Surgical management of brainstem cavernous malformations.

Bleeding from brainstem cavernomas may cause severe deficits due to the absence of non-eloquent nervous tissue and the presence of several ascending and descending white matter tracts and nerve nuclei. Surgical removal of these lesions presents a challenge to the most surgeons. The authors present their experience with the surgical treatment of 43 patients with brainstem cavernomas. Important aspects of microsurgical anatomy are reviewed. The surgical management, with special focus on new intraoperative technologies as well as controversies on indications and timing of surgery are presented. According to several published studies the outcome of brainstem cavernomas treated conservatively is poor. In our experience, surgical resection remains the treatment of choice if there was previous hemorrhage and the lesion reaches the surface of brainstem. These procedures should be performed by experienced neurosurgeons in referral centers employing all the currently available technology.

Edema and malignancy in meningiomas.

PURPOSE: In recent years there have been many attempts to define a subset of aggressive malignant meningiomas based on histopathology and imaging technologies. The purpose of this study was to evaluate the level of peritumoral edema and its volume using the imaging technologies, computer tomography and magnetic resonance imaging, and correlate these results with the histological WHO classification. Reported causes of tumoral edema and its relationships to the histological characteristics were also reviewed. METHODS: The cases of 55 patients with meningiomas who underwent surgery at the Hospital das Clinicas (Fac Med Univ Sao Paulo) between September 1993 and September 1997 were reviewed. The level of edema according to the classification of Ide et al. (1995) was compared to the histological WHO classification. RESULTS: Classification of the degree of edema was: level 0 edema--28 cases ; level I edema--19 cases; level II edema--8 cases. Histological classification was: benign meningioma--43 cases; atypical meningiomas--11 cases; malignant meningioma--1 case. There was a significant (P=.0089) correlation between the degree of tumoral edema and the histological characteristics. CONCLUSIONS: These results suggest that the degree of edema as revealed by computer tomography and magnetic resonance imaging can be an important clinical predictive factor for the histological grade of the meningioma.

Genetic therapy in gliomas: historical analysis and future perspectives.

High-grade gliomas are relatively frequent in adults, and consist of the most malignant kind of primary brain tumor. Being resistant to standard treatment modalities such as surgery, radiation, and chemotherapy, it is fatal within 1 to 2 years of onset of symptoms. Although several gene therapy systems proved to be efficient in controlling or eradicating these tumors in animal models, the clinical studies performed so far were not equally successful. Most clinical studies showed that methodologies that increase tumor infection/transduction and, consequently confer more permanent activity against the tumor, will lead to enhanced therapeutic results. Due to the promising practical clinical benefits that can be expected for the near future, an exposition to the practicing neurosurgeon about the basic issues in genetic therapy of gliomas seems convenient. Among the main topics, we shall discuss anti-tumoral mechanisms of various genes that can be transfected, the advantages and drawbacks of the different vectors utilized, the possibilities of tumor targeting by modifications in the native tropism of virus vectors, as well as the different physical methods for vector delivery to the tumors. Along with the exposition we will also review of the history of the genetic therapy for gliomas, with special focus on the main problems found during the advancement of scientific discoveries in this area. A general analysis is also made of the present state of this promising therapeutic modality, with reference to the problems that still must be solved and the new paradigms for future research in this area.

Cerebral melanoma metastases: a critical review on diagnostic methods and therapeutic options.

Malignant melanoma represents the third most common cause for cerebral metastases after breast and lung cancer. Central nervous system (CNS) metastases occur in 10 to 40% of patients with melanoma. Most of the symptoms of CNS melanoma metastases are unspecific and depend on localization of the lesion. All patients with new neurological signs and a previous primary melanoma lesion must be investigated. Although primary diagnosis may rely on computed tomography scan, magnetic resonance images are usually used in order to study more precisely the characteristics of the lesions in and to embase the surgical plan. Other possible complementary exams are: positron emission tomography, iofetamine cintilography, immunohistochemistry of liquor, monoclonal antibody immunocytology, optical coherence tomography, and transcriptase-polymerase chain reaction. Treatment procedures are indicated based on patient clinical status, presence of unique or multiple lesions, and family agreement. Often surgery, radiosurgery, whole brain radiotherapy, and chemotherapy are combined in order to obtain longer remissions and optimal symptom relieve. Corticoids may be also useful in those cases that present with remarkable peritumoral edema and important mass effect. Despite of the advance in therapeutic options, prognosis for patients with melanoma brain metastases remains poor with a median survival time of six months after diagnosis.

Juvenile nasopharyngeal angiofibroma with intracranial extension.

OBJECTIVE: To provide a critical evaluation of the historical evolution of the surgical treatment of juvenile nasopharyngeal angiofibroma (JNA) with intracranial extension. STUDY DESIGN: Case series with chart review. SETTING: Skull base multidisciplinary group at the Instituto de Neurologia de Curitiba, Brazil. SUBJECTS AND METHODS: From 1988 to 2000, the multidisciplinary skull base group surgically treated 67 adolescent boys with JNA, 20 of whom presented with intracranial extension. All patients presented involvement of the cavernous sinus, and 5 of them spread into the orbit. Before 2008, the authors combined microscopic-endoscopic techniques. After this period, the surgical approach used was facial degloving, associated with purely endoscopic technique patients. RESULTS: Total tumor removal was achieved in 17 cases in the first surgery. In this series, the intracranial extension was extradural in all cases. There was only 1 case of cerebrospinal fluid leakage, which was promptly identified and treated. There was no mortality or permanent morbidity. CONCLUSION: Radical removal of large JNA may be difficult because of its extreme vascularity and extension to the cavernous sinus, orbit, middle and anterior fossa. Nevertheless, most of JNA with intracranial extension can be resected in the first operation with minimal morbidity through a facial degloving and further combination of expanded endoscopic endonasal approaches.

Controversies on vertebroplasty and kyphoplasty for vertebral compression fractures / Controvérsias em vertebroplastia e cifoplastia para fraturas vertebrais em compressão / Controversias en vertebroplastia y cifoplastia para fracturas de compresión vertebral

Vertebroplasty and kyphoplasty are widely used for osteoporotic and cancer-related vertebral compression fractures refractory to medical treatment. Many aspects of these procedures have been extensively discussed in the literature during the last few years. In this article, we perform a critical appraisal of current evidence on effectiveness and ongoing controversies regarding surgical technique, indications and contraindications, clinical outcomes and potential complications of these procedures.

A vertebroplastia e a cifoplastia têm sido amplamente utilizadas para fraturas por compressão osteoporóticas e relacionadas a tumor refratárias ao tratamento clinico. Nos últimos anos, vários aspectos relacionados a esses procedimentos têm sido amplamente discutidos na literatura. Neste artigo, realizamos uma análise crítica da evidência atual sobre a efetividade desses procedimentos e sobre as controvérsias referentes a técnica cirúrgica, indicações e contraindicações, resultados clínicos e possíveis complicações.

La vertebroplastia y la cifoplastia han sido ampliamente utilizadas en fracturas por compresión osteoporóticas y relacionadas con tumor refractarias al tratamiento clínico. En los últimos años, diversos aspectos relacionados con estos procedimientos han sido ampliamente discutidos en la literatura. En este artículo, presentamos un análisis crítico de la evidencia actual sobre la eficacia y las controversias relativas a la técnica quirúrgica, indicaciones y contraindicaciones, resultados clínicos y posibles complicaciones.

Transitional lumbosacral vertebrae and low back pain: diagnostic pitfalls and management of Bertolotti's syndrome.

OBJECTIVE: Bertolotti's syndrome is a spine disorder characterized by the occurrence of a congenital lumbar transverse mega-apophysis in a transitional vertebral body that usually articulates with the sacrum or the iliac bone. It has been considered a possible cause of low back pain. METHOD: We analyzed the cases of Bertolotti's syndrome that failed clinical treatment and reviewed the literature concerning this subject. RESULTS: Five patients in our series had severe low back pain due to the neo-articulation and two of them were successfully submitted to surgical resection of the transverse mega-apophysis. Taking into account the clinical and surgical experience acquired with these cases, we propose a diagnostic-therapeutic algorithm. CONCLUSION: There is still no consensus about the most appropriate therapy for Bertolotti's syndrome. In patients in whom the mega-apophysis itself may be the source of back pain, surgical resection may be a safe and effective procedure.

Implementando o treinamento da técnica "free-hand" para instrumentação com parafusos pediculares na residência de neurocirurgia / Implementing

Introdução: Os estudos anatômicos realizados nas últimas décadas possibilitaram a emergência da técnica “Free-hand”para instrumentação da coluna tóraco-lombar baseada exclusivamente em parâmetros anatômicos. Entretanto, os riscos potenciais a ela associados levaram à necessidade de criação de modelos educacionais para o treinamento cirúrgico. Métodos: Após parceria multidisciplinar, foi realizada a instrumentação de dois espécimens cadavéricos, os quais foram, na sequencia, submetidos à Tomografia Computadorizada com cortex finos e posteriormente à descompressão do canal lombar para verificação da real posição dos parafusos pediculares tanto ao nível radiológico quanto anatômico. Resultados: Foram instrumentados ao total 28 níveis (T5-S1), totalizando 62 parafusos pediculares. Ao final, verificaram-se somente 4 violações críticas. O número de violações diminuiu de 32% para 25% do primeiro para o segundo especimen. Uma curva de aprendizado mais acentuada pôde ser observada considerando-se isoladamente a coluna torácica baixa(37,5% versus 12,5%). Conclusões: Os autores demonstraram que a incorporação do treinamento de instrumentação da coluna tóraco-lombar com parafusos pediculares no programa de residência médica é um método educacional com uma ótima relação custo-benefício, o qual possibilita que neurocirurgiões em treinamento desenvolvam suas habilidades antes de exercê-las na prática cirúrgica.

Transitional lumbosacral vertebrae and low back pain: diagnostic pitfalls and management of Bertolotti's syndrome / Dor lombar associada à vértebra de transição lombossacra: dificuldades no diagnóstico e manejo da síndrome de Bertolotti

OBJECTIVE: Bertolotti's syndrome is a spine disorder characterized by the occurrence of a congenital lumbar transverse mega-apophysis in a transitional vertebral body that usually articulates with the sacrum or the iliac bone. It has been considered a possible cause of low back pain. METHOD: We analyzed the cases of Bertolotti's syndrome that failed clinical treatment and reviewed the literature concerning this subject. RESULTS: Five patients in our series had severe low back pain due to the neo-articulation and two of them were successfully submitted to surgical resection of the transverse mega-apophysis. Taking into account the clinical and surgical experience acquired with these cases, we propose a diagnostic-therapeutic algorithm. CONCLUSION: There is still no consensus about the most appropriate therapy for Bertolotti's syndrome. In patients in whom the mega-apophysis itself may be the source of back pain, surgical resection may be a safe and effective procedure.

OBJETIVO: A síndrome de Bertolotti é uma desordem congênita da coluna vertebral caracterizada pela ocorrência de uma mega-apófise transversa lombar em uma vértebra de aspecto transicional, que geralmente se articula com o sacro ou com o osso ilíaco. Tal síndrome tem sido considerada possível causa de dor lombar. MÉTODO: Análise dos casos de síndrome de Bertolotti que apresentavam dor lombar sem melhora com tratamento conservador e revisão dos artigos publicados. RESULTADOS: Foram revisados cinco pacientes que não apresentaram melhora com o tratamento clínico, sendo que dois foram submetidos à ressecção cirúrgica da mega-apófise transversa. Considerando a experiência adquirida com estes casos, os autores propõem um algoritmo para diagnóstico e tratamento da Síndrome de Bertolotti. CONCLUSÃO: Ainda não há consenso sobre qual é a terapia mais apropriada para a Síndrome de Bertolotti. Em pacientes em que a mega-apófise parece ser a origem da lombalgia, a ressecção cirúrgica parece ser um procedimento seguro e efetivo.

Accesos quirúrgicos a los meningiomas petroclivales: indicaciones, complicaciones yresultados / Surgical accesses to petroclival meningiomas: indications, complications and results

Los meningiomas de la región petroclival son responsables de cerca del 13% de los meningiomas de la base del cráneo. El promedio de edad de los pacientes que los presentan es aproximadamente 45 años En la mayoría de los casos existe extensión a la región paraselar. Los autores realizan una revisión crítica de la literatura, presentando los posibles accesos quirúrgicos, sus indicaciones, efectividad y posibles complicaciones. Los accesos quirúrgicos para la región petroclival pueden ser: petroso, vía petrosa combinada anterior y posterior, vía presigmoidea combinada supra e infratemporal, orbitozigomático infratemporal, retrosigmoideo intradural, suprameatal, pterional, retromastoideo, subtemporal y vía combinada retromastoidea-subtemporal. Una valoración neurorradiológica precisa que permita escoger un abordaje quirúrgico apropiado, juntamente con avances en la técnica microquirúrgica y propuestas de nuevos accesos, son factores que han contribuido al progreso significativo en el tratamiento quirúrgico de los meningeomas petroclivales

Petroclival meningiomas account for about 13% of skull base meningiomas. The mean age of patients are 45 years. In most of the cases there is extension to paraselar region. The authors present a critical literature review with focus in possible surgical approaches for petroclival meningiomas, their precise indications, surgical results and eventual complications. Petroclival region can be accessed through thesefollowing approaches: petrosal, anterior and posterior combined approach, supra and infratentorial combined presigmoid approach, orbito-zigomatic infratemporal approach, suprameatal intradural retrosigmoid approach, pterional approach, retromastoid approach, subtemporal approach and combined subtemporal retromastoid approach. A correct pre-operative neuro-radiological evaluation which permits the selection of an appropriate surgical approach, combined with advances in microsurgical techniques and proposal on new approaches are factors that have contributed for the significant progress in surgical treatment of petroclival meningiomas

Diagnóstico diferencial e tratamento cirúrgico de lesões císticas no ângulo ponto-cerebelar / Differential Diagnosis and Surgical Management of Cerebellopontine Angle Cystic Lesions

A maioria dos tumores de ângulo ponto-cerebelar em adultos são benignos e extra-axiais. A lesão mais comum do ângulo ponto-cerebelar (schwannoma vestibular) é familiar à maioria dos neurocirurgiões. Entretanto lesões císticas do ângulo ponto-cerebelar merecem uma análise cuidadosa, levando-se em consideração uma ampla gama de diagnósticos diferenciais, dentre os quais: cistos epidermóides, cistos aracnóides, neurinomas císticos, meningiomas císticos, bem como outras entidades mais raras como lesões vasculares e tumorais malignas. Os autores apresentam uma revisão critica da literatura, proporcionando ao leitor uma visão geral sobre os possíveis diagnósticos diferenciais bem como atuais diretrizes para a avaliação imagenológica de lesões císticas no ângulo ponto-cerebelar.

Edema and malignancy in meningiomas

OBJETIVO: Nos últimos anos têm-se descrito alguns subtipos de meningiomas de comportamento peculiarmente agressivo. Muitas tentativas têm sido feitas no intuito de estabelecer critérios imagenológicos ou histopatológicos de malignidade. O objetivo desse estudo é avaliar, através de Tomografia Computadorizada e Ressonância Nuclear Magnética o grau de edema peritumoral e seu volume, correlacionando-os com a classificação histológica da OMS. As causas relatadas de edema peritumoral e sua possível correlação histológica foram também revistos. MÉTODOS: Foram estudados 55 casos de meningiomas operados no Hospital das Clinicas (FMUSP) entre Setembro de 1993 e Setembro de 1997. O grau de edema segundo a classificação de Ide et al. (1995) foi comparado com a classificação da OMS. RESULTADOS: Os achados relativos a edema foram: edema grau 0 - 28 pacientes; grau I - 19 pacientes; grau II - 8 pacientes. A classificação histológica demonstrou: meningiomas benignos - 43 casos; meningiomas atípicos - 11 casos meningioma maligno - 1 caso. Demonstrou-se uma correlação significativa (p = 0,0089) entre o grau de edema dos meningiomas e suas características histológicas. CONCLUSÕES: Esses resultados sugerem que o grau de edema avaliado imagenologicamente pela Tomografia Computadorizada e Ressonância Nuclear Magnética pode ser um importante fator preditivo da gradação histológica dos meningiomas.