Anatomy of the posterior Fossa: a comprehensive description for pediatric brain tumors.

Posterior fossa tumors are the most common pediatric brain tumors, and present unique challenges in terms of their location and surgical management. The posterior fossa comprehends complex anatomy and represents the smallest and deepest of the three cranial base fossae. An in-depth understanding of posterior fossa anatomy is crucial when it comes to the surgical resection of pediatric brain tumors. Mastering the knowledge of posterior fossa anatomy helps the neurosurgeon in achieving a maximal and safe volumetric resection, that impacts in both overall and progression free survival. With the advancements in microsurgery, the telovelar approach has emerged as the workhorse technique for the resection of posterior fossa tumors in pediatric patients. This approach involves meticulously dissecting of the natural clefts present in the cerebellomedullary fissure, making a comprehensive understanding of the underlying anatomy key for its success.

Posterior fossa tumors in children: current insights.

While in adults most intracranial tumors develop around the cerebral hemispheres, 45 to 60% of pediatric lesions are found in the posterior fossa, although this anatomical region represents only 10% of the intracranial volume. The latest edition of the WHO classification for CNS tumors presented some fundamental paradigm shifts that particularly affected the classification of pediatric tumors, also influencing those that affect posterior fossa. Molecular biomarkers play an important role in the diagnosis, prognosis, and treatment of childhood posterior fossa tumors and can be used to predict patient outcomes and response to treatment and monitor its effectiveness. Although genetic studies have identified several posterior fossa tumor types, differing in terms of their location, cell of origin, genetic mechanisms, and clinical behavior, recent management strategies still depend on uniform approaches, mainly based on the extent of resection. However, significant progress has been made in guiding therapy decisions with biological or molecular stratification criteria and utilizing molecularly targeted treatments that address specific tumor biological characteristics. The primary focus of this review is on the latest advances in the diagnosis and treatment of common subtypes of posterior fossa tumors in children, as well as potential therapeutic approaches in the future.   Conclusion: Molecular biomarkers play a central role, not only in the diagnosis and prognosis of posterior fossa tumors in children but also in customizing treatment plans. They anticipate patient outcomes, measure treatment responses, and assess therapeutic effectiveness. Advances in neuroimaging and treatment have significantly enhanced outcomes for children with these tumors. What is Known: • Central nervous system tumors are the most common solid neoplasms in children and adolescents, with approximately 45 to 60% of them located in the posterior fossa. • Multimodal approaches that include neurosurgery, radiation therapy, and chemotherapy are typically used to manage childhood posterior fossa tumors What is New: • Notable progress has been achieved in the diagnosis, categorization and management of posterior fossa tumors in children, leading to improvement in survival and quality of life.

Temporopolar Amygdalohippocampectomy for Mesial Temporal Lobe Epilepsy: A Two-Dimensional Anatomical Operative Video.

Mesial temporal lobe epilepsy is the most frequent type of focal epilepsy in young adults and the most commonly reported in surgical series worldwide.1,2 When seizures become refractory to drug therapy, they are unlikely to remit spontaneously, and for the 30% of patients with epilepsy that is refractory to antiepileptic drugs, resection of the mesial temporal lobe structures provides seizure control rates of 70%-80%.3,4 The transsylvian route for amygdalohippocampectomy has been used at our institution for many years, evolving from the first description of Yasargil through the inferior circular sulcus of insula to the most recent one through the amygdala trying to preserve the temporal stem.5,6 Despite good outcomes according to the Engel classification, analysis of late postoperative magnetic resonance imaging scans of our patients showed a high incidence of temporal pole atrophy and potential gliosis.7,8 Therefore, we decided to keep the transsylvian route, but we removed a portion of the temporal pole anterior to the limen insula, resulting in a temporopolar amygdalohippocampectomy.4,9 Temporopolar amygdalohippocampectomy demonstrated good temporal stem preservation, good visual outcomes, and good memory results.4 We also advocate that the transsylvian route has the potential to provide a superior view and resection of the piriform cortex, that is associated with seizure outcome after surgery.10 We present a case of a 42-year-old woman who had refractory seizures secondary to mesial temporal lobe epilepsy and underwent temporopolar amygdalohippocampectomy with a good outcome, remaining seizure-free (Engel IA) (Video 1). The patient provided consent for surgery and video publication.

Growing skull fracture in a child with Ehlers-Danlos syndrome: case report and literature review.

INTRODUCTION: Growing skull fracture (GSF) is a rare complication of head trauma in the pediatric population, commonly observed in children younger than 3 years. DISCUSSION: In this report, the authors describe a case of a 3-year-old male child, with clinical features of Ehlers-Danlos syndrome (EDS), who developed a GSF in frontal bone after a crib fall, treated with duraplasty and cranioplasty with autologous craft. Here, pertinent literature was reviewed with an emphasis on surgical techniques, and correlation with the mentioned syndrome. CONCLUSION: This is the first case of GSF in association with EDS in the literature. The relevance of the case described concerns the rarity of the condition itself, the atypical presentation, and the intraoperative findings, which showed the important fragility of the dura mater, probably due to EDS. Therefore, this syndrome, besides having influenced the pathogenesis, was also a challenging factor in the surgical treatment.

Peritoneal metastasis of a brainstem anaplastic ganglioglioma in a 2-year-old boy: case report and literature review.

Anaplastic gangliogliomas (AGG) are rare tumors of the central nervous system (CNS) that commonly affect children and young adults, with an unusual infratentorial presentation, which is related to hydrocephalus and a worse prognosis. We report a case of a brainstem AGG in a 2-year-old boy who underwent a ventriculoperitoneal shunting (VPS) and later presented peritoneal metastasis. We also reviewed the related literature. Even though rare, disease dissemination through VPS should be sought in patients with CNS tumors and VPS who develop new abdominal symptoms. The early diagnosis and intervention may minimize morbidity and improve quality of life of such patients.

Transcranial Approaches to the Orbit.

Transcranial approaches to the orbit provide familiar and flexible approaches with wide access to the majority of the orbit, only limited in the inferomedial orbit. A pterional craniotomy is the predominant approach but can be expanded with an orbital or zygomatic osteotomy for even wider access. Minimally invasive approaches, such as the lateral supraorbital or "eyebrow" supraorbital approach, are options for selected pathologies and minimize morbidity related to the approach.

Survival in patients with surgically treated spinal metastases.

BACKGROUND: Despite the various treatment protocols available, survival evaluation is a fundamental criterion for the definition of surgical management; there are still many inconsistencies in the literature on this topic, especially in terms of the value of surgery and its morbidity in patients with very short survival. OBJECTIVE: The objective was to analyze the association of clinical, oncological, and surgical factors in the survival of patients undergoing spinal surgery for spinal metastases (SM). MATERIALS AND METHODS: A retrospective cohort of forty patients who were surgically treated at our institution for SM between 2010 and 2018 were included in the study. We applied the prognostic scales of Tomita and Tokuhashi in each patient and evaluated the systemic status using Karnofsky Performance Scale (KPS) and Eastern Cooperative Oncology Group Performance Scale. Survival rate in months was estimated using the Kaplan-Meier curve, with death considered as primary outcome and, for the evaluation of the association between the variables, the Chi-square test, Fisher's exact test, or Fisher-Freeman-Halton test was applied for better survival. The level of statistical significance was considered as 5% (P ≤ 0.05). RESULTS: The mean survival was 8.4 months. Patients with KPS <70 had a mean survival of 6.36 months, while those with KPS >70 had a mean survival of 14.48 months (P = 0.04). The mean survival of patients classified as ECOG 2 was 7.05 months (95% confidence interval [CI]: 3.4-10.7), and that of patients classified as ECOG 3 and 4 was 1.24 months (95% CI: 0.8-1.59). The mean survival rate among the patients with unresectable metastases in other organs was 6.3 months (95% CI: 3.9-8.9), while the survival rate of those who did not have metastases was 13.8 months (95% CI: 10.0-17.68; P = 0.022). CONCLUSION: Survival was associated with the preoperative functional status defined by the KPS and ECOG scales and with the presence of nonresectable visceral metastases.

Temporal lobe structural evaluation after transsylvian selective amygdalohippocampectomy.

OBJECTIVE: Mesial temporal lobe epilepsy (MTLE) is the most common type of focal epilepsy in adolescents and adults, and in 65% of cases, it is related to hippocampal sclerosis (HS). Selective surgical approaches to the treatment of MTLE have as their main goal resection of the amygdala and hippocampus with minimal damage to the neocortex, temporal stem, and optic radiations (ORs). The object of this study was to evaluate late postoperative imaging findings on the temporal lobe from a structural point of view. METHODS: The authors conducted a retrospective evaluation of all patients with refractory MTLE who had undergone transsylvian selective amygdalohippocampectomy (SAH) in the period from 2002 to 2015. A surgical group was compared to a control group (i.e., adults with refractory MTLE with an indication for surgical treatment of epilepsy but who did not undergo the surgical procedure). The inferior frontooccipital fasciculus (IFOF), uncinate fasciculus (UF), and ORs were evaluated on diffusion tensor imaging analysis. The temporal pole neocortex was evaluated using T2 relaxometry. RESULTS: For the IFOF and UF, there was a decrease in anisotropy, voxels, and fibers in the surgical group compared with those in the control group (p < 0.001). An increase in relaxometry time in the surgical group compared to that in the control group (p < 0.001) was documented, suggesting gliosis and neuronal loss in the temporal pole. CONCLUSIONS: SAH techniques do not seem to totally preserve the temporal stem or even spare the neocortex of the temporal pole. Therefore, although the transsylvian approaches have been considered to be anatomically selective, there is evidence that the temporal pole neocortex suffers structural damage and potentially functional damage with these approaches.

Neurological Outcome and Complications in Patients With Surgically Treated Spinal Metastases.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: Evaluate the epidemiology of surgical patients with spinal metastases, identify the complications, and evaluate their neurological prognoses. SUMMARY OF BACKGROUND DATA: The development of new oncological treatments and screening tests have increased the survival of oncologic patients, and consequently, the incidence of metastatic lesions of the spine. METHODS: Retrospective cohort of 40 patients surgically treated at the Hospital de Clínicas of UNICAMP for spinal metastases from January 2010 to September 2018, after diagnosis of symptomatic spinal cord compression and/or mechanical instability of the spine. Retrospectively analyzed patient charts applied the SINS score to evaluate the presence of mechanical instability. Neurological function was classified based on the Frankel index preoperative and postoperatively. To evaluate the association between variables, the Chi-square test, Fisher exact test, or Fisher-Freeman-Halton test was applied. For evaluating the improvement of neurological status between the Frankel scores before and after surgery, the McNemar test was applied for categorical and qualitative variables. In both the tests, variables with values of P > 0.05 were considered. RESULTS: Pain as the reason for the first visit presented an odds ratio (OR) = 2.44 (95% [CI]: 1.14-5.2) for instrumentation need (P = 0.024). A higher SINS score corresponded to the indication for instrumentation surgery due to the instability of the spine (P = 0.004). Within 30 days postoperative, five patients (11.1%) had complications. There was a statistically significant neurological improvement in patients who underwent surgery (P = 0.002). CONCLUSION: Pain as the first symptom was related to mechanical instability of the spine and surgical instrumentation. Patients treated with surgery presented improvement of the neurological function in the postoperative period. LEVEL OF EVIDENCE: 3.

Reliability of the New AOSpine Classification System for Upper Cervical Traumatic Injuries.

BACKGROUND: The new AOSpine Upper Cervical Classification System (UCCS) was recently proposed by the AOSpine Knowledge Forum Trauma team to standardize the treatment of upper cervical traumatic injuries (UCI). In this context, evaluating its reliability is paramount prior to clinical use. OBJECTIVE: To evaluate the reliability of the new AOSpine UCCS. METHODS: A total of 32 patients with UCI treated either nonoperatively or with surgery by one of the authors were included in the study. Injuries were classified based on the new AO UCCS according to site and injury type using computed tomography scan images in 3 planes by 8 researchers at 2 different times, with a minimum interval of 4 wk between assessments. Intra- and interobserver reliability was assessed using the kappa index (K). Treatment options suggested by the evaluators were also assessed. RESULTS: Intraobserver agreement for sites ranged from 0.830 to 0.999, 0.691 to 0.983 for types, and 0.679 to 0.982 for the recommended treatment. Interobserver analysis at the first assessment was 0.862 for injury sites, 0.660 for types, and 0.585 for the treatment, and at the second assessment, it was 0.883 for injury sites, 0.603 for types, and 0.580 for the treatment. These results correspond to a high level of agreement of answers for the site and type analysis and a moderate agreement for the recommended treatment. CONCLUSION: This study reported an acceptable reproducibility of the new AO UCCS and safety in recommending the treatment. Further clinical studies with a larger patient sample, multicenter and international, are necessary to sustain the universal and homogeneity quality of the new AO UCCS.

Using the keystone design perforator island flap in large myelomeningocele closure.

OBJECTIVE: Many repair techniques have been proposed to treat large myelomeningocele (MMC), and although effective in many cases, some of these techniques can be complex and time consuming, with complications such as cerebrospinal fluid (CSF) leakage, flap loss, tip necrosis, and wound dehiscence. The purpose of this study was to analyze cases of large skin defects and the methods applied and to report the outcomes of the keystone design perforator island flap (KDPIF) technique for large MMC closure. METHODS: The authors performed a retrospective review of all neonatal patients who had undergone KDPIF for MMC closure in the period from 2013 to 2018. All patients had a diagnosis of lumbosacral MMC based on obstetric ultrasound. The neurosurgeons and plastic surgeons had selected the cases after concluding that primary closure would be unlikely. The design of the flap is based on the randomly located vascular perforators, creating two identical opposing flaps to fashion a double keystone flap. During wound closure, V-Y advancement of each end of the double flap in the longitudinal axis creates redundancy in the central portion of the flap and reduces the horizontal tension. After discharge, both the neurosurgery and plastic surgery teams followed up all patients, tracking the results with photography. RESULTS: No skin flap dehiscence or necrosis, infection, or CSF leakage was detected, proving the reliability of the flap. One of the patients required further surgery for the large skin defects after insufficient intrauterine closure of the MMC and successfully underwent KDPIF treatment. Another patient (14.3%) had severe neonatal sepsis, which ultimately led to death. A ventriculoperitoneal shunt was required after the skin defect repair in 5 (83.3%) of the 6 surviving patients. Exceptional aesthetic results were achieved for all patients during the follow-up. CONCLUSIONS: The KDPIF technique is based on well-known vascular perforators of the intercostal, lumbar, and gluteal regions. Wound tension is widely distributed by the flap and, as a consequence, relevant tissue bulk, reliable vascularity, and important geometrical versatility are provided. In addition, most of the muscles and fascia are preserved, which is another advantage in terms of minimizing secondary morbidity to local tissue rearrangement. The use of KDPIF closure was successfully shown to be a viable alternative for more complex MMCs that present with large skin defects.

Axis screws: results and complications of a large case series.

OBJECTIVE: To present the surgical results of patients who underwent axis screw instrumentation, discussing surgical nuances and complications of the techniques used. METHODS: Retrospective case-series evaluation of patients who underwent spinal surgery with axis instrumentation using screws. RESULTS: Sixty-five patients were included in this study. The most common cause of mechanical instability was spinal cord trauma involving the axis (36 patients - 55.4%), followed by congenital craniocervical malformation (12 patients - 18.5%). Thirty-seven (57%) patients required concomitant C1 fusion. Bilateral axis fixation was performed in almost all cases. Twenty-three patients (35.4%) underwent bilateral laminar screws fixation; pars screws were used in twenty-two patients (33.8%), and pedicular screws were used isolated in only three patients (4.6%). In fourteen patients (21.5%), we performed a hybrid construction. There was no neurological worsening nor vertebral artery injury in this series. CONCLUSION: Axis screw instrumentation proved to be a safe and efficient method for cervical stabilization. Laminar and pars screws were the most commonly used.

Axis screws: results and complications of a large case series

SUMMARY OBJECTIVE: To present the surgical results of patients who underwent axis screw instrumentation, discussing surgical nuances and complications of the techniques used. METHODS: Retrospective case-series evaluation of patients who underwent spinal surgery with axis instrumentation using screws. RESULTS: Sixty-five patients were included in this study. The most common cause of mechanical instability was spinal cord trauma involving the axis (36 patients - 55.4%), followed by congenital craniocervical malformation (12 patients - 18.5%). Thirty-seven (57%) patients required concomitant C1 fusion. Bilateral axis fixation was performed in almost all cases. Twenty-three patients (35.4%) underwent bilateral laminar screws fixation; pars screws were used in twenty-two patients (33.8%), and pedicular screws were used isolated in only three patients (4.6%). In fourteen patients (21.5%), we performed a hybrid construction. There was no neurological worsening nor vertebral artery injury in this series. CONCLUSION: Axis screw instrumentation proved to be a safe and efficient method for cervical stabilization. Laminar and pars screws were the most commonly used

RESUMO OBJETIVO: Apresentar os resultados cirúrgicos de pacientes submetidos à instrumentação com parafusos do áxis, discutindo nuances cirúrgicas e complicações das técnicas utilizadas. MÉTODOS: Série retrospectiva de pacientes submetidos à instrumentação do áxis utilizando parafusos. RESULTADOS: Sessenta e cinco pacientes foram incluídos neste estudo. A causa mais comum de instabilidade foi trauma raquimedular envolvendo o áxis (36 pacientes - 55,4%), seguida por malformação craniocervical congênita (12 pacientes - 18,5%). Trinta e sete (57%) pacientes necessitaram concomitante fusão de C1. Fixação bilateral foi realizada em quase todos os casos. Vinte e três pacientes (35,4%) foram submetidos à fixação com parafusos de lâmina; parafusos de pars foram utilizados em 22 pacientes (33,8%) e de pedículo, isoladamente, em três (4,6%). Em 14 casos (21,5%), realizamos técnicas combinadas. Não houve piora neurológica ou lesão de artéria vertebral nesta série de casos. CONCLUSÃO: A instrumentação com parafusos do áxis foi um método seguro e eficaz para estabilização cervical. A fixação da lâmina e a da pars foram as técnicas mais utilizadas.