11.60 ± 1.92 mm on the right (p = 0.001). Conclusion In summary, this study presents an in-depth morphometric analysis of important landmarks in the petrous bone, revealing notable differences between the left and right sides. These results emphasize the crucial variability that should be considered when planning surgeries involving the middle and posterior cranial fossa., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Atal Bihari Vajpayee Institute of Medical Sciences and Dr. Ram Manohar Lohia Hospital, New Delhi, India issued approval 270 (43/2018) IEC/PGIMER/RMLH/4029/18. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Rai et al.)

Endovascular treatment for isolated dural arteriovenous fistula (DAVF) in the middle cranial fossa (MCF) with pure cortical venous drainage poses challenges, including the absence of a safe access route for transvenous embolization (TVE) and the risk of ischemia to neuro feeding vessels and dangerous anastomosis at the sphenoid wing. Therefore, surgical treatment involving direct blockage of venous reflux via craniotomy is typically preferred. We describe the case of a 63-year-old woman presented with generalized seizures and was diagnosed with a Borden III left MCF-DAVF. Initial TVE was unsuccessful due to an occluded inferior petrosal sinus and a lack of connection between the cavernous sinus and the shunt point. After reducing the shunt flow with transarterial embolization, retrograde TVE through cortical drainage enabled successful treatment for the DAVF. We used a triple coaxial system (4-French guiding sheath, 3.2-French intermediate distal access catheter, and 1.5-French microcatheter) to retrogradely navigate a microcathter from the right jugular vein through the superior sagittal sinus, the vein of Trolard, and into the superficial middle cerebral vein, ultimately achieving shunt occlusion using several coils. This case demonstrates that TVE for MCF-DAVFs with pure cortical venous drainage is feasible when a safe anatomical route is established using appropriate strategies and instruments and provides a safe and effective treatment option for similar cases., (© 2024 The Authors. Published by Elsevier Inc. on behalf of University of Washington.)

Objective: To investigate the accuracy in localization of the anterosuperior margin of TSSJ by using the intersection point between the squamosal and parietomastoid sutures (A point) and the intersection of the squamosal suture and supramastoid crest (B point) as bony landmarks. Materials and Methods: The A and B points were marked on the inner surface of a skull by using the transillumination technique. The anatomical relationship between the projected A point, B point, and groove of TSSJ was investigated in 60 dried Thai human skulls (120 sides). Results: Of the 120 sides, the projected A points were located exactly on the anterosuperior margin of the TSSJ in 38 (31.7%) instances and adjacent (above and below) the anterosuperior margin in 82 (68.3%) cases. Of the 118 sides with identifiable supramastoid crests, the projected B points were located precisely on the anterosuperior margin of TSSJ in 60 (50.8%) cases and above the anterosuperior margin of the TSSJ in 57 (48.3%) cases. Hence, the projected B point was a more reliable bony landmark for localizing the anterosuperior margin of the TSSJ when compared with the projected A point (p = 0.003, OR 2.2, and 95% CI =1.3-3.8). Conclusion: The B point is a more reliable temporal bone landmark for localization of the TSSJ than the A point. In temporal craniotomy, an initial burr hole at the B point is relatively safe and carries a very low risk of inadvertent venous sinus injury.

Solitary fibrous tumors (SFTs) exceptionally occur at the middle cranial fossa. A midline search from January 1997 up to June 2021 selected 16 articles for a total of 19 patients, where the tumor attachment was completely or largely (>75%) at the middle cranial fossa. The unique personal case concerns a 35 years old woman complaining of left hypoacusia and moderate left facial paresis. A high grade SFT of the left middle fossa was resected, with no recurrence 8 years after surgery and irradiation. The 20 patients of the review, including ours, are 11 men and 9 women with a median age of 47 years. The location was mainly intradural (47%) or extra-intradural (42%); the invasion of the petrous bone was evidenced in a half of the patients. Symptoms of involvement of the Vth, VIIth and VIIIth cranial nerve were more frequent (3/4 of the cases). Variable T2 signal, lobulated margins and inhomogeneous enhancement were the most frequent MRI features. Histologically most tumors (70%) were WHO grade III and 23% grade I. A gross total resection was possible in 55% of the cases. The recurrence rate is significant (23,5%). Older patient age (>50 years), large tumor size, incomplete resection and high WHO grade histology are significant prognostic factors for recurrence. However, the outcome is sometimes unpredictable. Thus, a follow-up by serial MRI studies is strongly advisable.

Objectives/Hypothesis: To review hearing preservation after microsurgical resection of sporadic vestibular schwannomas according to tumor size. Study Design: Retrospective cohort. Methods: Baseline, intraoperative, and postoperative patient and tumor characteristics were retrospectively collected for a cohort who underwent hearing preservation microsurgery. Serviceable hearing was defined by a pure tone average ≤50 dB and word recognition score ≥50%. Results: A total of 243 patients had serviceable hearing preoperatively. Fifty (21%) tumors were confined to the internal auditory canal, and the median tumor size was 16.2 mm (interquartile range [IQR] 11.3–23.2) for tumors with cerebellopontine angle extension. Serviceable hearing was maintained in 64% of patients with tumors confined to the internal auditory canal, 28% with cerebellopontine angle extension <15 mm, and 9% with cerebellopontine angle extension ≥15 mm. On multivariable analysis, the odds ratios of acquiring nonserviceable hearing postoperatively for tumors extending <15 mm and ≥15 mm into the cerebellopontine angle were 5.75 (95% confidence interval [CI] 2.13–15.53; P <.001) and 22.11 (95% CI 7.04–69.42; P <.001), respectively, compared with intracanalicular tumors. Conclusions: The strongest predictor of hearing preservation with microsurgery after multivariable adjustment is tumor size. Approximately 10% of patients with tumors ≥15 mm of cerebellopontine angle extension will retain serviceable hearing after microsurgery. Furthermore, hearing preservation techniques offer cochlear nerve preservation and cochlear patency allowing for possible future cochlear implantation. An attempt at hearing preservation, including avoiding surgical approaches that necessarily sacrifice hearing, is worthwhile even in larger tumors if serviceable hearing is present preoperatively. Level of Evidence: 4 Laryngoscope, 132:1657–1664, 2022 [ABSTRACT FROM AUTHOR]

Background: Extradural transcranial release of the meningo-orbital band occupying the lateral part of the superior orbital fissure is used to approach the orbital apex and middle cranial fossa. The authors tested the feasibility of the release of the meningo-orbital band via an endonasal transmaxillary approach.Materials and Methods: Five injected cadaveric heads were assessed for dimensions of superior orbital fissure by computerized tomography. An endonasal transsphenoid transpterygoid approach was done to the superior orbital fissure and annulus of Zinn medially, down to the maxillary nerve. The periorbita was dissected superolaterally to expose the greater wing of the sphenoid and the meningo-orbital band. The superior orbital fissure was decompressed inferiorly by drilling the greater wing of the sphenoid and the maxillary strut after transposition of the maxillary nerve. The meningoorbital band was cut at the junction of the lateral part of the superior orbital fissure and the periorbita exposing the frontotemporal dural junction. The edge of the lesser wing of the sphenoid was drilled toward the annulus of Zinn and the optic canal. The temporal lobe dura was separated from the periorbita and lateral cavernous dural wall at the meningo-orbital band and the ophthalmic nerve.Results: The superior orbital fissure had an oblique angle (mean: 39 ± 2.75 degrees) to the midsagittal plane, the length of its lateral part corresponding to the meningo-orbital band was (mean: 6.08 ± 2.58 mm) and the distance from its lateral end to midline was (mean 2.97 ± 0.11 cm). The meningo-orbital band was released in 10 cadaveric head sides with a distinct plane between the periorbita and the dura propria. Transmaxillary endoscopy provided less orbital retraction and better visualization of the lateral wall of the cavernous sinus.Conclusion: Endonasal transmaxillary release of the meningoorbital band is feasible, allowing exposure of the orbital apex and the middle cranial fossa. [ABSTRACT FROM AUTHOR]

Introduction: Primary IgG4-related disease (IgG4-RD) of the temporal bone is a rare condition. Unlike typical petrous apicitis or Gradenigo syndrome, our patient presented exclusively with unilateral cranial nerve VI palsy and symptoms of diplopia. Skull base imaging demonstrated a destructive bony lesion in the petrous apex. Imaging and systemic investigations were insufficient to support a diagnosis. The diagnosis was achieved histologically after acquiring the specimen by middle cranial fossa craniotomy and temporal bone biopsy. This case report is thought to be the first published description of a diagnosis of IgG4-RD proven with the middle cranial fossa approach. Case Report: We describe a 29-year-old female with primary IgG4-RD of the petrous apex of the temporal bone. This patient presented with a few-month history of left-sided headache and recent-onset diplopia due to paralysis of cranial nerve VI. Imaging demonstrated a petrous apex lesion, and comprehensive systemic investigations could not reach a diagnosis. A middle cranial fossa craniotomy and a biopsy of the temporal bone lesion were undertaken to establish the diagnosis. Histological confirmation of IgG4-RD was proven. Following treatment with corticosteroids, the patient experienced complete recovery and resolution of her symptoms. Conclusion: This study describes a case of primary IgG4-RD of the petrous apex of the temporal bone that presented with diplopia and was diagnosed by middle fossa craniotomy and temporal bone biopsy. To the best of our knowledge, this is the first case description where primary diagnosis was made based on middle cranial fossa craniotomy and temporal bone biopsy. [ABSTRACT FROM AUTHOR]