Jugular Foramen Paragangliomas.

Paragangliomas are the most common tumors at jugular foramen and pose a great surgical challenge. Careful clinical history and physical examination must be performed to adequately evaluate neurological deficits and its chronologic evolution, also to delineate an overview of the patient performance status. Complete imaging evaluation including MRI and CT scans should be performed, and angiography is a must to depict tumor blood supply and sigmoid sinus/internal jugular vein patency. Screening for multifocal paragangliomas is advisable, with a whole-body imaging. Laboratory investigation of endocrine function of the tumor is necessary, and adrenergic tumors may be associated with synchronous lesions. Preoperative prepare with alpha-blockage is advisable in norepinephrine/epinephrine-secreting tumors; however, it is not advisable in exclusively dopamine-secreting neoplasms. Best surgical candidates are young otherwise healthy patients with smaller lesions; however, treatment should be individualized each case. Variations of infratemporal fossa approach are employed depending on extensions of the mass. Regarding facial nerve management, we avoid to expose or reroute it if there is preoperative function preservation and prefer to work around facial canal in way of a fallopian bridge technique. If there is preoperative facial nerve compromise, the mastoid segment of the nerve is exposed, and it may be grafted if invaded or just decompressed. A key point is to preserve the anteromedial wall of internal jugular vein if there is preoperative preservation of lower cranial nerves. Careful multilayer closure is essential to avoid at most cerebrospinal fluid leakage. Residual tumors may be reoperated if growing and presenting mass effect or be candidate for adjuvant stereotactic radiosurgery.

Simultaneous cochlear implantation as a therapeutic option in vestibular schwannoma surgery: case report.

Hearing loss is the most common symptom of vestibular schwannomas (VSs). The management of these lesions includes observation, radiosurgery, and microsurgical resection. Hearing preservation and rehabilitation are the major challenges after the tumor treatment. A 43-year-old man with previous left-sided profound hearing loss and tinnitus presented with a 2-mm left-sided intracanalicular VS. The decision was made to perform a simultaneous cochlear implantation (CI) and microsurgical resection of the tumor. The patient did well postoperatively, with significant improvement of tinnitus, sound localization, and speech recognition in noise. Previous reports of simultaneous CI and VS resection in patients with neurofibromatosis type 2 and sporadic VS in the only hearing ear have been described. The role of CI in patients with VS and normal contralateral hearing has been recently described, showing positive outcomes due to the binaural benefits. Tinnitus also can be treated by the implantation of the cochlear device. The simultaneous microsurgical removal of VS and implantation of a cochlear device is a feasible approach in patients with unilateral hearing loss and severe tinnitus.

The transcondylar approach to craniocervical meningiomas.

Surgical removal of foramen magnum meningiomas poses great challenges due their deep location within the central skull base and their proximity to vital neurovascular structures. This video depicts the operative nuances of surgical management for a 59-year-old female who presented with a right-sided spinocranial meningioma. Simpson Grade I resection was achieved through a right transcondylar approach. The patient's postoperative period was unremarkable, and she was discharged home on postoperative Day 5 for periodic follow-up. The transcondylar approach safely exposes the craniocervical junction at the anterior aspect of the neuraxis and still allows the surgeon to access the tumor through a parallel plane, with minimum morbidity. The video can be found here: https://youtu.be/P0-kXjAkw9U .

Microsurgical management of a high-grade brain arteriovenous malformation in the central lobe after unsuccessful radiosurgery.

The recommendation for the great majority of high-grade brain arteriovenous malformations (bAVMs) is observation, except for those patients with recurrent hemorrhages, progressive neurological deficits, steal-related symptoms, or AVM-related aneurysms, for whom intervention should be considered. These are general recommendations, and the decision should be made on an individual basis. Surgical resection of an AVM in the central lobe may cause postoperative sensorimotor deficits since this anatomical region includes the pre- and postcentral gyri on the lateral surface and the paracentral lobule on the medial surface. The authors present a patient with a ruptured high-grade bAVM in the central lobe who underwent previous surgery for hematoma evacuation and previous radiosurgery, and whose indication for reoperation was proposed based on progressive hemiparesis. Microsurgical resection was possible after a wide frontoparietal craniotomy, which made all the nidus borders accessible. This case illustrates the anatomy and surgical technique for large nidus AVMs in eloquent areas, showing that complete microsurgical resection is possible with good clinical outcome. The video can be found here: https://youtu.be/Cpd1PK6BLIM .

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 (Video 1). 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 1-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 was retrograde, coming from branches of the posterior cerebral artery, and the end-to-side anastomosis was placed to orientate the STA flow in the same direction as in the middle cerebral artery. 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.

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.

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.

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.