AB057. A rare case of anterior skull base metastasis secondary to follicular thyroid carcinoma presenting as proptosis: a systematic review and illustrative case.

BACKGROUND: Skull base metastasis from follicular thyroid carcinoma (FTC) is uncommon. A single study, encompassing 473 cases of thyroid carcinoma, revealed a mere 2.5% incidence of such metastasis. Much is unknown about FTC skull base metastasis, and a streamlined algorithm is yet to be created. METHODS: We present a case of a 63-year-old female, with a history of a non-toxic goiter, complaining of a chronic history of progressive L proptosis, associated with headache and vision loss. History and radiologic findings were incompatible, hence, a biopsy was performed, revealing FTC metastasis. With this experience, we performed a systematic review of available literature for FTC skull base metastasis to help guide management for future cases. Using PRISMA guidelines, a systematic search across PubMed, Google Scholar, and Cochrane Library using MeSH keywords "Skull base", "Metastasis", and "Follicular Thyroid Carcinoma", identified 18 records. Fifteen articles were assessed for eligibility, but only eight studies met the inclusion criteria for qualitative analysis, including demographics, pathological characteristics, surgical approaches, clinical outcomes, and follow-up data. RESULTS: Included studies showcased a consistent age range (43 to 69 years) among patients diagnosed with FTC, with variability in management for the primary malignancy. Metastatic presentation varied depending on tumor location, with symptoms including dysphagia, proptosis, epistaxis, facial dysesthesia, and visual impairment. Tumor size ranged from 3 cm × 3 cm × 2 cm to 6.8 cm × 3.9 cm × 5.3 cm, greatly influencing surgical management strategies, from punch biopsy to complete resection and reconstruction. Adjuvant therapies included combinations of intensity-modulated radiation therapy (IMRT) with immunotherapy, I-131 therapy, oral radioiodine ablation, and radiotherapy alone, with outcomes showing improvement in most cases. Follow-up duration varied from 12 to 60 months, reflecting a wide range of outcome results. CONCLUSIONS: FTC skull base metastasis remains to be an uncommon entity in neurosurgery. Its rarity creates a lack of established guidelines and treatment algorithms. A high index of suspicion as well as good history and physical examination skills are necessary to achieve an adequate diagnosis. Multi-disciplinary teams form the cornerstone of a patient-tailored approach to its management.

Oculomotor outcomes of cranial nerve palsy in patients with skull base tumors.

OBJECTIVES: Skull base tumors, can cause oculomotor dysfunction, presenting a management challenge given their proximity to cranial nerves. This study investigated the oculomotor outcomes in patients with skull base tumors presenting cranial nerve palsy due to tumor compression and aimed to identify associated factors. METHODS: This retrospective observational cohort study enrolled patients diagnosed with primary skull base tumors who exhibited cranial nerve palsy due to tumor compression, confirmed by magnetic resonance imaging treated at Asan Medical Center between January 2011 and December 2022. Patients were assessed for oculomotor function pre- and post-treatment, and categorized into recovery and non-recovery groups based on outcomes. Factors associated with oculomotor outcomes were also analyzed. RESULTS: Fifty-six patients were enrolled, with the majority (n = 37, 66.1%) demonstrating recovery in oculomotor function post-treatment. The duration from symptom onset to treatment initiation was short in the recovery group, suggesting that early treatment may contribute to improved oculomotor outcomes. The type of tumor was significantly associated with oculomotor outcomes, with patients with pituitary adenoma exhibiting better outcomes. In the recovery group, 19/37 (51.4%) patients underwent surgical resection alone. In contrast, in the non-recovery group, 17/19 (89.5%) patients received primary or adjuvant radiosurgery or radiation therapy. CONCLUSION: Approximately 70% of patients with skull base tumors experienced recovery in oculomotor function post-treatment. The duration before treatment and the type of tumor were significantly associated with the oculomotor outcome. These findings aid neuro-ophthalmologists in predicting oculomotor outcomes for patients with skull base tumors, guiding management strategies for oculomotor dysfunction.

Intracranial Phosphaturic Mesenchymal Tumors: A Systematic Literature Review of a Rare Entity.

BACKGROUND: Phosphaturic Mesenchymal Tumors (PMTs) are rare mesenchymal neoplasms known for producing Tumor-induced Osteomalacia (TIO). TIO is an uncommon paraneoplastic syndrome characterized by radiographic evidence of inadequate bone mineralization and analytical abnormalites. METHODS: We sought to present a case of TIO caused by skull base PMT with intracranial extension, manifesting with pain, progressive weakness, and multiple bone fractures. Furthermore, a systematic review was performed, following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. A search was conducted in PubMed database with title/abstract keywords "Phosphaturic mesenchymal tumor" and "Osteomalacia." Search results were reviewed looking for intracranial or skull base tumors. RESULTS: Our systematic review included 29 reported cases of intracranial PMT. In the reviewed cases there was a significative female predominance with 22 cases (75,86%). Osteomalacia was presented in 25 cases (86,20%). Bone fractures were present in 10 cases (34,48%). The most common site of involvement was the anterior cranial fossa in 14 cases (48,27%). Surgery was performed in 27 cases (93,10%) with previous tumor embolization in 4 cases (13,79%). Total recovery of the presenting symptoms in the first year was achieved in 21 cases (72,41%). Recurrence of the disease was described in 6 cases (25%). CONCLUSIONS: Skull base PMTs with intracranial extension are extremely rare tumors. Most patients are middle-aged adults with a PMT predominantly located in anterior cranial fossa. Surgery is the current treatment of choice with optimal outcome at 1-year follow-up, although recurrence could be present in almost 25% of the cases.

Surgical Strategy for Petroclival Meningioma-Related Trigeminal Neuralgia: The Role of Porus Trigeminus Opening.

OBJECTIVE: Petroclival meningiomas invade Meckel's cave through the porus trigeminus, leading to secondary trigeminal neuralgia. Microsurgery and stereotactic radiosurgery (SRS) are the typical treatment options. This study investigated symptom control, outcomes, and surgical strategies for PC meningioma-induced TN. METHODS: We retrospectively analyzed 28 TN patients with PC meningiomas who underwent microsurgical nerve decompression between January 2021 and February 2023. In all patients undergoing a transpetrosal approach, the porus trigeminus was opened to enable the removal of the entire tumor within Meckel's cave. Clinical outcomes were assessed using the Barrow Neurologic Institute (BNI) pain intensity scale. Risk factors for poor TN outcomes and poor facial numbness were analyzed. RESULTS: Among 28 patients, 21 (75%) underwent the transpetrosal approach, 5 (17.9%) underwent the retrosigmoid approach, and 2 (7.1%) underwent the Dolenc approach. Following microsurgery, 23 patients (82.1%) experienced TN relief without further medication (BNI I or II). TN recurrence occurred in 2 patients (7.1%), and 3 patients (10.7%) did not achieve TN relief. Cavernous sinus invasion was significantly correlated with poor TN outcomes (P = 0.047). A history of previous SRS (P = 0.011) and upper clivus type tumor (P = 0.018) were significantly associated with poor facial numbness. CONCLUSIONS: Microsurgical nerve decompression is effective in improving BNI scores in patients with TN associated with PC meningiomas. Considering the results of our study, the opening of the porus trigeminus can be considered as a suggested procedure in the treatment of PC meningiomas, especially in cases accompanied by TN.

Complications of the Superior Eyelid Endoscopic Transorbital Approach to the Skull Base: Preliminary Experience With Specific Focus on Orbital Outcome.

BACKGROUND: The endoscopic superior eyelid approach is a relatively novel mini-invasive technique that is currently investigating for skull base cancers. However, questions remain regarding specific approach-related complications when treating different skull base tumors. This study aims to analyze any surgical complications that occurred in our preliminary consecutive experience, with specific focus on orbital outcome. METHODS: A retrospective and consecutive cohort of patients treated via a superior eyelid endoscopic transorbital approach at the Division of Neurosurgery of the Hospital Clinic in Barcelona was analyzed. Patients features were described in detail. Complications were divided into 2 groups to analyze separately the approach-related complications, and those resulting from tumor removal. The ocular complications were subdivided into early ocular status (<3 weeks), late ocular status (3-8 weeks), and persistent ocular complications. The "Park questionnaire" was used to determine patient's satisfaction related to the transorbital approach. RESULTS: A total of 20 patients (5 spheno-orbital meningiomas, 1 intradiploic Meningioma, 2 intraconal lesions, 1 temporal pole lesion, 2 trigeminal schwannoma, 3 cavernous sinus lesions, and 6 petroclival lesions) were included in the period 2017-2022. Regarding early ocular status, upper eyelid edema was detected in all cases (100%) associated with diplopia in the lateral gaze in 30% of cases, and periorbital edema in 15% of cases. These aspects tend to resolve at late ocular follow-up (3-8 weeks) in most cases. Regarding persistent ocular complications, in one case of intraconal lesion, a limitation of eye abduction was detected (5%). In another patient with intraconal lesion, an ocular neuropathic pain was reported (5%). In 2 cases of petroclival menigioma, who were also treated with a ventriculo-peritoneal shunt, slight enophthalmus was observed as a persistent complication (10%). According to the Park questionnaire, no cosmetic complaints, no head pain, no palpable cranial irregularities, and no limited mouth opening were reported, and an average of 89% of general satisfaction was encountered. CONCLUSIONS: The superior eyelid endoscopic transorbital approach is a safe and satisfactory technique for a diversity of skull base tumors. At late follow-up, upper eyelid edema, diplopia, and periorbital edema tend to resolve. Persistent ocular complications are more frequent after treating intraconal lesions. Enophthalmus may occur in patients with associated ventriculo-peritoneal shunt. According to patient's satisfaction, fairly acceptable results are attained.

Analysis of visual impairment score in a series of 48 tuberculum sellae meningiomas operated on via the endoscopic endonasal approach.

OBJECTIVE: Tuberculum sellae meningioma (TSM) represents a complex skull base tumor. The primary goals of surgical treatment are represented by maximal safe resection and visual recovery; therefore, appropriate patient selection is critical to optimize results. In the last 2 decades, the endoscopic endonasal approach (EEA) has appeared as a successful and viable strategy for the management of these tumors. The authors identified preoperative factors associated with extent of resection and visual outcome after EEA for TSM. METHODS: In this retrospective cohort study, the authors analyzed patients who underwent extended endoscopic endonasal surgery for TSM between January 2005 and April 2022 at the Division of Neurosurgery, Università degli Studi di Napoli Federico II, Naples, Italy. Tumor size, vessel encasement, and optic canal involvement were classified according to University of California, San Francisco, score. Visual acuity and visual fields were analyzed according to the visual impairment score (VIS), defined as a four-level classification: grade 1 (VIS 0-25), grade 2 (VIS 26-50), grade 3 (VIS 51-75), and grade 4 (VIS 76-100). Ophthalmological functions were tested preoperatively and during the early postoperative period (within 6 months after surgery) and late postoperative period. RESULTS: A total of 48 patients were enrolled. Forty-one (85.4%) patients experienced blurred vision or visual field defect as a presenting sign. Gross-total resection was achieved in 40 (83.3%), near-total resection in 2 (4.2%), and subtotal resection in 6 (12.5%). Visual defect improved in 82.9% (34/41) of cases, 12.2% (5/41) had no significant changes, and 2.4% (1/41) had worsened visual defect. The mean change in VIS was 42% (95% CI 58.77-31.23). Visual outcome was poorer when preoperative VIS (VIS-pre) was greater than 25 (p = 0.02). Six postoperative CSF leaks occurred (12.5%), and 1 patient (2.1%) required revision surgery. CONCLUSIONS: The EEA is a safe and effective approach for TSM removal, with the advantage of preserving optic apparatus vascularization, and can promote gross-total resection and visual improvement. The authors have defined four categories based on VIS that relate to postoperative outcome: the lower the VIS-pre, the higher the rate of postoperative VIS improvement. This finding may be useful for predicting a patient's visual outcome at the preoperative stage.

[Anterior transpetrosal (Kawase) approach for petroclival meningioma with trigeminal neuralgia: case report and literature review]. / Perednii transpiramidnyi dostup (dostup Kawase) pri petroklival'noi meningiome s trigeminal'noi nevralgiei: opisanie klinicheskogo nablyudeniya i obzor literatury.

The authors present a patient with petroclival meningioma complicated by trigeminal neuralgia. Resection of tumor via anterior transpetrosal approach with microvascular decompression of the trigeminal nerve was performed. A 48-year-old female patient presented with left-sided (V1-V2) trigeminal neuralgia. Magnetic resonance imaging revealed a tumor 33´27´25 mm with a base adjacent to the top of petrous part of the left temporal bone, tentorium cerebelli and clivus. Intraoperative examination revealed true petroclival meningioma extending to trigeminal notch of petrous part of temporal bone. There was additional compression of trigeminal nerve by caudal branch of superior cerebellar artery. Total resection of tumor was followed by disappearance of vascular compression of trigeminal nerve and regression of trigeminal neuralgia. Anterior transpetrosal approach provides early devascularization and resection of true petroclival meningioma, as well as wide imaging of anterolateral surface of the brainstem, identification of neurovascular conflict and vascular decompression.

Does tumoral cavernous carotid stenosis predict an increased risk of future stroke in skull base meningiomas?

OBJECTIVE: Skull base meningiomas (SBMs) involving the cavernous sinus encase the internal carotid artery (ICA) and may lead to stenosis of the vessel. Although ischemic stroke has been reported in the literature, there are to the authors' knowledge no reported studies quantifying the risk of stroke in these patients. The authors aimed to determine the frequency of arterial stenosis in patients with SBMs that encase the cavernous ICA and to estimate the risk of ischemic stroke in these patients. METHODS: Records of all patients with SBM encasing the ICA whose cases were managed by the skull base multidisciplinary team at Salford Royal Hospital between 2011 and 2017 were reviewed using a two-stage approach: 1) clinical and radiological strokes were identified from electronic patient records, and 2) cases were reviewed to examine the correlation between ICA stenosis associated with SBM encasement and anatomically related stroke. Strokes that were caused by another pathology or did not occur in the perfusion territory were excluded. RESULTS: In the review of patient records the authors identified 118 patients with SBMs encasing the ICA. Of these, 62 SBMs caused stenosis. The median age at diagnosis was 70 (IQR 24) years, and 70% of the patients were female. The median follow-up was 97 (IQR 101) months. A total of 13 strokes were identified in these patients; however, only 1 case of stroke was associated with SBM encasement, which occurred in the perfusion territory of a patient without stenosis. Risk of acute stroke during the follow-up period for the entire cohort was 0.85%. CONCLUSIONS: Acute stroke in patients with ICA encasement by SBMs is rare despite the propensity of these tumors to stenose the ICA. Patients with ICA stenosis secondary to their SBM did not have a higher incidence of stroke than those with ICA encasement without stenosis. The results of this study demonstrate that prophylactic intervention to prevent stroke is not necessary in ICA stenosis secondary to SBM.

Differences in Hearing, Balance, and Quality-of-Life Outcomes in Petroclival Versus Nonpetroclival Posterior Fossa Meningiomas.

OBJECTIVE: To compare hearing, tinnitus, balance, and quality-of-life treatment outcomes of petroclival meningioma and nonpetroclival cerebellopontine angle meningioma cohorts. STUDY DESIGN: A retrospective cohort study of 60 patients with posterior fossa meningiomas, 25 petroclival and 35 nonpetroclival, who were treated at a single tertiary care center between 2000 and 2020. INTERVENTION: A survey battery that included the Hearing Effort of the Tumor Ear, Speech and Spatial Qualities of Hearing, Tinnitus Functional Index, Dizziness Handicap Inventory (DHI), and Short Form Health Survey. Petroclival and nonpetroclival cohorts were matched for tumor size and demographic features. MAIN OUTCOME MEASURES: Differences between groups in hearing, balance outcomes, and quality of life and patient factors that influence posttreatment quality of life. RESULTS: Petroclival meningioma patients reported poorer audiovestibular outcomes with a higher rate of deafness in the tumor ear (36.0% versus 8.6%, p = 0.032) and lower functional hearing by the Hearing Effort of the Tumor Ear, Speech and Spatial Qualities of Hearing (76.6 [6.1] versus 82.0 [4.4], p < 0.001). Current dizziness rate was higher (48.0% versus 23.5%, p = 0.05), with more severe dizziness by DHI (18.4 [4.8] versus 5.7 [2.2], p < 0.001). Both cohorts had similar high quality of life and low tinnitus severity indices. Quality-of-life Short Form Health Survey predictors were tumor size ( p = 0.012) and DHI ( p = 0.005) in multivariable analysis. CONCLUSIONS: Hearing and dizziness treatment outcomes of petroclival meningioma are poorer relative to other posterior fossa meningiomas. Despite audiovestibular outcome distinctions, the overall posttreatment quality of life was high for both petroclival and nonpetroclival meningioma.

Endoscopic transorbital approach for skull base lesions: a report of 16 clinical cases.

Due to the deep location, complex anatomy, and adjacent vital neurovascular structures, skull base surgery is challenging and requires specific approaches. The emerging endoscopic transorbital approach (eTOA) technique provides a new approach to the orbital content, spheno-orbital region, lateral cavernous sinus, and Meckel's cave. In this study, the clinical utility and effectiveness of the eTOA are reported. Sixteen cases who underwent the eTOA were included in the current study. The patients were divided into 3 groups according to tumor location: Group A (intraorbital, 6 cases), group B (spheno-orbital, 7 cases), and group C (cavernous sinus, and Meckel's cave, 3 cases). The clinical data and surgical results were analyzed. Eight meningiomas, 2 hemangiomas, 1 low-grade glioma, 1 instance of inflammatory hyperplasia tissue, 1 Langerhans cell histiocytosis, 1 epidermoid cyst, 1 trigeminal schwannoma, and 1 bone fibrosis hyperplasia were observed. The mean tumor diameter was 2.4 cm. A single case in Group A and Group C underwent biopsy (12.5%), and 1 case of fibrous dysplasia in Group B underwent sufficient orbit decompression (6.25%). The remaining 13 cases underwent gross total tumor resection (81.25%). No cerebral-spinal fluid leak or infection occurred. And no cosmetic problems or significant complications were observed during the follow-up. As a minimally invasive technique, the eTOA has unique advantages for carefully selected skull base lesions because of its direct route, short working distance, and distinct attack angle.

MRI Diagnosis of Clival Cancer and Sixth Nerve Palsy.

BACKGROUND: Imaging diagnosis of clival cancer may be difficult, in part because of normal variation in marrow signal with aging. Identifying whether clival cancer has damaged the sixth cranial nerve is a further challenge because minimal clival abnormalities could impinge on the nerve, which travels very close to the clivus. METHODS: Two neuroradiologists, who were unaware of previous imaging and clinical diagnoses, reviewed MRI studies of 25 patients with cancer but no clival involvement and no sixth nerve palsy, 24 patients with clival cancer but without sixth nerve palsy, and 31 patients with clival cancer and sixth nerve palsy. The radiologists were tasked with determining whether there was clival cancer, whether there was a sixth nerve palsy and its laterality, and with indicating the pulse sequences used to make those determinations. RESULTS: Both neuroradiologists correctly identified all 25 cases with a normal clivus. In about half of those cases, they depended on finding a homogeneously bright marrow signal; in the remaining cases, they excluded cancer by determining that the clivus was not expanded and that there were no focal signal abnormalities. Both neuroradiologists correctly identified clival cancer in 54 (98%) of the 55 cases with and without sixth nerve palsy. In doing so, they relied mostly on clival expansion but also on focal signal abnormalities. Both neuroradiologists were at least 80% correct in identifying a sixth nerve palsy, but they often incorrectly identified a palsy in patients who did not have one. When there was a one-sided signal abnormality or the clivus was expanded in one direction, both neuroradiologists were accurate in identifying the side of the sixth nerve palsy. CONCLUSION: Current MRI pulse sequences allow accurate differentiation of a normal from a cancerous clivus. When the marrow signal is not homogeneously bright in adults, cancer can be diagnosed on the basis of clival expansion or focal signal abnormalities. MRI is less accurate in predicting the presence of a sixth nerve palsy. However, the side of a unilateral palsy can be predicted when the clivus is clearly expanded in one direction or there is a focal signal abnormality on one side.

Pediatric Endoscopic Endonasal Skull Base Surgery: A Retrospective Review Over 11 Years.

OBJECTIVE: To show the safety and efficacy of the endoscopic endonasal approach (EEA) for skull base surgery in pediatric patients through descriptive analysis of cases over an 11-year period. METHODS: The study comprised 94 patients undergoing EEA for skull base surgery, between January 2007 and June 2018, at 2 tertiary pediatric hospitals. Descriptive statistics are presented regarding the presentation, intraoperative details, and complications. RESULTS: Over the study period, 130 surgeries were performed in 94 patients: 94 primary surgeries and 36 reoperations. The mean patient age was 13.8 years and 48.9% of patients were female. Presenting signs/symptoms included endocrinopathies (56.4%), vision abnormalities (37.2%), and cranial nerve deficits (20.2%). EEA alone was used in 95.7% of primary surgeries and 91.7% of reoperations. Diseases treated included craniopharyngioma (18.1%), pituitary adenoma (17.0%), Rathke cleft cyst (13.8%), chordoma (9.6%), osteosarcoma (5.3%), juvenile nasopharyngeal angiofibroma (4.3%), skull base fracture (4.3%), and encephalocele (3.2%). A lumbar drain was used in 20.2% of primary surgeries and 25% of reoperations. A nasoseptal flap was used in 36.2% of primary surgeries and 25% of reoperations. Postoperative complications included cerebrospinal fluid leak (12.8%), sinusitis (7.4%), bacterial meningitis (3.2%), and carotid artery injury in 1 reoperation. CONCLUSIONS: EEA for anterior cranial base disease is safe and efficacious in pediatric patients and can be used to treat many of the rare and heterogenous diseases that arise in this anatomic location. Management strategies and rates of sinonasal and intracranial complications including cerebrospinal fluid leak rate are similar to those reported in adult cohorts.

[Clinical observation of microsurgical removal of the hemilateral tuberculum sellae meningiomas through contralateral eyebrow arch approach].

The current study aimed to investigate the clinical feasibility of microscopic resection of hemilateral tuberculum sellae meningiomas (TSM) via the contralateral eye brow arch approach. The clinical data of 34 patients with TSM who underwent microsurgery from January 2016 to June 2021 in the Neurosurgery Department of Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine and the First Affiliated Hospital of Henan University were collected and reviewed. The postoperative visual acuity improvement rate was 88.5% (23/26), and the total tumor resection rate was 88.2% (30/34); the postoperative visual acuity improvement in patients with total tumor resection was better than that of patients with partial resection [90.9% (20/22) vs 3/4]. Meanwhile, the postoperative visual acuity improvement in patients with the superior optic nerve and laterl-superior optic nerve was better than that of patients with the lateral optic nerve type (12/14, 8/8 vs 3/4). Supraorbital skin numbness occurred in 3 cases after operation, and the symptoms disappeared during follow-up; 2 cases had mild disturbance of hormone level, and urine output of 2 cases increased after operation, which returned to normal level after symptomatic treatment; 1 case had subcutaneous effusion which was absorbed after treatment. There were no complications such as olfactory disturbance and intracranial infection. During follow-up for 3-60 (33±6) months, recurrence occurred in 2 cases and reoperation was performed. For the hemilateral TSM, according to the preoperative evaluation of the origin of the TSM and the side with visual impairment, the contralateral eyebrow approach is selected to fully expose the tumor base below the optic nerve. It is beneficial to fully resect the tumor under direct vision, and the symptoms of postoperative visual impairment are significantly improved, indicating that the current surgical method can be used in the clinical setting.

Advances in Pituitary Surgery.

Pituitary surgery has advanced considerably in recent years with the exploration and development of various endoscopic approaches and techniques. Different endoscopic skull base approaches are being applied to access sellar tumors in different locations. Moreover, extracapsular dissection and cavernous sinus exploration have enabled gross total resection of sellar tumors where it could not have been achieved in the past. Techniques for skull base reconstruction have also progressed, allowing surgeons to remove larger and more complicated tumors than before. This review article discusses different endoscopic skull base approaches, surgical techniques for removing pituitary adenomas, and reconstruction methods for repairing postoperative low-flow and high-flow cerebrospinal fluid leakage.

Does Endoscopic Transnasal Optic Nerve Decompression Followed by Radiosurgery Improve Outcomes in the Treatment of Parasellar Meningiomas?

INTRODUCTION: The clinical management of parasellar meningiomas (PM) is challenging due to their intimate association with critical neurovascular structures. Consensus regarding the recommended treatment protocol is lacking. This study will evaluate patients' visual outcomes following endoscopic transnasal optic nerve decompression (ETOND) and will investigate the possibility of reducing the rate of complications associated with stereotactic radiosurgery (SRS). METHODS: Retrospective analysis was conducted on all patients who underwent ETOND for PM between 2013 and 2020. The study comprised 12 patients (7 women and 5 men aged 36-75 years; mean, 55.2 years; median, 57.6 years) in which 14 optic nerve decompression procedures were carried out. Patients were followed up for 6 to 86 months (mean, 29.3 months; median, 25 months). There were five cases of spheno-orbital meningioma, four cases of cavernous sinus meningioma, and one case each of petro-clival meningioma, optic nerve sheath meningioma, and planum sphenoidale/tuberculum sellae meningioma. Visual outcome was evaluated and any postoperative complications noted. RESULTS: Improvements in visual acuity were noted in 10 of 14 eyes (71.4%) 3 to 6 months postoperation. Visual acuity remained stable in the remaining four eyes. No deterioration of visual acuity was noted during the follow-up period. In total, 9 of the 12 patients underwent SRS. No tumor growth was determined, while reduction in tumor volume was noted in five patients following SRS. No complications associated with SRS or the surgical procedure were noted. CONCLUSIONS: ETOND appears to be a promising technique for increasing rates of improved visual function, while reducing the risk of post SRS-related complications. In combination with subsequent SRS, it is an ideal treatment modality in the management of parasellar meningiomas. Confirmation of our findings would require a larger, prospective multicenter study.

Microsurgery versus stereotactic radiosurgery for small petroclival meningiomas presenting with intractable trigeminal neuropathy: A historical cohort study.

Background: Data on the outcomes of microsurgical resection (SR) and stereotactic gamma knife radiosurgery (GKRS) in patients with trigeminal neuralgia associated with small petrous apex meningiomas are scarce. Objective: We conducted this study to evaluate the pain relief, tumor control, and procedure costs following SR and GKRS for small petroclival meningiomas (less than 3 cm in maximal diameter) using real-world data from our center in Egypt. Material and Methods: We conducted a retrospective cohort study of 47 patients with small petrous apex meningiomas presenting with intractable trigeminal nerve pain (SR: n = 22 and GKRS: n = 25). Data regarding pain relief on Barrow Neurological Institute (BNI), procedure cost, and tumor control were retrieved and analyzed using appropriate statistical tests. Results: Patients who underwent SR had lower median BNI pain intensity scores compared to those patients who underwent GKRS, and a significantly higher proportion of patients in the SR group had good BNI scores compared to those in GKRS group (P < 0.05); however, the total costs of SR were significantly less than GKRS (30,519$ vs. 92,372$, respectively). Conclusion: Both SR and GKRS provide pain relief and tumor control in patients with trigeminal neuralgia associated with petrous apex meningioma. However, in the present study, SR achieved better pain control and was more affordable than GKRS.

[Surgical Strategy of Benign Skull Base Tumors Based on Membrane Structure].

Meningiomas, schwannomas, and pituitary adenomas are typically benign tumors of intracranial origin, but all of these tumors have a border with the surrounding tissue. The basic structure is a clear "boundary" between the tumor and its surroundings, with a thin membrane layer to create that separation. This layer of membrane is the boundary between the tumor and its surroundings and provides a space for the tumor to grow its cells, and can be viewed as the so-called "tumor capsule. Based on the relationship between the membrane structure of the tumor capsule and the surrounding normal tissues, we perform surgery to reduce surgical complications. We histologically evaluated three types of tumor capsules(meningioma, schwannoma, and pituitary adenoma)and compared the membrane structure of each tumor with that seen in clinical surgery.