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OBJECTIVE Pineal region tumors account for 2.7%–11% of all CNS tumors in children. In this series, the authors present their surgical results and long-term outcomes from a pediatric pineal region tumor cohort. METHODS A total of 151 children aged 0–18 years were treated from 1991 to 2020. Tumor markers were collected in all patients; if positive, chemotherapy was performed, and if negative, biopsy was performed, preferably endoscopically. Resection was performed when there was a residual germ cell tumor (GCT) lesion after chemotherapy. RESULTS The distribution based on histological type, as verified by markers, biopsy, or surgery, was germinoma (33.1%), nongerminomatous GCT (NGGCT) (27.2%), pineoblastoma (22.5%), glioma (12.6%), and embryonal tumor (atypical teratoid rhabdoid tumor) (3.3%). A total of 97 patients underwent resection, and gross-total resection (GTR) was achieved in 64%; the highest GTR rate (76.6%) was found in patients with GCTs, and the lowest (30.8%) was found in those with gliomas. The supracerebellar infratentorial approach (SCITA) was the most common, performed in 53.6% of patients, followed by the occipital transtentorial approach (OTA), performed in 24.7% of patients. Lesions were biopsied in 70 patients, and the diagnostic accuracy was 91.4. The overall survival (OS) rates at 12, 24, and 60 months as stratified by histological type were 93.7%, 93.7%, and 88% for patients with germinomas; 84.5%, 63.5%, and 40.7% for patients with pineoblastomas; 89.4%, 80.8%, and 67.2% for patients with NGGCTs; 89.4%, 78.2%, and 72.6% for patients with gliomas; and 40%, 20%, and 0% for patients with embryonal tumors, respectively (p < 0001). The OS at 60 months was significantly higher in the group with GTR (69.7%) than in the group with subtotal resection (40.8%) (p = 0.04). The 5-year progression-free survival was 77% for patients with germinomas, 72.6% for patients with gliomas, 50.8% for patients with NGGCTs, and 38.9% for patients with pineoblastomas. CONCLUSIONS The efficacy of resection varies by histological type, and complete resection is associated with higher OS rates. Endoscopic biopsy is the method of choice for patients presenting with negative tumor markers and hydrocephalus. For tumors restricted to the midline and with extension to the third ventricle, a SCITA is preferred, whereas for lesions with extension toward the fourth ventricle, an OTA is preferred.

Lesions in the ventral striatum region (above the anterior perforated substance) are a challenge for neurosurgeons due to their direct relationship with the lenticulostriate arteries, which difficult the surgical access. The standard approaches for this region include the following: 1) transfrontal approach, 2) transanterior perforating substance approach, 3) transcallosal transventricular approach, and 4) pterional transsylvian-transinsular route. In this study, we aimed to describe a novel anatomical approach through the anterior limiting sulcus of the insula in order to access the ventral striatum.We reviewed the literature and performed a detailed dissection of this region by using Klingler's technique with brain specimens injected with silicone, paying special attention to the white fibers and lenticulostriate arteries, and provided a description of an illustrative case of a cavernous malformation.Neuroanatomical dissections showed that the lenticulostriate arteries had an inverted C-shaped anterior concavity, leaving less significant vascular relationships in the depth of the anterior limiting sulcus of the insula. In the case we described, the cavernous malformation was completely resected and the patient was discharged without any neurological deficits.The transanterior limiting sulcus of the insula approach to the ventral striatum offers a safe access route for selected cases and can be performed on the basis of anatomical references. Three-dimensional understanding of the intrinsic brain architecture and its relationships with vascular structures in this specific area is important and can be acquired mainly through laboratory training.

Low-grade gliomas compose 30% of pediatric central nervous system tumors and outcomes of disease-free progression, and survival is directly correlated to the extent of resection. The use of sodium fluorescein (Na-Fl) is an intraoperative method in the localization of tumor cells in adult patients to optimize resection. Our purpose is to describe the use of Na-Fl in pediatric low-grade gliomas and its outcomes.Patients under 18 years of age with low-grade gliomas at the author's institution underwent resection with the use of Na-Fl, with review of preoperative imaging findings, intraoperative results, and follow-up. Then, a comprehensive, narrative literature review of the use of Na-Fl in pediatric low-grade glioma was performed.Our single-institution use of Na-Fl in pediatric patients with suspected low-grade glioma demonstrated excellent results of intraoperative enhancement of tumor cells as well as gross total resection. The literature demonstrated 84% Na-Fl staining and 59.2% of gross total resection in pediatric low-grade gliomas with few small case studies, a range of reported findings, and few side effects.Na-Fl has a promising use in low-grade glioma resection in the pediatric patient population. Further research is warranted, such as randomized controlled studies, to assess Na-Fl as a potential tool in improving resection and long-term favorable outcomes.

Schistosomiasis is an endemic parasitic disease in several tropical countries. In Brazil, the only prevalent species of parasite responsible for schistosomiasis is Schistosoma mansoni. Neuroschistosomiasis is the second most frequent form of infection and the primary ectopic manifestation, with predominant involvement of the lower thoracic spinal cord and lumbar and lumbosacral regions. The frequent contact of children with contaminated ponds and the immaturity of their immune systems make this age group especially susceptible to infection by this parasite. Therefore, neuroschistosomiasis mansoni should always be considered in cases of transverse myelitis in children from endemic regions. The treatment for this condition is quite simple and effective, resulting in total recovery of neurological deficits if the diagnosis is made early.

The cerebellar interpeduncular region, particularly the middle cerebellar peduncle (MCP) and interpeduncular sulcus (IPS) are significant surgical relevance areas due to the high prevalence of vascular and tumoral pathologies, such as cavernomas, arteriovenous malformations, and gliomas. We defined safer access areas of the MCP and the IPS, according to the surface anatomy, involved vessels, and fiber tracts of the cerebellar interpeduncular region.Fifteen formalin-fixed and silicone-injected cadaveric heads and 23 human brainstems with attached cerebellums prepared with the Klingler's technique were bilaterally dissected to study the vascular and intrinsic anatomy.Surface anatomy: The mean length of the IPS was 12.73 mm (standard deviation [SD],2.15 mm), and the average measured angle formed by the IPS and the lateral mesencephalic sulcus was 144.53°. The mean distance from the uppermost point of the IPS to cranial nerve IV was 2.63 mm (SD, 2.84 mm). Vascular anatomy: The perforating branches of the superior cerebellar peduncle, IPS, and MCP originated predominantly from the caudal trunk of the superior cerebellar artery. The inferior third of the superior cerebellar peduncle and IPS was the third most pierced by perforating arteries, and for the MCP, was its superior third. Crossing vessels: The branches of the pontotrigeminal vein and the caudal trunk of the superior cerebellar artery crossed the IPS mostly. The superior third of the IPS was the most crossed by arteries and veins.The middle thirds of the IPS and MCP as entry zones might be safer than their superior and inferior thirds due to fewer perforating branches, arterial trunks, and veins crossing the sulcus as fewer eloquent tracts.

OBJECTIVE The cerebellar interpeduncular region (CIPR) is a gate for dorsolateral pontine and cerebellar lesions accessed through the supracerebellar infratentorial approach (SCITa), the occipital transtentorial approach (OTa), or the subtemporal transtentorial approach (STa). The authors sought to compare the exposures of the CIPR region that each of these approaches provided. METHODS Three approaches were performed bilaterally in eight silicone-injected cadaveric heads. The working area, area of exposure, depth of the surgical corridor, length of the interpeduncular sulcus (IPS) exposed, and bridging veins were statistically studied and compared based on each approach. RESULTS The OTa provided the largest working area (1421 mm2; p < 0.0001) and the longest surgical corridor (6.75 cm; p = 0.0006). Compared with the SCITa, the STa provided a larger exposure area (249.3 mm2; p = 0.0148) and exposed more of the length of the IPS (1.15 cm; p = 0.0484). The most bridging veins were encountered with the SCITa; however, no significant differences were found between this approach and the other approaches (p > 0.05). CONCLUSIONS To reach the CIPR, the STa provided a more extensive exposure area and more linear exposure than did the SCITa. The OTa offered a larger working area than the SCIT and the STa; however, the OTa had the most extensive surgical corridor. These data may help neurosurgeons select the most appropriate approach for lesions of the CIPR.

Objective Brainstem safe entry zones (EZs) are gates to access the intrinsic pathology of the brainstem. We performed a quantitative analysis of the intrinsic surgical corridor limits of the most commonly used EZs and illustrated these through an inside perspective using 2-dimensional photographs, 3-dimensional photographs, and interactive 3-dimensional model reconstructions. Methods A total of 26 human brainstems (52 sides) with the cerebellum attached were prepared using the Klingler method and dissected. The safe working areas and distances for each EZ were defined according to the eloquent fiber tracts and nuclei. Results The largest safe distance corresponded to the depth for the lateral mesencephalic sulcus (4.8 mm), supratrigeminal (10 mm), epitrigeminal (13.2 mm), peritrigeminal (13.3 mm), lateral transpeduncular (22.3 mm), and infracollicular (4.6 mm); the rostrocaudal axis for the perioculomotor (11.7 mm), suprafacial (12.6 mm), and transolivary (12.8 mm); and the mediolateral axis for the supracollicular (9.1 mm) and infracollicular (7 mm) EZs. The safe working areas were 46.7 mm2 for the perioculomotor, 21.3 mm2 for the supracollicular, 14.8 mm2 for the infracollicular, 33.1 mm2 for the supratrigeminal, 34.3 mm2 for the suprafacial, 21.9 mm2 for the infrafacial, and 51.7 mm2 for the transolivary EZs. Conclusions The largest safe distance in most EZs corresponded to the depth, followed by the rostrocaudal axis and, finally, the mediolateral axis. The transolivary had the largest safe working area of all EZs. The supracollicular EZ had the largest safe area to access the midbrain tectum and the suprafacial EZ for the floor of the fourth ventricle.

To investigate certain aspects of hydrocephalus in patients with myelomeningocele. We retrospectively analyzed data of 1050 patients with myelomeningocele who underwent surgical treatment between June 1991 and June 2021. These patients were divided into three groups: group 1 consisted of patients who underwent surgery after the first 6 h of life, group 2 consisted of patients who underwent surgery within the first 6 h, and group 3 consisted of patients who underwent surgery during the fetal period and before 26 6/7 weeks of gestation. There were 125, 590, and 335 patients in groups 1, 2, and 3, respectively. In groups 1 and 2, 593 (83%) patients developed hydrocephalus after birth and required ventriculoperitoneal shunt placement in the maternity ward, mainly within the first 4 days of life. In contrast, in group 3, 24 (7.2%) patients required surgery to treat hydrocephalus after birth. Hydrocephalus was the primary cause of mortality in groups 1 and 2, with mortality rates of 35% and 10%, respectively. In group 3, the mortality rate was 0.8% and was not related to hydrocephalus. The onset of hydrocephalus is directly related to myelomeningocele closure in neurosurgery.

Spontaneous third ventriculostomy (STV) is characterized by the spontaneous rupture of one of the ventricle walls due to increased pressure in the third ventricle caused by obstructive hydrocephalus. Clinically, STV results in resolution of signs and symptoms of intracranial hypertension and head circumference stabilization. No spontaneous STV cases in patients with myelomeningocele have been reported in the literature. The objective of this study was to report three cases of STV in patients with type 2 Chiari malformation who underwent intrauterine treatment. All patients presented clinically with increased head circumference during outpatient follow-up. Only one patient required a ventriculoperitoneal shunt implantation. The other patients did not require further intervention. STV is a rare entity that is difficult to diagnose and should always be suspected in spontaneous hydrocephalus resolution, especially in early childhood. STV is not synonymous with hydrocephalus resolution.

Background In this study, we evaluated children who underwent prenatal myelomeningocele (MMC) repair to investigate the influence of the anatomical level of the lesion on functional motor skills and congenital orthopedic malformations. Methods This cross-sectional study evaluated children who underwent prenatal correction. The anatomical level of the lesion was classified by observing the magnetic resonance of the spine. The sensory/motor assessment was performed by physical examination to classify the status of ambulation, functional level, and functional performance according to chronological age using the Pediatric Evaluation of Disability Inventory (PEDI-CAT) scale. Results One hundred cases were evaluated; for 60%, lesions were located in the upper lumbar region and for 40%, they were located in the lower lumbar and sacral regions. The functionality, measured by the PEDI-CAT scale, showed a normal average according to age (mean 50), with 71% of children being community ambulators. Congenital orthopedic malformations were also unrelated to the injury levels, except for knee dislocation in relation to upper lumbar injury. At the functional level, we observed that for the majority, the levels of function of at least 2 vertebrae were below the anatomical level. Conclusions There were no differences in functional motor skills, walking pattern, or congenital orthopedic malformation when compared with the anatomical level of injury in patients who underwent prenatal repair of MMC, except for congenital knee dislocation.

Objective Anterior clinoidectomy is an important and essential skill for skull base and cerebrovascular neurosurgeons. We present a 1-piece intradural anterior clinoidectomy, providing a step-by-step description of the technique, independently of anatomic variations. Methods Between 2014 and 2020, 128 patients (119 women and 9 men; average age, 54.6 years) underwent intradural anterior clinoidectomy during microsurgical clipping of carotid-ophthalmic aneurysms. Results The anterior clinoid process continues medially with the planum sphenoidale, over the optic nerve, laterally with the lesser wing of the sphenoid bone, and inferiorly with the optic strut, which is always found anteriorly to the clinoid segment of the internal carotid artery, and separates the optic canal from the superior orbital fissure. The proposed anterior clinoidectomy followed, one after the other, these 3 fixation points for the detachment of the anterior clinoid process. The main indication for intradural anterior clinoidectomy was the management of vascular lesions around paraclinoid (clinoidal and ophthalmic) segments of the internal carotid artery. Complications of the procedure included injury to the internal carotid artery or the ophthalmic artery, thermal damage to the optic nerve, and invasion of the sphenoid sinus or a pneumatized anterior clinoid process, which could lead to postoperative cerebrospinal fluid leakage. Conclusions The anterior clinoidectomy technique described here minimizes the drilling surface for detachment of the anterior clinoid process and reduces operative time as well as the amount of bone dust produced by drilling. It also precisely delineates the localization of the optic strut, preventing carotid or optic nerve damage.

OBJECTIVETumors of the CNS are the main causes of childhood cancer and have an incidence that exceeds that of leukemia. In addition, they are the leading causes of cancer-related death in childhood. High-grade gliomas account for 11% of such neoplasms and are characterized by aggressive clinical behavior and high morbidity and mortality. There is a lack of studies focusing on the factors that can prolong survival in these patients or guide therapeutic interventions. The authors aimed to investigate the factors related to longer survival durations, with a focus on reoperation for gross-total resection (GTR).METHODSIn this retrospective cohort study, the authors analyzed 78 patients diagnosed with high-grade gliomas occurring across all CNS locations except diffuse intrinsic pontine gliomas. Patients 0 to < 19 years of age were followed up at the Pediatric Oncology Institute. Overall survival (OS) and progression-free survival (PFS) were analyzed in the context of various prognostic factors, such as age, sex, histology, extent of tumor resection, reoperation for GTR, adjuvant treatment, and treatment initiation from 2010 onward.RESULTSWith a mean age at diagnosis of 8.7 years, 50% of the patients were female and approximately 39% underwent GTR at some point, which was already achieved in approximately 46% of them in the first surgery. The median OS was 17 months, and PFS was 10 months. In terms of median OS, the authors found no significant difference between those with reoperation for GTR and patients without GTR during treatment. Significant differences were observed in the OS in terms of the extent of resection in the first surgery, age, sex, Ki-67 expression, adjuvant treatment, and treatment initiation from 2010 onward. Furthermore, the PFS values significantly differed between those with GTR in the first surgery and Ki-67 expression ≥ 50%.CONCLUSIONSThis study demonstrates the importance of GTR for these neoplasms, highlights the role of surgeons in its achievement in the first attempt, and questions the role of reoperation for this purpose. Finally, this study further supports the use of combined adjuvant treatment for the improvement of OS and PFS.

Background: Training in microsurgical neuroanatomy is a priority for neurosurgical education. During the 20th century, microsurgical laboratories arose and provided a way to develop surgical skills. Few reports addressed the assembly, construction, and details of a training laboratory. Methods: We have conducted a literature review and searched legislation on the need to plan the structure of the laboratory. Results: We projected and built a laboratory through a public-private partnership. High-tech workstations and instruments were planned to meet the needs of residents, fellows, and student. All steps and materials were in accordance with the Brazilian legislation and articles previously selected. Conclusion: We described our experience and demonstrated the implementation of a micro neurosurgical skills laboratory.

Background Wilms tumor is a rare renal tumor in adults. To the best of our knowledge, only a small number of cases of brain metastasis have been reported in the literature. We report the case of a 29-year-old female with headache and dizziness, with a parietal mass and pathologic diagnosis of Wilms tumor metastasis. Case Description The patient was admitted with a 3-month history of lumbar pain and 2 months of progressive headache associated with dizziness. Abdomen magnetic resonance imaging showed a renal mass. Post nephrectomy, the neurologic signs worsened and a head magnetic resonance imaging presented in the right parietal lobe, convexity, heterogeneous lesion with little perilesional edema. The patient underwent a complete surgical resection with success. The adjuvant treatment was chemotherapy. Conclusions Few cases of brain metastasis of Wilms tumor exist in the literature. Surgical management is considered in cases with intracranial hypertension or focal signs. The adjuvant treatment options are immunotherapy and chemotherapy.

Glioependymal cysts are a rare, congenital, and benign condition. The authors report a case of a 2-year-old female patient who presented with a large exophytic glioependymal cyst located in the left cerebral peduncle, which began with a history of deteriorating function of the left third cranial nerve (CN III). A left 3-piece fronto-orbitozygomatic approach and a microsurgical complete excision of the cyst were performed without complications by accessing the midbrain through the perioculomotor entry zone. The patient’s CN III function completely recovered after 3 months. Because there are currently no widely approved and used classification systems for these cysts, their reporting, naming, and classification are quite confusing in the literature. Thus, their origin, classification, and most common locations warrant further investigation. In addition to reporting this case, the authors present their review of the literature.

Background The extended supraorbital approach through a modified eyebrow incision is a minimally invasive variant of the frontotemporal or pterional approach that enriches a neurosurgeon's armamentarium for the treatment of pathologies lateral to the anterior clinoid process, by advancing laterally with frontal facial nerve branches monitoring. To demonstrate the steps of the approach, we studied 2 formalin-fixed and artery/vein silicone-injected adult cadaveric heads, and reviewed 1 of the 3 clinical cases operated on to illustrate the applicability of the approach. Clinical Presentation A 56-year-old woman presented with a history of seizures and a complaint of headache that started 2 months ago. She underwent an examination with brain magnetic resonance imaging that showed a dural-based lesion at the medial third of the lesser wing of sphenoid (which is consistent with meningioma). The patient underwent craniotomy with an extended supraorbital approach through a modified eyebrow incision that allowed Simpson grade II removal to be performed and good aesthetic outcome to be achieved. Conclusions The extended supraorbital approach through a modified eyebrow incision is a minimally invasive approach that can add to a neurosurgeon's armamentarium and be used with microscopy, assisted by endoscope, or both to reach the anterior and middle cranial fossae.