The ligament of barkow is a solid structure in human fetuses / O ligamento de barkow é uma estrutura individualizada em fetos humanos / El ligamento de barkow es una estructura individualizada en fetos humanos

ABSTRACT: Objective: The present study aims to dissect and identify the Barkow ligament (LB) in fetal specimens and describe its anatomical characteristics to contribute to its knowledge in the pediatric population and the clinical and surgical application of conditions associated with the Craniovertebral Junction (CVJ). ). Methods: This work evaluated 19 human fetuses aged 28-38 weeks. Of these, six specimens constituted the final sample and were studied through detailed dissections using coronal sections in an anterior approach up to the region described by the LB. Results: In all specimens, a thin fibrous band was found, horizontal and anterior to the axis tooth, with bilateral fixation on the occipital condyles, corroborating the results found for describing LB in adults. Conclusion: The LB is a congenital ligament that resists the extension of the atlantooccipital joint and may play a role in the stability of the CVJ. Level of Evidence III; Diagnostic Study.

RESUMO: Objetivo: O presente estudo tem como objetivo dissecar e identificar o ligamento de Barkow (LB) em espécimes fetais, e descrever suas caraterísticas anatômicas visando contribuir para o seu conhecimento em população pediátrica e na aplicação clínica e cirúrgica das condições associadas à Junção Craniovertebral (JCV). Métodos: Esse trabalho avaliou 19 fetos humanos de 28-38 semanas de vida. Destes, 6 espécimes constituíram a amostra final e foram estudados através de dissecções minuciosas utilizando secções coronais, em uma abordagem anterior, até a região de descrição do LB. Resultados: Em todos os espécimes foi encontrada uma delgada banda fibrosa, de disposição horizontal e anterior ao dente do áxis, com fixação bilateral nos côndilos occipitais, corroborando com os resultados encontrados para a descrição do LB em adultos. Conclusão: O LB é um ligamento congênito, que resiste a extensão da articulação atlantoccipital, e que pode ter papel na estabilidade da JCV. Nível de Evidência III; Estudo diagnóstico.

RESUMEN: Objetivo: El presente estudio tiene como objetivo diseccionar e identificar el ligamento de Barkow (LB) en especímenes fetales, y describir sus características anatómicas con el fin de contribuir a su conocimiento en la población pediátrica y en la aplicación clínica y quirúrgica de las condiciones asociadas a la unión craneovertebral. (UCV).). Métodos: Este trabajo evaluó 19 fetos humanos de entre 28 y 38 semanas. De estos, 6 ejemplares constituyeron la muestra final y fueron estudiados mediante disecciones detalladas mediante cortes coronales, en abordaje anterior, hasta la región descrita por el LB. Resultados: En todos los ejemplares se encontró una delgada banda fibrosa, horizontal y anterior al diente axis, con fijación bilateral en los cóndilos occipitales, corroborando los resultados encontrados para la descripción de LB en adultos. Conclusión: El LB es un ligamento congénito, que resiste la extensión de la articulación atlantooccipital, y que puede desempeñar un papel en la estabilidad de la UCV. Nivel de Evidencia III; Estudio Diagnóstico.

Congenital atlanto-occipital fusion and its effect on the myodural bridge: a case report utilizing the P45 plastination technique / Fusión atlanto-occipital congénita y su efecto sobre el puente miodural: reporte de un caso utilizando la técnica de plastinación P45

SUMMARY: The atlanto-occipital joint is composed of the superior fossa of the lateral masses of the atlas (C1) and the occipital condyles. Congenital Atlanto-occipital fusion (AOF) involves the osseous union of the base of the occiput (C0) and the atlas (C1). AOF or atlas occipitalization/assimilation represents a craniovertebral junction malformation (CVJM) which can be accompanied by other cranial or spinal malformations. AOF may be asymptomatic or patients may experience symptoms from neural compression as well as limited neck movement. The myodural bridge (MDB) complex is a dense fibrous structure that connects the suboccipital muscular and its related facia to the cervical spinal dura mater, passing through both the posterior atlanto-occipital and atlanto-axial interspaces. It is not known if atlas occipitilization can induce structural changes in the MDB complex and its associated suboccipital musculature. The suboccipital region of a cadaveric head and neck specimen from an 87-year-old Chinese male having a congenital AOF malformation with resultant changes to the MDB complex was observed. After being treated with the P45 plastination method, multiple slices obtained from the cadaveric head and neck specimen were examined with special attention paid to the suboccipital region and the CVJM. Congenital atlanto-occipital fusion malformations are defined as partial or complete fusion of the base of the occiput (C0) with the atlas (C1). In the present case of CVJM, unilateral fusion of the left occipital condyle with the left lateral mass of C1 was observed, as well as posterior central fusion of the posterior margin of the foramen magnum with the posterior arch of C1. Also noted was a unilateral variation of the course of the vertebral artery due to the narrowed posterior atlanto-occipital interspace. Surprisingly, complete agenesis of the rectus capitis posterior minor (RCPmi) and the obliques capitis superior (OCS) muscles was also observed in the plastinated slices. Interestingly, the MDB, which normally originates in part from the RCPmi muscle, was observed to originate from a superior bifurcation within an aspect of the nuchal ligament. Therefore, the observed changes involving the MDB complex appear to be an effective compensation to the suboccipital malformations.

RESUMEN: La articulación atlanto-occipital está compuesta por las caras articulares superiores de las masas laterales del atlas (C1) y los cóndilos occipitales. La fusión atlanto-occipital congénita (FAO) implica la unión ósea de la base del occipucio (C0) y el atlas (C1). La FAO u occipitalización/asimilación del atlas representa una malformación de la unión craneovertebral (MUCV) que puede presentar otras malformaciones craneales o espinales. La FAO puede ser asintomática o los pacientes pueden experimentar síntomas de compresión neural así como movimiento limitado del cuello. El complejo del puente miodural (PMD) es una estructura fibrosa densa que conecta el músculo suboccipital y su fascia relacionada con la duramadre espinal cervical, pasando a través de los espacios intermedios atlanto-occipital posterior y atlanto-axial. No se sabe si la occipitilización del atlas puede inducir cambios estructurales en el complejo PMD y en la musculatura suboccipital. Se observó en la región suboccipital de un espécimen cadavérico, cabeza y cuello de un varón chino de 87 años con una malformación congénita de FAO con los cambios resultantes en el complejo PMD. Se examinaron múltiples cortes obtenidos de la muestra de cabeza y cuello después de ser tratados con el método de plastinación P45, con especial atención a la región suboccipital y la MUCV. Las malformaciones congénitas por fusión atlanto-occipital se definen como la fusión parcial o completa de la base del occipucio (C0) con el atlas (C1). En el presente caso de MUCV se observó la fusión unilateral del cóndilo occipital izquierdo con la masa lateral izquierda de C1, así como fusión posterior central del margen posterior del foramen magnum con el arco posterior de C1. También se observó una variación unilateral del curso de la arteria vertebral por el estrechamiento del espacio interatlanto-occipital posterior. Se observó además agenesia completa de los músculos Rectus capitis posterior minor (RCPmi) y oblicuos capitis superior (OCS) en los cortes plastinados. Curiosamente, se observó que el MDB, que normalmente se origina en parte del músculo RCPmi, se origina en una bifurcación superior dentro de un aspecto del ligamento nucal. Por lo tanto, los cambios observados en el complejo PMD parecen ser una compensación de las malformaciones suboccipitales.

Traumatic Atlanto-occipital Dislocation in Children Followed by Hydrocephalus ­ A Case Report and Literature Review / Deslocamento atlanto-occipital em crianças seguido por hidrocefalia ­ Relato de caso e revisão da literatura

Traumatic atlanto-occipital dislocation (TAOD) are uncommon injuries associated with high immediate mortality rate and occurs more than twice in children than adults, due to biomechanical properties and immaturity of children's cervical spine. We report a pediatric patient with TAOD, who underwent occipitocervical stabilization and also developed a late hydrocephalus requiring a shunt procedure. A six-year-old boy was admitted to the emergency department after a car accident with refractory cervical pain. A cervical computed tomography (CT) scan showed an anterior C1­C2 level hematoma, and a dynamic CT scan demonstrated an increasing basion-dens interval on extension. Cervical magnetic resonance imaging (MRI) showed discontinuity of the tectorial membrane and diffused hyperintense signal on the left alar ligament. These findings were attributed to TAOD, and an occipitocervical fusion was performed. The pain and neurological status improved after surgery, but after 3 months he returned with persistent vomiting, headache, and a CT scan showing hydrocephalus. Then, a ventriculoperitoneal shunt was performed, improving the symptoms. One year after the injury, the patient remained asymptomatic, and a later radiography demonstrated satisfactory bone fusion. In conclusion, the decision-making process regarding treatment should consider several clinical and radiographic findings. Occipitocervical fusion is the treatment of choice, while hydroceph alus is not an unusual complication in children.

O deslocamento atlanto-occipital (DAO) é uma lesão incomum associada a uma alta taxa de mortalidade imediata que ocorre duas vezes mais em crianças do que em adultos, fato relacionado às propriedades biomecânicas e à imaturidade da coluna cervical pediátrica. Relatamos o caso de um paciente pediátrico com DAO traumático submetido à fixação occipitocervical, evoluindo com hidrocefalia e necessidade de um procedimento de derivação liquórica. Paciente do sexo masculino de 6 anos de idade admitido no pronto-socorro após um acidente automobilístico, apresentando dor cervical refratária. A tomografia computadorizada (TC) de coluna cervical demostrou um hematoma epidural ao nível de C1­C2, e a TC dinâmica evidenciou um intervalo basion-odontoide aumentado em extensão. A ressonância magnética (RM) da coluna cervical demonstrou descontinuidade da membrana tectorial e hiperintensidade difusa no ligamento alar esquerdo. Esses achados permitiram o diagnóstico de um DAO, sendo realizada uma fusão occipitocervical. A dor e o status neurológico melhoraram após a cirurgia, mas 3 meses após, o paciente evoluiu com vômitos persistentes, cefaleia e TC de crânio evidenciando hidrocefalia. Em seguida, foi realizada uma derivação ventriculoperitoneal, com melhora dos sintomas. Um ano após, o paciente permaneceu assintomático, e a radiografia demonstrou fusão óssea satisfatória. Em conclusão, o processo de tomada de decisão quanto ao tratamento deve levar em consideração diversos achados clínicos e radiográficos. A fixação occipitocervical é o tratamento de escolha, enquanto a hidrocefalia não é uma complicação incomum em crianças.

Traumatic Atlanto-Occipital Dislocation-A Comprehensive Analysis of All Case Series Found in the Spinal Trauma Literature.

BACKGROUND: Traumatic atlanto-occipital dislocation (TAOD) is one of the most devastating traumatic injuries, generally associated with immediate death after high-energy trauma. The aim of this study was to perform a systematic literature review of all cases series of TAOD and present the current state of this entity. METHODS: A systematic literature review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Only case series with at least 5 cases were included in the analysis. We focused on survival rates, diagnostic methods, delays in diagnosis, outcomes, and cases successfully treated nonoperatively. RESULTS: A total of 17 articles were included (16 retrospective and 1 prospective study) with 341 patients. Six studies included pediatric patients only. The mean Glasgow Coma Scale at admission was ≤8 in all studies. Many different diagnostic criteria were used, but none of them had high accuracy. The overall mortality rate was 34.8%, but the studies' designs were heterogeneous (some included only survivors). A high rate of concomitant traumatic brain injury was documented in some studies. We found it interesting that some patients were treated with cervical immobilization (37/341; 10.8%), which was generally used in less unstable injuries; however, the majority of patients were managed with an occipito-cervical fusion (193/341; 56.5%). CONCLUSIONS: TAOD is a devastating traumatic injury, with a high mortality rate. An MRI may be recommended when there are subtle findings of TAOD and a normal computed tomography scan, such as subarachnoid hemorrhage in the posterior fossa, upper cervical injuries, or consistent neurological findings. Further studies are necessary to identify patients with mild MRI findings and TAOD that may be managed nonoperatively.

Observational study of patients with occipital condyle fracture at a brazilian referral trauma center / Estudo observacional de pacientes com fratura de côndilo ocipital em centro de referência em trauma no brasil

ABSTRACT Objective: to evaluate the clinical-epidemiological characteristics, treatment, and evolution of patients with occipital condyle fracture (OCF) at one of the largest referral trauma centers in Latin America. Methods: this was a retrospective observational study of OCF identified from trauma cases admitted between December 2011 and December 2019 by the neurosurgery team at a Type 3 trauma center. Results: a total of twenty-eight occipital condyle fractures were identified in twenty-six patients. The incidence was less than 0.2% per year and more common in male patients (4:1 ratio) involved in traffic accidents. The mean age was 42.08 years. Anderson and Montesano type II and Tuli type 1 were the most frequent (67.9% and 89.3%, respectively) and no case presented C0-C1-C2 instability. All patients were treated with a cervical collar for 3 to 6 months. About 65% of the patients exhibited good progression (Glasgow Outcome Scale equal to 4), and the severity of traumatic brain injury was the main determinant for negative outcomes. Conclusion: the findings of this study are in accordance with available literature data. The use of external stabilization with a cervical collar is reinforced for the treatment of stable lesions, even when these are bilateral. Assessment of the patients' follow-up results in the studied sample may contribute with useful information for the treatment of occipital condyle fractures.

RESUMO Objetivo: avaliar o perfil clínico-epidemiológico, o tratamento e a evolução de pacientes com fraturas do côndilo occipital (FCO) em um dos maiores centros especializados em trauma na América Latina. Método: este é um estudo observacional retrospectivo de FCO identificadas em casos de trauma que foram atendidos no período de Dezembro de 2011 a Dezembro de 2019 pela equipe de trauma de centro de trauma Tipo 3. Resultados: um total de vinte e oito fraturas do côndilo occipital foram identificadas em 26 pacientes. A incidência foi inferior a 0.2% ao ano e mais comum em pacientes do sexo masculino (proporção 4:1) envolvidos em acidentes de trânsito. A idade média foi de 42.08 anos. O Tipo II de Anderson e Montesano e o Tipo 1 de Tuli foram os mais frequentes (67.9% e 89.3%, respectivamente) e nenhum caso teve instabilidades C0C1C2. Todos os pacientes foram tratados com colar cervical por período de 3 a 6 meses. Cerca de 65% dos pacientes apresentaram boa evolução (Escala de Resultados de Glasgow maior ou igual a 4), e a gravidade da lesão cerebral foi o principal determinante para os resultados negativos. Conclusão: os achados deste estudo são similares a dados disponíveis na literatura. O uso de colar cervical para estabilização externa é reforçado para o tratamento de lesões estáveis, mesmo quando bilaterais. A avaliação dos resultados do acompanhamento dos pacientes na amostra estudada pode contribuir com informações úteis para o tratamento de fraturas de côndilo occipital.

Morphological Analysis on the Occipital Condyles and Review of the Literature / Análisis Morfológico de los Cóndilos Occipitales y Revisión de la Literatura

Most anatomical and biomechanical studies on the craniovertebral junction have involved morphological or morphometric analysis on the occipital condyles. Some of these studies have provided important findings based on different surgical procedures. The shape, size and angle of the occipital condyles and the locations of the intracranial and extracranial orifices of the hypoglossal canal are highly important because they may affect the lateral approaches to the craniovertebral junction. To determine the frequency of occurrence of different morphological types of occipital condyle. 214 occipital condyles in 107 dry human skulls were analyzed and the classification of their morphological types was determined through assessing digitized photographic images. Among the 107 skulls analyzed, 59.8 % were male and 40.2 % were female. Their ages ranged from 11 to 91 years, with a mean of 57.56 years. Of the total of 10 morphological types of occipital condyle that were found, more than 50 % were of the "8", "S" and ring types. Condyles of "8" and "S" shape were the main types found in male skulls: the "8" shape prevailed on the left side and the "S" shape on the right side. However, in female skulls, these two types had equal bilateral distribution.

La mayor parte de los estudios anatómicos y biomecánicos de la unión cráneo-vertebral han sido realizados sobre el análisis morfológico o de la morfometría de los cóndilos occipitales. Algunos de estos trabajos tienen previsto importantes hallazgos basados en diferentes procedimientos quirúrgicos. De tal forma, el tamaño y ángulo del cóndilo occipital bien como su localización de los orificios intracraneales y extracraneales del canal hipogloso son de gran importancia, ya que pueden afectar a los enfoques laterales de la unión cráneo-vertebral. El objetivo del estudio fue determinar la prevalencia de los tipos morfológicos de cóndilos occipitales. Fueron analizados 214 cóndilos de 107 cráneos secos de humanos y la clasificación de los tipos morfológicos fue determinada a partir de los análisis de estudio de imágenes fotográficas digitalizadas. De los 107 cráneos que fueron analizados, 59,8 % eran de sexo masculino y 40,2 % de sexo femenino, cuyas edades comprendidas entre 11 y 91 años con una media de 57.56 años. De un total de 10 tipos morfológicos de los cóndilos occipitales encontrados, más del 50 % eran de tipo ocho, S y anillo. Los cóndilos en forma de "8" y "S" fueron los principales tipos encontrados, en el sexo masculino, la forma en "8" prevaleció en el lado izquierdo, y el tipo morfológico en "S", en el lado derecho del cráneo. Mientras que en el sexo femenino esos dos tipos tuvieron una equitativa distribución bilateral.

Tratamento com imunoglobulina anti-toxina tetânica homóloga por via intratecal em tétano neonatal equino - relato de caso / Treatment with intrathecal administration of anti-tetanus toxoid immunoglobulin in neonatal foal tetanus - case report

Tetanus is a severe and highly fatal infectious disease caused by the toxin of Clostridium tetani, an anaerobic spore-forming Grampositive bacterium. The disease is characterized by muscle rigidity (tetany) and can lead to death by respiratory failure or seizures. The present study reports a case of tetanus in a 6-day-old Quarter Horse foal. The animal showed apathy, lateral recumbency, umbilical thickening, protrusion of the third eyelid, seizures and hyperesthesia. Was treated with 50,000 IU/kg of potassium penicillin; with anti-tetanus toxoid immunoglobulin in a dose of 25,000 IU, 20,000 IU and 20,000 IU intravenously, intramuscular and intrathecal, respectively; with acepromazine hydrochloride (0.05 mg / kg); fluid therapy of Ringer"s lactate solution and dressing for umbilical cord. After 48 hours of treatment, the animal demonstrated hyperacute symptoms and died, showing unsuccessful in treating. Possibly the infection has been caused by inadequate umbilical cord cleansing.(AU)

O tétano é uma doença infecciosa grave e altamente fatal, causada pela toxina Clostridium tetani, uma bactéria Gram-positiva formadora de esporos anaeróbicos. A doença é caracterizada por rigidez muscular (tetania) e pode levar à morte por parada respiratória ou convulsões. O presente trabalho relata um caso de tétano em um potro Quarto de Milha de 6 dias de idade. O animal apresentava apatia, decúbito lateral, espessamento umbilical, protrusão da terceira pálpebra e convulsões em resposta a estímulos externos, como som, luz e toque. Foi tratado com 110.000 IU / kg de penicilina potássica; com imunoglobulina anti-toxina tetânica homóloga, numa dose de 25000 UI, 20.000 UI e 20000 UI por via intravenosa, intramuscular e intratecal, respectivamente; com cloridrato de acepromazina (0,05 mg / kg); fluidoterapia à base de Ringer com lactato e curativo no cordão umbilical. Decorridas 48 horas de tratamento, o animal demonstrou sintomas hiperagudos e veio à óbito, mostrando insucesso no tratamento. Possivelmente, a infecção foi causada pela limpeza inadequada do cordão umbilical.(AU)

Tratamento com imunoglobulina anti-toxina tetânica homóloga por via intratecal em tétano neonatal equino - relato de caso / Treatment with intrathecal administration of anti-tetanus toxoid immunoglobulin in neonatal foal tetanus - case report

Tetanus is a severe and highly fatal infectious disease caused by the toxin of Clostridium tetani, an anaerobic spore-forming Grampositive bacterium. The disease is characterized by muscle rigidity (tetany) and can lead to death by respiratory failure or seizures. The present study reports a case of tetanus in a 6-day-old Quarter Horse foal. The animal showed apathy, lateral recumbency, umbilical thickening, protrusion of the third eyelid, seizures and hyperesthesia. Was treated with 50,000 IU/kg of potassium penicillin; with anti-tetanus toxoid immunoglobulin in a dose of 25,000 IU, 20,000 IU and 20,000 IU intravenously, intramuscular and intrathecal, respectively; with acepromazine hydrochloride (0.05 mg / kg); fluid therapy of Ringer"s lactate solution and dressing for umbilical cord. After 48 hours of treatment, the animal demonstrated hyperacute symptoms and died, showing unsuccessful in treating. Possibly the infection has been caused by inadequate umbilical cord cleansing.

O tétano é uma doença infecciosa grave e altamente fatal, causada pela toxina Clostridium tetani, uma bactéria Gram-positiva formadora de esporos anaeróbicos. A doença é caracterizada por rigidez muscular (tetania) e pode levar à morte por parada respiratória ou convulsões. O presente trabalho relata um caso de tétano em um potro Quarto de Milha de 6 dias de idade. O animal apresentava apatia, decúbito lateral, espessamento umbilical, protrusão da terceira pálpebra e convulsões em resposta a estímulos externos, como som, luz e toque. Foi tratado com 110.000 IU / kg de penicilina potássica; com imunoglobulina anti-toxina tetânica homóloga, numa dose de 25000 UI, 20.000 UI e 20000 UI por via intravenosa, intramuscular e intratecal, respectivamente; com cloridrato de acepromazina (0,05 mg / kg); fluidoterapia à base de Ringer com lactato e curativo no cordão umbilical. Decorridas 48 horas de tratamento, o animal demonstrou sintomas hiperagudos e veio à óbito, mostrando insucesso no tratamento. Possivelmente, a infecção foi causada pela limpeza inadequada do cordão umbilical.

Biomechanical effects of the transcondylar approach on the craniovertebral junction.

The transcondylar variation of the far-lateral, retrosigmoid approach is intended for pathologies in the anterolateral portion of the foramen magnum. That area is more clearly visualized when a fraction of the ipsilateral occipital condyle is removed. In this study, the biomechanical effect of this approach on occiput-C2 rotation was investigated. Our hypothesis was that the biomechanical characteristics are significantly altered following the transcondylar approach. Five human cadaveric upper cervical spine specimens (occiput-C7) were used in the study. Torsional moments were applied from zero to a maximum of 1.5 N m to the left and to the right using a mechanical testing machine. The resulting rotational motions of the O-C1, C1-2, and O-C2 segments were measured in the intact specimen and after a simulated right-sided transcondylar approach with resection of 2/3 of the condyle, confirmed by CT scanning and visual inspection. After the posterior two-thirds of the occipital condyle were removed, the neutral zone (NZ) increased 1.3° to the left and 2° to the right at C0-C1, and 7.4° to the left and 6.2° to the right at C1-2. The cumulative increase in NZ between O and C2 was 8.7° to the left and 8.2° to the right. The transcondylar approach also resulted in significant increases in range of motion (ROM) in axial rotation to both sides in all segments. ROM increased 2.8° to the left and 2.4° to the right between C0 and C1, 7.3° to the left and 5.4° to the right between C1 and C2, and 10.1° to the left and 7.8° to the right between CO and C2. Upon inspection, the area of the occipital condyle where the alar ligament attaches had been completely removed in three of the five specimens. Removing the posteromedial two-thirds of one occipital condyle alters the normal axial rotational movements of the craniovertebral junction on both sides. The insertion of the alar ligament can be inadvertently removed during condylar resection, and this could contribute to atlanto-axial instability. There is a biomechanical substrate to cranio-cervical instability following a transcondylar approach; these patients may need to be followed over several years to ensure it does not progress and necessitate occipito-cervical fusion.

Posterior atlanto-occipital and atlanto-axial area and its surgical interest / Interesse cirúrgico da junção atlanto-occipital e atlanto-axial

Classic anatomical studies describe two membranes – atlanto-occipital and atlanto-axial in the posterior aspect of the craniocervical region. During many surgical procedures in this area, however, we have not found such membranes. Objective To clarify the anatomical aspects and structures taking part of the posterior atlanto-occipital and atlanto-axial area. Method Analysis of histological cuts of three human fetuses and anatomical studies of 8 adult human cadavers. Results In both atlanto-occipital and atlanto-axial areas, we have observed attachment between suboccipital deep muscles and the spinal cervical dura. However, anatomical description of such attachments could not be found in textbooks of anatomy. Conclusion Our study shows the absence of the classical atlanto-occipital and atlanto-axial membranes; the occipito-C1 and C1-C2 posterior intervals are an open area, allowing aponeurotic attachment among cervical dura mater and posterior cervical muscles. .

Em livros clássicos de anatomia é referida a existência de duas membranas, atlanto-occipital e atlanto-axial, participando do fechamento da região cranio-cervical. Entretanto, em frequentes procedimentos cirúrgicos que envolvem esta região, jamais detectamos a presença de tais membranas. Objetivo Estudar os aspectos anatômicos e as estruturas que participam do fechamento posterior dos espaços atlanto-occipital e atlanto-axial. Método Estudo de cortes histológicos de três fetos humanos e estudos anatômicos em 8 cadáveres humanos adultos. Resultados Em ambos os espaços, atlanto-occipital e atlanto-axial, encontramos uma aderência entre as estruturas musculares profundas e a dura-mater, sem as membranas atlanto-occipital e atlanto-axial descritas nos livros clássicos de anatomia. Conclusão Não foram encontradas as membranas atlanto-occipital e atlanto-axial no material estudado; os espaços atlanto-occipital e atlanto-axial são abertos permitindo expansões aponeuróticas entre os músculos profundos e a dura-mater. .

Fratura de côndilos occipitais / Occipital condyles fractures

A fratura de côndilos occipitais é uma afecção considerada rara, mas que pode estar sendo subdiagnosticada. Fatores como a apresentação clínica variável, o exame físico frustro e a não identificação por radiografia simples dificultam esse diagnóstico, podendo levar a complicações como paralisia de nervos cranianos caudais e até mesmo a óbito. O presente estudo tem como objetivo revisar a literatura pertinente às fraturas de côndilos occipitais, com enfoque nas considerações anatômicas da junção craniocervical e ressaltando aspectos fisiopatológicos, parâmetros clínicos e as controvérsiasquanto ao tratamento. O incremento das técnicas radiológicas e a maior disponibilidade e uso de tomografia computadorizada possibilitaram o aumento do número de casos descritos dessas fraturas nas últimas décadas. A apresentação clínica é inespecífica e a tomografia da junção craniocervical é o método diagnóstico de escolha. A ausência de diagnóstico é responsável por sequelas, como déficits neurológicos, e foram descritas taxas de mortalidade de até 16% em casos de fraturas bilaterais. Omecanismo de injúria exato não é bem conhecido, mas a maioria dos autores indica a hiperextensão do pescoço associada à força vertical sobre a junção craniocervical. O tratamento é controverso, por causa da inconsistência nos resultados obtidos com o tratamento conservador baseado na classificação de Anderson e Montesano, em comparação com o escasso número de doentes tratados cirurgicamente.

The occipital condyle fractures are rare lesions, but they may have been under-diagnosed. Factors such as variable clinical presentation, inconclusive physical examination and no identification in the simple radiography difficult the diagnosis and may lead to complications such as paralysis of cranial nerves and death. This study aims to review the literature about occipital condyle fractures, emphasizing the anatomical considerations of the craniovertebral junction, pathophysiological view, clinical presentationand controversies regarding treatment. The improvement in radiological techniques and the increased availability and usage of computed tomography allowed the growth of reported cases of these fracturesin recent decades. The clinical presentation is nonspecific and CT of the craniocervical junction is the diagnostic method of choice. The absence of a diagnosis is responsible for sequel, such as neurologic deficits, and as mortality rates are of up to 16% in cases of bilateral fractures. The exact mechanism of injury is not well known, but most authors indicate the hyperextension of the neck associated with the vertical force on the craniocervical junction. The treatment is controversial due to the inconsistencies in the results obtained with conservative treatment based on the classification of Anderson and Montesano, compared to the small number of patients treated surgically.

Gunshot wound to the upper cervical spine leading to instability.

Gunshot wounds (GSW) to the cervical spine leading to instability are rare. Also, the presence of vital vascular and neurological structures in the surround area lead to death or severe disability in the vast majority of cases. In this brief report, we present a rare case of C1 fracture due to GSW leading to instability of the atlanto-occipital joint in a neurologically intact patient.

Prevalence of atlanto-occipital and atlantoaxial instability in adults with Down syndrome.

OBJECTIVE: This study sought to evaluate the presence of atlanto-occipital and atlantoaxial instabilities as well as their clinical significance in patients with Down syndrome. METHODS: The present study retrospectively evaluated 80 adults with Down syndrome for the presence of atlanto-occipital and atlantoaxial instability in lateral craniocervical radiographic images. Atlanto-occipital instability was defined by the Rules of 12 or Harris measurements, using the values of the basion-dens interval or the basion-axial interval. Atlantoaxial instability was radiologically identified by the space between the anterior border of the odontoid apophysis and the posterior border of the atlas arch, as well as by the Wiesel-Rothman line. RESULTS: Eighty patients were assessed; 14 (17.5%) presented with atlanto-occipital instability and 9 (11.2%) with atlantoaxial instability. Only 3 patients (3.8%) had specific symptoms for cervical instability. There was no statistical correlation with patient age or gender. CONCLUSIONS: High cervical instability in patients with Down syndrome can also be observed among adults, and there is a low correlation between the radiological findings and symptoms. These findings emphasize the importance of periodic follow-up on these patients, particularly when sports activities are considered.

Atlanto-occipital fusion and its neurological complications: a case report

During routine activities in the Laboratory of Human Anatomy at the University of Santa Cruz do Sul – Brazil, an atlanto-occipital fusion was observed in a Caucasian cadaver skull. The skull used in our study had complete fusion of the occipital bone with the atlas vertebra, except in traffic areas of the vertebral arteries. Some important neurological disorders seem to be related with atlanto-occipital fusion. The presence of other anatomical variations was not verified. Thus, the present study shall be important for health sciences and those who keep some interest in pathologies associated with brain.

Luxação traumática atlanto-occipital: relato de caso / Traumatic atlanto-occipital dislocation: a case report

A luxação traumática atlanto-occipital é lesão rara, de incidência desconhecida e está associada a elevada taxa de mortalidade. Os autores relatam o diagnóstico, tratamento e seguimento de dois anos de uma paciente de 25 anos de idade, vítima de acidente automobilístico e luxação atlanto-occipital traumática confirmada por exames de imagem.

Traumatic atlanto-occipital dislocation is a rare lesion whose incidence is not know, and which is associated to a high rate of mortality. The authors report the diagnosis, treatment, and two-year follow-up of a 25 year-old patient who had had an automobile accident with imaging-confirmed traumatic atlanto-occipital dislocation.

Estudio Ultrasonográfico de las Estructuras Nerviosas del Canal Vertebral a Nivel de la Articulación Atlantooccipital en Caninos Adultos / Ultrasonographic Study of the Nervous Structures of the Vertebral Canal at the Atlantooccipital Joint Level in Adult Dogs

Los objetivos de este estudio fueron describir y comparar, mediante el ultrasonido, las estructuras nerviosas que se encuentran en el canal vertebral a nivel de la articulación atlanto-occipital en caninos adultos de talla corporal pequeña y grande. Se utilizaron 20 caninos adultos clínicamente sanos: 10 caninos de talla corporal pequeña (peso < a 10 kg) y 10 a caninos de talla corporal grande (peso > a 20 kg). Se realizó el examen ultrasonográfico con un transductor de 7,5 MHz, utilizando para ello el espacio atlantooccipital como ventana ecográfica. Se midieron diámetros verticales y horizontales del saco dural y médula espinal, y áreas del saco dural, médula espinal y espacio subaracnoídeo. Se calcularon razones entre algunas mediciones. Las estructuras estudiadas se observaron ecográficamente de modo similar en los caninos de ambos grupos. La duramadre se observó como una línea hiperecoica continua, adherida al borde óseo del canal vertebral. La médula espinal se observó como una estructura ovalada hipoecoica, con un parénquima homogéneo. Los diámetros verticales y horizontales del saco dural, médula espinal y las áreas del saco dural, médula espinal y espacio subaracnoídeo fueron significativamente menores (p<0,05) en los caninos de talla corporal pequeña. Las diferencias entre las áreas de médula espinal entre los grupos fue menor a 0,1 cm² y entre las áreas de saco dural y espacio subaracnoídeo fue de aproximadamente 1 cm². Se concluye que el ultrasonido permite visualizar adecuadamente la médula espinal y estructuras asociadas en la región de la articulación atlanto-occipital en caninos adultos. Finalmente, existieron diferencias mínimas en los valores de áreas de médula espinal y notoriamente mayores en los valores de áreas del saco dural y espacio subaracnoídeo entre ambos grupos de animales.

The goals of this study were to describe and compare by ultrasound the nervous structures in the vertebral canal at the atlanto-occipital joint region in small and large size adult dogs. A total of 20 healthy adult dogs were selected for the study. They were 10 small dogs (< 10 kg) and 10 large dogs (> 20 kg). Ultrasonographic examination was performed with a 7,5 MHz transducer and using the atlanto-occipital space as an echographic window. In transverse images, vertical and horizontal diameters of the dural sac and spinal cord and areas of the dural sac, spinal cord and subarachnoid space were measured. Some ratios between measurements were also calculated. Analysed structures were observed in a similar way in both groups of dogs. The dura mater was observed as an echogenic continuous line and attached to the bony border. The subarachnoid space has an anechoic appearance. The pia mater was observed as a thin echogenic line covering the spinal cord surface. The spinal cord was observed as an oval hypoechogenic structure inside the vertebral canal and with a homogeneous parenchyma without differentiation between gray and white matter. Vertical and horizontal diameters of the dural sac and spinal cord and areas of the dural sac, spinal cord and subarachnoid space were significantly different (P<0,05) in both group of dogs. Differences of spinal cord areas between small and large dogs were minimal (<0,1 cm²), compared with differences between dural sac and subarachnoid space areas (around 1 cm x). In conclusion, ultrasound allows an adequate examination of spinal cord and associated structures at the atlanto-occipital joint region in adult dogs. Differences between groups are minor in areas of spinal cord and larger in areas of dural sac and subarachnoid space.