The Technique for Transorbital Ventricular Puncture: An Anatomic Approach.

BACKGROUND AND OBJECTIVES: Transorbital ventricular puncture is a minimally invasive described procedure with poor landmarks and anatomic references. This approach can be easily performed to save patients with intracranial hypertension, especially when it is secondary to an acute decompensated hydrocephalus. This study aims to describe anatomic structures and landmarks to facilitate the execution of transorbital puncture in emergency cases. METHODS: We analyzed 120 head computed tomographies to show the best area to perform the procedure in the orbital roof. Two adult cadavers (4 sides) were punctured in the predetermined area. Angles, distances, landmarks, and anatomic structures were registered. This approach to the ventricular system may be performed at bedside to relieve intracranial hypertension only in specific cases. RESULTS: The perforation point is 2.5 cm (female) or 3.0 cm (male) lateral to the midline and immediately inferior to the superciliary arch. A vertical line, parallel to midline, was drawn on the outer edge of the patient's forehead, the needle was 45° inferiorly and 20° medially and then progressed 2.0 cm backwards to reach the bone perforation point. After that, it was advanced another 4.5cm approximately until it reached the anterior horn of the lateral ventricle. CONCLUSION: Based on statistical and experimental evidences, we were able to establish reliable anatomic reference points to access the anterior horn of the lateral ventricle through transorbital puncture.

Middle fossa triangles - A step-by-step dissection.

Background: The anatomy and surgical approach to the cavernous sinus and the middle fossa can constitute a considerable challenge, specially for young surgeons. Although their surgical explorations have gone through a popular phase in the past, to this date, they remain an uncomfortable subject for many neurosurgeons. The aim of this paper is to systematically review its anatomy and multiple corridors through a step-by-step dissection of the middle fossa triangles, providing a roadmap for surgeons. Methods: A step-by-step dissection of the cavernous sinus was performed in two fresh-frozen cadavers aiming to describe the anatomy of ten different middle fossa triangles, demonstrating the feasibility of the use of their spaces while surgically approaching this area. Results: The intradural opening of the roof of the cavernous sinus was obtained by dissection of clinoidal, carotid-oculomotor, supratrochlear, optic-carotideal, and oculomotor triangles, allowing an expanded superior view. On the counterpart, the extradural exploration of the lateral wall through the middle fossa floor peeling exposed the infratrochlear, anteromedial, and anterolateral triangles. The middle fossa floor itself was the door to approaching posterior fossa through anterior petrosectomy. The dissection of each individual triangle can be amplified exponentially with exploration of its adjacents, providing broader surgical corridors. Conclusion: The cavernous sinus still remains far from an "every man's land," but its systematic study based on direct approaches can ease the challenges of its surgical exploration, allowing surgeons to feel more comfortable with its navigation, with consequently benefit in the treatment of patients.

Diffuse spinal cord metastasis after resection of SMARCB1 sinonasal carcinoma manifesting with a right foot drop-a case report.

INTRODUCTION: The sinonasal carcinoma are rare tumors of the head and neck. The undifferentiated sinonasal carcinoma subtypes are constantly being explored and new mutations, with different prognosis markers and biological behaviors are being described. The SMARCB1 negative sinonasal carcinoma subtypes have been recently described with few reports of leptomeningeal and spinal cord invasion. CASE PRESENTATION: This study presents the case of a 59-year-old woman, with no previous disease, presenting initially with epistaxis that evolved to cranial nerve deficits and a left eye complete oftalmoplegia. After diagnostic investigation, she had a diagnosis of a left ethmoid sinus sinonasal carcinoma. Following resection of the tumor, she evolved with a right foot drop that eventually has been linked to diffuse spinal cord impairment. The histopathological diagnosis confirmed a SMARCB1 negative sinonasal carcinoma. Due to the diffuse metastasis, she underwent palliative care and died eight months after the surgery. DISCUSSION: Spinal cord metastasis may manifest with different clinical signs. Our case shows a rare manifestation of SMARCB1-deficient sinonasal carcinoma, a new subtype of sinonasal carcinoma, summarizing the importance of a high grade of suspicion of spinal cord invasion on these patients. SMARCB1 sinonasal carcinomas are rare new tumors of the head and neck, whose biological behaviors are yet to be explored. To the best of our knowledge, this is one of the few case reports describing simultaneous spread of this tumor to the central nervous system and spinal cord.

Brain cryptococcoma mimicking a glioblastoma in an immunocompetent patient: A rare case report and comprehensive review.

Background: Cryptococcosis is an invasive fungal infection primarily affecting lungs and potentially spreading to the central nervous. This fungal infection might be misdiagnosed as other infection diseases, such as tuberculosis; granulomatous diseases, like sarcoidosis; and even neoplastic diseases. Some previous reports described cases of cryptococcomas resembling brain tumors. In this paper, we present a very rare presentation of brain cryptococcoma mimicking a malignant glioma. To the best of our knowledge, this is the third case description in the literature. Case Description: A 64-year-old male patient presented at the hospital with a history of progressive frontal headache for 1 month, becoming moderate to severe, associated with visual changes, without nausea or vomiting. No fever was reported. He was a heavy smoker and denied other relevant previous medical data. Neuroimage disclosed a right temporal expansive lesion initially considered a malignant glioma. The patient underwent a right temporal craniotomy and biopsy revealed a cryptococcoma. Conclusion: Cryptococcomas characteristics in magnetic resonance are quite nonspecific. They should always be included in differential diagnosis of expansive brain lesions, both malignant and benign. Therefore, once cryptococcomas may resemble like other intracranial expansive lesions, biopsy should always be carried out to clarify diagnosis and avoid inadequate treatment and definition of prognosis only based on radiological patterns.

3-Step didactic white matter dissection of human cerebellum: Micro-neuroanatomical training.

OBJECTIVES: A thorough understanding of cerebellum anatomy is essential in 4th ventricle approaches (more frequent in pediatric neurosurgery), avoiding relevant complications such as cerebellar mutism. The aim of the present work is to show the feasibility of a didactic dissection of human cerebellum focusing on cerebellar peduncles and dentate nucleus (DN), which are structures at high risk during these surgical procedures. MATERIAL AND METHODS: The cerebellum was dissected according to the Klingler method for white matter, using standard and specific microsurgery tools. Surgical microscope magnification (×6-×40) provided by a D.F. Vasconcellos M900 was required. A Canon EOS T7 18-55 mm digital camera was used and Adobe Lightroom Classic CC and Keynote were selected as photo enhancing software. Special methods such as LED light endoscopic transillumination were used for photographical reasons. RESULTS: DN dissection was successfully achieved and the relations between these nucleus and the cerebellar peduncles, inferior vermis and medullary velums were described. Through this three steps dissection guide (1. tentorial surface; 2. suboccipital surface; 3. 4th ventricle structures), the most relevant anatomical structures were shown and its implications in different 4th ventricle approaches were characterised. CONCLUSION: 3 D perspective provided by real specimen anatomical dissection is critical for learning neuroanatomy. LED transillumination was shown as a useful technique for the 4th ventricle structures photographic documentation which improves spatial recognition. This benefit can be applied for the study of the relations between the medullary velums and the rhomboid fossa foramina, which are permeable to light. The proposed three-steps dissection guide helps to a better understanding of human cerebellum and to gain self-confidence, allowing safer practice for neurosurgeons in all stages of their career.

From Above and Below: The Microsurgical Anatomy of Endoscopic Endonasal and Transcranial Microsurgical Approaches to the Parasellar Region.

INTRODUCTION: The parasellar region is one of the most complex of the skull base. In this study, we review the anatomy and approaches to this region through a 360° perspective, correlating microsurgical and endoscopic anatomic nuances of this area. METHODS: An endoscopic endonasal approach (EEA) and microsurgical dissections were performed. The parasellar anatomy is reviewed and common areas of tumor extensions are assessed. Surgical approaches are discussed based on the anatomic nuances of those regions. RESULTS: The cavernous sinus (CS) can be divided into 2 spaces: posterosuperior, above and behind the internal carotid artery (ICA); and anterior, in front of the cavernous ICA. Those spaces can be approached through the CS walls: anterior and/or medial wall via EEA; or superior and/or lateral wall via transcranial approaches. The relationship of the Meckel cave, adjacent to the lateral and posterior wall of the CS, is relevant for surgical planning. Areas often affected by tumor extension can be divided into 6 regions: superior (cisternal), superolateral (parapeduncular), posterolateral (Meckel cave and petrous bone), medial (sella), anterior (superior orbital fissure), and anterior inferior (pterygopalatine fossa). Anatomic and technical nuances of each of those regions should be taken into consideration when dealing with tumors in the parasellar space. CONCLUSIONS: A transcranial approach and EEA provide effective access to the parasellar region. Management of cavernous sinus and Meckel cave tumors requires familiarity with those approaches. Understanding of the surgical anatomy of the parasellar region, from above and below, is therefore necessary for adequate surgical planning and execution.

Cerebellar mutism following head trauma: A case report and literature review.

BACKGROUND: Cerebellar mutism (CM) is defined as the lack of speech production, despite an intact state of consciousness and cognitive function, that happens secondary to a cerebellar insult. To the best of our knowledge, only five cases have thus far been described in the English literature. In this paper, we report the sixth incidence overall, which is also the first case of a CM associated with penetrating head injury. The relevant literature is reviewed and analyzed, our current knowledge of the neuroanatomical and functional relations is summarized, and potential future research endeavors are indicated. CASE DESCRIPTION: An 8-year-old girl was transferred to our hospital having had fallen on a rod that penetrated her neck behind the ear. An urgent computed tomography scan of the head revealed a right cerebellar contusion with surrounding edema. Three days later, she became mute but was still obeying commands. Repeat imaging showed a resolving cerebellar contusion with increased edema and mass effect. By day 9, she had uttered a few words. At 1-month follow-up, the child had regained normal speech. CONCLUSION: Posttraumatic CM is a rare and probably underreported condition with only six documented cases to date. Although it may well be on the same spectrum as postoperative CM, further understanding of the exact mechanism, clinical course, and prognosis of this entity is bound to significantly improve the recovery and quality of life of head trauma patients.

A decision support system for fault detection and definition of the quality of wet blue goat skins.

The vast majority of goat skin processed by traditional tanneries comes from small rural producers. Thus, with the predominance of rustic creation, slaughter, and skinning methods, the batches of hides processed by tanneries have a very heterogeneous quality. Thus, there is a need to categorize the samples according to the quantity and location of defects. The categorization process is subjective and strongly influenced by the experience of the professional classifier, causing a lack of homogeneity in the composition of the goat hide lots for sale. Aiming to reduce failures in the categorization of goatskin samples, the authors investigate the application of computer vision and artificial intelligence on a set of previously categorized wet blue goatskin photographic samples. That said, is analyzed the capacity of different classifiers, with different paradigms, in detecting defects in goatskin samples and in categorizing these samples among seven possible quality levels. A hit rate of 95.9% was achieved in detecting defects and 93.3% in categorizing quality levels. The results suggest that the proposed methodology can be used as a decision aid tool in the qualification process of goat leather samples, which can reduce sample labeling errors.

Desarrollo de técnicas microquirúrgicas usando tinción vascular con y sin silicona en placenta humana con modelos craneales 3D / Development of microsurgical techniques using vascular staining with and without silicone in human placenta with 3D cranial models

En las ultimas décadas, ha habido un cambio en la formación en las especialidades quirúrgicas, lo cual ha llevado a plantearse la necesidad de adquisición de habilidades por fuera del quirófano por medio de la simulación. El objetivo de este trabajo es demostrar que el uso de placentas humanas con modelo craneal tridimensional (3D), es un método de alta fidelidad y retroalimentación para el desarrollo de técnicas microquirúrgicas. Se realizó un estudio de evaluación técnica en el Laboratorio de Microcirugía Dr. Evandro de Oliveira del Hospital de la Beneficiencia de Portugal de São Paulo, utilizando 15 placentas con técnicas de coloración y preservación vascular con silicona para moldes; realizando ejercicio de anastomosis vasculares, ejercicios de disección parenquimatosa placentaria que remedan la disección aracnoidea y del valle silviano, además de simulación de resección de tumores. Cualitativamente la placenta humana es un método con alta fidelidad y retroalimentación, además, es de acceso universal para la adquisición de habilidades microquirúrgicas, que asociada a un modelo craneal 3D permite el perfeccionamiento de craneotomías, coordinación visomotriz, propiocepción y relación de profundidad que se requieren para abordajes neuroquirúrgicos.

In the last decades, there has been a change in training in surgical specialties, which has led to the need to acquire skills outside the operating room through simulation. The aim of this work is to demonstrate that the use of human placentas with a three-dimensional (3D) cranial model is a high fidelity and feedback method for the development of microsurgical techniques. A technical evaluation study was carried out in the Dr. Evandro de Oliveira Microsurgery Laboratory of the Hospital de la Beneficiencia de Portugal in São Paulo, using 15 placentas with coloration techniques and vascular preservation with silicone for molds; performing vascular anastomosis, placental parenchymal dissection exercises that mimic arachnoid and sylvian fissure dissection, in addition to simulating tumor resection. Qualitatively, the human placenta is a method with high fidelity and feedback, and it is also universally accessible for the acquisition of microsurgical skills, which, associated with a 3D cranial model, allows the refinement of the craniotomies, visomotor coordination, proprioception, and depth relationship required for neurosurgical approaches.

3-Step didactic white matter dissection of human cerebellum: Micro-neuroanatomical training. / Disección didáctica de fibra blanca en cerebelo humano en tres pasos: entrenamiento microneuroanatómico.

OBJECTIVES: A thorough understanding of cerebellum anatomy is essential in 4th ventricle approaches (more frequent in pediatric neurosurgery), avoiding relevant complications such as cerebellar mutism. The aim of the present work is to show the feasibility of a didactic dissection of human cerebellum focusing on cerebellar peduncles and dentate nucleus (DN), which are structures at high risk during these surgical procedures. MATERIAL AND METHODS: The cerebellum was dissected according to the Klingler method for white matter, using standard and specific microsurgery tools. Surgical microscope magnification (x6-x40) provided by a D.F. Vasconcellos M900 was required. A Canon EOS T7 18-55 mm digital camera was used and Adobe Lightroom Classic CC and Keynote were selected as photo enhancing software. Special methods such as LED light endoscopic transillumination were used for photographical reasons. RESULTS: DN dissection was successfully achieved and the relations between these nucleus and the cerebellar peduncles, inferior vermis and medullary velums were described. Through this three steps dissection guide (1. tentorial surface; 2. suboccipital surface; 3. 4th ventricle structures), the most relevant anatomical structures were shown and its implications in different 4th ventricle approaches were characterised. CONCLUSION: 3 D perspective provided by real specimen anatomical dissection is critical for learning neuroanatomy. LED transillumination was shown as a useful technique for the 4th ventricle structures photographic documentation which improves spatial recognition. This benefit can be applied for the study of the relations between the medullary velums and the rhomboid fossa foramina, which are permeable to light. The proposed three-steps dissection guide helps to a better understanding of human cerebellum and to gain self-confidence, allowing safer practice for neurosurgeons in all stages of their career.

Optical and Photocatalytic Properties of In-Situ Gr@ZnO Microspindle Composites Prepared by Hydrothermal Method.

In-Situ composite materials of graphene (Gr) and ZnO microspindle with different Gr contents (1, 2 and 5 wt.%) were prepared via a facile one-step hydrothermal route with the assistance of hexamethylenetetramine. Graphene does not affect the hexagonal wurtzite crystal structure of composite materials but strongly affects the morphological, structural, optical and photocatalytic properties of composite materials. In detail, Gr causes a decrease in both the dimensions of ZnO microspindle and photoluminescence efficiency. The average crystalline size and microstrain first increase from 28.9 nm and 0.00394 to 49.5 nm and 0.00524 when Gr content increases from 0 to 1 wt.%, respectively; then decrease to 39.6 nm and 0.00404 when Gr content increase from 1 to 5 wt.%, respectively. Both pristine and composite materials show high photocatalytic activity with high methylene blue degradation efficiency?more than 90%-just after 40 min under UV irradiation. Composite material having a Gr content of 5 wt.% shows the highest degradation efficiency of 96.5% which confirms the role of Gr in enhancing the photocatalytic activity of ZnO.

Postmortem Dissections of the Papez Circuit and Nonmotor Targets for Functional Neurosurgery.

BACKGROUND: The Papez circuit was first described as the anatomic basis of emotion. Subsequent studies consolidated recognition of its limbic activities but showed a more important role in memory. Anatomic dissections and advanced neuroimaging have deepened our understanding of the various interconnections and white matter tracts present in this circuit. The aim of our study is to describe the anatomy of the Papez circuit through cadaveric dissection with correlation to ultrahigh-field magnetic resonance imaging (MRI) and MRI tractography. METHODS: White fiber dissection was performed on 5 cadaveric human brain hemispheres. The Papez circuit was dissected mediolaterally to show its anatomy and relation to other nuclei and tracts. Open-source MRI tractography data from the Human Connectome Project is combined with ultrahigh resolution, 7T structural MRI, and 17.6T diffusion tractography to further show the anatomy. RESULTS: The network connecting the anterior and posterior cingulate, entorhinal cortex, hippocampus, fimbria, dentate gyrus, fornix, mammillary bodies, and anterior thalamus was described using white matter fiber dissection and compared with MRI tractography and ultrahigh-field structural and diffusion MRI. We showed for the first time (through portmortem dissection) fibers directly connecting the anterior thalamic nucleus and the subgenual cingulate via the septal area. CONCLUSIONS: The description of the anatomy of the Papez circuit through cadaveric dissection and comparisons with advanced neuroimaging studies allow a better understanding of its three-dimensional spatial layout, in addition to showing new areas of connectivity with adjacent structures and possibilities for surgical approaches or stimulation.

Microsurgical Anatomy Review of Bifrontal Limited Transbasal Approach - Quantitative and Anatomy Study.

INTRODUCTION: The bifrontal transbasal approach is an anterior midline skull base approach to anterior skull base, sellae region and, if needed, to posterior skull base in the midline, often used for tumoral lesions but also useful for vascular or infectious pathologies. METHODS: Descriptive anatomic study, 5 formalin-fixed human cadaveric heads were used injected with colored silicone. The dissection was made step-by-step to describe every anatomic structure encountered. The working distance was obtained from the posterior wall of the frontal sinus with and without orbital rim to the pituitary stalk, the sellae, the pontomedullary sulcus, and the anterior margin of the foramen magnum. RESULTS: Stepwise anatomic dissection was performed dividing the surgical technique into 6 stages: soft-tissue stage, bone stage, sinus stage, clival stage, intradural, and measurements. The objective of making the supraorbital osteotomy was to improve the vision over the neural structures without brain retraction and limited to the midline supraorbital rim to avoid aggressive manipulation and injury to the orbit. The working distances measured with the orbital rim were on average: to the pituitary stalk, 70.5 mm; to the sellae, 81.3 mm; to the pontomedullary sulcus, 97 mm; and the foramen magnum, 99.5 mm. Without the orbital rim measures were: to the pituitary stalk, 57 mm; to the sellae, 62.5 mm; to the pontomedullary sulcus, 96 mm; and the foramen magnum, 98.5 mm. CONCLUSIONS: The addition of osteotomies including removing of the orbital rim improves the access to the central skull base with special benefits on the working distances to the sellae region.

Comparison Between Transcortical and Interhemispheric Approaches to the Atrium of Lateral Ventricle Using Combined White Matter Fiber Dissections and Magnetic Resonance Tractography.

OBJECTIVE: The objective of this study was to compare transcortical and posterior interhemispheric approaches to the atrium using a combined approach of white matter fiber dissections and magnetic resonance (MR) tractography. METHODS: Ten cerebral hemispheres were examined and dissected from the lateral-to-medial surface and from the medial-to-lateral surface, with special attention to the white matter tracts related to the atrium. MR tractography was used to show the relationship of three-dimensional white matter fibers with the atrium of the lateral ventricle and to compare with cadaveric dissection results. RESULTS: The atrium was related laterally to the superior longitudinal fasciculus II and III, middle longitudinal fasciculus, arcuate fasciculus, vertical occipital fasciculus, and sagittal stratum. Medially, it is related to the superior longitudinal fasciculus I, cingulum, sledge runner, and forceps major. CONCLUSIONS: A combined approach of cadaveric white matter fiber dissections and MR tractography were used to describe the main white matter tracts related to the posterior interhemispheric approach and the transcortical approach, providing an in-depth understanding of the three-dimensional anatomy of white matter fibers and the atrium. In the present study, among approaches examined, the posterior interhemispheric parasplenial transprecuneus approach placed fewer eloquent tracts at risk; however, traversing the sledge runner and the forceps major is unavoidable by this approach.

White Matter Relationships Examined by Transillumination Technique Using a Lateral Transcortical Parietal Approach to the Atrium: Three-Dimensional Images and Surgical Considerations.

BACKGROUND: Numerous lesions are found in the ventricular atrium (VA). Access is gained through many white matter tracts with great relevance and specific neurologic functions. It is important to understand the configuration of the most relevant structures surrounding this zone and, thus, select the safest entry zone on the lateral cerebral surface. OBJECTIVE: We studied the white matter layers traversed in the lateral transcortical parietal approach through the intraparietal sulcus (IPS), adding a transillumination technique. With this knowledge, we selected the safest highway to improve this particular approach. METHODS: An in-depth study of the white matter tracts was performed on 24 cerebral hemispheres (12 human whole brains). The Klingler technique and microsurgical dissection techniques were used under ×6 to ×40 magnification. The transillumination technique (torch illuminating the ventricular cavity) was used to expose the layers surrounding the VA and, thus, guide the dissection. RESULTS: Taking the IPS on the cerebral surface as a reference, we identified the following white matter layers ordered from the surface to the ependyma: U fibers, superior longitudinal fascicle, arcuate fascicle, vertical occipital fascicle, sagittal stratum with the optic radiations, and tapetum fibers. The transillumination technique allowed for the easier identification of the white matter deep periventricular layers. CONCLUSIONS: Knowledge of the main fascicles in the path and neighborhood of the VA allowed us to understand how certain neurologic functions can be affected by lesions at this level and to select the most appropriate way to avoid damaging relevant fascicles.

Tentorial Venous Anatomy: Cadaveric and Radiographic Study with Discussion of Origin and Surgical Significance.

BACKGROUND: Described variations of tentorial venous anatomy impact surgical sectioning of the tentorium in skull base approaches; however, described configurations do not consistently explain postoperative complications. To understand the outcomes of 2 clinical cases we studied the tentorial venous anatomy of 2 cadavers. METHODS: The venous anatomy of the tentorium isolated in 2 uninjected fresh cadaver head specimens with preserved bridging veins was observed by transillumination before and after methylene blue injection of the dural sinuses and tentorial veins. Our findings in cadavers were applied to explain the clinical and radiologic (magnetic resonance imaging and computed tomographic venography) findings in the 2 cases presented. RESULTS: A consistent transtentorial venous system, arising from transverse and straight sinuses, communicating with supra- and infratentorial bridging veins was seen in the cadaver and patient radiography (magnetic resonance imaging and computed tomographic venography). Our first patient had a cerebellar venous infarct from compromise of the venous drainage from the adjacent brain after ligation of a temporal lobe bridging vein to the tentorium. Our second patient suffered no clinical effects from bilateral transverse sinus occlusion due to drainage through the accessory venous system within the tentorium. CONCLUSIONS: Herein, we elaborate on transtentorial venous anatomy. These veins, previously reported to obliterate in completed development of the tentorium, remain patent with consistent observed configuration. The same transtentorial venous system was observed in both cases and provided insight to their outcomes. These findings emphasize the importance of the transtentorial venous system physiologically and in surgical approaches.

Microsurgical Anatomy of the Insular Region and Operculoinsular Association Fibers and its Neurosurgical Application.

OBJECTIVE: To analyze the three-dimensional relationships of the operculoinsular compartments, using standard hemispheric and white matter fiber dissection and review the anatomy of association fibers related to the operculoinsular compartments of the Sylvian fissure and the main white matter tracts located deep into the insula. The secondary aim of this study was to improve the knowledge on this complex region to safely address tumor, vascular, and epilepsy lesions with an integrated perspective of the topographic and white matter fiber anatomy using 2D and 3D photographs. METHODS: Six cadaveric hemispheres were dissected. Two were fixed with formalin and the arteries were injected with red latex dye; the remaining four were prepared using the Kingler method and white fiber dissections were performed. RESULTS: The insula is located entirely inside the Sylvian fissure. The topographic hemispheric anatomy, Sylvian fissure, opercula, surrounding sulci and gyri, as well as the M2, M3, and M4 segments were identified. The anatomy of the insula, with the sulci and gyri and the limiting sulci, were also identified and described. The main white matter fiber tracts of the operculoinsular compartments of the Sylvian fissure as well as the main association and commissural fibers located deep in the insula were dissected and demonstrated. CONCLUSIONS: Complementing topographic anatomy with detailed study of white matter fibers and their integration can help the neurosurgeon to safely approach lesions in the insular region, improving postoperative results in the microsurgical treatment of aneurysmal lesions, insular tumors, or epilepsy surgery.

Suboccipital Lateral Approach for Resection of Cerebellopontine Angle Meningioma: Operative Video and Technical Nuances.

We present the case of a 34-year-old woman, who presented to our department with a 4 months history of dizziness, hearing loss, and tinnitus on the right side. MRI (magnetic resonance imaging) scan demonstrated a large extra-axial lesion, suggestive of a meningioma, with dural attachments to the petrosal bone surface and tentorium, closely related with the trigeminal, abducens, facial, vestibulocochlear, and lower cranial nerves in the right side. Treatment options were discussed with the patient, and surgical resection was selected to remove the lesion, and decompress the cranial nerves and brainstem. The surgery was performed with a patient in a semi-seated position with head placed in a flexed, nonrotated position. A right lateral suboccipital approach was performed, exposing the right transverse and sigmoid sinuses. After dura opening, microsurgical dissection was used to open the cisterna magna, and obtain cerebellum relaxation. That was followed by identification of cranial nerves VII-XII and then identification of the tumor itself. Tumor debulking was then performed with use of suction and ultrasonic aspirator. After extensive resection, the tumor margins were dissected away from brainstem, cerebellum, and cranial nerves. Finally, the tumor attachment to the tentorium was coagulated and cut and the tumor was completely removed. Postoperative MRI confirmed complete resection of the tumor. The patient was discharged on the 1st week after surgery, with no additional postoperative deficits or complications. The link to the video can be found at: https://youtu.be/aZ3jhZTAeAA .