The lateral retrocanthal transorbital endoscopic approach to the middle fossa: cadaveric stepwise approach and review of quantitative cadaveric data.

OBJECTIVE: The lateral retrocanthal transorbital endoscopic approach (LRCTEA) facilitates trajectory to the middle fossa, preserving the lateral canthal tendon and thus avoiding postoperative complications such as eyelid malposition. Here, the authors sought to define the surgical anatomy and technique of LRCTEA using a stepwise approach in cadaveric heads and offer an in-depth examination of existing quantitative data from cadaveric studies. METHODS: The authors performed LRCTEA to the middle cranial fossa under neuronavigation in 7 cadaveric head specimens that underwent high-resolution (1-mm) CT scans preceding the dissections. RESULTS: The LRCTEA provided access to middle fossa regions including the cavernous sinus, Meckel's cave, and medial temporal lobe. The trajectories and endpoints of the approach were confirmed using electromagnetic neuronavigation. A stepwise approach was delineated and recorded. CONCLUSIONS: The authors' cadaveric study delineates the surgical anatomy and technique of the LRCTEA, providing a stepwise approach for its implementation. As these approaches continue to evolve, their development and refinement will play an important role in expanding the surgical options available to neurosurgeons, ultimately improving outcomes for patients with complex skull base pathologies. The LRCTEA presents a promising advancement in skull base surgery, particularly for accessing challenging middle fossa regions. However, surgeons must remain vigilant to potential complications, including transient diplopia, orbital hematoma, or damage to the optic apparatus.

Defining the limits and indications of the Draf III endoscopic approach to the lateral frontal sinus and maximizing visualization and maneuverability: a cadaveric and radiological study.

PURPOSE: The DRAF III procedure has been used for access to the lateralmost part of the frontal sinus. We sought to identify anatomical and radiological measurements as well as modifications that predict the lateral limits of visualization and surgical access after this procedure. METHODS: Seven cadaver heads were imaged with computed tomography scan. The distance from midline to the medial orbital wall (MOWD), midline to the lateral end of the frontal sinus (MLD), the sum of MLDs (SMLD), interorbital distance (IOD) and the shortest anteroposterior distance of the frontal recess (APD) were utilized. The ratios MLD/MOWD, and SMLD/IOD were calculated. The same distances were measured on 41 CT scans. Orbital transposition (OT) and partial resection of the piriform aperture (PAR) were performed; the visualization and reach were assessed. The angle of insertion was measured before and after the modifications. RESULTS: Only the ratio MLD/MOWD was consistently predictive of access to the lateral, superior and posterior wall of the frontal sinus. Following the modifications, a visualization of 100% laterally was achieved with the 30- and 45 degree endoscopes and every lateral recess could be reached with the 70 degree suction. A mean increase of the angle of insertion of 25.3 and 59.6% was recorded after OT and PAR, respectively. CONCLUSIONS: IOD rather than APD defines the limits of the Draf III approach to the lateral frontal sinus and MLD/MOWD ratio can serve as a useful preoperative tool. Along to the already described OT, PAR increases visualization and reach of the lateral frontal sinus.

Machine Learning in Meningioma MRI: Past to Present. A Narrative Review.

Meningioma is one of the most frequent primary central nervous system tumors. While magnetic resonance imaging (MRI), is the standard radiologic technique for provisional diagnosis and surveillance of meningioma, it nevertheless lacks the prima facie capacity in determining meningioma biological aggressiveness, growth, and recurrence potential. An increasing body of evidence highlights the potential of machine learning and radiomics in improving the consistency and productivity and in providing novel diagnostic, treatment, and prognostic modalities in neuroncology imaging. The aim of the present article is to review the evolution and progress of approaches utilizing machine learning in meningioma MRI-based sementation, diagnosis, grading, and prognosis. We provide a historical perspective on original research on meningioma spanning over two decades and highlight recent studies indicating the feasibility of pertinent approaches, including deep learning in addressing several clinically challenging aspects. We indicate the limitations of previous research designs and resources and propose future directions by highlighting areas of research that remain largely unexplored. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY STAGE: 2.

Effects of brain radiotherapy on cognitive performance in adult low-grade glioma patients: A systematic review.

Grade II gliomas are slow growing tumours that usually affect younger patients. The mainstream treatment modality at present is surgical. The role of radiation therapy in the management of grade II gliomas has been the subject of considerable debate. Radiation therapy has a proven potential to prolong progression free and overall survival in high-risk patients, but may also produce long-term cognitive deficits. Since grade II glioma patients are expected to live several years, retention of cognitive capacity and quality of life is an equally important endpoint as prolonging progression free survival. Our overarching goal is to critically review the available evidence on the possible neuropsychological effects of postoperative radiotherapy in adult grade II glioma patients. We performed a systematic literature search in Medline, Embase and Cochrane databases up to 1st of May 2020 for studies assessing the cognitive effects of radiation therapy on grade II glioma patients. Eleven studies meeting our inclusion criteria provide either negative or contradictory data regarding the cognitive domains affected, while major confounding variables remain incompletely addressed. The available evidence does not adequately support the notion that current radiation therapy protocols independently produce substantial cognitive decline in grade II glioma patients and therefore it would be premature to argue that radiation associated cognitive morbidity outweighs the benefit of prolonged survival. A large prospective study incorporating a full battery of neuropsychological testing, sufficiently long-term follow-up period and tight control of confounders is due to provide high quality data.

A systematic review of surgical treatments of idiopathic intracranial hypertension (IIH).

Idiopathic intracranial hypertension denotes raised intracranial pressure in the absence of an identifiable cause and presents with symptoms relating to elevated ICP, namely headaches and visual deterioration. Treatment of IIH aims at reducing intracranial pressure, relieving headache and salvaging patients' vision. Surgical interventions are recommended for medically refractory IIH and include CSF diversion techniques, optic nerve sheath fenestration, bariatric surgery and venous sinus stenting. Prospective studies on the surgical options for IIH are scant and no evidence-based guidelines for the surgical management of medically refractory IIH have been established. A search in Cochrane Library, MEDLINE and EMBASE from 1 January 1985 to 19 April 2019 for controlled or observational studies on the surgical treatment of IIH (defined in accordance with the modified Dandy or the modified Friedman criteria) in adults yielded 109 admissible studies. VSS improved papilledema, visual fields and headaches in 87.1%, 72.7% and 72.1% of the patients respectively, with a 2.3% severe complication rate and 11.3% failure rate. CSF diversion techniques diminished papilledema, visual field deterioration and headaches in 78.9%, 66.8% and 69.8% of the cases and are associated with a 9.4 severe complication rate and a 43.4% failure rate. ONSF ameliorated papilledema, visual field defects and headaches in 90.5, 65.2% and 49.3% of patients. Severe complication rate was 2.2% and failure rate was 9.4%. This is currently the largest systematic review for the available operative modalities for IIH. VSS provided the best results in headache resolution and visual outcomes, with low failure rates and a very favourable complication profile. In light of this, VSS ought to be regarded as the first-line surgical modality for the treatment of medically refractory IIH.

Angiosarcoma-related cerebral metastases: a systematic review of the literature.

Angiosarcoma-related cerebral metastases have only been recorded in a few case reports and case series and have not been systematically reviewed to date. Our objective was therefore to perform a systematic literature review on cases of angiosarcomas metastasizing to the brain to inform current practice. All three major libraries-PubMed/MEDLINE, Embase, and Cochrane-were systematically searched, until January 2019. Articles in English reporting angiosarcoma-related cerebral metastases via hematogenous route were included. Our search yielded 45 articles (38 case reports, 5 retrospective studies, 1 case series and 1 letter to the editor), totaling 48 patients (mean age 47.9 years). The main primary site was the heart. The mean time of diagnosis of cerebral metastases following primary tumor identification was 4.9 months. In 15 cases, the brain was the only metastatic site. In cases of multiple extracerebral metastases, the most common sites were the lung and bone. Acute intracerebral supratentorial hemorrhage was the most common presenting radiological feature. Treatment strategies were almost equally divided between the surgical (with or without adjuvant treatment) and the medical arm. Mean overall survival was 7.2 months while progression-free survival was 1.5 months. To our knowledge, this is the first systematic literature review on angiosarcoma-related cerebral metastases. This pathology proves to be an extremely rare clinical entity and carries a poor prognosis, and no consensus has been reached regarding treatment.

Fibrous dysplasia of occipital and temporal bone. A case report.

Fibrous dysplasia is a rare non-malignant condition where fibrous tissue replaces the normal bone architecture. Involvement of temporal and occipital bones is exceptionally rare and is associated with unique complications. A 10-year-old boy presented with right retroauricular enlargement and pain. Imaging studies and biopsy revealed fibrous dysplasia of the temporal and occipital bones. There was no hearing loss or sequelae arising from posterior fossa compression. The patient was discharged with follow-up instructions. Only 10 cases of occipital bone fibrous dysplasia have been reported in the medical literature. Occipital bone fibrous dysplasia can be complicated with Chiari malformation and syringomyelia while temporal bone involvement is associated with hearing loss. These potential developments require close follow-up that includes detailed neurologic examination, imaging and audiology.

Spinal Atypical Rhabdoid Teratoid Tumor in an Adult Woman: Case Report and Review of the Literature.

BACKGROUND: Atypical rhabdoid teratoid tumors are very rare embryonal tumors that typically affect children younger than 3 years old and are encountered intracranially. CASE DESCRIPTION: Here, we describe the case of a 19-year-old woman who presented with gait disturbances and coccydynia. Imaging revealed a cauda equina mass. The tumor was partially resected. Histology reported loss of SMARCB1/INI1 expression and therefore the diagnosis of atypical rhabdoid teratoid was established. The patient underwent radiation treatment, but within 3 months 2 relapses were manifested. CONCLUSIONS: Atypical rhabdoid teratoids are exceptionally rare in adults and are seldom found in spine; only 8 such cases have been reported in the medical literature. They are invariantly characterized by multiple relapses and dismal prognosis. The clinician must be attentive of leptomeningeal disseminations and 22q11 deletion-associated comorbidities.

Paediatric gliomas: diagnosis, molecular biology and management.

Paediatric gliomas represent the most common brain tumour in children. Early diagnosis and treatment greatly improve survival. Histological grade is the most significant classification system affecting treatment planning and prognosis. Paediatric gliomas depend on pathways and genes responsible for mitotic activity and cell proliferation as well as angiogenesis (MAPK, VEGF, EFGR pathways). Symptoms such as focal neurologic deficit or seizures can facilitate diagnosis, but they are not always present and therefore diagnosis is occasionally delayed. Imaging has adequate diagnostic accuracy (surpassing 90%), and novel imaging techniques such as MR spectroscopy and PET increase only slightly this percentage. Low grade gliomas (LGG) can be approached conservatively but most authors suggest surgical excision. High grade gliomas (HGG) are always operated with exception of specific contradictions including butterfly or extensive dominant hemisphere gliomas. Surgical excision is universally followed by radiotherapy and chemotherapy, which slightly increase survival. Inoperable cases can be managed with or without radiosurgery depending on location and size, with adjunctive use of radiotherapy and chemotherapy. Surgical excision must be aggressive and gross total resection (GTR) should be attempted, if possible, since it can triple survival. Radiosurgery is effective on smaller tumours of <2 cm2. Surgical excision is always the treatment of choice, but glioma recurrences, and residual tumours in non-critical locations are candidates for radiosurgery especially if tumour volume is low. Management of recurrences includes surgery, radiosurgery and chemoradiotherapy and it should be individualized according to location and size. In combination with molecular targeted therapeutic schemes, glioma management will be immensely improved in the next years.