Development and Evaluation of a Mixed Reality Model for Training the Retrosigmoid Approach.

BACKGROUND: The use of simulation has the potential to accelerate the learning curves and increase the efficiency of surgeons. However, there is currently a scarcity in models dedicated to skull base surgical approaches. Thus, the objective of this study was to develop a cost-effective mixed reality system consisting of an ultrarealistic physical model and augmented reality and evaluate its use in training surgeons on the retrosigmoid approach. METHODS: The virtual models were developed from images of patients with vestibular schwannoma. The tumor was mirrored to allow bilateral approaches and the model has drawers for repositioning structures, allowing reuse of the material and cost reduction. Pre and posttest assessments were applied to 10 residents and young neurosurgeons, divided into control and test groups. Only the control group was exposed to the model. The difference in scores obtained by participants before and after exposure to the models was considered for analysis and participants in the control group answered self-satisfaction questionnaires. RESULTS: The mean differences were 4.80 in the control group (95% credibility intervals=1.08-9.79) and 5.43 in the test group (95% credibility intervals=1.67-8.20). The average score of the self-satisfaction questionnaires was 24.0 (23-25). CONCLUSIONS: The ultrarealistic model efficiently allowed retromastoid access to the cerebellopontine angle. A tendency toward greater gains in performance in the group exposed to the model was verified. Scores from the self-satisfaction questionnaires demonstrated that participants considered the model relevant for neurosurgical training and increased confidence among surgeons.

Posterior fossa choroidplexus papilloma in the pediatric population: case series and literature review / Papiloma de plexo coroide na fossa posterior na população pediátrica: série de casos e revisão da literatura

Abstract Choroid plexus papillomas (CPPs) are rare benign neoplasms which are particularly uncommon in the posterior fossa in children. We herein present a case series of five patients treated at a tertiary care hospital. A comprehensive literature review was also carried out. The patients treated at the tertiary care hospital were aged between 4 and 16 years. Gross total resection (GTR) was initially achieved in two patients. All patients showed clinical improvement. Moreover, 27 articles published between 1975 and 2021 were selected for the literature review, totaling 46 patients; with the 5 patients previously described, the total sample was composed of 51 cases, With a mean age was 8.2 years. The lesions were located either in the fourth ventricle (65.3%) or the cerebellopontine angle (34.7%). Hydrocephalus was present preoperatively in 66.7% of the patients, and a permanent shunt was required in 31.6% of the cases. The GTR procedure was feasible in 64.5%, and 93.8% showed clinical improvement. For CPPs, GTR is the gold standard treatment and should be attempted whenever feasible, especially because the role of the adjuvant treatment remains controversial. Neuromonitoring is a valuable tool to achieve maximal safe resection. Hydrocephalus is common and must be recognized and promptly treated. Most patients will need a permanent shunt. Though there is still controversy on its efficacy, endoscopic third ventriculostomy is a safe procedure, and was the authors' first choice to treat hydrocephalus.

Resumo Os papilomas do plexo coroide (PPCs) são neoplasias benignas raras e, na população pediátrica, são particularmente incomuns na fossa posterior. Apresentamos uma série de casos de cinco pacientes atendidos em um hospital terciário. Além disso, foi realizada uma ampla revisão da literatura. Os pacientes atendidos no hospital terciário tinham entre 4 e 16 anos. Ressecção macroscópica total (RMT) foi inicialmente realizada em dois pacientes. Todos os pacientes apresentaram melhora clínica. Além disso, 27 artigos publicados entre 1975 e 2021 foram selecionados para a revisão da literatura, totalizando 46 pacientes. Somados à série de casos atuais, encontramos 51 pacientes, com média de idade de 8,2 anos. As lesões localizavam-se no quarto ventrículo (65,3%) ou no ângulo pontocerebelar (34,7%). Hidrocefalia estava presente no pré-operatório em 66,7% dos pacientes, e derivação ventricular permanente foi necessária em 31,6% dos casos. A RMT foi possível em 64,5%, e 93,8% tiveram melhora clínica. Para os CPPs, a RMT é o tratamento padrão-ouro e deve ser tentado sempre que possível, especialmente porque ainda existem controvérsias quanto ao papel do tratamento adjuvante. A neuromonitorização é uma ferramenta importante para se atingir a máxima ressecção segura. A hidrocefalia é comumente vista nesses pacientes e deve ser identificada e tratada. A maioria dos pacientes irá precisar de uma derivação permanente. Apesar de persistirem controvérsias sobre sua eficácia, a terceiro-ventriculostomia endoscópica foi a primeira escolha para tratar a hidrocefalia na experiência dos autores e é uma opção segura.

Posterior fossa choroidplexus papilloma in the pediatric population: case series and literature review.

Choroid plexus papillomas (CPPs) are rare benign neoplasms which are particularly uncommon in the posterior fossa in children. We herein present a case series of five patients treated at a tertiary care hospital. A comprehensive literature review was also carried out. The patients treated at the tertiary care hospital were aged between 4 and 16 years. Gross total resection (GTR) was initially achieved in two patients. All patients showed clinical improvement. Moreover, 27 articles published between 1975 and 2021 were selected for the literature review, totaling 46 patients; with the 5 patients previously described, the total sample was composed of 51 cases, With a mean age was 8.2 years. The lesions were located either in the fourth ventricle (65.3%) or the cerebellopontine angle (34.7%). Hydrocephalus was present preoperatively in 66.7% of the patients, and a permanent shunt was required in 31.6% of the cases. The GTR procedure was feasible in 64.5%, and 93.8% showed clinical improvement. For CPPs, GTR is the gold standard treatment and should be attempted whenever feasible, especially because the role of the adjuvant treatment remains controversial. Neuromonitoring is a valuable tool to achieve maximal safe resection. Hydrocephalus is common and must be recognized and promptly treated. Most patients will need a permanent shunt. Though there is still controversy on its efficacy, endoscopic third ventriculostomy is a safe procedure, and was the authors' first choice to treat hydrocephalus.

Os papilomas do plexo coroide (PPCs) são neoplasias benignas raras e, na população pediátrica, são particularmente incomuns na fossa posterior. Apresentamos uma série de casos de cinco pacientes atendidos em um hospital terciário. Além disso, foi realizada uma ampla revisão da literatura. Os pacientes atendidos no hospital terciário tinham entre 4 e 16 anos. Ressecção macroscópica total (RMT) foi inicialmente realizada em dois pacientes. Todos os pacientes apresentaram melhora clínica. Além disso, 27 artigos publicados entre 1975 e 2021 foram selecionados para a revisão da literatura, totalizando 46 pacientes. Somados à série de casos atuais, encontramos 51 pacientes, com média de idade de 8,2 anos. As lesões localizavam-se no quarto ventrículo (65,3%) ou no ângulo pontocerebelar (34,7%). Hidrocefalia estava presente no pré-operatório em 66,7% dos pacientes, e derivação ventricular permanente foi necessária em 31,6% dos casos. A RMT foi possível em 64,5%, e 93,8% tiveram melhora clínica. Para os CPPs, a RMT é o tratamento padrão-ouro e deve ser tentado sempre que possível, especialmente porque ainda existem controvérsias quanto ao papel do tratamento adjuvante. A neuromonitorização é uma ferramenta importante para se atingir a máxima ressecção segura. A hidrocefalia é comumente vista nesses pacientes e deve ser identificada e tratada. A maioria dos pacientes irá precisar de uma derivação permanente. Apesar de persistirem controvérsias sobre sua eficácia, a terceiro-ventriculostomia endoscópica foi a primeira escolha para tratar a hidrocefalia na experiência dos autores e é uma opção segura.

Adult giant cerebellar cavernous malformations: case report and review of the literature.

Cavernous malformations are vascular malformations that can occur anywhere in the central nervous system (CNS). Giant cavernous malformations (GCM) are extremely rare in adults, especially in the posterior fossa. Herein, we described a 48-year-old male who presented with vertigo and postural instability for three months. Neuroimaging revealed a 131.15 cm3 heterogeneous midline upper cerebellar lesion. After a suboccipital craniotomy, a gross total resection (GTR) was accomplished. Histopathologic examination revealed a huge cavernous malformation. Only 27 GCM adult cases were reported in the English-based literature. Only two patients had cerebellar lesions and, to the best of our knowledge, this is the first case of cerebellar vermis GCM. We concluded that cerebellar GCM (CGCM) in adults are exceedingly rare and indolent lesions. These lesions can radiologically and clinically mimic neoplastic lesions that have to be considered in the differential diagnosis. GTR is the mainstay of treatment and, whenever possible, should be attempted.

Pediatric neurosurgery during the COVID-19 pandemic: update and recommendations from the Brazilian Society of Pediatric Neurosurgery.

OBJECTIVES: Coronavirus disease (COVID-19) is a potentially severe respiratory illness that has threatened humanity globally. The pediatric neurosurgery practice differs from that of adults in that it treats children in various stages of physical and psychological development and contemplates diseases that do not exist in other areas. The aim of this study was to identify the level of knowledge and readiness of the healthcare providers, as well as to evaluate new preventive practices that have been introduced, psychological concerns, and the impact of the COVID-19 pandemic on pediatric neurosurgical units in Brazil. METHODS: Pediatric neurosurgeons were given an online questionnaire developed by the Brazilian Society of Pediatric Neurosurgery to evaluate the impact of the COVID-19 pandemic on their clinical practice. RESULTS: Of a cohort of 110 active members of the Brazilian Society of Pediatric Neurosurgery, 76 completed the survey (69%). Ninety-six percent were aware of the correct use of and indication for the types of personal protective equipment in clinical and surgical practices, but only 73.7% of them had unrestricted access to this equipment. Ninety-eight percent of participants agreed or strongly agreed that the pandemic had affected their pediatric neurosurgical practice. The COVID-19 pandemic interfered with outpatient care in 88% of the centers, it affected neurosurgical activity in 90.7%, and it led to the cancellation of elective neurosurgical procedures in 57.3%. Concerning the impact of COVID-19 on surgical activity, 9.2% of the centers had less than 25% of the clinical practice affected, 46.1% had 26%-50% of their activity reduced, 35.5% had a 51%-75% reduction, and 9.2% had more than 75% of their surgical work cancelled or postponed. Sixty-three percent affirmed that patients had been tested for COVID-19 before surgery. Regarding the impact of the COVID-19 pandemic on the mental health of those interviewed, 3.9% reported fear and anxiety with panic episodes, 7.9% had worsening of previous anxiety symptoms, 60.5% reported occasional fear, 10.5% had sadness and some depressive symptoms, and 2.6% reported depressive symptoms. CONCLUSIONS: The COVID-19 pandemic has posed unprecedented challenges to healthcare services worldwide, including neurosurgical units. Medical workers, pediatric neurosurgeons included, should be aware of safety measures and follow the recommendations of local healthcare organizations, preventing and controlling the disease. Attention should be given to the psychological burden of exposure to SARS-CoV-2 in healthcare workers, which carries a high risk of anxiety and depression.

Midface distraction osteogenesis using a modified external device and 3D virtual simulation: technical note.

INTRODUCTION/BACKGROUND: Distraction osteogenesis (DO) with an external distraction device such as the rigid external distraction frame has become an established method for treating midface hypoplasia in faciocraniosynostosis. It allows for greater advancement of the midface in comparison with traditional Le Fort III osteotomies, associated or not with fronto-orbital osteotomies (Le Fort IV). However, the forward movement of the bone segments may not always be performed obeying an ideal distraction vector, resulting in asymmetries, anterior open bite, and loosening of screws. In addition, the cost of the distraction devices is significant and may preclude their routine use in developing countries. METHOD: We present an alternative device and method for craniofacial advancement in a clinical case of Crouzon's syndrome. RESULTS: A 3D virtual simulation of the distraction vector and a modified external device were used in the current case. CONCLUSION: The alternative external device in this case proved to be safe, effective, and reliable.

Decompressive craniectomy for severe traumatic brain injury in children: analysis of long-term neuropsychological impairment and review of the literature.

OBJECTIVE: The effectiveness of decompressive craniectomy (DC) in the context of neurocritical care in adult patients has been recently under debate. The aim of our study was to evaluate the impact of decompressive craniectomy in severe traumatic brain injury (TBI) in children, focusing on short and long-term neurological and neuropsychological outcomes. METHODS: Retrospective review of the medical records of children admitted at a level I trauma center, between January 2012 and December 2015, submitted to DC due to severe TBI. Additionally, an extensive review of literature on this subject was carried out. RESULTS: Sixteen patients underwent DC for TBI at our institution during the evaluated period. 62.5% were males and the mean age was 12 years. Road traffic accident (RTA) was the main mechanism of trauma (62.5%). Average Glasgow Coma Scale (GCS) at admission was 5.2, whereas 75% of the patients presented with pathological pupillary reaction. Initial computed tomography (CT) showed skull fractures in 62.5% and acute subdural hemorrhage (ASH) in 56.3% of the patients. The mean intracranial pressure (ICP) was 27.2 mmHg prior to surgery, and the mean time window between admission and DC was 36.3 h. Unilateral DC was performed in 68.8% of the cases. The average Glasgow Outcome Scale (GOS) at 6-month follow-up was 3.7, whereas 70% of the survivors presented good recovery (GOS 4-5). Abnormal pupillary reaction at hospital admission increased 3-fold the risk of long-term neuropsychological disturbances. Follow-up evaluation revealed cognitive abnormality in 55.6% of the patients. The overall mortality at 6-month follow-up was 37.5%. CONCLUSION: The present study indicates towards a potential benefit of DC in children with severe TBI; nevertheless, our data demonstrated a high incidence of neuropsychological impairment in the long-term follow-up. Psychological and cognitive assessment should be computed in prognosis evaluation in future prospective studies.

Cranial morcellation decompression for refractory idiopathic intracranial hypertension in children.

BACKGROUND: Primary idiopathic intracranial hypertension (PIIH) in children is rare and has a poorly understood pathophysiology. It is characterized by raised intracranial pressure (ICP) in the absence of an identified brain lesion. Diagnosis is usually confirmed by the measurement of a high cerebrospinal fluid (CSF) opening pressure and exclusion of secondary causes of intracranial hypertension. Refractory PIIH may lead to severe visual impairment. The purpose of this study was to evaluate a cranial morcellation decompression (CMD) technique as a new surgical alternative to stabilize intracranial pressure in PIIH. MATERIALS AND METHODS: A literature review was carried out, disclosing only 7 pediatric cases of PIIH treated with surgical skull expansion. In addition, we describe here one case of our own experience treated by CMD. CONCLUSIONS: CMD surgery is a safe and effective option to control refractory PIIH in selected patients.

Hypertrophic olivary degeneration in children after posterior fossa surgery. An underdiagnosed condition.

BACKGROUND: Hypertrophic olivary degeneration (HOD) is a rare transsynaptic form of degeneration occurring after injury to the dentato-rubro-olivary pathway ("Guillain-Mollaret triangle"). The majority of studies have described HOD resulting from posterior fossa (PF) hemorrhage or infarction. HOD in patients undergoing PF surgery has not been well characterized. These lesions are rare and symptomatic children with HOD are even more uncommon. The purpose of this study was to evaluate HOD that develops after PF operations in children. MATERIALS AND METHODS: A literature review was carried out describing 37 pediatric cases of HOD in 13 articles. In addition, two new cases of our own experience were included. CONCLUSIONS: HOD is a rare complication related after PF tumors surgery and symptoms may be misdiagnosed with pediatric cerebellar mutism syndrome. Children with HOD usually do not develop palatal tremor but ataxia is common.