Research Progress on the Application of Goel Technique in Craniovertebral Junction Anomalies / 中国医学科学院学报

Craniovertebral junction anomalies are a group of diseases characterized by the pathological changes of occipital bone,atlantoaxial bone,cerebellar tonsil,surrounding soft tissue,and nervous system,which are caused by a variety of factors.Chiari malformation is a common type of craniovertebral junction anomalies,the conventional surgical therapy of which is posterior fossa decompression.Currently,scholars represented by Goel have proposed a new theory on the classification,pathogenesis,and treatment of Chiari malformation based on posterior atlantoaxial fixation (Goel technique).This article introduces the progress in Goel technique,aiming to provide reference for the clinical work.

Management of Chiari I Deformity in Children and Adolescents: A Report from the Consensus Taskforce of the Brazilian Society of Pediatric Neurosurgery

Much controversy remains on the current management of Chiari I deformity (CID) in children, with many clinical, surgical and ethic-legal implications. The Brazilian Society of Pediatric Neurosurgery (SBNPed, in the Portuguese acronym) has put together a panel of experts to analyze updated published data on the medical literature about this matter and come up with several recommendations for pediatric neurosurgeons and allied health professionals when dealing with CID. Their conclusions are reported herein, along with the respective scientific background.

Hemifacial Spasm Associated with Chiari Type I Malformation: Surgical Considerations and Case Report

Hemifacial spasm (HS) is a movement disorder characterized by paroxysmal and irregular contractions of the muscles innervated by the facial nerve. Chiari malformation type I (CM I) is a congenital disease characterized by caudal migration of the cerebellar tonsils, and surgical decompression of foramen magnum structures has been used for treatment. The association of HS with CM I is rare, and its pathophysiology and therapeutics are speculative. There are only a few cases reported in the literature concerning this association. The decompression of the posterior fossa for the treatment of CM I has been reported to relieve the symptoms of HS, suggesting a relation between these diseases. However, the possible complications of posterior fossa surgery cannot be underrated. We report the case of a 66-year-old patient, in ambulatory follow-up due to right HS, no longer responding to botulinum toxin treatment. Magnetic resonance imaging (MRI) of the skull revealed compression of the facial nerve and CM I. The patient underwent surgery for HS by neurovascular microdecompression of the facial nerve via right lateral suboccipital craniectomy, but presented significant clinical worsening in the postoperative period even though the cerebellum edema related to surgical manipulation was mild. Due to the clinical worsening, the patient underwent a median suboccipital craniectomy with decompression of the foramenmagnum structures. After this second surgery, the patient had progressive improvement and was discharged from the hospital for ambulatory care.

Basilar invagination associated with chiari malformation type I: A literature review

Basilar invagination (BI) and Chiari malformation type I (CM-I) are very important anomalies that introduce instability and compression in the occipitocervical transition region and have complex clinical characteristics. These anomalies vary according to the affected structures. The present study revises current knowledge regarding the anatomy, anatomo-physiology, clinical manifestations, and radiological findings of these entities and the associated surgical treatment approaches. A bibliographic survey was performed through a search in the Medline, PubMed, SciELO, Science and LILACS databases. When associated, these craniovertebral malformations result in neurological deficits due to neural parenchyma compression; however, the presence of microtraumas due to repetitive lesions caused by the bulb and cervical marrow instability has been highlighted as a determinant dysfunction. Surgical treatment is controversial and has many technical variations. Surgery is also challenging due to the complex anatomical characteristics and biomechanics of this region. Nevertheless, advances have been achieved in our understanding of related mechanisms, and compression and atlantoaxial instability are considered key elements when selecting the surgical approach.

Un enfoque clínico e histórico de la Malformación de Chiari Tipo I en adultos / A clinical and historic approach Type I Chiari malformation in adults

RESUMEN Se revisó la literatura existente sobre la Malformación de Chiari Tipo I en el adulto, haciendo énfasis en su diagnóstico imagenológico y tratamiento médico-quirúrgico. La malformación de Chiari es una enfermedad poco frecuente. Representa entre el 1 y el 4 % de todas las patologías neuroquirúrgicas. El diagnóstico se realiza meses y hasta años después de comenzada la sintomatología y se confirma en el 100 % de los casos con resonancia magnética de cráneo. El tratamiento es quirúrgico en los pacientes sintomáticos, siendo controversial en aquellos oligosintomáticos o con diagnóstico casual. La cirugía siempre debe realizarse con el apoyo de monitoreo neurofisiológico, que puede ser determinante en la técnica quirúrgica a emplear. La mortalidad asociada a la cirugía es muy baja, oscilando entre el 0 y 0,5 % según la mayoría de las series. Lo más importante es la selección de los pacientes para el tratamiento quirúrgico. No debe asumirse una actitud expectante en espera de un deterioro neurológico que justifique la cirugía, cuando ésta se hace a tiempo los resultados son mejores y con un mínimo de complicaciones (AU).

ABSTRACT The existent literature on Type I Chiari Malformation in adults was reviewed, making emphasis in its imaging diagnosis and medico-surgical treatment. Chiari malformation is a few frequent disease. It represents between 1 % and 4 % of all the neurosurgery pathologies. The diagnosis is made up months and even years after the beginning of the symptoms and it is confirmed by cranial magnetic resonance in the 100 % of the cases. The treatment is surgical in symptomatic patients, and it is controversial in the oligosymptomatic ones and in those with casual diagnosis. The surgery should be performed with the support of neurophysiological monitoring that might be determinant in the surgical technique to use. The mortality associated to the surgery is low, ranging from 0 and 0.5 % in most of the series. The most important thing is the choice of the patients for the surgical treatment. The neurological deterioration should not be expected to justify the surgery; when the surgery is carried out on time the results are better and with the minimum of complications (AU).

Posterior fossa decompression with duraplasty in Chiari surgery: A technical note / Descompressão de fossa posterior com duroplastia no tratamento cirúrgico do Chiari: nota técnica

Summary Chiari malformation (CM) is the most common and prevalent symptomatic congenital craniocervical malformation. Radiological diagnosis is established when the cerebellar tonsils are located 5 mm or more below the level of the foramen magnum on magnetic resonance imaging (MRI). Surgical treatment is indicated whenever there is symptomatic tonsillar herniation or syringomyelia/hydrocephalus. The main surgical treatment for CM without craniocervical instability (such as atlantoaxial luxation) is posterior fossa decompression, with or without duraplasty. The authors describe in details and in a stepwise fashion the surgical approach of patients with CM as performed at the State University of Campinas, emphasizing technical nuances for minimizing the risks of the procedure and potentially improving patient outcome.

Resumo A malformação de Chiari (MC) é a malformação craniocervical congênita sintomática mais comum e prevalente. O diagnóstico radiológico é definido quando as tonsilas cerebelares estão localizadas pelo menos 5 mm abaixo do nível do forame magno na ressonância magnética (RM). Quando há hérnia tonsilar sintomática, siringomielia ou hidrocefalia, o tratamento cirúrgico é indicado. O principal tratamento cirúrgico para MC sem instabilidade craniocervical (como a luxação atlantoaxial) é a descompressão da fossa posterior com ou sem duroplastia. Os autores descrevem detalhadamente a abordagem cirúrgica de pacientes com MC realizada na Universidade Estadual de Campinas, enfatizando nuances técnicas para minimizar os riscos relacionados ao procedimento e melhorar os resultados pós-operatórios.

Malformación de Chiari Tipo I en adultos. Un enfoque médico-quirúrgico. Parte I / Type I Chiari malformation in adults. A medico-surgical approach. Part I

Se revisó la literatura existente sobre la Malformación de Chiari Tipo I en el adulto, haciendo énfasis en su diagnóstico imagenológico y tratamiento médico-quirúrgico. La malformación de Chiari es una enfermedad poco frecuente. Representa entre el 1 y el 4% de todas las patologías neuroquirúrgicas. El diagnóstico se realiza meses y hasta años después de comenzada la sintomatología y se confirma en el 100% de los casos con Resonancia magnética de cráneo. El tratamiento es quirúrgico en los pacientes sintomáticos, siendo controversial en aquellos oligosintomáticos o con diagnóstico casual. La cirugía siempre debe realizarse con el apoyo de monitoreo neurofisiológico, que puede ser determinante en la técnica quirúrgica a emplear. La mortalidad asociada a la cirugía es muy baja, oscilando entre el 0 y 0,5% según la mayoría de las series. Lo más importante es la selec­ción de los pacientes para el tratamiento quirúrgico. No debe asumirse una actitud expectante en espera de un deterioro neurológico que justifique la cirugía, cuando ésta se hace a tiempo los resultados son mejores y con un mínimo de complicaciones (AU).

The aim of this article is reviewing the existent literature on Type I Chiari malformation in adults and making emphasis in its imaging diagnosis and medico-surgical treatment. Chiari malformation is a few frequent diseases. It represents 1-4 % of all the neurosurgical diseases. The diagnosis is made months and even years after the beginning of the symptoms and it is confirmed by cranial magnetic resonance in the 100 % of the cases. The treatment is surgical in symptomatic patients, and it is controversial in the oligosymptomatic ones and in those with casual diagnosis. The surgery should be performed with the support of neurophysiological monitoring that might be determinant in the surgical technique to use. The mortality associated to the surgery is low, ranging from 0 and 0.5 % according to most of the series. The most important thing is the choice of the patients for the surgical treatment. The neurological deterioration should not be expected to justify the surgery; when the surgery is carried out on time the results are better and with the minimum of complications (AU).

Suboccipital craniectomy with opening of the fourth ventricle and duraplasty: study of 192 cases of craniovertebral malformations / Descompressao da fossa posterior sem tonsilectomia em 192 casos de impressao basilar, malformacao de Chiari e/ou siringomielia

The prime objective in the surgical treatment of basilar impression (BI), Chiari malformation (CM), and/or syringomyelia (SM) is based on restoration of the normal cerebrospinal fluid (CSF) dynamics at the craniovertebral junction and creation of a large artificial cisterna magna, avoiding the caudal migration of the hindbrain. It is observed that a large craniectomy might facilitate an upward migration of the posterior fossa structures. There are many surgical techniques to decompress the posterior fossa; however, a gold standard approach remains unclear. The authors present the results of 192 cases of BI, CM, and SM treated between 1975 and 2008 and whose surgical treatment was characterized by a large craniectomy without tonsillectomy with the patient in the sitting position, large opening of the fourth ventricle, and duraplasty.

O principal objetivo no tratamento cirúrgico da impressão basilar, malformação de Chiari e/ou siringomielia fundamenta-se na restauração da dinâmica do líquido cefalorraqueano ao nível da transição craniovertebral e criação de cisterna magna ampla. Isto é fator importante para evitar a migração caudal das estruturas da fossa posterior. A craniectomia ampla facilita a migração cranial dessas estruturas. Existem várias técnicas cirúrgicas para descomprimir a fossa posterior, mas não há evidência sobre qual a melhor.. Os autores apresentam os resultados de 192 casos de impressão basilar, malformação de Chiari e siringomielia, operados entre 1975 e 2008, nos quais o tratamento cirúrgico se baseou em ampla craniectomia com o paciente em posição sentada, sem tonsilectomia, abertura ampla do quarto ventrículo e enxerto dural.

Posterior fossa decompression with tonsillectomy in 104 cases of basilar impression, Chiari malformation and/or syringomyelia / Descompressão da fossa posterior com tonsilectomia em 104 casos de impressão basilar, malformação de Chiari e/ou siringomielia

The prime objective in the surgical treatment of basilar impression (BI), Chiari malformation (CM) and/or syringomyelia (SM) is based on the restoration of the normal cerebrospinal fluid (CSF) dynamics at the craniovertebral junction through the creation of a large artificial cisterna magna. A small suboccipital craniectomy has been emphasized to avoid caudal migration of the hindbrain structures into the vertebral canal. Nevertheless, the results showed downward migration of the hindbrain related to that type of craniectomy. The authors present, otherwise, the results of 104 cases of BI, CM and/or SM, whose surgical treatment was characterized by a large craniectomy with the patient in the sitting position, tonsillectomy, large opening of the fourth ventricle and duraplasty with creation of a large artificial cisterna magna. A significant upward migration of the posterior fossa structures was detected by postoperative magnetic resonance imaging.

O principal objetivo no tratamento cirúrgico da impressão basilar, malformação de Chiari e/ou siringomielia fundamenta-se na restauração dinâmica do líquido cefalorraqueano ao nível da transição craniovertebral e criação de ampla cisterna magna. Uma craniectomia suboccipital de pequenas dimensões foi proposta para evitar a migração caudal de estruturas rombencefálicas no canal vertebral. Entretanto, os resultados evidenciaram migração caudal do rombencéfalo. Os autores apresentam, por outro lado, os resultados de 104 casos de malformação de Chiari e/ou siringomielia, nos quais o tratamento cirúrgico se baseou em ampla craniectomia com o paciente em posição sentada, tonsilectomia, abertura ampla do quarto ventrículo e enxerto dural com consequente criação de ampla cisterna magna. Uma significante migração cranial das estruturas da fossa posterior foi detectada pelo emprego pós-operatório da ressonância magnética.

Suboccipital craniectomy and duraplasty for Arnold-Chiari malformation 1: experience with 26 patients / Craniectomia suboccipital e duroplastia para o tratamento da malformação de Arnold-Chiari tipo 1: experiência com 26 pacientes

Objective: Observe whether the suboccipital foramen magno decompression, duraplasty and microsurgery lyses of arachninodal bands are a safe and an effective treatment. Method: A retrospective study was carried out with 26 consecutives patients with CM1 malformations diagnosed, evaluated and operated at the Neurosurgical department of Servidores do Estado Hospital (HSE), from 1986 to 2010. The radiological studies, patient records, surgical descriptions, and when available, surgical videos, were reviewed, creating a database from which information pertinent to the present study was collected. The follow-up varied from 8 to 168 months (mean, 48 months). Results: Twenty-six patients underwent posterior fossa decompression with duraplasty. In this series, there is no operative death. We noticed beneficial outcome in 69.2% of patients, and 4 cases of transient postoperative complications. Conclusion: This experience with 26 cases CM1 proved that suboccipital craniectomy; duraplasty with autologus pericranium and microlysis of adhesions is a safe and effective procedure.

Objetivo: Observar se a descompressão cirúrgica do forâmen magno associada à duroplastia é um procedimento seguro e eficaz para o tratamento da malformação de Arnold-Chiari tipo 1. Método: Realizaram-se revisão retrospectiva dos prontuários, descrições cirúrgicas e imagens de 26 pacientes com malformação de Arnold-Chiari 1 operados no Hospital dos Servidores do Estado (HSE) no período entre 1996 e 2010. Resultados: O tratamento em 18 pacientes (68%) constitui-se de craniectomia suboccipital, remoção do arco posterior de C1 e duroplastia. Os mesmos procedimentos foram acrescidos de laminectomia de C2 em 8 indivíduos (32%). Nesta série, não ocorreu nenhum óbito cirúrgico e observou-se melhora sintomática em 68% dos pacientes. Conclusão: A craniotomia occipital com a remoção do arco de C1 e/ou laminectomia de C2 e duroplastia mostrou-se eficaz, com baixa morbidade e sem mortalidade.

Resolution of syringomyelia in ten cases of "up-and-down Chiari malformation" after posterior fossa decompression / Resolução de siringomielia em dez casos de malformação de Chiari observada apenas com o paciente em posição sentada durante a descompressão da fossa posterior

The authors describe ten cases of syringomyelia without hindbrain herniation depicted by preoperative magnetic resonance imaging (MRI) in supine position. However, the herniation was observed in all cases during the operation with the patient in sitting position. The postoperative MRI revealed an intense reduction of the syrinx in all patients, as well as it was also observed a clinical amelioration in all cases. The surgical treatment was based on a large craniectomy with the patient in sitting position, tonsillectomy, large opening of the fourth ventricle and duraplasty with creation of a large cisterna magna.

Os autores descrevem 10 casos de siringomielia sem herniação do rombencéfalo, observada na ressonância magnética realizada em decúbito dorsal. Por outro lado, a herniação foi observada em todos os pacientes durante a operação com o paciente em posição sentada. A ressonância magnética pós-operatória evidenciou redução da cavidade siringomiélica nos dez pacientes, bem como foi observada melhora clínica em todos os casos. O tratamento cirúrgico consistiu de craniectomia ampla da fossa posterior, tonsilectomia, abertura ampla do quarto ventrículo e duroplastia com a criação de ampla cisterna magna.

Malformación de Arnold Chiari tipo I: presentación de un caso / Arnold-Chiari malformation Type I: presentation of a case

La malformación de Arnold Chiari es una rara enfermedad incapacitante que afecta al 0,5 por ciento de la población, siendo el 80 por ciento mujeres. La hidrocefalia resultante es causada por el exceso de líquido cefalo raquídeo en el sistema ventricular, o por una falta de equilibrio entre la formación y su absorción, lo que da lugar a un progresivo aumento de las cavidades ventriculares. Se presenta el caso de una paciente con malformación de Arnold Chiari tipo I, en la cual hay un descenso anormal en grado variable de la porción inferior del cerebelo, del bulbo y el cuarto ventrículo hacia el conducto raquídeo a través del agujero occipital. El objetivo de este trabajo es describir el cuadro clínico y compararlo con la literatura médica revisada, del caso en cuestión...

Suboccipital craniectomy with or without duraplasty: what is the best choice in patients with Chiari type 1 malformation? / Craniectomia suboccipital com ou sem duroplastia: qual a melhor escolha em pacientes com malformação de Chiari tipo 1?

The best surgical treatment for Chiari malformation is unclear, especially in patients with syringomyelia. We reviewed the records of 16 patients who underwent suboccipital craniectomy at our institution between 2005 and 2008. Of the six patients who did not undergo duraplasty, four showed improvement postoperatively. Two patients without syringomyelia showed improvement postoperatively. Of the four patients with syringomyelia, three showed improvement, including two with a decrease in the cavity size. One patient showed improvement in symptoms but the syringomyelia was unchanged. The cavity size increased in the one patient who did not show improvement. Among the 10 patients who underwent duraplasty, improvements were noted in four of the five patients without syringomyelia and in all of the five with syringomyelia. There is a suggestion that patients with syringomyelia may have a higher likelihood of improvement after undergoing duraplasty.

A melhor opção de tratamento cirúrgico na malformação de Chiari é desconhecido, especialmente em paciente com siringomielia. Nós revisamos casos de 16 pacientes submetidos à craniectomia suboccipital em nossa instituição de 2005 à 2008. Dos 6 pacientes que não foram submetidos à duroplastia, quatro tiveram melhora pós operatória. Dois pacientes sem siringomielia tiveram melhora pós operatória. Dos quatro pacientes com siringomielia, três tiveram melhora, incluindo dois com diminuição do tamanho da cavidade. Um paciente teve melhora da sintomatologia mas a siringomielia não se modificou. Dez pacientes foram submetidos à duroplastia. Melhora foi observada em 4 de 5 pacientes sem siringomielia e 5 de 5 casos com siringomielia. Há uma sugestão de que pacientes com siringomielia possam ter uma maior taxa de melhora após serem submetidos à duroplastia.

Comportamiento de los pacientes con diagnóstico de malformación de Chiari Tipo I / Behavior of patients with Chiari malformation Type I

Se realiza un estudio descriptivo retrospectivo para caracterizar el comportamiento de la malformación de Chiari tipo I en los pacientes atendidos durante el período de 2003 al 2007 en el servicio de Neurocirugía del Hospital Universitario “Carlos J. Finlay”. El estudio se basa en la comparación de nuestros resultados con lo referido en la bibliografía especializada consultada y donde se comprobó que la totalidad de los casos pertenecían al sexo femenino, sólo dos de los casos no tenía piel blanca y el rango de edad osciló entre los 16 y 55 años de edad, con una media de 37.7 +/- 12.6 años. Se constató que predominaron la inestabilidad para la marcha, la cervicalgia y la pérdida de la fuerza muscular dentro de los síntomas de debut, al igual que la ataxia, la hiperreflexia y la paresia como signos clínicos. El período sintomático pre-quirúrgico promedio fue de 3.016 años. Más de la mitad de los casos presentó alguna enfermedad asociada, resaltando por su frecuencia la siringomielia y la aracnoiditis periamigdalina. Todos los casos fueron sometidos a tratamiento quirúrgico, mediante una descompresión de la charnella occipitocervical y duroplastia en “tienda de campaña”, apareciendo alguna complicación solo en la tercera parte de ellos, siendo el pseudomeningocele la más frecuente. Teniendo en cuenta que las tres cuartas partes de los pacientes han tenido una evolución favorable después del tratamiento, consideramos que el manejo terapéutico de estos pacientes fue adecuado.

Retrospective study of patients with Chiari: malformation submitted to surgical treatment / Estudo retrospectivo de pacientes com malformação de Chiari tratados cirurgicamente

The Chiari malformation (CM) is characterized by variable herniation of one or both cerebellar tonsils, associated or not with displacement of the hindbrain structures into the vertebral canal. This is a retrospective study of 29 patients with CM submitted to surgical procedure between 1990 and 2003. There were 14 females and 15 males whose ages ranged from 16 to 65 years. There were seven patients with isolated CM, 12 associated with syringomyelia (SM), three associated with basilar impression (BI) and seven associated with SM and BI. The surgery was based on posterior fossa decompression. In seven patients a catheter was introduced from the subarachnoid space into the III ventricle and five were submitted to tonsillectomy. Twenty-one patients improved, one worsened, one remained unchanged, four missed follow up and two died. We conclude that the best results with CM surgery are obtained by an effective posterior fossa decompression. Those CM cases associated with other abnormalities, such as SM and BI, probably need complementary techniques which will be the theme for new prospective studies.

A malformação de Chiari (MC) é o deslocamento variável de uma ou ambas as tonsilas cerebelares para o canal vertebral. Este trabalho é um estudo retrospectivo de pacientes com MC tratados com cirurgia de 1990 até 2003. Foram analisados 29 prontuários, sendo 15 pacientes do sexo masculino e 14 do feminino, com idade variando entre 16 a 65 anos. Destes, sete só apresentavam MC, 12 tinham MC associada com siringomielia (SM), três associada com impressão basilar (IB) e sete associada com SM e IB. Foi realizada descompressão da fossa posterior e plástica da dura-máter em todos. Em sete pacientes, foi acrescida a colocação de catéter do espaço subaracnóideo para o interior do IV ventrículo e em cinco a tonsilectomia. Ocorreu melhora dos sintomas em 21 pacientes, um permaneceu inalterado, houve piora em um caso, quatro não tiveram seguimento e dois faleceram. Conclui-se que a boa evolução da MC está relacionada com a descompressão efetiva da fossa posterior. Os casos de MC associadas a outras malformações, como IB e SM, talvez necessitem variações técnicas, as quais serão temas de novos estudos prospectivos.

Validation of the ovine fetus as an experimental model for the human myelomeningocele defect

PURPOSE: To produce a myelomeningocele-like human defect in the ovine fetus and validate this experimental model in our population. METHODS: A prospective study on 12 pregnant sheep of a crossed Hampshire/Down breed where a spinal defect was surgically created between Day 75 and Day 77 after conception. The technique consisted of a hysterotomy with exposure of fetal hind limbs and tail up to the mid spine. Fetal skin, paravertebral muscles, and 4 posterior spinal arches were excised, exposing the spinal cord. Duramater was opened and the medulla was incised until the medullar canal. Animals were euthanized at 139 days of gestation for fetal evaluation. The central nervous system was submitted to post-mortem magnetic resonance imaging (MRI) and the spine was submitted to pathological examination. RESULTS: The defect was created in 13 fetuses and 5 survived. Mean gestational age at necropsy was 121.6 days (varying from 93 to 145 days). Macroscopically, the defect was present in 4 cases. Microscopy revealed a flattened medulla with disappearance of the medullar canal and disruption of normal medullar architecture with neuronal apoptosis and/or fusion of the piamater and duramater. The MRI showed herniation of the cerebellum into the cervical canal and syringomyelia. CONCLUSIONS: The surgically produced defect mimics the defect found in the human fetus, including the Arnold-Chiari malformation. Post-mortem MRI was used for the first time in our study and proved an excellent alternative for demonstrating the cerebellar herniation. We standardized the technique for creating the defect in our population.

OBJETIVO: Produzir um defeito semelhante a meningomielocele humana em feto de ovinos, validando este modelo experimental, em nosso meio. MÉTODOS: Estudo prospectivo com 12 ovelhas de cruzamento das raças Hampshire e Down, onde um defeito na coluna foi criado cirurgicamente com 75 a 77 dias de gestação. A técnica consistiu em histerotomia com exposição das patas traseiras e cauda até a metade da coluna fetal. Foram retirados pele, musculatura paravertebral e 4 arcos vertebrais posteriores, expondo a medula. A dura foi aberta e uma incisão até o canal medular foi realizada. O sacrifício foi realizado com 139 dias de gestação para avaliação fetal. O sistema nervoso central foi submetido a ressonância magnética (REMA) post-mortem e a coluna foi submetida a exame anátomo-patológico. RESULTADOS: O defeito foi criado em 13 fetos e 5 sobreviveram. A idade gestacional média da necropsia foi de 121,6 dias (variando de 93 a 145 dias). Macroscopicamente o defeito estava presente em 4 casos. A microscopia revelou achatamento da medula, com desaparecimento do canal medular e desarranjo da citoarquitetura medular com apoptose neuronal e/ou fusão da pia e dura-máter. A REMA demonstrou herniação do cerebelo para o canal cervical e siringomelia. CONCLUSÕES: O defeito produzido foi muito semelhante à meningomielocele em fetos humanos, levando inclusive à mal-formação de Arnold-Chiari. A REMA post-mortem, utilizada de forma inédita neste estudo, demonstrou ser uma excelente alternativa para demonstrar a presença da herniação do cerebelo. A técnica para produzir o defeito foi padronizada em nosso meio.

Amigdalopexia cerebelosa en el manejo de la malformación de chiari de tipo I / Cerebellar amygdalopexy in the management of Chiari I malformation

Antecedentes. El tratamiento de la malformación de Chiari de tipo I asociada a siringomielia es controvertido. En este trabajo se presenta un análisis clínico, quirúrgico y radiológico de los pacientes con esta afección que fueron manejados durante un periodo de doce años. Material y métodos. Se incluyeron 48 pacientes, donde se encontró un discreto predominio en el sexo femenino. El cuadro clínico estuvo dominado por cefalea, dolor cervical, signos y síntomas cerebelosos, afección de nervios craneales bajos y lesión de la vía piramidal. Resultados. Tanto el grado de descenso amigdalino como el tamaño de la siringomielia fueron muy variables, sin encontrar correlación entre ambos. La cirugía consistió en una craniectomía occipital, laminectomía de C1, ascenso de amígdalas cerebelosas mediante coagulación bipolar y plastía de duramadre. Los mejores resultados clínicos se obtuvieron en el dolor y los síntomas cerebelosos, mientras que los peores fueron en la afección de los nervios craneales bajos y de la vía piramidal, sin embargo, en la gran mayoría de los pacientes se logró detener la progresión de los síntomas. No se presentaron complicaciones serias en el presente estudio. Conclusión. El procedimiento propuesto ofrece una alternativa segura, efectiva y comparable con otros métodos más riesgosos para el manejo de esta malformación.

BACKGROUND: The treatment of Chiari I malformation associated with syringomyelia is controversial. OBJECTIVE: We describe a series of patients with this disease treated during a twelve-year period. We also present clinical, surgical and radiological findings. MATERIAL AND METHODS: Forty eight patients were included; a non significant female predominance was found. Clinical course was characterized by headache, cerebellar signs and symptoms, neck pain and involvement of lower cranial nerves and pyramidal tract. The degree of tonsillar descent and syringomyelia size varied and a correlation between them was not found. Surgery consisted in an occipital craniectomy, C1 laminectomy and tonsillar elevation through bipolar coagulation and duraplasty. RESULTS: The best results were observed in pain and cerebellar symptoms, while a deficit of lower cranial nerves and pyramidal tract were observed. However, in most patients we were able to slow symptom progression. No adverse effects were documented. CONCLUSIONS: The surgicalprocedureproposed herein is an effective and safe treatment alternative for this malformation, and its results are comparable to other riskier procedures.

Basilar impression associated with impacted cisterna magna, spastic paraparesis and distress of balance: case report / Impressão basilar associada com cisterna magna impactada, paraparesia espástica e distúrbios do equilíbrio: relato de caso

We report on a 48 years-old man with basilar impression without syringohydromyelia, in which the cisterna magna was impacted by the cerebellar tonsils. Six months after posterior fossa decompression there was the disappearance of nuchal rigidity, vertigo, spastic paraparesis and improvement of balance. Nevertheless hyperreflexia and diminished pallesthesia of the lower limbs persisted.

O presente relato descreve um homem de 48 anos com impressão basilar, sem siringo-hidromielia, no qual a cisterna magna se achava impactada pelas tonsilas cerebelares. O quadro clínico era caracterizado, especialmente, por paraparesia espástica. Seis meses após a descompressão da fossa posterior houve regressão da rigidez de nuca, vertigem, paraparesia espástica inicialmente observadas e melhora do equilíbrio. A hiperreflexia e a hipopalestesia persistiram nos membros inferiores.