Percutaneous transluminal angioplasty and stenting (PTAS) in patients with symptomatic intracranial vertebrobasilar artery stenosis (IVBS).

BACKGROUND: Approximately 20% of all transient ischaemic attacks (TIAs) and ischaemic strokes occur within the posterior circulation, with vertebrobasilar stenosis identified as the cause in roughly 25% of the cases. Studies have shown that about a quarter of these patients have atherosclerotic stenosis of at least 50% of the vertebrobasilar artery. Stenosis has been shown to be associated with an increased risk of 90-day recurrent vertebrobasilar stroke, particularly in the first few weeks, which is significantly higher when compared with patients with stenosis of the anterior circulation. Therefore, aggressive treatment is important for the patient's prognosis. Stenting is emerging as a promising therapeutic strategy for persistent ischaemia events that do not respond to the best medical treatment, but it is not without complications. We systematically reviewed the literature on percutaneous transluminal angioplasty and stenting (PTAS) for intracranial vertebrobasilar artery stenosis (IVBS). METHODS: PubMed, Web-of-Science and Scopus were searched upon the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to include prospective/retrospective cohort, randomised/non-randomised clinical trials and case series studies describing PTAS for IVBS. Pooled rates of intervention-related complications and outcomes were analysed with random-effect model meta-analysis using StataMP V.18.0 software. RESULTS: 31 studies were found eligible which included 1928 cases. 1103 basilar artery stenosis cases were reported in 27 studies 0.65 (95% CI 0.53, 0.76), I2: 99.72%. 648 vertebral cases were reported in 18 studies 0.60 (95% CI 0.49, 0.70), I2: 97.49%. In four studies, the rate of vertebrobasilar stenosis cases calculated as a proportion of the total sample size was 0.10 (95% CI 0.05, 0. 15). Mean stenosis in 21 included studies was found to be 0.83 (95% CI 0.79, 0.88), I2: 0.00%, which shows variation of baseline stenosis between studies was minimal. 51 deaths were recorded in 24 studies. Meta-analysis of mortality showed the overall rate of mortality was 0.03 (95% CI 0.02, 0.05), I2: 44.90%. In 14 studies, symptomatic intracranial haemorrhage events were recorded at an overall rate of 0.01 (95% CI 0.00, 0.02), I2: 0.00%. Generally, a follow-up period of at least 3 months was reported in the included studies. Furthermore, procedural stroke/TIA was evaluated in seven studies, four of which reported no events (0.03 (95% CI 0.00, 0.08), I2: 20.38%). Mean time from initial symptoms to recanalisation was 23.98 (95% CI 18.56, 29.40), I2=98.8%, p=0.00 days. CONCLUSION: In certain individuals with medically unresolved, severe, symptomatic and non-acute IVBS, elective vertebrobasilar PTAS appears to be both safe and effective. Various stent designs and angioplasty-assisted techniques should be taken into consideration based on the specific clinical and radiological traits of the lesions. Future randomised controlled trials are required to verify these results.

Predictors of malignant swelling in space-occupying cerebellar infarction.

BACKGROUND: Malignant swelling is a fatal complication that can occur abruptly in space-occupying cerebellar infarction. We aimed to establish markers that predict malignant swelling in cerebellar infarction. METHODS: We retrospectively analysed data of stroke patients who were treated in our hospital between 2014 and 2020. Malignant swelling was defined as a mass effect in the posterior cranial fossa, accompanied by a decrease in consciousness due to compression of the brainstem and/or the development of obstructive hydrocephalus. Statistical analyses were performed on multiple variables to identify predictors of malignant swelling. RESULTS: Among 7284 stroke patients, we identified 487 patients with an infarct in the cerebellum. 93 patients were suitable for analysis having space-occupying cerebellar infarction. 33 of 93 (35.5%) patients developed malignant swelling.Multivariable analysis revealed infarct volume as the main predictor being independently associated with the development of malignant swelling with a cut-off infarct volume of 38 cm3 being associated with a swelling rate of >50% (OR 32.0, p<0.001).Higher NIHSS (National Institutes of Health Stroke Scale) score on admission (median NIHSS 12 vs 4, OR 1.078; p=0.008) and the presence of additional brainstem infarction (51.5% vs 16.7%, OR 5.312; p=0.013) were associated with the development of malignant swelling in univariate analyses.13 of 33 (39.4%) cases of malignant swellings occurred after more than 3 days. CONCLUSIONS: Infarct volume was the key significant predictor of malignant swelling in space-occupying cerebellar infarction. With many cases of malignant swelling occurring after more than 72 hours, we advocate prolonged neurological monitoring.

Congenital malformations of the posterior fossa: a review of clinical and radiological features through an Illustrated guide / Malformações congênitas da fossa posterior: uma revisão das características clínicas e radiológicas por meio de um guia ilustrado

Congenital malformations of the posterior fossa (PF) encompass a wide spectrum of morphological anomalies that arise during embryonic development. This paper provides a narrative review of these most common disorders from a morphological approach based on the division into cystic (Dandy-Walker malformation, Blake's Pouch cyst, mega cisterna magna, arachnoid cyst, and cerebellar vermis hypoplasia) and non-cystic malformations (Joubert syndrome, rhomboencephalosynapsis, and pontocerebellar hypoplasia). The embryogenesis of PF structures is briefly outlined. While magnetic resonance imaging is the preferred modality for evaluation, computerized tomography and ultrasonography serve complementary roles. In conjunction with clinical aspects, specific radiological features, such as cerebellar vermis morphology, Torcular Herophili position, and the presence/absence of mass effect, are highlighted for accurate diagnosis. We also present some typical radiological findings in non-cystic malformations, such as molar tooth sign, diamondshaped fourth ventricle, and dragonfly-shaped cerebellum. This comprehensive review aims to assist radiologists, neuropediatricians, and general neurologists in recognizing and describing PF malformations, thereby facilitating appropriate management strategies.

As malformações congênitas da fossa posterior (FP) abrangem um amplo espectro de anomalias morfológicas que surgem durante o desenvolvimento embrionário. Este artigo fornece uma revisão narrativa desses distúrbios mais comuns a partir de uma abordagem morfológica baseada na divisão em malformações císticas (malformação de Dandy-Walker, cisto da bolsa de Blake, mega cisterna magna, cisto aracnoide e hipoplasia do vermis cerebelar) e não císticas (syndrome de Joubert, rombencefalossinapse e hipoplasia pontocerebelar). A embriogênese das estruturas da FP é brevemente descrita. Embora a ressonância magnética seja a modalidade preferida para avaliação, a tomografia computadorizada e a ultrassonografia desempenham funções complementares. Em conjunto com os aspectos clínicos, características radiológicas específicas, como a morfologia do vermis cerebelar, a posição da torcula Herophili e a presença/ausência de efeito de massa, são destacadas para um diagnóstico preciso. Apresentamos também alguns achados radiológicos típicos de malformações não císticas, como sinal do dente molar, quarto ventrículo em forma de diamante e cerebelo em forma de libélula. Esta revisão abrangente visa auxiliar radiologistas, neuropediatras e neurologistas gerais no reconhecimento e na descrição das malformações da FP, facilitando, assim, estratégias de manejo adequadas.

Treatment of Clival Giant Cell Tumor: A Case Report and Literature Review.

Giant cell tumors (GCTs) are locally aggressive primary bone tumors of osteoclast-like cells. Most GCTs occur within the long bones, and primary GCTs involving the clivus are extremely rare. We present the case of an 18-year-old boy with binocular horizontal diplopia with an insidious onset who was found to have a hypointense enhancing mass involving the clivus and left side dorsum sellae on magnetic resonance images. The tumor was completely resected via an endoscopic endonasal transclival approach, and histopathologic examination via immunohistochemistry indicated a GCT. The patient's left abducens nerve palsy improved slightly after surgery. Because of the rarity of GCTs, there is no consensus about the definitive treatment protocol. However, we suggest that gross total resection is the treatment of choice, and denosumab plays a critical role in patients with subtotal resection.

Comparison of Cerebral Autoregulation Above and Below the Tentorium of the Cerebellum In Neurosurgical Patients with Transtentorial ICP Gradient.

INTRODUCTION: Cerebral autoregulation is an essential mechanism for maintaining cerebral blood flow stability. The phenomenon of transtentorial intracranial pressure (ICP) gradient after neurosurgical operations, complicated by edema and intracranial hypertension in the posterior fossa, has been described in clinical practice but is still underinvestigated. The aim of the study was to compare autoregulation coefficients (i.e., pressure reactivity index [PRx]) in two compartments (infratentorial and supratentorial) during the ICP gradient phenomenon. METHODS: Three male patients, aged 24 years, 32 years, and 59 years, respectively, were involved in the study after posterior fossa surgery. Arterial blood pressure and ICP were invasively monitored. Infratentorial ICP was measured in the cerebellar parenchyma. Supratentorial ICP was measured either in the parenchyma of the cerebral hemispheres or through the external ventricular drainage. Cerebral autoregulation was evaluated by the PRx coefficient (ICM + , Cambridge, UK). RESULTS: In all patients, ICP was higher in the posterior fossa, and the transtentorial ICP gradient in each patient was 5 ± 1.6 mm Hg, 8.5 ± 4.4 mm Hg, and 7.7 ± 2.2 mm Hg, respectively. ICP in the infratentorial space was 17 ± 4 mm Hg, 18 ± 4.4 mm Hg, and 20 ± 4 mm Hg, respectively. PRx values in the supratentorial and infratentorial spaces had the smallest difference (- 0.01, 0.02, and 0.01, respectively), and the limits of precision were 0.1, 0.2, and 0.1 in the first, second, and third patients, respectively. The correlation coefficient between the PRx values in the supratentorial and infratentorial spaces for each patient was 0.98, 0.95, and 0.97, respectively. CONCLUSIONS: A high degree of correlation was established between the autoregulation coefficient PRx in two compartments in the presence of transtentorial ICP gradient and persistent intracranial hypertension in the posterior fossa. Cerebral autoregulation, according to the PRx coefficient in both spaces, was similar.

Motor Functioning and Intelligence Quotient in Paediatric Survivors of a Fossa Posterior Tumor Following a Multidisciplinary Rehabilitation Program.

BACKGROUND: Short- and long-term consequences after treatment for childhood fossa posterior tumors are extensively reported in the literature; however, papers highlighting physical function throughout rehabilitation and its correlation with Intelligence Quotient (IQ) are sparse. This study aims to describe the physical functioning and IQ of these survivors, their progression during rehabilitation, and the association with histopathological tumor classification. Additionally, the correlation between gross motor functioning and cognitive functioning was investigated. METHODS: This retrospective single-center cohort study included 56 children (35 (62.5%) males and 21 (37.5%) females, with an average age of 6.51 years (SD 4.13)) who followed a multidisciplinary program at the Child Rehabilitation Centre, Ghent University Hospital in the period from 2005 to 2020. Descriptive statistical analysis was performed with the use of non-parametric tests and linear regression to determine the relationship between gross motor functioning and IQ. RESULTS: This report shows impaired motor and intelligence performance in children with a fossa posterior tumor. Although multidisciplinary rehabilitation is beneficial, it is not able to counteract the further decline of several motor skills and intelligence during oncological treatment, more specifically in children with a medulloblastoma. A correlation between gross motor function and total IQ was found. CONCLUSION: Pediatric survivors of a fossa posterior tumor experience impaired physical and intellectual functions, with more decline during oncological treatment despite simultaneous multidisciplinary rehabilitation.

Dural-Based Posterior Fossa Medulloblastoma Mimicking a Petrous Meningioma in Late Adulthood.

Background: Medulloblastoma of the posterior fossa is commonly encountered in pediatric populations but rarely reported in adults. Adult cases of medulloblastoma typically occur in younger patients, tend to arise intra-axially within the cerebellar hemisphere, and usually exhibit classic histopathologic features. Case Report: A 54-year-old male presented with headaches, dizziness, gait instability, and frequent falls that had worsened during the prior 3 months. Imaging and histopathologic analysis revealed extra-axial, dural-based posterior fossa medulloblastoma with desmoplastic/nodular histopathology, mimicking a petrous meningioma. The mass occupied the left cerebellopontine angle. The patient underwent microsurgical gross total resection of the tumor followed by proton beam radiation therapy and was disease-free at 1-year follow-up. Conclusion: Few dural-based posterior fossa medulloblastomas resembling petrous meningiomas have been reported, and to our knowledge, this is the first description of a case to be treated successfully with proton beam therapy in an older adult. Although rare, medulloblastoma can occur extra-axially in the cerebellopontine angle of older adults, potentially mimicking a petrous meningioma. This rare possibility should always be kept in mind, especially if expectant, nonsurgical management is being considered. To optimize outcome, posterior fossa medulloblastoma should be treated with aggressive microsurgical resection followed by radiation therapy. When available, proton beam therapy should be considered.

Values of the apparent diffusion coefficient in the differential diagnosis of tumors of the posterior fossa in the pediatric population of Colombia / Valores del coeficiente de difusión aparente en el diagnóstico diferencial de los tumores de la fosa posterior en población pediátrica de Colombia

Abstract Introduction: Posterior fossa tumors are common in the pediatric population and require adequate characterization by means of structural magnetic resonance imaging (MRI) and advanced MRI techniques to achieve an appropriate therapeutic approach. Objectives: To determine the usefulness of apparent diffusion coefficient (ADC) values for the differential diagnosis of posterior fossa tumors in the pediatric population treated at a reference hospital in Bogotá D.C., Colombia. Materials and methods: Diagnostic accuracy study carried out in 28 pediatric patients diagnosed with posterior fossa tumor between 2017 and 2019 at the Fundación Hospital de la Misericordia, a quaternary care institution. ADC values were measured and compared with histopathological diagnosis as gold standard, obtaining sensitivity, specificity, and positive and negative predictive values. Differences between medians were determined using the Kruskall-Wallis test. The p value between the quantitative ADC value and the gold standard was calculated using Pearson's chi-squared test, with a significance level of p<0.05. Results: The mean age of the participants was 83.9 months (SD=57 months), and 64.28% of them were boys. Medulloblastoma was the most frequent tumor (39.29%). For the diagnosis of medulloblastoma, an ADC value of 0.6210x10-3mm2/s was established, obtaining a sensitivity and specificity of 81.82% and 76.47%, respectively. For the diagnosis of pilocytic astrocytoma, an ADC of 1.03x10-3mm2/s was determined, with a sensitivity of 66.67% and a specificity of 89.40%. Conclusions: ADC value is useful to classify and differentiate posterior fossa tumors in the Colombian pediatric population, showing an inversely proportional relationship with the tumor grade.

Resumen Introducción. Los tumores de la fosa posterior son frecuentes en población pediátrica y requieren de una adecuada caracterización mediante resonancia magnética (RM) estructural y técnicas avanzadas de RM para lograr un enfoque terapéutico apropiado. Objetivo. Determinar la utilidad de los valores del coeficiente de difusión aparente (ADC cuantitativo) en el diagnóstico diferencial de los tumores de la fosa posterior en población pediátrica de un hospital de referencia en Bogotá D.C., Colombia. Materiales y métodos. Estudio de validez de prueba diagnóstica realizado en 28 pacientes pediátricos diagnosticados con tumor de fosa posterior entre 2017 y 2019 en la Fundación Hospital Pediátrico de la Misericordia, hospital de IV nivel de complejidad. Se midieron los valores del ADC cuantitativo, los cuales fueron comparados con el diagnóstico histopatológico como estándar de oro, obteniendo datos de sensibilidad, especificidad, valores predictivos positivos y negativos. Las diferencias entre medianas fueron determinadas mediante la prueba de Kruskall-Wallis. El valor p entre el valor del ADC cuantitativo y el estándar de oro se calculó con la prueba X2 de Pearson, con un nivel de significancia de p<0.05. Resultados. La edad media fue 83.9 meses (DE=57 meses) y 64.28% fueron niños. El tumor más frecuente fue el meduloblastoma (39.29%). Para el diagnóstico de meduloblastoma se estableció un valor ADC cuantitativo de 0.6210x10-3mm2/s, obteniéndose una sensibilidad y especificidad de 81.82% y 76.47%, respectivamente, y para el diagnóstico de astrocitoma pilocítico, un ADC cuantitativo de 1.03x10-3mm2/s, con una sensibilidad de 66.67% y una especificidad de 89.40%. Conclusiones. El valor del ADC cuantitativo es útil para clasificar y diferenciar los tumores de la fosa posterior en población pediátrica colombiana, mostrando una relación inversamente proporcional con el grado tumoral.

A clival-cervical plate fixation for the craniovertebral instability: a biomechanical study / 中华骨科杂志

Objective:To develop a specialized clival-cervical plate fixation (CCPF) for anterior surgery to treat craniovertebral instability, and to compare it with a posterior occipitocervical fixation (POCF) in biomechanical validation.Methods:Based on the measurement of 40 adult dry bones and 30 volunteers CT images, the clival-cervical plate was designed and manufactured. 8 cadaveric specimens (occiput-C 3) were tested in five conditions including the intact status, the intact+CCPF status, the injury status, the injury+CCPF status, and the injury+POCF status. Specimens were applied a pure moment of 1.5 N·m in flexion, extension, lateral bending, and axial rotation. Calculating and comparing the range of motion (ROM) and neutral zone (NZ) for the occiput to C 2. The effects of different fixation methods on the distribution of ROMs at the occipitocervical region were compared. Results:The injury+CCPF status constrained ROMs to 1.7° in flexion ( q=4.68, P=0.055) , 1.2° in extension ( q=0.39, P=0.9922) , 2.8° in lateral bending ( q=1.25, P=0.814) , and 4.3° in axial rotation ( q=5.08, P=0.035) , resulted in larger ROM in axial rotation but similar ROMs in other directions ( P>0.05) when compared with the injury+POCF status. There were no significant differences between the above two fixation methods in flexion-extension ( q=1.94, P=0.554) , lateral bending ( q=1.79, P=0.611) and axial rotation ( q=2.14, P=0.478) for the NZs. For the flexion, extension,lateral bendingand axial rotation direction, the proportion of the C 1, 2 ROM to the overall ROM was 28%, 25%, 34% and 56% respectively in the injury+CCPF status, and it was 59%, 53%, 42% and 71% respectively in the injury+POCF status. Conclusion:CCPF is a biomechanically effective alternative or supplemental method of POCF for the craniocervical instability.

Dealing with a Pediatric Posterior Fossa Tumor after COVID-19 Infection: Report of One Case / Manejo de um tumor da fossa posterior em paciente pediátrica após infecção por COVID-19: Relato de um caso

There are still some conditions that pediatric neurosurgeons may face in the context of coronavirus disease 2019 (COVID-19) which have not been fully addressed so far. Authors have postulated an ongoing inflammatory myocardial status in a significant proportion of patients who have recovered from COVID-19. We report our experience with a 10-month-old girl who had recovered form COVID-19 and had a case of fourthventricle mass in the midline of the posterior fossa. She was scheduled for microneurosurgical resection of the mass following the insertion of a ventriculoperitoneal shunt. There were no significant issues regarding the induction of anesthesia. A midline suboccipital approach was chosen, and the patient was fully prepared and draped. Suboccipital soft tissues and muscles were dissected layer by layer through the midline avascular line. A marked gush of blood off the midline was observed during the opening in Y of the dura mater. Then, we started to approach the occipital sinus. However, there was an unusual loss of 200 mL of blood lost from this area. Despite the proper packed cell transfusion, the patient developed bradycardia and a sudden rhythm of asystole. The cardiopulmonary cerebral resuscitation (CPCR) was initiated immediately. Despite the maximal effort, the heart rate did not change and remained asystole. We recommend that pediatric neurosurgeons postpone the procedures to be performed in patients who have recovered from COVID-19 for more than one month after a thorough preoperative cardiac evaluation has been performed.

Ainda existem algumas condições que os neurocirurgiões pediátricos podem enfrentar no contexto da doença por coronavírus 2019 (COVID-19) que não foram totalmente abordadas até agora. Os autores postularam um estado inflamatório miocárdico contínuo em uma proporção significativa de pacientes que se recuperaram da COVID-19. Relatamos nossa experiência com uma menina de 10 meses que se recuperou da COVID-19 e teve um caso de massa no quarto ventrículo na linha média da fossa posterior. Ela foi programada para ressecção microneurocirúrgica da massa após a inserção de uma derivação ventrículoperitoneal. Não houve problemas significativos em relação à indução da anestesia. Uma abordagem suboccipital na linha média foi escolhida e a paciente foi totalmente preparada e coberta. Tecidos moles e músculos suboccipitais foram dissecados camada por camada através da linha avascular da linha média. Durante a abertura em Y da dura-máter observou-se um jorro marcado de sangue na linha média. Em seguida, iniciamos a abordagem do seio occipital. No entanto, houve uma perda incomum de 200 ml de sangue perdido nesta área. Apesar da transfusão de hemácias adequada, a paciente evoluiu com bradicardia e ritmo súbito de assistolia. A ressuscitação cerebral cardiopulmonar (RCCP) foi iniciada.

Fetal ventricles and posterior cranial fossa development in second and third trimesters and their variations with gestational age: a quantitative MRI study / 中华围产医学杂志

Objective:To investigate the normal range of fetal ventricles and posterior cranial fossa development in the second and third trimesters and their variations with gestational age using quantitative MRI analysis.Methods:This retrospective study enrolled 675 pregnant women who underwent prenatal MRI examination with an average gestational week of 29.0±8.5 in the Third Affiliated Hospital of Guangzhou Medical University from January 2016 to January 2020. MRI data of all the subjects were collected and analyzed, including left lateral ventricle trigonometric width (LLVTW) and right lateral ventricle trigonometric width (RLVTW), third ventricle width (TVW), fourth ventricle width (FVW), the anterior-posterior diameter of the fourth ventricle (APDFV), cavum septum pellucidum width (CSPW), cisterna magna width (CMW), etc. Spearman, Pearson correlation analysis, and t-test were used for the statistical analysis. Results:(1) Totally 675 fetuses were recruited, including 392 female and 283 male fetuses. No statistical difference of gestational weeks at MRI was found between male and female fetuses. (2)The mean value of TVW and CMW of the female fetuses were significantly higher than those of male fetuses [(0.60±0.05) vs (0.63±0.04) cm, t=－5.059; (0.57±0.14) vs (0.67±0.15) cm, t=－7.445; both P<0.001]. Spearman correlation analysis showed that TVW and CMW were negatively correlated with fetal gender ( r=－0.179 and－0.312, both P<0.001). (3)Pearson correlation analysis showed that LLVTW, RLVTW, TVW, FVW, APDFV, CSPW, and CMW were all positively correlated with gestational weeks ( r=0.310, 0.267, 0.205, 0.801, 0.829, 0.216 and 0.284, all P<0.001). FVW and APDFV were significantly linearly correlated with gestational weeks (r=0.801 and 0.829, both P<0.001). (4) There was no significant change in LLVTW and RLVTW in the second trimester, but a slight increase was found in the third trimester. TVW showed a scattered distribution in the second and third trimesters and increased slightly with the gestational week at 26 to 27 +6 gestational weeks. FVW and APDFV increased linearly while. CSPW increased slowly with gestational weeks in the second and third trimesters. CMW increased slightly with gestational weeks in the second and third trimesters but showed little change in the third trimester. Conclusions:The development of fetal ventricles and posterior cranial fossa in the second and third trimesters show a growth trend of varying degrees with the increase of gestational weeks. TVW and CMW are significantly negatively correlated with the fetal gender.

Pediatric multicompartmental trigeminal schwannoma: illustrative case.

BACKGROUND: Trigeminal schwannoma (TS) is an uncommon and histologically benign intracranial lesion that can involve any segment of the fifth cranial nerve. Given its often impressive size at diagnosis and frequent involvement of critical neurovascular structures of the skull base, it represents a challenging entity to treat. Pediatric TS is particularly rare and presents unique challenges. Similarly, tumors with extension into multiple compartments (e.g., middle cranial fossa, posterior cranial fossa, extracranial spaces) are notoriously difficult to treat surgically. Combined or staged surgical approaches are typically required to address them, with radiosurgical treatment as an adjunct. OBSERVATIONS: The authors presented the unusual case of a 9-year-old boy with a large, recurrent multicompartmental TS involving Meckel's cave, the cerebellopontine angle, and the infratemporal fossa. Near-total resection was achieved using a frontotemporal-orbitozygomatic craniotomy with a combined interdural and extradural approach. LESSONS: The case report adds to the current literature on multicompartmental TSs in children and their management. The authors also provided a simplified classification of TS that can be generalized to other skull base tumors. Given a lack of precedent, the authors intended to add to the discussion regarding surgical management of these rare and challenging skull base lesions.

Orthostatic hypotension after cervicomedullary junction surgery: illustrative case.

BACKGROUND: Surgery at the cervicomedullary junction carries a risk of damaging vital brainstem functions. Because the nucleus of the solitary tract (NS) is involved in the baroreceptor reflex, damage to its integrity may lead to orthostatic hypotension. OBSERVATIONS: A 56-year-old man with a medical history of hypertension, von Hippel-Lindau disease, and previous bilateral adrenalectomy due to pheochromocytoma was referred with symptoms of dysphagia and paralysis of the left vocal cord. Paralysis of the left vagus nerve was suspected. Magnetic resonance imaging revealed a contrast-enhancing cystic process in the cervicomedullary junction. Twenty-three years earlier, the patient had undergone surgical treatment for a hemangioblastoma in the same region. After repeated surgery, the patient temporarily developed orthostatic hypotension. At discharge, the patient no longer needed antihypertensive medication. LESSONS: Surgery near the cervicomedullary junction can affect the NS, leading to disruption of the baroreceptor response that regulates blood pressure.

[Classification of the types of pediatric posterior fossa brain tumors based on routine MRI using wavelet transformation analysis of whole tumor].

Objective: To evaluate the classification of the types of pediatric posterior fossa brain tumors based on routine MRI (T(1)WI, T(2)WI and ADC) using wavelet transformation analysis of whole tumor. Methods: MRI images of medulloblastoma (n=59), ependymoma (n=13) and pilocytic astrocytoma (n=27) confirmed by pathology before treatments in Children's Hospital of Nanjing Medical University from January 2014 to February 2019 were enrolled in this retrospective study as well as the clinical data of age, gender and symptoms. Registration was performed among the three sequences and wavelet features of ROI were acquired. Afterwards, the top ten features were ranked and trained among groups by using random forest classifier. Finally, the results were compared and analyzed according to the classification. Results: The top ten contribution three sequences and wavelet features of ROI were acquired from the ADC sequence. The random forest classifier achieved 100% accuracy on training data and was validated best accuracy (86.8%) when combined of first and third wavelet features. The sensitivity was 100%, 94.8%, 76.9%, and the specificity was 97.6%, 88.0%, 98.8% respectively. Conclusions: Features based on wavelet transformation of ADC sequence of entire tumor can provide more quantitative information, which could provide help in the differential diagnosis of pediatric posterior fossa brain tumors. The optimum combination to distinguish three pediatric posterior fossa brain tumors is sixth and twelfth wavelet features of ADC sequence.

Fetal posterior fossa malformations: review of the current knowledge / Malformações da fossa posterior fetal: revisão do conhecimento atual

Abstract Ultrasound diagnosis of posterior fossa malformations in the prenatal period is a challenge, having major implications for the counseling and follow-up of pregnant women. The purpose of this study was to review aspects of the ultrasound evaluation of the fetal posterior fossa, as well as to describe the most relevant ultrasound findings of the main posterior fossa malformations that can affect the fetus in the prenatal period.

Resumo O diagnóstico ultrassonográfico das malformações da fossa posterior no período pré-natal é um desafio, com importantes implicações no aconselhamento e acompanhamento dessas gestações. O objetivo deste estudo é revisar aspectos da avaliação ultrassonográfica da fossa posterior do feto e descrever os principais achados ultrassonográficos das principais malformações da fossa posterior que podem acometer o feto no período pré-natal.

[Quantitative study on the development of fetal ventricles and cisterna magna in second and third trimesters with MRI].

Objective: To analyze the changes of growth and development of normal fetal ventricles and cisterna magna with gestational age(GA) and the correlation with fetal gender in the second and third trimester,and establish the MR prenatal diagnosis reference standards. Methods: A total of 633 fetuses (mean GA (27.0±4.1) weeks (18.9-40.6 weeks))without central nervous system abnormalities were retrospectively collected from the Obstetrics and Gynecology Hospital of Fudan University from June 2012 to August 2017. The lateral ventricle trigonometric width (LVTW), third ventricle width (TVW), fourth ventricle width (FVW), anterior-posterior diameter of the fourth ventricle(APDFV), cavum septum pellucidum width (CSPW) and cisterna magna width (CMW) were obtained in the standard measure planes on MR image.The correlation between the biometrics and GA and the correlation between the biometrics and fetal gender were analyzed respectively, and the normal reference values of the biometrics were calculated. Spearman correlation analysis, Pearson correlation analysis,linear regression analysis, independent samples t-test and paired samples t-test were used for statistic analysis. Results: (1)Fetal LLVTW,RLVTW,TVW,CSPW and CMW in second and third trimesters were correlated with GA at medium and low levels(the correlation coefficient r were 0.311, 0.277, 0.207, 0.226, 0.295, respectively, all P<0.01). FVW and APDFV were statistically correlated with GA, and the linear regression equations were as follows: y=0.022×GA-0.043 (adjusted R(2)=0.642); y=0.018×GA-0.159 (adjusted R(2)=0.690). (2)Fetal LLVTW,RLVTW,FVW,APDFV and CSPW were not correlated with fetal gender in second and third trimesters(r=-0.078,-0.057,-0.087,-0.004 and 0.024, P=0.124,0.258,0.085,0.931 and 0.618, all P>0.05). TVW and CMW were statistically correlated with fetal gender(r=-0.310, -0.180, P=0.000, 0.006, all P<0.05). (3) The mean values of LLVTW and RLVTW were (0.71±0.13) cm and (0.68±0.13) cm, respectively, and significant difference was found between them(t=3.180, P=0.002). The mean value of CSPW was (0.59±0.15) cm. And the mean values of male and female fetuses for TVW and CMW were (0.17±0.05) cm, (0.16±0.06) cm and (0.68±0.15) cm, (0.58±0.15) cm, respectively. The corresponding prenatal MRI diagnostic criteria were as follows: LLVTW 1.1 cm, RLVTW 1.0 cm, CSPW 1.0 cm, TVW 0.3 cm, CMW (male 1.1 cm, female 1.0 cm). Conclusions: The normal fetal ventricles and cisterna magna are increased with the GA in the second and third trimesters. TVW and CMW are related to fetal gender. The establishment of normal reference values of fetal ventricles and cisterna magna based on GA and fetal gender are conducive to enhance the accuracy of MRI prenatal diagnosis.

Delayed fenestration of Blake's pouch with or without vermian hypoplasia: fetal MRI at 3 tesla versus 1.5 tesla.

BACKGROUND: Fetal magnetic resonance imaging (MRI), mainly performed at standard field strength, plays a role in the classification of posterior fossa malformations. In the context of early second-trimester screening, upward rotation of the cerebellar vermis per se is usually compatible with a more favorable outcome than Dandy-Walker malformation and profound vermian hypoplasia. Delayed fenestration of Blake's pouch may either mimic vermian hypoplasia by compression or be associated with it in individual cases. To increase specificity, there is a growing interest in the use of high-field MRI which is believed to be safe as long as the specific absorption rate is kept within accepted limits. We aim to illustrate its added value during the second and third trimester. CASE PRESENTATION: In the first case, fetal MRI at 1.5 Tesla was performed at 21 and 27 weeks' gestation with sonographic follow up postnataly. In the second case, 3 Tesla MR images were acquired at 21 and 34 weeks' gestation as well as in the neonatal period. CONCLUSIONS: This pictorial case vignette supports the suggestion that mid-gestational MRI at 3 Tesla has the potential to exclude pronounced vermian hypoplasia with higher confidence than at 1.5 Tesla. However, the discrimination of mild hypoplasia from slight deformation of the cerebellar vermis will likely remain challenging.

[Chondromucinous tumors involving craniocerebral slope area: a clinicopathological analysis of eight cases].

Objective: To investigate the histological type and clinicopathological characteristics of the craniocerebral slope tumors with chondromucinous features. Methods: Retrospective analysis was conducted to analyze chondromucinous tumors in the slope area diagnosed at Henan Provincial People's Hospital from October 2011 to June 2018. Relevant clinical and pathological data were reviewed, and immunohistochemistry was used to investigate the immunophenotype of the tumors. Results: Eight cases were identified, including 4 males and 4 females with patient age ranging from 20 to 48 years. Histologically, there were 1 case of chordoid meningioma, 1 chondromyxoid fibroma, 1 mucinous chondrosarcoma, 1 Maffucci syndrome, and 4 chondroid chordomas. Conclusion: Chondromucinous tumors of the slope area include chordoma, chordoid meningioma, chondromyxoid fibroma, and myxoid chondrosarcoma and their correct diagnosis is mainly based on the morphological characteristics, immunophenotype and comprehensive analysis of clinical data.

Fetal posterior fossa malformations: review of the current knowledge.

Ultrasound diagnosis of posterior fossa malformations in the prenatal period is a challenge, having major implications for the counseling and follow-up of pregnant women. The purpose of this study was to review aspects of the ultrasound evaluation of the fetal posterior fossa, as well as to describe the most relevant ultrasound findings of the main posterior fossa malformations that can affect the fetus in the prenatal period.

Chondromucinous tumors involving craniocerebral slope area: a clinicopathological analysis of eight cases / 中华病理学杂志

Objective@#To investigate the histological type and clinicopathological characteristics of the craniocerebral slope tumors with chondromucinous features.@*Methods@#Retrospective analysis was conducted to analyze chondromucinous tumors in the slope area diagnosed at Henan Provincial People′s Hospital from October 2011 to June 2018. Relevant clinical and pathological data were reviewed, and immunohistochemistry was used to investigate the immunophenotype of the tumors.@*Results@#Eight cases were identified, including 4 males and 4 females with patient age ranging from 20 to 48 years. Histologically, there were 1 case of chordoid meningioma, 1 chondromyxoid fibroma, 1 mucinous chondrosarcoma, 1 Maffucci syndrome, and 4 chondroid chordomas.@*Conclusion@#Chondromucinous tumors of the slope area include chordoma, chordoid meningioma, chondromyxoid fibroma, and myxoid chondrosarcoma and their correct diagnosis is mainly based on the morphological characteristics, immunophenotype and comprehensive analysis of clinical data.