Sex estimation based on foramen magnum: a three-dimensional geometric morphometrics approach / Estimación del sexo basado en el foramen magno: un enfoque de morfometría geométrica tridimensional

SUMMARY: The foramen magnum is an important topographic opening which connects cranial cavity and spinal canal. The analysis of the bone material established that there are differences in the shape of the foramen magnum between individuals. The aim of this study was to determine sex based on shape and size of foramen magnum using geometric morphometrics method. A study was performed on three-dimensional models (3D models) of 214 human skulls of known sex and known age (141 male skulls and 73 female skulls). The skulls are located at the museum of Medical Faculty, University of Sarajevo. Skulls belong to Bosnian population from the mid-twentieth century. All examined skulls were scanned with a laser scanner to obtain their 3D models. On 3D models of the examined skulls, four landmarks were marked on foramen magnum. Analysis of sex determination was performed using the MorphoJ program. Results of this study showed that there are sex differences in the shape and size of the foramen magnum. Sex determination based on the shape and size of the foramen magnum was showed 65.25 % accuracy for male and 63.01 % accuracy for female using geometric morphometrics method. Examination of the effect of size of foramen magnum on sexual dimorphism of shape of foramen magnum showed a statistically significant effect. Sex determination based just on the shape of foramen magnum using geometric morphometrics method was possible with 62.41 % accuracy for male and 58.90 % accuracy for female on examined sample. Sex differences on shape and size of foramen magnum were found using geometric morphometrics method on three-dimensional models of the examined skulls. The percentage of accuracy was higher for male based on the shape and size of the foramen magnum than for female.

El foramen magno es una importante abertura topográfica que conecta la cavidad craneal y el canal espinal. El análisis del material óseo estableció que existen diferencias en la forma del foramen magno entre individuos. El objetivo de este estudio fue determinar el sexo en función de la forma y el tamaño del foramen magno utilizando morfometría geométrica. El estudio se realizó en modelos tridimensionales (modelos 3D) de 214 cráneos humanos de sexo y edad conocidos (141 cráneos masculinos y 73 cráneos femeninos). Los cráneos se encuentran en el museo de la Facultad de Medicina de la Universidad de Sarajevo. Los cráneos pertenecen a población bosnia de mediados del siglo XX. Todos los cráneos examinados fueron escaneados con un escáner láser para obtener sus modelos 3D. En los modelos 3D de los cráneos examinados, se marcaron cuatro puntos de referencia en el foramen magno. El análisis de determinación de sexo se realizó utilizando el programa MorphoJ. Los resultados de este estudio mostraron que existen diferencias de sexo en la forma y el tamaño del foramen magno. La determinación del sexo basada en la forma y el tamaño del foramen magno mostró una precisión del 65,25 % para los hombres y del 63,01 % para las mujeres utilizando morfometría geométrica. El examen del efecto del tamaño del foramen magno sobre el dimorfismo sexual de la forma del foramen magno mostró un efecto estadísticamente significativo. La determinación del sexo basada solo en la forma del foramen magno utilizando morfometría geométrica fue posible con una precisión del 62,41 % para los hombres y del 58,90 % para las mujeres en la muestra examinada. Se encontraron diferencias de sexo en la forma y el tamaño del foramen magno utilizando morfometría geométrica en modelos tridimensionales de los cráneos examinados. El porcentaje de precisión fue mayor para los hombres en función de la forma y el tamaño del foramen magno que para las mujeres.

Magnificent harmony in morphometric measurements of orbita and foramen magnum / Armonía magnífica en medidas morfométricas de órbita y foramen magno

SUMMARY: The foramen magnum (FM) is the key component of the craniovertebral junction, which connects the brain stem and medulla spinalis and is closely related to vital structures. FM dimensions are of great clinical importance. Considering the similarity in shape between FM and orbita, we thought that there might be a relationship between the lengths (sagittal diameter) and widths (transverse diameter) of these structures. Since it is not possible to reach FM directly, we set up our hypothesis as can we calculate the foramen magnum dimensions from orbital measurements before proceeding to costly tests. We also investigated this harmony in the skulls we used in the study. In the study, 21 dried skull bones from the Turkish population were used. FM and right Orbital length and width measurements were made. Precision digital caliper was used for measurements. Statistical validity and reliability analyzes were performed to prove the agreement between the measurements. We found that the length of the orbit and FM in the sagittal plane is close to each other, with 34.74±2.11 mm and 34.99±3.0 mm, and the width of the orbit in the coronal plane is approximately 1.40 times the width of the FM. We proved that the estimation of FM dimensions based on orbital measurements is also statistically valid and safe. Using orbital measurements, it is possible to estimate FM dimensions which are difficult to reach directly in living humans.

El foramen magno (FM) es el componente clave de la unión craneovertebral, que conecta el tronco encefálico y el bulbo raquídeo y está estrechamente relacionado con las estructuras vitales. Las dimensiones FM son de gran importancia clínica. Teniendo en cuenta la similitud de forma entre FM y órbitas, consideramos que podría haber una relación entre las longitudes (diámetro sagital) y las anchuras (diámetro transversal) de estas estructuras. Dado que no es posible llegar al FM directamente, establecimos nuestra hipótesis y calculamos las dimensiones del foramen magno a partir de mediciones orbitales antes de proceder a costosas pruebas. También investigamos esta armonía en los cráneos que usamos en el estudio. En el estudio, se utilizaron 21 huesos de cráneo secos de la población turca. Se realizaron mediciones FM y de longitud y anchura orbitales. Para las mediciones se utilizó un calibrador digital de precisión. Se realizaron análisis estadísticos de validez y confiabilidad para probar la concordancia entre las mediciones. Encontramos que la longitud de la órbita y FM en el plano sagital es cercana entre sí, con 34,74±2,11 mm y 34,99±3,0 mm, y el ancho de la órbita en el plano coronal es aproximadamente 1,40 veces el ancho de la FM. Demostramos que la estimación de las dimensiones FM basadas en mediciones orbitales también es estadísticamente válida y segura. Empleando mediciones orbitales, es posible estimar dimensiones FM que son difíciles de alcanzar directamente en humanos vivos.

Golden ratio for the foramen magnum on CT images: a morphological and morphometrical study / Proporción áurea para el foramen magnum en imágenes de TC: un estudio morfológico y morfométrico

SUMMARY: The foramen magnum (FM) is a transition zone between the spine and skull. There is a study in the literature showing the golden ratio (4.62) and harmony between both FM and the anteroposterior and transverse diameters of the skull. The aim of this study is to examine the existence of this ratio on CT images and to investigate whether this ratio changes according to the FM shape types. In this study, 402 adult CT images belonging to the Turkish population were examined. Maximum cranial length (MCL), maximum cranial width (MCW) and the FM length (FML) and FM width (FMW) were measured. The different shapes of the FM were macroscopically classified. The number and incidence of each type in the studied skull was registered. In the 402 CT images used in the study, 12 FM shapes were detected. Three of the shape types observed in our study have not been reported in the literature until now, and were found in our study for the first time. In addition, our data supported that by using the ratio of 4.62, there was a great harmony between the skull and FM. The results obtained from the research show that there is a ratio of 4.62 between the basic cranial measurements and FM dimensions in all shapes except triangular shape. It is thought that repeating the calculated coefficients over more different FM shapes will contribute to the effectiveness of the proposed golden ratio.

RESUMEN: El foramen magno (FM) es una zona de transición entre la columna y el cráneo. Existe un estudio en la literatura que muestra la proporción áurea (4,62) y la armonía entre el FM y los diámetros anteroposterior y transversal del cráneo. El objetivo de este estudio fue examinar la existencia de esta relación en las imágenes de TC e investigar si esta relación cambia según los tipos de forma del FM. Se examinaron 402 imágenes de TC de adultos pertenecientes a la población turca. Se midieron la longitud craneal máxima, el ancho craneal máximo y la longitud del FM y la anchura del FM. Las diferentes formas del FM se clasificaron macroscópicamente. Se registró el número e incidencia de cada tipo en el cráneo estudiado. En las 402 imágenes de TC utilizadas en el estudio, se detectaron 12 formas de FM. Tres de los tipos de formas observados en nuestro estudio no se han reportado en la literatura consultada describiéndose por primera vez. Además, nuestros datos respaldaron que al usar la proporción de 4,62, había una armonía importante entre el cráneo y el FM. Los resultados obtenidos de la investigación muestran que existe una relación de 4,62 entre las medidas craneales básicas y las dimensiones de la FM en todas las formas excepto en la triangular. Se cree que la repetición de los coeficientes calculados en más formas de FM diferentes contribuirá a la eficacia de la proporción áurea propuesta.

Meningiomas de fosa posterior: nomenclatura con orientación anatomo-quirúrgica y presentación de casos ilustrativos / Posterior fossa meningiomas: nomenclature with anatomical-surgical orientation and presentation of illustrative cases

Introducción: Los meningiomas de la fosa posterior representan el 20% de todos los meningiomas intracraneales. Cada subtipo tiene una base de implantación, abordaje quirúrgico y morbimortalidad postoperatoria muchas veces diferente. Advertimos que en reuniones científicas y publicaciones no se sigue una forma de clasificar uniforme, sencilla y clara con orientación netamente quirúrgica. Esto genera que el neurocirujano en formación no cuente con herramientas suficientes para la toma de decisiones. Objetivos: Proponer una clasificación sencilla de los meningiomas de la fosa posterior con un fundamento anatomo-quirúrgico y presentar casos ilustrativos de cada subtipo. Materiales y métodos: Se estableció una nomenclatura considerando reportes previos, el criterio anatómico y la experiencia quirúrgica de los autores. Se presentaron casos revisando las historias clínicas y los archivos de imágenes correspondientes a cada subtipo de la clasificación. Resultados: Representamos a la fosa posterior como un compartimento con 3 anillos: el superior se divide en medial, lateral-anterior y lateral-posterior; el medio se divide en 6 variantes: clivales puros, esfeno-petro-clivales, petrosos anteriores, petrosos posteriores y de la convexidad suboccipital medial y lateral; el inferior se divide en anterior, lateral derecho, lateral izquierdo y posterior. Conclusión: Los meningiomas del anillo superior pueden resolverse mediante una vía suboccipital medial o lateral; los del anillo medio tienen un espectro de opciones más diverso; los del anillo inferior -siguiendo el esquema de división en cuadrantes de un reloj- pueden resolverse por medio de un abordaje suboccipital medial o extremolatera

Introduction: Posterior fossa meningiomas represent 20% of all meningiomas, being each location associated with a specific approach, morbidity and mortality. The actual classifications are focus on the dural attachment, without associating the anatomical with the surgical aspects, useful to the young neurosurgeons for decision making. Objectives: To propose a classification of the posterior fossa meningiomas with an anatomical-surgical view including the presentation of cases. Materials and Methods: A nomenclature was established concerning previous reports, the anatomical criteria and the surgical experience of the authors. Cases were presented by reviewing the medical records corresponding to each subtype of the proposed classification. Results: We represent the posterior fossa as a 3 rings compartment: the upper one is divided into medial, anterior-lateral and posterior-lateral; the middle ring is divided into 6 variants: pure clival, spheno-petro-clival, anterior petrosal, posterior petrosal, and medial and lateral suboccipital convexity; the lower ring is divided into anterior, right lateral, left lateral, and posterior. Conclusion: Superior ring meningiomas can be resolved by a medial or lateral suboccipital approach; middle ring meningiomas have a more diverse spectrum of options; while meningiomas of the inferior ring - following the scheme of division into quadrants of a clock - can be resolved by means of a medial or extreme-lateral suboccipital approach.

Tailored Surgical Approaches for Foramem Magnum Tumors

Objective To describe our surgical techniques, analyze their safety and their postoperative outcomes for foramen magnum tumors (FMTs). Methods From 1986 to 2014, 34 patients with FMTs underwent surgeries using either the lateral suboccipital approach, standard midline suboccipital craniotomy, or the far lateral approach, depending on the anatomic location of the lesions. Results In the present series, there were 22 (64.7%) female and 12 (35.2%)male patients. The age of the patients ranged from12 to 63 years old.We observed 1 operativemortality (2.9%). A total of 28 patients (82.3%) achieved a score of 4 or 5 in the Glasgow Outcome Scale (GOS). Gross total resection (GTR) was obtained in 22 (64.7%) patients. After the surgery, 9 (26%) patients developed lower cranial nerve dysfunction (LCNd) weakness. The follow-up varied from 1 to 24 years (mean: 13.2 years). Conclusion Themajority of tumors located in the FMcan be safely and efficiently removed usingeither thelateral suboccipital approach, standardmiddlelinesuboccipital craniotomy, or the far lateral approach, depending on the anatomic location of the lesions.

Morbimortalidad Asociada A La Cirugia De Meningioma Del Foramen Magno. Revision De La Literatura: Reporte De Caso / Morbimortality Associated With The Foramen Magno Meningioma Surgery: A Case Report

Resumen Los meningiomas son tumores del sistema nervioso central que representan alrededor del 14,3% a 19%, de ellos solo un 1.8% a 3,2% surge en el foramen magno, por años el abordaje de esta clase de tumores conllevaba una gran morbimortalidad asociada debido a que el foramen magno contiene una serie de estructuras anatómicas y neurovasculares críticas, sin embargo con el progreso de las técnicas quirúrgicas, el manejo de la anestesia neurológica y la formación de neurocirujanos con experiencia en cirugías de base de cráneo, ha podido revertir estos resultados y hacer de la cirugía una alternativa segura con bajas tasas de complicaciones. El presente trabajo pretende revisar la literatura acerca de la morbimortalidad asociada a los meningiomas de foramen magno y presentar un caso abordado en nuestro centro.

The meningiomas are tumors of the central nervous system that represent around 14.3% to 19%, of them only 1.8% to 3.2% arise in the foramen magnum, for years the approach of this class of tumors entailed a great associated morbidity and mortality because the foramen magnum contains a series of critical anatomical and neurovascular structures, however with the progress of surgical techniques, the management of neurological anesthesia and the training of neurosurgeons with experience in skull base surgeries, it has been able to reverse these results and make surgery a safe alternative with low complication rates. The present work aims to review the literature about morbidity and mortality associated with meningiomas of foramen magnum and present a case addressed in our center.

Aplicabilidade do índice forame magno em crânios humanos de indivíduos do nordeste brasileiro / Applicability of the foramen magnum index on human skulls of individuals from northeastern Brazil

Introdução: O Índice Forame Magno (IFM) é um método secundário para o estabelecimento do sexo no processo de identificação humana. Objetivo: Averiguar a aplicabilidade do IFM para a determinação do sexo em uma amostra brasileira. Material e Método: Estudo cego e transversal, com amostra composta por 209 crânios pertencentes ao Centro de Estudos em Antropologia Forense da Faculdade de Odontologia de Pernambuco/Universidade de Pernambuco (CEAF/FOP/UPE). Com o uso de paquímetro digital de precisão, foram realizadas medidas correspondentes à largura e ao comprimento do forame magno, aplicando-as à fórmula IFM = largura/comprimento x 100. O sexo foi classificado de acordo com tabela de referência para o índice supracitado. Para a análise estatística utilizaram-se os testes T-Student e Qui-Quadrado de Pearson, com nível de significância de 5,0%. Resultados: Todas as variáveis quantitativas apresentaram diferenças estatisticamente significantes para os sexos (p<0,05), porém não houve discrepâncias entre os mesmos quanto à utilização do IFM (p=0,965). O acerto do IFM para o sexo masculino (99,1%), mas para o sexo feminino este método não classificou nenhum crânio corretamente. Conclusão: As dimensões do Forame Magno apresentaram dimorfismo sexual, porém o IFM não deve ser utilizado como metodologia para a determinação do sexo da amostra brasileira estudada.

Introduction: The Foramen Magnum Index (IMF) is a secondary method for the establishment of the sex in the process of human identification. Objective: To investigate the applicability of FMI to the determination of sex in a Brazilian sample. Material and Method: Blind and transversal study, with sample composed of 209 skulls belonging to the Forensic Anthropology Center of the Dentistry School of Pernambuco/Universidade de Pernambuco (CEAF/FOP/UPE). With the aid of a digital caliper, measurements were made on the width and length of the Foramen Magnum, applying them to the FMI formula FMI = width/length x 100. The sex was classified according with the reference table to the above mentioned index. For the statistical procedures, were used the testes Student T and Pearson's Chi-Square, with a significance level of 5%. Results: All the quantitative variables presented statistically significant differences for the sexes (p<0,05), but there were no discrepancies between them regarding the use of the FMI (p=0.965). The concordances of the FMI for males (99.1%) were higher than those of females, which did not have any cranial classification correctly. Conclusion: The FMI should not be used as a single methodology for determining the sex of the Brazilian sample studied

The morphometry and morphology of the foramen magnum in age and sex determination within the south african black population utilizing computer tomography (CT) scans / Morfometría y morfología del foramen magnum en la determinación de edad y sexo dentro de la población negra sudafricana mediante tomografía computarizada (TC)

SUMMARY: The morphology and morphometry of the foramen magnum aid forensic studies in identifying unknown individuals according to age and sex. Moreover, these parameters of the foramen magnum have clinical relevance to surgeons in the transcondylar approach. This study aimed to analyze the morphometry and morphology in relation to the age and sex of individuals within the South African Black population, utilizing computerized tomography images. The use of computerized tomography images allowed for accurate morphometric diameters using the SLICER 3-D software version 4.7.0. Radiological images also provide a patient's clinical history. Thus, the process of exclusion in respect to patients with pathological conditions of the skull is achieved. The sample studied included 150 computerized tomography images (93 males and 57 females) arranged according to age cohorts (children aged 1-12 years, adolescents aged 13-17 years and adults aged 18-25 years). The morphometric parameters viz. antero-posterior diameter, transverse diameter and area of the foramen magnum was analyzed in relation to age and sex. The morphological variations of the foramen magnum was simultaneously observed between males and females and within the age groups. The objective of this study were to improve data on the morphological and morphometric parameters of the foramen magnum in the South African Black population. This study also attempted to associate the morphological and morphometric parameters of the foramen magnum with age and sex determination.

RESUMEN: La morfología y morfometría del foramen magnum ayuda a los estudios forenses en la identificación de individuos desconocidos según la edad y el sexo. Además, parámetros del foramen magnum tienen relevancia clínica para los cirujanos en el abordaje transcondilar. Este estudio tuvo como objetivo analizar la morfometría y la morfología del foramen magnum, en relación con la edad y el sexo, dentro de la población negra sudafricana, utilizando imágenes de tomografía computarizada. El uso de imágenes de tomografía computarizada permitió definir diámetros morfométricos precisos utilizando el software SLICER 3-D versión 4.7.0. Las imágenes radiológicas también proporcionan antecedentes de la historia clínica de un paciente. De este modo, se logra el proceso de exclusión con respecto a los pacientes con afecciones patológicas del cráneo. La muestra estudiada incluyó 150 imágenes de tomografía computarizada (93 hombres y 57 mujeres) organizadas según cohortes de edad (niños de 1 a 12 años, adolescentes de 13 a 17 años y adultos de 18 a 25 años). Los parámetros morfométricos que se consideraron fueron: diámetro antero-posterior, diámetro transversal y área del foramen magnum. Las variaciones morfológicas del foramen magnum se observaron simultáneamente entre hombres y mujeres y dentro de los grupos de edad. El objetivo de este estudio fue mejorar los datos sobre los parámetros morfológicos y morfométricos del foramen magnum en la población negra sudafricana. Este estudio también intentó asociar los parámetros morfológicos y morfométricos del foramen magnum con la determinación de la edad y el sexo.

The Clock Is Ticking – Brain Atrophy in Case of Acute Trauma? / 대한신경손상학회지

OBJECTIVE: Brain atrophy and brain herniation are gaining a lot of attention separately, but a limited amount of studies connected them together, and because of this, we are going to review and examine the subject in the current meta-analysis. METHODS: The authors collected data reporting brain atrophy of alcoholic and schizophrenic cause, as well as data on control patients, all of which was published on MEDLINE between 1996 and 2018. The included 11 articles were processed with a statistical program. RESULTS: We found that the pericerebral space is unequal among the groups, while the intracranial volume is strongly correlated to the biggest foramen of the body. The effect of this inequality, however, is expressed in emergency cases, where the patients with brain atrophy will have more time before the final stage of brain herniation CONCLUSION: The current study raises a controversial issue that requires careful investigation and high attention from the health care personnel.

Arnold-Chiari Type 1 Malformation Mimicking Benign Paroxysmal Positional Vertigo / 대한평형의학회지

Arnold-Chiari malformation type 1 is a congenital disease characterized by herniation of the cerebellar tonsils through the foramen magnum. Most common clinical symptom is pain, including occipital headache and neck pain, upper limb pain exacerbated by physical activity or valsalva maneuvers. Various otoneurological manifestations also occur in patients with the disease, which has usually associated with dizziness, vomiting, dysphagia, poor hand coordination, unsteady gait, numbness. Patients with Arnold-Chiari malformation may develop vertigo after spending some time with their head inclined on their trunk. Positional and down-beating nystagmus are common forms of nystagmus in them. We experienced a 12-year-old female who presented complaining of vertigo related to changes in head position which was initially misdiagnosed as a benign paroxysmal positional vertigo.

Endoscopic Endonasal Approach to Foramen Magnum Meningioma­Technical Note and Case Example

Foramen magnum (FM) tumors represent one of the most complex cases for the neurosurgeon, due to their location in a very anatomically complex region surrounded by the brainstem and the lower cranial nerves, by bony elements of the craniocervical junction, and by the vertebrobasilar vessels. Currently, the open approach of choice is a lateral extension of the posteriormidline approach including far lateral, and extremelateral routes. However, the transoraltranspharyngeal approach remains the treatment of choice in cases of diseases affecting the craniocervical junction. For very selective cases, the endoscopic endonasal route to this region is another option.We present a case of a ventral FM meningioma treated exclusively with the endoscopic endonasal approach.

Foramen Magnum Meningioma Presenting with Cough Syncope (Case Report and Review of the Literature)

Foramen magnum meningiomas cause different symptoms based on the size and the location of the tumor. They often present with involvement of the long tracts and of the lower cranial nerves.Ataxia and occipitocervical headache are other common symptoms. In the present study, we report a case of foramen magnum meningioma presenting with cough syncope. A mass lesion located anterolateral to the foramenmagnumwas detected in a 38-year-oldmanduring amagnetic resonance imaging (MRI) exam; the lesion extended from the inferior clivus to the level of the C2 vertebra. The neural axis has pushed towards posterior and contralateral side by the mass. We think that syncope occurred due to the encasement of the vertebral arteries by the tumor in addition to the compression of the neural axis. The posterolateral approach without condylar resection provides a safe surgical plane for total excision of these tumors. In our case, the tumor was totally removed and the syncope episodes were resolved.

Sexing the cranium from the foramen magnum using discriminant analysis in a brazilian sample

Abstract In the identification process, the foramen magnum has shown controversial results in sex estimation. The present study aimed to analyze the morphometric variables of the foramen magnum in Brazilian adult cranium for sex estimation. The sample was composed of 100 craniums (53 males and 47 females) from the documented collection of the Institute of Teaching and Research in Forensic Sciences. The protocol measurement was constituted of two linear measurements: maximum length of the foramen magnum and maximum breadth of the foramen magnum and two formulas to calculate the area, method one (M1) and method two (M2). Descriptive statistics showed statistically significant differences between sex (p<0.05) for all variables. The univariate discriminant functions showed an accuracy between 56.0-62.0%, and the multivariate analysis showed a percentage of accuracy between 60.0-65.0%, the greatest accuracy was found combining the two linear measurements with M1(71.7%), even after cross-validation (66%). Receiver Operating Characteristic (ROC) curve analysis showed that M2 is the best parameter for estimating sex (AUC=0.693). A reference table for Brazilians using the foramen magnum parameters was developed based on the results of the ROC curve analysis. In conclusion, the foramen magnum should be used with caution to estimate sex in forensic cases of fragmentary craniums, due to the limited accuracy.

Resumo No processo de identificação humana, a análise do forame magno apresenta resultados controversos para estimativa do sexo. O presente estudo teve como objetivo analisar as variáveis morfométricas do forame magno em crânios adultos brasileiros para estimação sexual. A amostra foi composta por 100 crânios (53 sexos masculino e 47 sexo feminino) pertencentes a coleção osteológica documentada do Instituto de Ensino e Pesquisa em Ciências Forenses. A medida do protocolo foi constituída por duas medidas lineares: comprimento máximo do forame magno e largura máxima do forame magno e duas fórmulas para calcular a área, método um (M1) e método dois (M2). As estatísticas descritivas evidenciaram diferenças estatisticamente significativas (p<0,05) para todas as variáveis. As funções discriminantes univariadas apresentaram uma porcentagem de acerto entre 56,0-62,0% e a análise multivariada mostrou uma porcentagem de acerto entre 60,0-65,0%. A análise da curva ROC apontou que M2 é o melhor parâmetro para estimar o sexo (AUC=0,693). Uma tabela de referência para brasileiros que utilizam os parâmetros do forame magnum foi desenvolvida com base nos resultados da análise da curva ROC. Em conclusão, o foram e magnum deve ser usado com precaução para estimar o sexo em casos forenses de cranio fragmentado, devido à precisão limitada.

Rotatory Vertebral Artery Syndrome in Foramen Magnum Stenosis / 대한평형의학회지

Rotatory vertebral artery syndrome (RVAS) is characterized by recurrent attacks of vertigo, nystagmus, and syncope induced by compression of the vertebral artery during head rotation. A 60-year-old man with atlas vertebrae fracture presented recurrent attacks of positional vertigo. Left-beat, upbeat and count clock-wise torsional nystagmus occurred after lying down and bilateral head roll (HR) showing no latency or fatigue. Magnetic resonance imaging revealed foramen magnum stenosis (FMS) and dominancy of right vertebral artery (VA). The flow of the right VA on transcranial Doppler decreased significantly during left HR. The slower the velocity was, the more the nystagmus was aggravated. RVAS can be evoked by FMS causing compression of the VA. And the nystagmus might be aggravated according to the blood flow insufficiency.

A Rare Case of Subarachnoid Hemorrhage caused by Ruptured Venous Varix Due to Dural Arteriovenous Fistula at the Foramen Magnum Fed Solely by the Ascending Pharyngeal Artery

Dural arteriovenous fistula (D-AVF) at the foramen magnum is an extremely rare disease entity. It produces venous hypertension, and can lead to progressive cervical myelopathy thereafter. On the other hand, the venous hypertension may lead to formation of a venous varix, and it can rarely result in an abrupt onset of subarachnoid hemorrhage (SAH) when the venous varix is ruptured. The diagnosis of D-AVF at the foramen magnum as a cause of SAH may be difficult due to its low incidence. Furthermore, when the D-AVF is fed solely by the ascending pharyngeal artery (APA), it may be missed if the external carotid angiography is not performed. The outcome could be fatal if the fistula is unrecognized. Herein, we report on a rare case of SAH caused by ruptured venous varix due to D-AVF at the foramen magnum fed solely by the APA. A review of relevant literatures is provided, and the treatment modalities and outcomes are also discussed.

Morphometric analysis of the foramen magnum / Análisis morfométrico del foramen magno

SUMMARY: The foramen magnum is morphometrically typified by two perpendicular diameters and a distinct margin. This important anatomical landmark is subject to high interindividual variation. The objective of this study was to evaluate the dimensions and morphology of the foramen magnum in a Jordanian population. In this retrospective study, 247 individuals were consecutively sampled using the institutional picture archiving and communication system. The anteroposterior and transverse diameters of the foramen magnum were measured; the foramen magnum index was calculated; and, the shape of the foramen magnum was visually assessed. The sex-pooled anteroposterior and transverse diameters were 35.1 ± 3.2 mm and 29.3 ± 2.5 mm, respectively. The sex-pooled foramen magnum index was 1.20 ± 0.10. The diameters were significantly different (P<0.001) and positively correlated (r=0.52, P<0.001). Participant age was negatively correlated with the anteroposterior (rs=-0.15, P=0.02) and transverse (rs=-0.14, P=0.03) diameters. After controlling for participant age, there was a statistically significant difference in the anteroposterior diameter (P<0.001), the transverse diameter (P<0.001), and the foramen magnum index (P=0.02) between sexes. The foramen magnum was most commonly irregular in shape (36 % of all cases). In contrast to previous studies, we report, for the first time, a negative correlation between age and the diameters of the foramen magnum. In addition, a predominance of irregularly shaped foramen magnum was found. The finding makes an already heterogenous group of published data even more variable, prompting reconsideration of the role of visual assessment in morphometric studies.

RESUMEN: El foramen magno está morfométricamente tipificado por dos diámetros perpendiculares y un margen. Este punto importante de referencia anatómica está sujeto a una alta variación interindividual. El objetivo del estudio fue evaluar las dimensiones y la morfología del foramen magno en una población jordana. En este estudio retrospectivo, 247 individuos fueron muestreados consecutivamente utilizando el sistema institucional y de comunicación de imágenes. Se midieron los diámetros anteroposterior y transversal del foramen magno; Se calculó el índice del foramen magno y se evaluó visualmente la forma dede éste. Los diámetros anteroposterior y transversal agrupados por sexo fueron 35,1±3,2 mm y 29,3±2,5 mm, respectivamente. El índice del foramen magno, agrupado por sexo, fue 1,20±0,10. Los diámetros fueron significativamente diferentes (P <0,001) y positivamente correlacionados (r = 0,52, P <0,001). La edad de los participantes se correlacionó negativamente con los diámetros anteroposterior (rs = -0,15, P = 0,02) y transversal (rs = -0,14, P = 0,03). Después de verificar la edad de los participantes, hubo una diferencia estadísticamente significativa entre el diámetro anteroposterior (P <0,001), el diámetro transversal (P <0,001) y el foramen magno (P = 0,02) entre ambos sexos. El foramen magno era más comúnmente de forma irregular (36 % de todos los casos). A diferencia de estudios anteriores, se informa por primera vez de una correlación negativa entre la edad y los diámetros del foramen magno. Además, se encontró un predominio de forámenes de forma irregular. El hallazgo indica que un grupo heterogéneo de datos ya publicados, sea aún más variable, lo que lleva a reconsiderar el papel de la evaluación visual en los estudios morfométricos.

Extra-Axial Mass in the Foramen Magnum Causing Cervical Compressive Myelopathy as a Complication of Rosai-Dorfman Disease

No abstract available.

Lesión como malformación de Chiari secundaria a quiste aracnoidal de la cisterna cuadrigémina / Chiari malformation-like lesion secondary to arachnoid cyst of the quadrigeminal cistern

Se presenta el caso de una mujer de 31 años de edad con cefalea y cervicalgia que se agravaba con la maniobra de Valsalva, presentando además mareos, encontrándose una malformación de Chiari secundario a un quiste aracnoideo cuadrigeminal. Después de efectuada la resonancia magnética diagnóstica, la paciente fue sometida a descompresión del agujero magno y extirpación del quiste cuadrigeminal, seguido por la resolución tanto de la malformación de Chiari y el quiste. Los síntomas desaparecieron después de la cirugía y han permanecido completamente resuelto hasta la actualidad. En pacientes adultos que presentan signos y síntomas de una malformación de Chiari debido a la compresión de la médula por las las amígdalas cerebelosas, la presencia de un quiste aracnoideo de cisterna cuadrigéminal es una rara patología asociada que puede ser tratada quirúrgicamente.

We report a rare case of a 31-year-old woman with headache and pain manifested by cervicalgia that worsened with the Valsalva maneuver and dizziness, who was found to have a Chiari malformation secondary to a posterior fossa arachnoid cyst. After magnetic resonance imagining (MRI), the patient was submitted to foramen magnum decompression and arachnoid cyst removal that were followed by resolution of both the Chiari malformation and the cyst. The symptoms disappeared after surgery and have remained completely resolved to the present day. In adult patients who present with signs and symptoms of Chiari malformation due to direct medulla compression by the tonsils, a quadrigeminal cistern arachnoid cyst is a rare associated pathology that can be treated surgically.

Surgical Outcome of Adult Idiopathic Chiari Malformation Type 1

OBJECTIVE: The pathophysiology of idiopathic Chiari malformation (CM) type 1 is disturbance of free cerebrospinal fluid (CSF) flow and restoration of normal CSF flow is the mainstay of treatment. Additional migration of the medulla oblongata in pediatric patients is referred to as CM type 1.5, but its significance in adult patients is unknown. This study is to compare surgical outcomes of adult idiopathic CM type 1.5 with that of type 1. METHODS: Thirty-eight consecutive adult patients (M : F=11 : 27; median, 33.5; range, 18–63) with syringomyelia due to idiopathic CM type 1 were reviewed. Migration of the medulla oblongata was noted in 13 patients. The modified McCormick scale (MMS) was used to evaluate functional status before and one year after surgery. All patients underwent foramen magnum decompression and duroplasty. Factors related to radiological success (≥50% decrease in the diameter of the syrinx) were investigated. The follow-up period was 72.7±55.6 months. RESULTS: Preoperative functional status were MMS I in 11 patients and MMS II in 14 of CM type 1 and MMS I in 8 and II in 5 of CM type 1.5. Of patients with MMS II, 5/14 patients in group A and 3/5 patients in group B showed improvement and there was no case of deterioration. Radiological success was achieved in 32 (84%) patients and restoration of the cisterna magna (p=0.01; OR, 46.5) was the only significant factor. CONCLUSION: Migration of the medulla oblongata did not make a difference in the surgical outcome when the cisterna magna was restored.

Type I Chiari malformation presenting orthostatic syncope who treated with decompressive surgery / 소아과

Chiari malformations are a congenital anomaly of the hindbrain. The most common, Chiari malformation type I (CM-I), is characterized by herniation of the cerebellar tonsils extending at least 3 mm below the plane of the foramen magnum. Consequently, CM-I is associated with hydrocephalus and symptoms involving compression of the cervicomedullary junction by ectopic tonsils. Several studies have reported the clinical symptoms associated with CM-I, including suboccipital headache, weakness in the upper extremities, facial numbness, loss of temperature sensation, ataxia, diplopia, dysarthria, dysphagia, vomiting, vertigo, nystagmus, and tinnitus. Syncope is one of the rarest presentations in patients with CM-I. There are many hypotheses regarding the causes of syncope in patients with CM-I; however, the mechanisms are not clearly understood. Although surgical decompression for CM-I in patients with syncope has yielded good clinical results in some studies, such cases are rarely reported. We report a case of orthostatic syncope in a patient with CM-I who was treated with surgical intervention.