CRANIOPLASTY WITH DIRECT REVASCULARIZATION IN HEMORRHAGIC MOYAMOYA DISEASE: 2-DIMENSIONAL OPERATIVE VIDEO.

Moyamoya disease is a progressive nonatherosclerotic stenosis of the terminal segments of the arteries of the Circle of Willis. Hemorrhagic presentation is a life-threatening condition, associated with an increased risk of rebleeding and ischemic events.1-7 We present the case of a 65-year-old woman with a right intracerebral hemorrhage who underwent emergency hematoma evacuation without bone flap replacement. The investigation confirmed the diagnosis of Moyamoya disease and demonstrated hypoperfusion of the right cerebral hemisphere. Late angiography depicted no transdural collaterals through the bone defect and demonstrated preservation of the superficial temporal artery (STA). Next, it was chosen to perform one-stage cranioplasty with direct revascularization. We detached the temporal fascia from the muscle and created a window through the fascia to give STA passage in a corridor through the temporal muscle until the brain's surface. Vascular anastomosis was performed with an interrupted suture line employing a 10-0 nylon thread. Flow within the right middle cerebral artery (MCA) was retrograde, coming from branches of the posterior cerebral artery (PCA), and the end-to-side anastomosis was placed to orientate the STA flow in the same direction as in the MCA. We used a custom-made titanium plate for the cranioplasty and gave enough room inferiorly for the course of STA. In the end, we sutured the temporal fascia to the titanium plate for a better cosmetic result. To avoid additional unnecessary procedures, the performance of direct revascularization during the cranioplasty is feasible and deserves additional investigation as a tool to prevent new hemorrhagic or ischemic events. Informed consent was obtained from the patient for the procedure and publication of this operative video.

Bipolar, high-voltage, long-duration pulsed radiofrequency ablation of the Gasserian ganglion for the treatment of trigeminal neuralgia in a patient with a cardiac implantable electronic device: illustrative case.

BACKGROUND: One of the common methods of treating trigeminal neuralgia (TN) nowadays is radiofrequency therapy. However, it has serious limitations in patients with a cardiac pacemaker because of electromagnetic interference. Therefore, it is crucial to select optimal radiofrequency ablation parameters to make this procedure safe with favorable outcomes for such patients. OBSERVATIONS: In this study, the authors present a case of a 70-year-old man with a history of cardiac pacemaker dependency and previous microvascular decompression with complaints of severe, constant facial pain. After reprogramming the cardiac implantable electronic device (CIED), the authors performed bipolar, high-voltage, long-duration pulsed radiofrequency therapy (PRFT) of the Gasserian ganglion under electrocardiography and pulse rate control in the pre-, intra-, and postoperative periods. There were no cardiovascular or neurological complications after PRFT. The patient reported relief of pain after the procedure, and at the 9-month follow-up, he was pain-free. LESSONS: This clinical case demonstrates that the use of bipolar, high-voltage PRFT for TN treatment in patients with a CIED can be safe and effective, provided that the rules and pacemaker instructions are followed. It is necessary to use ablative treatment with caution and to guide the patient in collaboration with a cardiac surgeon and an anesthesiologist resuscitator.

Proteomics reveals differentially regulated pathways when comparing grade 2 and 4 astrocytomas.

Astrocytic tumors are known for their high progression capacity and high mortality rates; in this regard, proteins correlated to prognosis can aid medical conduct. Although several genetic changes related to progression from grade 2 to grade 4 astrocytoma are already known, mRNA copies do not necessarily correlate with protein abundance and therefore could shadow further comprehension about this tumor's biology. This motivates us to seek for complementary strategies to study tumor progression at the protein level. Here we compare the proteomic profile of biopsies from patients with grade 2 (diffuse, n = 6) versus grade 4 astrocytomas (glioblastomas, n = 10) using shotgun proteomics. Data analysis performed with PatternLab for proteomics identified 5,206 and 6,004 proteins in the 2- and 4-grade groups, respectively. Our results revealed seventy-four differentially abundant proteins (p < 0.01); we then shortlist those related to greater malignancy. We also describe molecular pathways distinctly activated in the two groups, such as differences in the organization of the extracellular matrix, decisive both in tumor invasiveness and in signaling for cell division, which, together with marked contrasts in energy metabolism, are determining factors in the speed of growth and dissemination of these neoplasms. The degradation pathways of GABA, enriched in the grade 2 group, is consistent with a favorable prognosis. Other functions such as platelet degranulation, apoptosis, and activation of the MAPK pathway were correlated to grade 4 tumors and, consequently, unfavorable prognoses. Our results provide an important survey of molecular pathways involved in glioma pathogenesis for these histopathological groups.

Two-Stage Pulsatile Human Placenta Model for Microvascular Anastomosis Training in Neurosurgery.

OBJECTIVE: The development of microsurgical skills is crucial for neurosurgical education. The human placenta is a promising model for practicing vascular anastomosis due to its similarities with brain vessels. We propose a 2-stage model for training in extracranial-to-intracranial anastomosis using the placenta. METHODS: Initially, we propose practicing anastomosis in 2 adjacent placentas. Once successful, the procedure advances to a more challenging configuration that employs a 3-dimensionally printed skull with a window simulating a pterional craniotomy. It is positioned an intracranial placenta and an extracranial one, and the latter has a prominent vessel exposed toward the side of the craniotomy. Both placentas have one artery and vein cannulated in the umbilical cord, and we present an artificial placental circulation system for microvascular training that regulates pulsation and hydrodynamic pressure while keeping veins engorged with a pressurized bag. To verify anastomosis patency, we utilize sodium fluorescein and iodine contrast. RESULTS: The 2-stage model simulated several aspects of microvascular anastomosis. Our perfusion system allowed for intraoperative adjustments of hydrodynamic pressure and pulsation. Using iodine contrast and fluorescein enabled proper evaluation of anastomosis patency and hydrodynamic features. CONCLUSIONS: Training in the laboratory is essential for developing microsurgical skills. We have presented a model for microvascular anastomosis with artificial circulation and postoperative imaging evaluation, which is highly beneficial for enhancing the learning curve in microvascular procedures.

Clinical and anatomical analysis of the epileptogenic spread patterns in focal cortical dysplasia patients.

Background: Focal cortical dysplasia (FCD) is one of the main causes of intractable epilepsy, which is amendable by surgery. During the surgical management of FCD, the understanding of its epileptogenic foci, interconnections, and spreading pathways is crucial for attaining a good postoperative seizure free outcome. Methods: We retrospectively evaluated 54 FCD patients operated in Federal Center of Neurosurgery, Tyumen, Russia. The electroencephalogram findings were correlated to the involved brain anatomical areas. Subsequently, we analyzed the main white matter tracts implicated during the epileptogenic spreading in some representative cases. We prepared 10 human hemispheres using Klinger's method and dissected them through the fiber dissection technique. Results: The clinical results were displayed and the main white matter tracts implicated in the seizure spread were described in 10 patients. Respective FCD foci, interconnections, and ectopic epileptogenic areas in each patient were discussed. Conclusion: A strong understanding of the main implicated tracts in epileptogenic spread in FCD patient remains cardinal for neurosurgeons dealing with epilepsy. To achieve meaningful seizure freedom, despite the focal lesion resection, the interconnections and tracts should be understood and somehow disconnected to stop the spreading.

Liquid biopsy and tumor DNA/RNA detection in the cerebrospinal fluid of patients diagnosed with central nervous system glioma - A review article.

Background: Gliomas are the most common primary malignant neoplasms of the central nervous system and their characteristic genetic heterogeneity implies in a prominent complexity in their management. The definition of the genetic/molecular profile of gliomas is currently essential for the classification of the disease, prognosis, choice of treatment, and it is still dependent on surgical biopsies, which in many cases become unfeasible. Liquid biopsy with detection and analysis of biomarkers such as deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) from the tumor and circulating in the bloodstream or cerebrospinal fluid (CSF) has emerged as a minimally invasive alternative to aid in diagnosis, follow-up, and response to treatment of gliomas. Methods: Through a systematic search in the PubMed MEDLINE, Cochrane Library, and Embase databases, we reviewed the evidence on the use of liquid biopsy to detect tumor DNA/RNA in the CSF of patients diagnosed with central nervous system gliomas. Results: After a systematic review applying all inclusion and exclusion criteria, as well as a double review by independent authors, 14 studies specifically addressing the detection of tumor DNA/RNA in the CSF of patients diagnosed with central nervous system glioma were selected in the final analysis. Conclusion: Sensitivity and specificity of liquid biopsy in CSF are still very variable depending on factors such as the diagnostic method, collection timing, biomarker (DNA and RNA), tumor type, extension and volume of the tumor, collection method, and contiguity from neoplasm to CSF. Despite the technical limitations that still exist and prevent the routine and validated use of liquid biopsy in CSF, the growing number of studies around the world is increasingly improving this technic, resulting in promising prospects for its use in diagnosis, evolutionary follow-up, and response to the treatment of complex diseases such as central nervous system gliomas.

Transmastoid/Infralabyrinthine Approach to the Jugular Foramen: 2-Dimensional Operative Video.

INDICATIONS CORRIDOR AND LIMITS OF EXPOSURE: This approach is intended for tumors centered in the jugular foramen with extensions between intracranial and extracranial spaces, possible spread to the middle ear, and variable bony destruction. 1,2. ANATOMIC ESSENTIALS NEED FOR PREOPERATIVE PLANNING AND ASSESSMENT: Jugular foramen paragangliomas are complex lesions that usually invade and fill related venous structures. They present complex relationships with skull base neurovascular structures as internal carotid artery, lower cranial nerves (CNs), middle ear, and mastoid segment of facial nerve. In this way, it is essential to perform an adequate preoperative vascular study to evaluate sinus patency and the tumor blood supply, besides a computed tomography scan to depict bone erosion. ESSENTIAL STEPS OF THE PROCEDURE: Mastoidectomy through an infralabyrinthine route up to open the lateral border of jugular foramen, allowing exposure from the sigmoid sinus to internal jugular vein. Skeletonization of facial canal without exposure of facial nerve is performed and opening of facial recess to give access to the middle ear in way of a fallopian bridge technique. 2-10. PITFALLS/AVOIDANCE OF COMPLICATIONS: If there is preoperative preservation of lower CN function, it is important to not remove the anteromedial wall of the internal jugular vein and jugular bulb. In addition, facial nerve should be exposed just in case of preoperative facial palsy to decompress or reconstruct the nerve. VARIANTS AND INDICATIONS FOR THEIR USE: Variations are related mainly with temporal bone drilling depending on the extensions of the lesion, its source of blood supply, and preoperative preservation of CN function.Informed consent was obtained from the patient for the procedure and publication of his image.Anatomy images were used with permission from:• Ceccato GHW, Candido DNC, and Borba LAB. Infratemporal fossa approach to the jugular foramen. In: Borba LAB and de Oliveira JG. Microsurgical and Endoscopic Approaches to the Skull Base. Thieme Medical Publishers. 2021.• Ceccato GHW, Candido DNC, de Oliveira JG, and Borba LAB. Microsurgical Anatomy of the Jugular Foramen. In: Borba LAB and de Oliveira JG. Microsurgical and Endoscopic Approaches to the Skull Base. Thieme Medical Publishers. 2021.

Usefulness of Intraoperative ultrasound for cortical dysplasia type I treatment - A single-center experience.

Background: Focal cortical dysplasias (FCD) cause a subgroup of malformations of cortical development that has been closely linked to cause drug intractable epilepsy. Attaining adequate and safe resection of the dysplastic lesion has proved to be a viable option to archive meaningful seizure control. Of the three types of FCD (types I, II, and III), type I has the least detectable architectural and radiological abnormalities. This makes it challenging (preoperatively and intraoperatively) to achieve adequate resection. Intraoperatively, ultrasound navigation has proven an effective tool during the resection of these lesions. We evaluate our institutional experience in surgical management of FCD type I using intraoperative ultrasound (IoUS). Methods: Our work is a retrospective and descriptive study, where we analyzed patients diagnosed with refractory epilepsy who underwent IoUS-guided epileptogenic tissue resection. The surgical cases analyzed were from January 2015 to June 2020 at the Federal Center of Neurosurgery, Tyumen, only patients with histological confirmation of postoperative CDF type I were included in the study. Results: Of the 11 patients with histologically diagnosed FCD type I, 81.8% of the patients postoperatively had a significant reduction in seizure frequency (Engel outcome I-II). Conclusion: IoUS is a critical tool for detecting and delineating FCD type I lesions, which is necessary for effective post-epilepsy surgery results.

Improvement of optic nerve pial blood supply visualized through indocyanine green videoangiography after resection of a tuberculum sellae meningioma: 2-dimensional operative video.

Ischemia of the optic nerve (ON) is an important cause of visual field deficit provoked by tuberculum sellae (TS) meningiomas. Indocyanine green (ICG) videoangiography could provide prognostic information. Moreover, it allows new insight into the pathophysiology of visual disturbance. The authors present the case of a 48-year-old woman with visual field impairment. Magnetic resonance imaging (MRI) depicted a lesion highly suggestive of a TS meningioma. Following microsurgical resection, ICG videoangiography demonstrated improvement of right ON pial blood supply. In this case, there was one lesion causing visual impairment through both direct compression over the left ON and ischemia to the right nerve. The video can be found here: https://stream.cadmore.media/r10.3171/2021.10.FOCVID21155.

Microsurgical Resection of Giant Petroclival Meningioma via the Posterior Petrosal Approach: 2-Dimensional Operative Video.

Petroclival meningiomas are challenging deep-seated lesions related to many critical neurovascular structures of the skull base.1-5 We present the case of a 45-year-old male presenting with a 3-year history of progressive headache associated gradually with multiple cranial nerves deficits and progressive tetraparesis leading to use of a wheelchair (Video 1) Preoperative magnetic resonance imaging demonstrated a mass highly suggestive of a giant left petroclival meningioma. Considering worsening of symptoms and impressive mass effect, microsurgical resection employing the posterior petrosal approach was performed. Mastoidectomy with skeletonization of semicircular canals and a craniotomy approaching both posterior and middle cranial fossae were done. Dural incision at the base of the temporal lobe was communicated to other incision in the presigmoid dura by ligation and sectioning of superior petrosal sinus. Tentorium was cut all the way toward the incisura, with attention to preserve the fifth nerve along its division and fourth nerve in the last cut. After a complete tentorium incision, the presigmoid space enlarged, exposing both supratentorial and infratentorial spaces. The lesion was totally resected employing microsurgical techniques. Postoperative magnetic resonance imaging demonstrated complete tumor resection. The patient experienced improvement of complaints and no new neurologic deficit on follow-up. The posterior petrosal approach gives great exposure and a more lateral angle of attack to the ventral surface of brainstem, allowing in this case to approach the whole tumor attachment. Informed consent was obtained from the patient for the procedure and publication of this operative video. Anatomic images were courtesy of the Rhoton Collection, American Association of Neurological Surgeons/Neurosurgical Research and Education Foundation.

Burnout, Discrimination, Abuse, and Mistreatment in Latin America Neurosurgical Training During the Coronavirus Disease 2019 Pandemic.

BACKGROUND: Discrimination, abuse, and mistreatment are prevailing problems reported in neurosurgical training programs globally. Moreover, the current coronavirus disease 2019 (COVID-19) pandemic may also show a negative impact on burnout levels in neurosurgery residents. This study aims to evaluate burnout, discrimination, and mistreatment in neurosurgical residents training in Latin America during the severe acute respiratory syndrome coronavirus 2 era. METHODS: A 33-item electronic survey was sent to neurosurgery residents from Latin America from May 10 to 25, 2021. Statistical analysis was performed using SPSS version 25. RESULTS: A total of 111 neurosurgery residents responded to the survey. Mean age was 29.39 ± 2.37 years; 22.5% were female and 36% were training in Mexico. Residents who reported experiencing discrimination for testing positive to COVID-19 had the highest levels of depersonalization (66.7%; P = 0.043) and emotional exhaustion (75%; P = 0.023). Female respondents reported higher rates of gender discrimination (80% vs. 1.2%; P = 0.001), abuse (84% vs. 58.1%; P < 0.005), and sexual harassment (24% vs. 0%; P < 0.001) than did male respondents. Residents training in Mexico reported lower rates of emotional or verbal abuse (59.2% vs. 32.5%; P = 0.007) and bullying (P < 0.005) than did those in other countries in Latin America. Older age was a protective factor for high depersonalization scores (odds ratio [OR], 0.133; 95% confidence interval [CI], 0.035-0.500). Experiencing discrimination represented a risk factor for presenting high emotional exhaustion scores (OR, 3.019; 95% CI, 1.057-8.629). High levels of depersonalization were associated with a 7-fold increased risk of suicidal ideation (OR, 7.869; 95% CI, 1.266-48.88). CONCLUSIONS: The COVID-19 pandemic has been a significant burden on several aspects of health care workers' lives. Our results provide a broad overview of its impact on burnout, discrimination, and mistreatment as experienced by neurosurgery residents training in Latin America, laying the groundwork for future studies and potential interventions.

Endoscopic Treatment of Middle Cranial Fossa Arachnoid Cysts in Children: Surgical Results of 65 Cases.

OBJECTIVE: Congenital arachnoid cysts in the middle fossa accounts for 50% of all intracranial arachnoid cysts. Several management options have been described; however, no single technique has been universally adopted. We describe a series of pediatric patients with middle cranial fossa arachnoid cyst that were treated through an innovative minimally invasive endoscopic technique, along with their clinical aspects and surgical outcomes. METHODS: Data from 65 patients operated between 2012 and 2018 were retrospectively analyzed. Follow-up ranged from 12 to 96 months. Clinical presentation and surgical outcomes were collected. Endoscopic cystocisternostomy was performed in all patients using a mini endoscope. RESULTS: There were 41 male and 24 female patients, with a mean age of 5.3 years at the time of treatment. Except for 4 patients, all presented with 1 or more symptoms, and the most frequent were intracranial hypertension signs. All patients were treated with the same surgical technique, with an efficacy of 81.5%. CONCLUSIONS: Using a mini endoscope allow us to perform multiple fenestrations along the arachnoid and deeply inspect the basal cisterns, achieving a much wider communication between the cyst and subarachnoid space with a high success rate and minimal invasiveness.

Microsurgical Resection of Trigeminal Schwannoma via Anterior Petrosal Approach: 2-Dimensional Operative Video.

Trigeminal schwannomas are complex lesions that may be related to many critical neurovascular structures. We present the case of a 59-year-old male presenting a history of left-sided trigeminal neuralgia. Preoperative imaging demonstrated a mass highly suggestive of a trigeminal schwannoma, and microsurgical resection was indicated considering the progressive symptomatology and important mass effect (Video 1). A middle fossa route including an anterior petrosectomy was chosen. The patient was placed supine with the head rotated to the contralateral side, and an arcuate incision was performed. A V-shaped zygomatic osteotomy was done to mobilize the temporalis muscle more inferiorly and better expose the middle fossa floor. Following craniotomy, peeling of the dura propria from the lateral wall of cavernous sinus was carried out starting by coagulation of middle meningeal artery. Some tumor was already identified and removed, and then the anterior petrosectomy was performed until we exposed the posterior fossa dura. The middle fossa dural incision was connected with the other one at the posterior fossa dura, by coagulation of the superior petrosal sinus. The tentorium was completely cut toward the incisura. After lesion debulking, the tumor was progressively removed by peeling the arachnoid from the lesion to maintain arachnoid planes and preserve the nerves and their blood supply. Postoperative imaging demonstrated complete tumor resection. The patient's symptoms improved, and there were no neurologic deficits on follow-up. Extensive laboratory training is fundamental to be familiarized with the normal anatomic nuances and prepared to face the anatomy distorted by lesion. Informed consent was obtained from the patient for the procedure and publication of this operative video.

Microsurgical Resection of Intracanalicular Vestibular Schwannoma via Retrosigmoid Approach: 3-Dimensional Operative Video.

Vestibular schwannomas are a multifaceted group of tumors that can present with different sizes and involvement of critical neurovascular structures.1-6 While operating on these tumors, a critical goal is postoperative preservation of facial nerve function and hearing. We present the case of a 66-year-old male with a history of severe left-sided tinnitus and progressive hearing loss (Video 1). Preoperative imaging depicted a lesion highly suggestive of an intracanalicular vestibular schwannoma. Due to worsening of symptoms and after thoughtful discussion with the patient, microsurgical resection was indicated under constant neurophysiologic monitoring. A retrosigmoid approach was employed, and the posterior wall of the internal auditory canal was opened, allowing exposure of tumor and its total resection. Postoperative imaging demonstrated complete tumor resection. The patient's symptoms improve, and there were no new neurologic deficits on follow-up. Anatomical images were a Courtesy of the Rhoton Collection, American Association of Neurological Surgeons (AANS)/Neurosurgical Research and Education Foundation (NREF).

Impact of the Coronavirus Disease 2019 Pandemic on Working and Training Conditions of Neurosurgery Residents in Latin America and Spain.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has exerted a significant impact on health care workers. Recent studies have reported the detrimental effects of the pandemic on neurosurgery residents in North America, Asia, and Italy. However, the impact of the pandemic on neurosurgical training in Latin America and Spain has not yet been reported. In the present report, we describe effects of COVID-19 on training and working conditions of neurosurgery residents in these countries. METHODS: An electronic survey with 33 questions was sent to neurosurgery residents between September 7, 2020 and October 7, 2020. Statistical analysis was made in SPSS version 25. RESULTS: A total of 293 neurosurgery residents responded. The median age was 29.47 ± 2.6 years, and 79% (n = 231) were male. Of respondents, 36.5% (n = 107) were residents training from Mexico; 42% surveyed reported COVID symptoms and 2 (0.7%) received intensive care unit care; 61.4% of residents had been tested for COVID and 21.5% had a positive result; 84% of the respondents mentioned persisted with the same workload (≥70 hours per week) during the pandemic. Most residents from Mexico were assigned to management of patients with COVID compared with the rest of the countries (88% vs. 68.3%; P < 0.001), mainly in medical care (65.4% vs. 40.9%; P < 0.001), mechanical ventilators (16.8% vs. 5.9%; P = 0.003), and neurologic surgeries (94% vs. 83%; P = 0.006). CONCLUSIONS: Our results offer a first glimpse of the changes imposed by the COVID-19 pandemic on neurosurgical work and training in Latin America and Spain, where health systems rely strongly on a resident workforce.

Microsurgical Resection of Petroclival Meningioma via the Posterior Petrosal Approach: Three-Dimensional Operative Video.

Petroclival meningiomas are complex, deep-seated lesions related to many critical neurovascular structures. We present the case of a 44-year-old woman who had presented with a history of severe facial pain, hearing loss, and tinnitus on the left side, associated with left facial hypoesthesia (Video 1). Preoperative magnetic resonance imaging demonstrated a mass highly suggestive of a left petroclival meningioma. Considering the worsening symptoms and important mass effect, microsurgical resection using the posterior petrosal approach was performed. Mastoidectomy was performed first, followed by craniotomy encompassing both posterior and middle cranial fossae. The posterior fossa and middle fossa dural incisions were connected, coagulating and sectioning the superior petrosal sinus. Next, the tentorium was cut all the way toward the incisura, with care to preserve the fourth nerve in the last cut. After completion of the tentorium incision, the presigmoid space increased. The lesion was totally resected using microsurgical techniques, with the aid of an ultrasonic aspirator to debulk the mass and allow for its circumferential dissection. Postoperative magnetic resonance imaging demonstrated complete tumor resection. The patient presented with improvement of symptoms and no new neurological deficit during follow-up. Skull base approaches, such as the posterior petrosal approach, are useful for successfully treating challenging lesions such as the one presented, with low morbidity. Laboratory training is essential to be familiarized with the complex intraoperative neuroanatomical nuances. The patient provided written informed consent for the report of her case and operative video. The anatomical images were provided courtesy of the Rhoton Collection, American Association of Neurological Surgeons/Neurosurgical Research and Education Foundation.