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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.
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Background: Hemangioblastomas are benign vascular neoplasms, World Health Organization grade I, with the most frequent location in the cerebellum. Complete microsurgical resection can be a challenge due to excessive bleeding, which is why preoperative embolization takes importance. Case Description: Two clinical cases are presented, a 25-year-old woman and a 75-year-old man, who presented with intracranial hypertension symptoms due to obstructive hydrocephalus; a ventriculoperitoneal shunt was placed in both cases; in addition, they presented with cerebellar signs. Both underwent embolization with ethylene vinyl alcohol copolymer, with blood flow reduction. After that, they underwent microsurgical resection within the 1st-week post embolization, obtaining, in both cases, gross total resection without hemodynamic complications, with clinical improvement and good surgical outcome. It is worth mentioning that surgical management is the gold standard that allows a suitable surgical approach, like in our patients, for which a lateral suboccipital craniotomy was performed. Conclusion: Solid hemangioblastomas are less frequent than their cystic counterparts. The treatment is the surgical resection, which is a challenge and always has to be considered as an arteriovenous malformation in the surgical planning, including preoperative embolization to reduce perioperative morbidity and mortality and get good outcomes.
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Dural Arteriovenous Fistulas (dAVFs) of the anterior cranial fossa (ACF) are uncommon but carry a high risk of hemorrhage and pose substantial treatment challenges. Recent advancements in endovascular treatment (EVT), including the introduction of novel liquid embolic agents, have markedly bolstered EVT's role in managing ACF-dAVFs, with notable series published in the last five years. We aimed to assess the feasibility, safety, and efficacy of EVT for ACF-dAVFs. We searched Medline, Scopus, Web of Science, and Cochrane Library databases following PRISMA guidelines. Eligible studies included those with ≥ 5 patients undergoing embolization of ACF-dAVFs, detailing both angiographic and clinical outcomes. We used single proportion analysis with 95% confidence intervals under a random-effects model, I2 to assess heterogeneity, and Baujat and sensitivity analysis to address high heterogeneity. Publication bias was assessed by funnel-plot analysis and Egger's test. Outcomes included complete occlusion following embolization, unsuccessful endovascular embolization attempts, incomplete occlusion following embolization, symptom resolution or clinical improvement following embolization, recurrence; procedure-related complications, morbidity, and mortality. Additionally, a subanalysis for studies exclusively utilizing Onyx™ embolic system was done. Eighteen studies comprising 231 ACF-dAVF were included. Unsuccessful endovascular embolization attempts rate was 2%. Complete occlusion rate was 85%, with 4% of complications. Incomplete occlusion rate was 10%. Successfully embolized patients experienced either symptom resolution or clinical improvement in 94% of cases. Morbidity and mortality rates were 1% and 0%, respectively. Onyx subanalyses showed an overall rate of 0% for unsuccessful attempts, 95% for complete occlusion, and 5% for incomplete occlusion. Symptom resolution or clinical improvement was 98% and recurrence rate was 0%. EVT for ACF-dAVF is highly feasible, effective, and safe, with a low rate of complications, morbidity, and mortality. The subanalyses focusing on Onyx embolizations revealed superior efficacy and safety outcomes compared to the findings of the primary analyses involving all included studies.
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Malformações Vasculares do Sistema Nervoso Central , Fossa Craniana Anterior , Embolização Terapêutica , Procedimentos Endovasculares , Polivinil , Humanos , Malformações Vasculares do Sistema Nervoso Central/terapia , Embolização Terapêutica/métodos , Procedimentos Endovasculares/métodos , Polivinil/uso terapêutico , Resultado do Tratamento , Dimetil Sulfóxido/uso terapêutico , Estudos de ViabilidadeRESUMO
SUMMARY: The asterion presents a significant anthropological marking and meeting point between three sutures. It is a surface landmark for the transverse-sigmoid venous sinus complex and is also a surgical landmark for access to the posterior cranial fossa, giving it clinical importance. The aim of this research was to analyze the shape of the asterion and to set the measurement methods that will determine distance between the asterion and surrounding features. The study sample, as a part of the Osteological collection of the Department of Anatomy, Faculty of Medicine Novi Sad, consisted of 43 skulls. Morphometric analysis was related to the measurement of the defined parameters and descriptive analysis presented the classification of asterion in relation to the presence of sutural bones, as well as the determination of the position of the asterion according to the transverse-sigmoid venous complex. There was a statistically significant difference between male and female skulls for all the measured parameters. The results show that 34.88 % were type 1 (one or more sutural bones are present) and 65.12 % were type 2 asteria (no sutural bones are present). More frequent occurrence of asteria type 2 was seen on both, male and female skulls. The most frequent position of the asteria on both sides of the skull was in the transverse- sigmoid venous complex (76.92 % on the right side vs. 72.22 % on the left cranial side). Clinical significance of knowing the area of asterion is reflected in order to make the surgical, as well as diagnostic procedures, as successful as possible.
El asterion presenta una importante marca antropológica y punto de encuentro entre tres suturas. Es un punto de referencia de superficie para el complejo del seno venoso sigmoideo transverso y también es un punto de referencia quirúrgico para el acceso a la fosa craneal posterior, lo que le confiere importancia clínica. El objetivo de esta investigación fue analizar la forma del asterión y establecer los métodos de medición que determinarán la distancia entre el asterión y las características circundantes. La muestra del estudio, que forma parte de la colección osteológica del Departamento de Anatomía de la Facultad de Medicina de Novi Sad, estuvo compuesta por 43 cráneos. El análisis morfométrico se relacionó con la medición de los parámetros definidos y el análisis descriptivo presentó la clasificación del asterion en relación a la presencia de huesos suturales, así como la determinación de la posición del asterion según el complejo venoso transverso-sigmoideo. Hubo una diferencia estadísticamente significativa entre los cráneos masculinos y femeninos para todos los parámetros medidos. Los resultados muestran que el 34,88 % eran tipo 1 (hay uno o más huesos suturales presentes) y el 65,12 % eran asteria tipo 2 (no hay huesos suturales presentes). Se observó una aparición más frecuente de asteria tipo 2 en cráneos tanto masculinos como femeninos. La posición más frecuente de la asteria en ambos lados del cráneo fue en el complejo venoso sigmoideo transverso (76,92 % en el lado derecho vs. 72,22 % en el lado craneal izquierdo). La importancia clínica de conocer el área de asterion se refleja en que los procedimientos quirúrgicos y de diagnóstico tengan el mejor resultado posible.
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Humanos , Masculino , Feminino , Crânio/anatomia & histologia , Fossa Craniana Posterior/anatomia & histologia , Suturas Cranianas/anatomia & histologia , Pontos de Referência AnatômicosRESUMO
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.
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The posterior inferior cerebellar artery (PICA) is often involved in pathologies of the posterior cranial fossa. Therefore, a good understanding of the vessel's normal and variant courses is important to the neurosurgeon or neurointerventionalist. During the routine microdissection of the craniocervical junction, an unusual arrangement between the highest denticulate ligament and PICA was observed. On the right side, the PICA was given rise to by the V4 segment of the vertebral artery 9 mm after the artery entered the dura mater of the posterior cranial fossa. The artery made an acute turn around the lateral edge of the highest denticulate ligament to then recur 180 degrees and travel medially toward the brainstem. Invasive procedures that target the PICA should be aware of the variant as described herein.
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Introduction Currently, skull base surgery faces the dilemma of achieving the maximum possible tumor resection through less aggressive approaches and with minimal retraction of brain tissue. The objective of this work is to report a minimally invasive step-by-step approach to anterior cranial fossa tumors and to perform a literature review. Methods In our work, we describe a step-by-step approach, with images, which is a variation of the transglabellar approach. Results In all cases, we achieved maximum total resection of the lesion. There were no postoperative complications related to the surgery. In one case, we used the access to remove a foreign body in the frontal lobe. Conclusion The frontal trans-sinusal transglabellar access allows direct access to anterior cranial fossa tumors and other frontal lobe lesions close to the floor of the anterior fossa, without the need for brain retraction, allowing early devascularization of the tumor. However, this access is not recommended for all types of tumors, and is being improved for more anteriorly located lesions.
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Objective The purpose of this study was to analyze and discuss the clinical characteristics, long-term outcome, and prognostic factors of cerebellar strokes treated in a single health care facility in Mexico. Methods We retrospectively reviewed the medical records of adult patients admitted to our hospital with diagnosis of cerebellar ischemic and hemorrhagic stroke between 2018 and 2020. Baseline data included sociodemographic and radiological variables, treatment (surgical versus conservative), and Glasgow Coma Scale on arrival (GCSOA). The final neurological outcome was evaluated with the Glasgow Outcome Scale (GOS) six months after hospital discharge. Results Ten patients (seven male and three female) with a mean age of 57.9 ± 9.3 years were included, six with cerebellar ischemic infarction and four with cerebellar hemorrhage. Out of the 10 patients, four underwent surgery (suboccipital decompressive craniectomy {SDC} ± ventriculostomy). The outcome was favorable in four cases (40%) and unfavorable in six (60%). Patients who underwent surgical treatment fared worse with all four cases associating poor outcome. The comparison between good and poor outcome groups showed significant differences in the presence of obstructive hydrocephalus (one versus six, p = 0.05) and poorer GCSOA (6.16 ± 1.72 versus 12.5 ± 3.6, p = 0.05), associating poorer outcome. Conclusion There is still controversy regarding the appropriate management of cerebellar strokes. The presence of obstructive hydrocephalus and poorer GCSOA are associated to worse outcomes.
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AIM: Describe our stereotactic brain biopsy (SBB) technique for intra-axial lesions of the posterior fossa, evaluate its effectiveness and safety, and compare them with other series. MATERIAL AND METHODS: Retrospective study in ten consecutive patients, whose variables were age, gender, location of the lesions, clinical, radiological, and histopathological diagnoses, complications, and mortality, for analysis using descriptive statistics and tests of concordance and diagnostic validity. RESULTS: Lesions were pontine in seven cases, and pontomedullary in three occasions, with histopathological diagnoses of four Grade II astrocytomas, two Grade IV astrocytomas, two infectious process, one neuroblastic tumor, and one cavernous malformation, whose frequency differs from the previous reports (χ2 = 0.07). The clinical-radiological concordance was poor (κ = 0.20). The validity of the clinical diagnosis had intermediate values (Sn = 66.7%, Sp = 75%), while radiological studies were more sensitive (Sn = 100%, Sp = 25%). A definitive diagnosis was obtained in all procedures, with no permanent morbidity or mortality because of the surgery. CONCLUSION: The SBB technique for posterior fossa implemented in our hospital shows high diagnostic yield, as well as absolute safety for the patient.
OBJETIVO: Describir nuestra técnica de biopsia cerebral estereotáctica (SBB) para lesiones intraaxiales de fosa posterior, evaluar su eficacia y seguridad y compararlas con otras series. MATERIAL Y MÉTODOS: Estudio retrospectivo en 10 pacientes consecutivos, cuyas variables fueron edad, sexo, localización de las lesiones, diagnósticos clínicos, radiológicos e histopatológicos, complicaciones y mortalidad, para análisis mediante estadística descriptiva y pruebas de concordancia y validez diagnóstica. RESULTADOS: Las lesiones fueron pontinas en 7 casos y pontomedulares en 3 ocasiones, con diagnósticos histopatológicos de 4 astrocitomas grado II, 2 astrocitomas grado IV, 2 procesos infecciosos, 1 tumor neuroblástico y 1 malformación cavernosa, cuya frecuencia difiere de reportes previos (χ2 = 0.07). La concordancia clínico-radiológica fue mala (κ = 0.20). La validez del diagnóstico clínico tuvo valores intermedios (Sn = 66.7%, Sp = 75%), mientras que los estudios radiológicos fueron más sensibles (Sn = 100%, Sp = 25%). Se obtuvo un diagnóstico definitivo en todos los procedimientos, sin morbimortalidad permanente por la cirugía. CONCLUSIÓN: La técnica SBB para fosa posterior implementada en nuestro hospital muestra un alto rendimiento diagnóstico, así como una seguridad absoluta para el paciente.
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Astrocitoma , Neoplasias Encefálicas , Astrocitoma/diagnóstico por imagem , Astrocitoma/cirurgia , Biópsia/métodos , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Hospitais , Humanos , Estudos Retrospectivos , Técnicas EstereotáxicasRESUMO
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.
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Neoplasias Encefálicas , Neoplasias do Sistema Nervoso Central , Ganglioglioma , Hidrocefalia , Neoplasias Peritoneais , Neoplasias Encefálicas/complicações , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/cirurgia , Tronco Encefálico/patologia , Neoplasias do Sistema Nervoso Central/cirurgia , Criança , Pré-Escolar , Ganglioglioma/complicações , Ganglioglioma/diagnóstico por imagem , Ganglioglioma/cirurgia , Humanos , Hidrocefalia/cirurgia , Masculino , Neoplasias Peritoneais/complicações , Neoplasias Peritoneais/diagnóstico por imagem , Neoplasias Peritoneais/cirurgia , Qualidade de Vida , Derivação Ventriculoperitoneal/efeitos adversosRESUMO
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.
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BACKGROUND: Solitary bone plasmacytoma is a plasmatic cell dyscrasia; its presentation in the posterior fossa is very rare. CASE DESCRIPTION: We present two cases, a 59-year-old male and a 50-year-old female, both with heterogeneous clinical presentation. One had symptoms compatible with endocranial hypertension, and the other presented with a hemispheric cerebellar syndrome and ipsilateral trigeminal neuralgia. They were both related to an intraosseous tumor of the occipital region near the torcula with large extension to the posterior fossa. The diagnosis of a plasma cell neoplasm arising from the diploe of the squamous portion of the occipital bone was confirmed with immunohistochemistry. CONCLUSION: The treatment for a cranial tumor that is suspected to be a solitary bone plasmacytoma requires a multidisciplinary team to diagnose, plan a total resection, and after surgery continue with the follow-up of the patient. Solitary bone plasmacytoma should be considered as a differential diagnosis for a tumor that produces cancellous bone widening without sclerotic borders.
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SUMMARY: This paper determined the morphometric measurements of posterior cranial fossa using MRI in Turkish healthy population. Two hundred thirty one (231; 131 females and 100 males) subjects ranging from 20 up to 85 years were included in this study. Measurements of the posterior cranial fossa were taken from subjects having brain MRI in the Radiology Department, Adana, Turkey. Statistical analysis were done by SPSS 21.00 package programme. ANOVA Test and Chi-Square Test were used to determine the relation between measurements and age groups. The p<0.05 value was considered as significant. The overall means and standard deviations of the measurements were: Clivus length,31.10?5.45 mm; McRae line, 32.59?3.89 mm; Supraocciput length,41.99 ? 4.37 mm; Twining line, 79.23?5.53 mm; Posterior cranial fossa height, 66.76?5.06 mm; Cerebellum height, 55.17?5.29 mm; Clival angle, 125.59??6.57?; Cerebellar tentorium angle, 128.30??7.77? mm, Occipital protuberance angle, 93.27??8.02? and hindbrain vertical length, 50.56?3.47 mmin females, respectively, whereas the corresponding values were 32.43?5.99 mm; 32.85?3.77 mm; 42.46?4.68 mm; 80.95?5.94 mm; 69.70?4.67mm; 57.01?3.43 mm; 123.90??7.12? 128.80?8.33?; 95.35?9.19? and 52.71?3.33 mm in males, respectively. Significant difference was found in some parameters such as twining line, posterior cranial fossa height, cerebellum height and hindbrain vertical length between sex (p<0.05). Also, ages were divided into six groups as decades. Significant difference between six decades was also found in parameters including McRae line, twining line, posterior cranial fossa height, cerebellum height, clival angle, cerebellar tentorium angle, occipital tuberance angle and hindbrain vertical length (p<0.05). The posterior cranial fossa dimensions of healthy population provides important and useful knowledge in terms of comparison of abnormalities clinically, and data can be used as an anatomical landmark during surgery involving posterior cranial fossa.
RESUMEN: Se determinaron las medidas morfométricas de la fosa craneal posterior mediante resonancia magnética en una población turca. Se incluyeron doscientos treinta y un (231; 131 mujeres y 100 hombres) sujetos sanos con edades entre los 20 y los 85 años. Por medio de una resonancia magnética cerebral se tomaron medidas de la fosa craneal posterior de sujetos en el Departamento de Radiología de Adana, Turquía. El análisis estadístico se realizó mediante el programa de SPSS 21.00. Se utilizó la prueba ANOVA y la prueba de chi-cuadrado para determinar la relación entre las medidas y los grupos de edad. Se consideró significativo el valor de p <0,05. Las medias generales y las desviaciones estándar de las medidas en las mujeres fueron: longitud del clivus, 31,10 ? 5,45 mm; Línea McRae, 32,59 ? 3,89 mm; Longitud del supraoccipucio, 41,99 ? 4,37 mm; línea de Twining (desde el tubérculo selar hasta la confluencia de los senos), 79,23 ? 5,53 mm; Altura posterior de la fosa craneal, 66,76 ? 5,06 mm; Altura del cerebelo, 55,17 ? 5,29 mm; Ángulo clival, 125,59 ? ? 6,57 ?; Ángulo del tentorio cerebeloso, 128,30 ? ? 7,77 ? mm, Angulo de protuberancia occipital, 93,27 ? ? 8,02 ? y Longitud vertical del rombencéfalo, 50,56 ? 3,47 mm. En los hombres los valores obte- nidos fueron 32,43 ? 5,99 mm; 32,85 ? 3,77 mm; 42,46 ? 4,68 mm; 80,95 ? 5,94 mm; 69,70 ? 4,67 mm; 57,01 ? 3,43 mm; 123,90 ? ? 7,12 ? 128,80 ? 8,33 ?; 95,35 ? 9,19 ? y 52,71 ? 3,33 mm, respectivamente. Se encontraron diferencias significativas entre ambos sexos (p <0,05) en algunos de los parámetros, como la línea de Twining, la altura de la fosa craneal posterior, la altura del cerebelo y la longitud vertical del rombencéfalo. También se encontró una diferencia significativa entre las edades de los individuos (división en seis décadas) en los parámetros que incluyen la línea de McRae, la línea de Twining, la altura de la fosa craneal posterior, la altura del cerebelo, el ángulo de clivación, el ángulo de la tienda del cerebelo, el ángulo de protuberancia occipital y la longitud vertical del rombencéfalo (p <0,05). La población estudiada nos proporciona información importante y útil en términos de comparación clínica de anomalías y los datos pueden eventualmente ser utilizados como un punto de referencia anatómico durante la cirugía que involucra la fosa craneal posterior.
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Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Adulto Jovem , Fossa Craniana Posterior/anatomia & histologia , Fossa Craniana Posterior/diagnóstico por imagem , Turquia , Imageamento por Ressonância Magnética , Fatores Sexuais , Fatores EtáriosRESUMO
Abstract Introduction The middle cranial fossa approach is performed by fewer neurotologists owing to a reduced number of indications. Consistent landmarks are mandatory to guide the surgeon in a narrow field. Objectives We have evaluated the incus and malleus head and the incudomalleal joint (IMJ) as a key landmark for identifying the superior semicircular canal (SSC) and to get oriented along the floor of the middle cranial fossa. Methods A combination of 20 temporal bone dissections and CT imaging were utilized to test and describe these landmarks. Results The blue line of the SSC is consistently identified along the prolongation of a virtual line through the IMJ and the angulation toward the root of zygoma. The mean distance from the zygoma toward the IMJ ranged from 1.60 to 1.90cm. Once the IMJ was identified, the blue line of the SSC was consistently found along the virtual line through the IMJ within 5 to 9mm. Conclusions The IMJ is a safe and consistent anatomical marker in the surgical approach to the middle cranial fossa floor. Opening the tegmen 1.5 to 2cm medial to the root of the zygoma and identifying the joint allows to trace a virtual line toward the SSC within 5 to 9mm. Knowledge of the close relationship between the direction of the IMJ and the superior canal can be used in all transtemporal approaches, thus orienting the surgeon in a rather narrow field with limited retraction of the dura and brain.
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Introduction The middle cranial fossa approach is performed by fewer neurotologists owing to a reduced number of indications. Consistent landmarks are mandatory to guide the surgeon in a narrow field. Objectives We have evaluated the incus and malleus head and the incudomalleal joint (IMJ) as a key landmark for identifying the superior semicircular canal (SSC) and to get oriented along the floor of the middle cranial fossa. Methods A combination of 20 temporal bone dissections and CT imaging were utilized to test and describe these landmarks. Results The blue line of the SSC is consistently identified along the prolongation of a virtual line through the IMJ and the angulation toward the root of zygoma. The mean distance from the zygoma toward the IMJ ranged from 1.60 to 1.90cm. Once the IMJ was identified, the blue line of the SSC was consistently found along the virtual line through the IMJ within 5 to 9mm. Conclusions The IMJ is a safe and consistent anatomical marker in the surgical approach to the middle cranial fossa floor. Opening the tegmen 1.5 to 2cm medial to the root of the zygoma and identifying the joint allows to trace a virtual line toward the SSC within 5 to 9mm. Knowledge of the close relationship between the direction of the IMJ and the superior canal can be used in all transtemporal approaches, thus orienting the surgeon in a rather narrow field with limited retraction of the dura and brain.
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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.
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BACKGROUND: Posterior cranial fossa (PCF) is an important area in terms of anatomy and surgery. It is a common site of many neoplastic, vascular, and degenerative lesions. Craniovertebral surgeries require special attention regarding detailed information about the morphology and morphometry of this region. The aim of this study was to analyze the morphometric characteristics of PCF and distances between the inner base of the skull. MATERIALS AND METHODS: An observational, retrospective cross-sectional study was made. Fifty-five dry human skulls of unknown sex were measured ascertained using digital Vernier caliper with 0.01 mm precision. RESULTS: The morphometric analysis of the mean length and width of the FM was 34.51 mm and 29.85 mm, respectively. We found a significant difference (P < 0.05) among the distance between the posterior tip of occipital condyle and basion of the right and left sides. CONCLUSION: According to our observations, the present study yielded detailed morphometry of the PCF and neurovascular relationship. It can facilitate successful instrumentation and minimize neurovascular injuries. Furthermore, it provides safe and suitable data for guiding neurosurgical procedures. The major limitation of this study was the lack of knowledge regarding the age and gender of the participants whose skull base was studied.
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Hearing preservation is a cornerstone in the management of intracanalicular vestibular schwannomas. This video demonstrates a middle fossa approach to an intracanalicular schwannoma and highlights some technical and anatomical nuances relevant to the procedure. The patient had sustained hearing preservation in the postoperative period. There are potential benefits in favor of the middle fossa when the tumor reaches the fundus of the internal auditory canal, but the surgeon's individual experience plays a decisive role in the choice of approach. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID21121.
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Although the sphenoidal emissary foramen (SEF) and its content are anatomically and clinically relevant, accurate description of them in the modern literature is lacking. This study aimed to examine and describe the SEF and its content (the sphenoidal emissary vein [SEV]). We analyzed 1,000 computed tomography (CT) images, 170 dry skulls, 50 formalin-fixed specimens, and three specimens (heads) following guidelines proposed by Dr. Albert L. Rhoton Jr. MD for latex injection. SEV morphology was determined by histological staining and electron microscopy. The SEF was observed in 46.8% of the CTs studied (25.4% bilateral and 21.4% unilateral), and 45.2% of the dry skulls (18.8% bilateral and 26.4% unilateral). In 9.5% of CTs and 21.1% of dry skulls there was a blind channel in the external surface of the cranial base; since there was no communication with the cranial cavity, it was not considered as the SEF. During the dissections, the SEF was found in seven individuals. In three of them, the SEV was an alternative route for venous drainage of the venous plexus of the foramen ovale. Its walls were composed of collagen fibers and its endothelium contained rhomboid cells resembling those commonly found in the superior sagittal sinus. The presence of the SEF and SEV can anatomically explain the spread of certain cranial base pathologies from or toward Meckel's cave or the cavernous sinus, and should be taken into account during procedures in the middle cranial fossa, percutaneous approaches, odontological procedures, and treatment of dural arteriovenous fistulas. Clin. Anat., 33:767-781, 2020. © 2019 Wiley Periodicals, Inc.
Assuntos
Cavidades Cranianas/anatomia & histologia , Cavidades Cranianas/diagnóstico por imagem , Base do Crânio/anatomia & histologia , Base do Crânio/diagnóstico por imagem , Osso Esfenoide/anatomia & histologia , Osso Esfenoide/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Cadáver , Dissecação , Humanos , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios XRESUMO
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.