The M-Point A Novel Landmark in Middle Fossa Surgery: A Cadaveric Morphometric Study.

BACKGROUND: 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. OBJECTIVE: 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." METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

The state of art of awake craniotomy in Latin American countries: a scoping review.

BACKGROUND AND OBJECTIVE: Awake craniotomy (AC) is a valuable technique for surgical interventions in eloquent areas, but its adoption in low- and middle-income countries faces challenges like limited infrastructure, trained personnel shortage, and inadequate funding. This scoping review explores AC techniques in Latin American countries, focusing on patient characteristics, tumor location, symptomatology, and outcomes. METHODS: A scoping review followed PRISMA guidelines, searching five databases in English, Spanish, and Portuguese. We included 28 studies with 258 patients (mean age: 43, range: 11-92). Patterns in AC use in Latin America were analyzed. RESULTS: Most studies were from Brazil and Mexico (53.6%) and public institutions (70%). Low-grade gliomas were the most common lesions (55%), most of them located in the left hemisphere (52.3%) and frontal lobe (52.3%). Gross-total resection was achieved in 34.3% of cases. 62.9% used an Asleep-Awake-Asleep protocol, and 14.8% used Awake-Awake-Awake. The main complication was seizures (14.6%). Mean post-surgery discharge time was 68 h. Challenges included limited training, infrastructure, and instrumentation availability. Strategies discussed involve training in specialized centers, seeking sponsorships, applying for awards, and multidisciplinary collaborations with neuropsychology. CONCLUSION: Improved accessibility to resources, infrastructure, and adequate instrumentation is crucial for wider AC availability in Latin America. Despite disparities, AC implementation with proper training and teamwork yields favorable outcomes in resource-limited centers. Efforts should focus on addressing challenges and promoting equitable access to this valuable surgical technique in the region.

The Hibiscus Model: A Feasible Cadaveric Model Using Continuous Arterial Circulation for Intracranial Bypass Training and Its Validation.

OBJECTIVE: The frequency of intracranial bypass procedures has declined. Thus it is difficult for neurosurgeons to develop the necessary skills for this complex procedure. We present a perfusion-based cadaveric model to provide a realistic training experience with high anatomic and physiological fidelity, as well as instantaneous assessment of bypass patency. Validation was assessed by evaluating the educational impact and skill improvement of the participants. METHODS: Fourteen participants attended a hands-on revascularization course with 7 cadaveric models connected to a continuous arterial circulation system pumping a red-colored solution through the entire cranial vasculature, mimicking blood circulation. The ability to perform a vascular anastomosis was evaluated initially. Further, a questionnaire on prior experience was provided. At the end of the 36-hour course, the ability to perform an intracranial bypass was reexamined and the participants completed a self-assessment questionnaire. RESULTS: Initially, only 3 attendees were able to perform an end-to-end anastomosis within the time limit, and only 2 of these anastomoses showed adequate patency. After having accomplished the course, all participants were able to complete a patent end-to-end anastomosis within the time limit, thus demonstrating a significant improvement. Further, both overall educational gain and surgical skills were regarded as remarkable (n = 11 and n = 9). CONCLUSIONS: Simulation-based education is considered an important aspect of medical and surgical development. The presented model is a feasible and accessible alternative to the prior models used for cerebral bypass training. This training may serve as a helpful and widely available tool to improve neurosurgeons' development irrespective of financial resources.

Anterior occipital condyle screw placement through the endonasal corridor: proof of concept study with cadaveric analysis.

PURPOSE: Odontoidectomy for ventral compressive pathology may result in O-C1 and/or C1-2 instability. Same-stage endonasal C1-2 spinal fusion has been advocated to eliminate risks associated with separate-stage posterior approaches. While endonasal methods for C1 instrumentation and C1-2 trans-articular stabilization exist, no hypothetical construct for endonasal occipital instrumentation has been validated. We provide an anatomic description of anterior occipital condyle (AOC) screw endonasal placement as proof-of-concept for endonasal craniocervical stabilization. METHODS: Eight adult, injected cadaveric heads were studied for placing 16 AOC screws endonasally. Thin-cut CT was used for registration. After turning a standard inferior U-shaped nasopharyngeal flap endonasally, 4 mm × 22 mm AOC screws were placed with a 0° driver using neuronavigation. Post-placement CT scans were obtained to determine: site-of-entry, measured from the endonasal projection of the medial O-C1 joint; screw angulation in sagittal and axial planes, proximity to critical structures. RESULTS: Average site-of-entry was 6.88 mm lateral and 9.74 mm rostral to the medial O-C1 joint. Average angulation in the sagittal plane was 0.16° inferior to the palatal line. Average angulation in the axial plane was 23.97° lateral to midline. Average minimum screw distances from the jugular bulb and hypoglossal canal were 4.80 mm and 1.55 mm. CONCLUSION: Endonasal placement of AOC screws is feasible using a 0° driver. Our measurements provide useful parameters to guide optimal placement. Given proximity of hypoglossal canal and jugular bulb, neuronavigation is recommended. Biomechanical studies will ultimately be necessary to evaluate the strength of AOC screws with plate-screw constructs utilizing endonasal C1 lateral mass or C1-2 trans-articular screws as inferior fixation points.

Meningiomas de fosa posterior: nomenclatura con orientación anatomo-quirúrgica y presentación de casos ilustrativos / Posterior fossa meningiomas: nomenclature with anatomical-surgical orientation and presentation of illustrative cases

Introducción: Los meningiomas de la fosa posterior representan el 20% de todos los meningiomas intracraneales. Cada subtipo tiene una base de implantación, abordaje quirúrgico y morbimortalidad postoperatoria muchas veces diferente. Advertimos que en reuniones científicas y publicaciones no se sigue una forma de clasificar uniforme, sencilla y clara con orientación netamente quirúrgica. Esto genera que el neurocirujano en formación no cuente con herramientas suficientes para la toma de decisiones. Objetivos: Proponer una clasificación sencilla de los meningiomas de la fosa posterior con un fundamento anatomo-quirúrgico y presentar casos ilustrativos de cada subtipo. Materiales y métodos: Se estableció una nomenclatura considerando reportes previos, el criterio anatómico y la experiencia quirúrgica de los autores. Se presentaron casos revisando las historias clínicas y los archivos de imágenes correspondientes a cada subtipo de la clasificación. Resultados: Representamos a la fosa posterior como un compartimento con 3 anillos: el superior se divide en medial, lateral-anterior y lateral-posterior; el medio se divide en 6 variantes: clivales puros, esfeno-petro-clivales, petrosos anteriores, petrosos posteriores y de la convexidad suboccipital medial y lateral; el inferior se divide en anterior, lateral derecho, lateral izquierdo y posterior. Conclusión: Los meningiomas del anillo superior pueden resolverse mediante una vía suboccipital medial o lateral; los del anillo medio tienen un espectro de opciones más diverso; los del anillo inferior -siguiendo el esquema de división en cuadrantes de un reloj- pueden resolverse por medio de un abordaje suboccipital medial o extremolatera

Introduction: Posterior fossa meningiomas represent 20% of all meningiomas, being each location associated with a specific approach, morbidity and mortality. The actual classifications are focus on the dural attachment, without associating the anatomical with the surgical aspects, useful to the young neurosurgeons for decision making. Objectives: To propose a classification of the posterior fossa meningiomas with an anatomical-surgical view including the presentation of cases. Materials and Methods: A nomenclature was established concerning previous reports, the anatomical criteria and the surgical experience of the authors. Cases were presented by reviewing the medical records corresponding to each subtype of the proposed classification. Results: We represent the posterior fossa as a 3 rings compartment: the upper one is divided into medial, anterior-lateral and posterior-lateral; the middle ring is divided into 6 variants: pure clival, spheno-petro-clival, anterior petrosal, posterior petrosal, and medial and lateral suboccipital convexity; the lower ring is divided into anterior, right lateral, left lateral, and posterior. Conclusion: Superior ring meningiomas can be resolved by a medial or lateral suboccipital approach; middle ring meningiomas have a more diverse spectrum of options; while meningiomas of the inferior ring - following the scheme of division into quadrants of a clock - can be resolved by means of a medial or extreme-lateral suboccipital approach.

Extradural Devascularization for Resection of a Lesser Sphenoid Wing Meningioma: 2-Dimensional Operative Video.

We describe the case of a 42-yr-old female patient with a 2-yr history of headache that has progressively worsened. Physical examination revealed no neurological deficit. Magnetic resonance imaging showed a large tumor of the left lesser sphenoid wing that enhanced with gadolinium and produced displacement of the midline and the Sylvian fissure. A thorough analysis of the origin of the tumor was done to establish the surgical strategy. With the patient positioned supine with the head slightly turned to the right side, fixed in a 3-pin head clamp, a pterional craniotomy was performed. Since the origin of the tumor is in the lesser wing an early extradural devascularization of the tumor was done with drilling out all the hyperostotic bone of the lesser sphenoid wing, including the lateral base of the anterior clinoid process. Intradural debulking and resection showed the effect of extradural devascularization with an important decrease in bleeding, allowing the total resection of the tumor. An immediate postop magnetic resonance showed a complete removal of the tumor. The patient presented a paresis of the oculomotor nerve that completely resolved in the 3-mo follow-up. In the following video illustration, we narrate this operative case and highlight the nuances of this approach.1 The patient has given assent and written consent for videos, images, or clinical or genetic information to be published.

Pterional Craniotomy for Resection of Clinoidal Meningioma Associated With an Aerated Anterior Clinoid Process: 2-Dimensional Operative Video.

Extradural removal of the clinoid performed prior to resection of clinoidal meningiomas has been advocated as a way to facilitate devascularization of the tumor and provide early identification and/or decompression of adjacent neurovascular structures. A small number of video publications exist in the literature that provides useful guidance to surgeons preparing for resection of clinoidal region meningiomas.1-3 However, none of these videos portray the variable anatomy associated with an aerated clinoid process. This known anatomical variant can increase the risk profile associated with resection of clinoidal meningomas-especially with regards to postoperative cerebrospinal fluid (CSF) fistula. In this video publication, we discuss the care of a 54 yr-old male who presented with visual deterioration in the right eye. Magnetic resonance imaging (MRI) revealed findings consistent with a right clinoidal meningioma. Computed tomography demonstrated bilateral aeration of the anterior clinoid processes. The patient was taken to the operating room for right pterional craniotomy for resection of the neoplasm. Edited, intraoperative 2-dimensional-video demonstrates the variable anatomy encountered during removal of an aerated clinoid process. Relevant steps associated with subsequent tumor resection are summarized. Following resection, MRI obtained in the early postoperative period demonstrated gross total resection of the neoplasm without untoward finding. The patient noted marked improvement in his vision following surgery and did not suffer any complications relating to postoperative CSF fistula. Full patient consent for photography and/or recording of other forms of video/imaging was obtained in the preoperative period.

Risk of Infection Associated with Transmucosal Placement of Instrumentation in Clean-Contaminated Field: Systematic Analysis.

Instability of the craniovertebral junction (CVJ) following odontoidectomy is relatively common. Traditionally, separate stage posterior atlantoaxial ± occipitocervical fusion is used for treatment. A transmucosal approach using a clean-contaminated route is associated with hypothetical risks of infectious complications. There is a paucity of information in the literature assessing the risk of surgical site infection (SSI) using the transmucosal approach for hardware placement. The authors conducted a literature search through PubMed identifying patients with pathology requiring transmucosal (i.e., transnasal or transoral) CVJ fixation. Studies that described 1) cases requiring a transmucosal approach and 2) associated infectious complications were included. Rates of SSIs, device removal, unplanned reoperation, and hardware failures were analyzed. Descriptive statistics and odds ratios (ORs) were used to compare complications. Nine studies with a total of 431 patients were identified. There were 4 (0.93%) superficial SSIs and 4 (0.93%) deep SSIs. In total, 1.86% of patients experienced SSI. There were 18 (4.18%) cases of unplanned reoperation, 4 (0.93%) related to SSI. Five (1.16%) patients required removal of their anterior fixation device, 4 (0.93%) related to SSI. ORs comparing our results with Medvedev et al's retrospective National Surgical Quality Improvement Program study assessing the risk associated with posterior cervical fixation showed no statistical difference between postoperative infection rates (OR = 0.72, P = 0.36). An extensive review of the literature found no evidence to suggest placement of spinal hardware via transmucosal corridor is associated with an increased risk of SSI.

Clasificación del tubérculo suprameatal y análisis morfométrico con enfoque quirúrgico del hueso temporal / Classification of the suprameatal tubercle and morphometric analysis with a surgical approach to the temporal bone

Introducción: El hueso temporal es una estructura valiosa en el abordaje de patologías intracraneales a la fosa media y posterior, requiriendo en ocasiones la realización de petrosectomías anteriores, posteriores o abordajes combinados para la resección de tumores en dichas regiones. El propósito del presente estudio es realizar análisis morfométrico con enfoque quirúrgico del hueso temporal, en cráneos adultos, con énfasis en el tubérculo suprameatal (TSM) teniendo en consideración sus relaciones anatómicas. Material y métodos: El presente estudio se realizó en las instalaciones de la Facultad de Medicina de la Universidad Nacional Autónoma de México (UNAM). Se analizaron 200 huesos temporales de 100 cráneos humanos adultos. Se dio énfasis al TSM de acuerdo a su ubicación y tamaño, clasificándolo en: anterior medio o posterior y en tipo I (0-1 mm), tipo II (2-3 mm) y tipo III (>3 mm). Además, se realizaron mediciones con enfoque quirúrgico de la porción petrosa del hueso temporal y de la cresta supramastoidea. Resultados: El TSM se observó en 171 especímenes estudiados (85.5%). Entre ellos, la posición posterior fue la más frecuente 85 de 171 (49.70%), seguida de la posición media 43 (25.14%) y por último la posición anterior 43 (25.14%). En cuanto al tamaño, se encontró con mayor frecuencia el tipo II en 99 de los especímenes (49.5%), el tipo I en 82 especímenes (41%) y tipo III en 19 (9.5%). El asterion se reflejó dentro de la impresión de los senos en la mayoría 48.5%, la unión de la cresta supramastoidea con sutura escamosa se reflejaba en 98.5% de los casos a la fosa media. Discusión: En nuestra búsqueda de información no se cuenta con datos para realizar comparación con la obtenida en este estudio del tubérculo suprameatal, el hallazgo encontrado parece indicar que se encuentra una relación directa con la presencia de la impresión del surco del seno petroso superior. La distribución de acuerdo a su posición reviste importancia cuando se encuentra en grado III puesto que plantea una dificultad técnica, en abordajes como en petrosectomías, o bien, al cavum de Meckel desde un abordaje retrosigmoideo. Conclusión: La observación anatómica y clasificación que realizamos del tubérculo suprameatal, una estructura muy poco evaluada, nos da una consideración preoperatoria y transoperatoria cuando realizamos abordaje que involucra la cara posterior de la porción petrosa del hueso temporal

Introduction: The temporal bone is a valuable structure in the approach of intracranial pathologies to the middle and posterior fossa. Sometimes requiring the performance of petrosectomies or combined approaches for the resection of tumors in these regions. The purpose of this study is to perform morphometric analysis in adult skulls with a surgical approach to the temporal bone, with emphasis on the suprameatal tubercle (SMT) taking into account their anatomical relationships. Material and methods: The present study was carried out in the facilities of the Faculty of Medicine of the National Autonomous University of Mexico (UNAM). 200 temporal bones from 100 adult human skulls were analyzed. The SMT was emphasized according to its location and size, classifying it as: anterior, middle, or posterior and type I (0-1 mm), type II (2-3 mm) and type III (> 3mm). In addition, measurements were made with a surgical approach of the petrosal portion of the temporal bone and the supramastoid crest. Results: The SMT was observed in 171 specimens studied (85.5%). Among them, the posterior position was the most frequent 85 of 171 (49.70%), followed by the middle position in 43 (25.14%) and finally the anterior position in 43 (25.14%). In terms of size, type II was more frequently found in 99 of the specimens (49.5%), type I in 82 specimens (41%) and type III were found in 19 (9.5%). The asterion was reflected within the impression of the sinuses in the majority 48.5%, the union of the supramastoid crest with squamous suture was reflected in 98.5% of the cases to the middle fossa.Discussion: In our search for information, there is no data to make a comparison with that obtained in this study of the suprameatal tubercle. The findings seems to indicate that there is a direct relationship with the presence of the impression of the groove of the upper petrosal sinus. The distribution according to its position is important when it is in grade III since it poses a technical difficulty, in approaches such as petrosectomies, or approach to Meckel's cave from a retrosigmoid approach. Conclusion: The anatomical observation and classification that we perform of the suprameatal tubercle, a very poorly evaluated structure, gives us a preoperative and transoperative consideration when we perform an approach that involves the posterior aspect of the petrosal portion of the temporal bone

Anterior Petrosal Approach for the Resection of a Petrous Apex Meningioma with Tentorial Infiltration.

Objective The anterior petrosal approach is an extension of the middle fossa approach, characterized by drilling of the posteromedial triangle of the middle fossa. Drilling the Kawase's rhomboid creates a surgical corridor to the posterior fossa after splitting the tentorium. We present a case of a petrous apex meningioma invading the tentorium and causing trigeminal neuralgia. Results The patient was positioned in a Mayfield with the head rotated. A frontotemporal incision was done. A basal craniotomy was done to allow epidural dissection. The anatomical landmarks were identified. The surgical video is analyzed together with cadaveric dissections to highlight landmarks when doing an anterior petrosectomy. The tentorium was identified and the infiltrated region was coagulated and removed. The tentorium was sharply sectioned until the free edge of the tentorium was opened. The tumor in the petrous apex was identified and removed. The trigeminal nerve was decompressed and a gross total resection was achieved with resolution of the symptoms. Conclusion The anterior petrosal approach is a useful corridor to remove tumors in the petrous apex that infiltrate the tentorium. A thorough knowledge of the anatomical landmarks is crucial to identify and delineate the limits of the Kawase's rhomboid. After evaluating different surgical corridors, the anterior petrosal approach allows a gross total resection including the removal of the infiltrated tentorium and a resolution of the symptoms. The link to the video can be found at: https://youtu.be/p4KPUnM_bww .

Management of a complex glomus jugulare tumor with severe brainstem compression.

Surgery of glomus jugulare tumors is complex, but when these tumors have a large intradural component and cause brainstem compression they became a challenge to the surgeon. It is crucial to preoperatively understand the anatomy of the tumor and analyze its relationship with the temporal bone, facial nerve, and foramen jugular neurovascular structures. We present a case of a male patient with a complex glomus jugulare tumor causing severe brainstem compression. Nuances of technique and surgical pearls related to the management of complex jugulare tumors are discussed and illustrated in this operative video. The video can be found here: https://youtu.be/oCjzp0kFRGc.

Subtemporal approach for the resection of a midbrain cavernous malformation: evaluation of safe surgical corridors.

Brainstem cavernous malformation management is complex due to its critical location and deleterious effect when bleeding. Therefore, every case should be thoroughly analyzed preoperatively. We present the case of a female patient with a midbrain cavernous malformation. A comprehensive anatomical and clinical analysis of the surgical corridors is done to decide the safest route. A subtemporal approach was done and the lateral mesencephalic sulcus and vein were important anatomical landmarks to guide the safe entry zone. Nuances of technique and surgical pearls related to the safe entry zones of the midbrain are discussed and illustrated in this operative video. The video can be found here: https://youtu.be/vYA-IgiT2lU.

The Supra/Infra Transtentorial Transfalcine Approach for the Removal of a Falcotentorial Meningioma: 2-Dimensional Video.

Falcotentorial meningiomas originate in the junction of the falx cerebri and the tentorium. Due to its anatomic vicinity, these tumors have a close relationship with important neurovascular structures surrounding the pineal region including the deep venous system. Surgical approaches would normally consider posterior midline corridors, but decision between supra or infratentorial access should be considered by the size, anatomic displacement of structures, and the infiltration of the dural attachment. This surgical video1,2 demonstrates the surgical technique and pearls to achieve a stepwise resection of a complex falcotentorial meningioma. We present a case of a 42-yr-old female patient, neurologically intact at presentation. A semi-sitting position was used. Appropriate management of cerebrospinal fluid was obtained with an external ventricular drainage which is kept closed until the dura is opened. A suprainfratentorial craniotomy was done with adequate exposure of the superior sagittal sinus and torcula. The supracerebellar infratentorial corridor was used for inferior internal debulking and arachnoidal dissection of the tumor while the exposure obtained in the posterior interhemispheric allowed a corridor which exposed widely the tumor with transtentorial transfalcine extension. Adequate management of adjacent structures was done while preserving the straight sinus and vein of Galen. A gross total removal of the tumor was achieved and the patient was discharged without complications. After this surgical video, the viewer will have learned the steps to safely achieve a surgical removal of a falcotentorial meningioma taking care of its relationship with the venous and neural adjacent structures.

Neurocisticercosis ventricular: manejo multimodal y revisión de la bibliografía / Ventricular neurocysticercosis: multimodal management and bibliographic review

Resumen La neurocisticercosis es la infección parasitaria más común del sistema nervioso central; es causada por Taenia solium en su estado de larva. Se estima que existen millones de personas afectadas en países en desarrollo, es la primera causa de convulsiones y de epilepsia adquirida. Comunicamos el caso de una paciente de 40 años, sin antecedentes importantes, que de forma súbita tuvo pérdida del estado de alerta y datos clínicos de hipertensión intracraneana. En la tomografía axial computada se encontró edema cerebral e hidrocefalia no comunicante, por lo que se le colocó una válvula de derivación ventrículo-peritoneal. El abordaje se complementó con una resonancia magnética en secuencia FIESTA en la que se observó el quiste del cisticerco intraventricular anterior. El abordaje terapéutico multidisciplinario incluyó la extracción del quiste por neuroendoscopia y tratamiento farmacológico con esteroides y cisticidas. La paciente evolucionó favorablemente, con recuperación total del estado de alerta y como única secuela tuvo alteración de la memoria del trabajo. En los últimos años, el desarrollo del tratamiento antiparasitario y de técnicas de neurocirugía mínimamente invasivas ha mejorado el pronóstico de los pacientes.

Abstract Neurocysticercosis (NCC) is the most common parasitic infection of the central nervous system caused by Taenia solium in its larval stage. It is estimated that there are millions of people affected in developing countries, being the first cause of seizures and acquired epilepsy. We present the case of a 40-year-old woman, with no relevant history, who presented sudden loss of alertness and clinical data of intracraneal hypertension, which was confirmed by CT in addition to finding non-communicating hydrocephalus, the patient underwent to the placement of a ventriculo-peritoneal bypass valve without complications and the approach was complemented by a magnetic resonance in a FIESTA sequence in which the cysticercus cyst intraventricular was observed. The patient underwent removal of the cyst by neuroendoscopy and treatment based on steroids and cysticides. The patient evolved favorably, with full recovery of alertness and the only sequelae was the alteration of work memory. In recent years, the development of antiparasitic therapy and minimally invasive neurosurgery techniques has improved the prognosis of patients.

Feasibility of endoscopic endonasal approach for clip application of cerebral aneurysms: a systematic review.

INTRODUCTION: While open, microsurgical clipping and endovascular coiling remain the gold standards for treatment of cerebral aneurysms, a growing number of aneurysms treated via endoscopic endonasal methods have been reported in the literature. The aim of this study was to conduct a systematic review of the literature to gain a more thorough appreciation of the potential benefits and drawbacks of the endoscopic endonasal strategy in this setting. EVIDENCE ACQUISITION: We performed a detailed systematic review of the medical literature on endoscopic endonasal skull base surgery for treatment of cerebral aneurysms utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We identified 9 clinical studies describing treatment of 23 aneurysms utilizing the EEA. Eleven additional cadaveric studies investigating aspects of operative exposure and/or technique in this setting were identified. The full text of these articles was reviewed. EVIDENCE SYNTHESIS: In the 9 clinical studies that met inclusion criteria, 23 aneurysms were treated in 21 patients. The mean patient age was 52.6 years. 15 aneurysms were unruptured and 8 were ruptured. Fourteen aneurysms involved the anterior circulation and 9 involved the posterior circulation. In 21 of 23 aneurysms, complete occlusion was achieved with endonasal clipping. Two aneurysms required additional treatment that included a takeback for clip repositioning and staged endovascular coiling. Complications included post-operative CSF leak (23.8%), stroke (19%), and meningitis (14.3%). Analysis of the combined literature revealed a significantly higher rate of CSF leak with endonasal clipping of posterior circulation aneurysms compared to anterior circulation aneurysms (P=0.047, Fisher's Exact Test). While there was a trend towards increased post-operative neurologic deficit following EEA for posterior circulation aneurysms, this did not reach statistical significance (P=0.063). The majority of post-operative complications in posterior circulation aneurysms occurred during clip application of aneurysms at the level of the basilar apex. In addition to the aforementioned clinical reports, 11 cadaveric studies were identified. 4 of these reports investigated approaches for individual anterior circulation aneurysms, 5 investigated approaches for posterior circulations aneurysms, and 2 involved both anterior and posterior circulation aneurysms. CONCLUSIONS: Despite a moderate increase in utilization, caution should be exercised when choosing an endonasal strategy for treatment of aneurysmal pathology over more traditional and established methods such as microsurgical clip application and endovascular methods. Anecdotal evidence suggests that inferior and/or medial projecting aneurysms involving the paraclinoid ICA not amenable to traditional open/endovascular strategies may be reasonable to consider for EEA clip application. Wide-necked, midline, ventrolaterally-projecting aneurysms involving the vertebrobasilar system may represent an additional exception, as long as the location along the rostrocaudal axis is low enough so as not to compromise visualization. Future improvements in operative technology, including anticipated advances in endoscopic 3-D visualization, may further alter the landscape of treatment involving this complex pathology.

Tumores malignos de la vaina nerviosa periférica como origen de dolor orofacial / Malignant peripheral nerve sheath tumours as the source of orofacial pain

Los tumores malignos de la vaina nerviosa periférica (TMVNP), también llamados neurofribrosarcomas o schwannomas malignos, representan el 10% de todos los sarcomas de tejidos blandos. El tumor usualmente se encuentra en las extremidades inferiores, y solo del 10 al 20% de las lesiones ocurren en la región de cabeza y cuello, convirtiéndolas en una entidad rara. Los neurofibromas son tumores de la vaina nerviosa que aparecen comúnmente en la neurofibromatosis 1 o enfermedad de Von Recklinghausen. Se ha reportado que los individuos con antecedentes familiares de neurofibromatosis 1 tienen un riesgo incrementado de desarrollar TMVNP en el transcurso de sus vidas, sin embargo, esta asociación no se ha confirmado en TMVNP a nivel de los nervios craneales. En este artículo los autores analizaron la literatura actual con respecto a los TMVNP del nervio trigémino, así como la inclusión de un caso inusual que involucra las 3 ramas de dicho nervio (AU)

Malignant peripheral nerve sheath tumours (MPNSTs), also called neurofibrosarcomas or malignant schwannomas, represents 10% of all soft tissue sarcomas. The tumour is usually found in the lower extremities, and only 10 to 20% of all lesions occur in head and neck region, thus making it a rare entity. Neurofibroma is one of the common nerve sheath tumours occurring in the soft tissues, and generally appears in neurofibromatosis 1 or Von Recklinghausen's disease. Individuals with a family history of neurofibromatosis 1 are reported to have an increased risk of developing MPNSTs in their lifetime. However, this association is not seen in MPNSTs of the cranial nerves. In this study, the authors reviewed the current literature on MPNSTs of the trigeminal nerve to analyse the presentations, treatment options, and outcomes for patients with this disease, as well as the report of a case involving the 3 branches of the trigeminal nerve (AU)

Plasma taurine as a predictor of poor outcome in patients with mild neurological deficits after aneurysmal subarachnoid hemorrhage.

OBJECT: The object of this study was to determine the relationship between plasma taurine and subarachnoid hemorrhage (SAH) outcome. METHODS: Forty patients with SAH and mild neurological deficits were included in this prospective, blinded cohort study. Plasma taurine levels were measured using high-performance liquid chromatography on admission and were correlated with patient outcomes at discharge. RESULTS: Twenty-five percent of the patients ultimately had a poor outcome. Plasma taurine concentrations at admission were increased (2-fold) in SAH patients with a favorable outcome and were further increased (6-fold) in those who had a poor outcome. Increased taurine levels identified patients who would be discharged with a poor outcome, with sensitivity and specificity values of approximately 80% and 100%, respectively, and positive and negative predictive values of approximately 90%. Delayed cerebral vasospasm showed an OR of 27.9 (95% CI 1.090-714.9) for a poor outcome, whereas an increased taurine concentration had an OR of 105 for a poor outcome (95% CI 8.3-1328.0, p < 0.001). CONCLUSIONS: Increased plasma taurine concentrations on admission predict a poor outcome in SAH.

[Standardizing a central nervous system tumor DNA biobank]. / Estandarización de un biobanco de ADN de tumores del sistema nervioso central.

BACKGROUND: Brain tumors are one of the leading cancers worldwide; in the National Institute of Neurology and Neurosurgery (INNN) these tumors are the leading cause of morbitity and mortality. OBJECTIVE: Standardize biopsies, colletion, processing and storage biologic material of molecular studies. METHODS: with a previously signed surgical consent, a tumor and blood biopsy was done to 134 patients. Their DNA was extracted and a database was filled considering technical, ethical and legal aspects. In order to have optimal biologic material the procedure was standardized between the surgical and research laboratory teams. RESULTS: The biopsy, transportation, processing and storage were standardized. 134 patients were included (67 male and 67 female) with an average age of 46.28 years (range 15-81). The most frequently biopsied tumor was the meningioma (42%). The integrity of the obtained material was determined by agarose gel electrophoretic analysis. CONCLUSION: the INNN biobank has a standardized system that biopsies, processes and stores optimum quality biologic material that will be the basis of future molecular studies.

A look at Mayan artificial cranial deformation practices: morphological and cultural aspects.

Induced deformation of the cranial vault is one form of permanent alteration of the body that has been performed by human beings from the beginning of history as a way of differentiating from others. These procedures have been observed in different cultures, but were particularly widespread in Mesoamerica. The authors examined and reviewed the historical and anthropological literature of intentional deformation practices in Mayan culture. The Mayans performed different types of cranial deformations and used different techniques and instruments to deform children's heads. The most remarkable morphological alteration is seen in the flattening of the frontal bone. Some archeological investigations link deformation types with specific periods. This article provides a glance at the cultural environment of the Mayans and demonstrates the heterogeneity of this interesting cultural phenomenon, which has changed over time.