Tuberculous brain abscesses in immunocompetent patients: management and outcome.

BACKGROUND: Tuberculosis (TB) remains an important public health problem in developing countries. OBJECTIVE: To evaluate the clinical presentation, management, and long-term outcome in 6 patients with tuberculous brain abscesses (TBA), an uncommon form of central nervous system (CNS) TB. METHODS: A search of medical records of a single referral neurological center in Mexico City from 2002 to 2007 retrieved 149 patients with CNS TB; 6 of them (4%) met Whitener's criteria for TBA and were included in this review. RESULTS: Five of six patients had a previous history of TB. Three patients were referred to our center under antituberculous treatment (ATT) for pulmonary and lymph node TB, and two patients were receiving ATT for TB meningitis at diagnosis of TBA. All presented with symptoms of intracranial hypertension and hemiparesis. On imaging studies, 3 patients had a single, deep multiloculated lesion and another three had separated lesions, all patients underwent surgery and received long courses of ATT. One patient died after surgery and the rest recovered with moderate to severe neurological sequelae. The residual lesions in 5 patients resolved in follow-up CT or MRI studies at a mean time of 10 months. CONCLUSIONS: Early surgery confirms the diagnosis of TBA. Some patients may require additional surgical procedures if enlargement or recurrence of the lesion occurs. No evidence of drug resistance was found in our cases, and we found only two reports of TBA with primary resistance to ATT in a selective literature review. TBA does not seem to be a consequence of drug resistance. Sequelae are common, and long-term ATT with close clinical and imaging follow-up is mandatory.

Meios contínuos em neurocirurgia vascular e neurorradiologia intervencionista. Parte I / Mechanics of continuous media in vascular neurosurgery and endovascular neuroradiological procedures

Os aneurismas e as placas de ateroma compartem não somente um elevado índice de morbimortalidade, como também sua localização. Isso sugere que fatores hemodinâmicos contribuam no seu desenvolvimento. A quantificação de forças hemodinâmicas é complicada, especialmente em vasos intracranianos; porém, avanços recentes em mecânica computacional têm permitido calcular sua magnitude e distribuição em modelos arteriais com ajuda de técnicas de dinâmica de fluidos computacionais. No entanto, a compreensão desses modelos e a verificação de sua validade e limitações dependem do conhecimento de seu desenho e dos parâmetros hemodinâmicos utilizados. Por outro lado, a determinação das propriedades mecânicas das paredes arteriais é crucial, não somente para a compreensão das alterações do sistema cardiovascular no tempo e das causas responsáveis que dão origem às lesões vasculares, bem como para a realização da angioplastia, o planejamento de pontes arteriais e a seleção de próteses endovasculares. Dessa forma, a mais importante contribuição que podemos obter do conhecimento da biomecânica, em geral, e da mecânica dos meios contínuos, em particular, se encontra no melhor entendimento da fisiologia. Nesta revisão, passamos pelos conceitos fundamentais utilizados na formulação dos problemas da mecânica dos meios contínuos, com ênfase na pesquisa biomecânica das lesões vasculares, no intuito de oferecer algumas definições que promovam a análise crítica dos resultados nesse campo.

Cerebral aneurysms and atherosclerosis share not only a high rate of morbidity and mortality, but also its location. It suggests that hemodynamic factors contribute to their development. Quantification of hemodynamic forces is complicated, especially in intracranial arteries. However, recent advances in computational mechanics have allowed calculating the magnitude and distribution of these forces in arterial models with the help of techniques of computational fluid dynamics. However, the understanding of these models and verification of their validity and limitations depend on the knowledge of its design and hemodynamic parameters. Furthermore, the determination of mechanical properties of the arterial walls is crucial, not only for the understanding of the changes of the cardiovascular system in time and the causes of the injuries that they develop, as well as to the realization of angioplasty, planning of arterial bypass or the selection of endovascular prosthesis, for example. Thus, concepts on mechanics of continuous media are needed in the body of knowledge of all interested in cerebrovascular disease. In this review, we look the fundamental concepts used in the formulation of the problems of the mechanics of continuous media, focusing on biomechanics research of vascular lesions, in order to provide some definitions that promote the critical analysis of the results in this . The most important contribution that we can get from the knowledge of biomechanics, in general, and from the mechanics of continuous media, in particular, is a better understanding of physiology.

Hemangioblastomas aparentemente esporádicos e doença de von Hippel-Lindau não suspeita / Apparently sporadic hemangioblastomas and not suspected von Hippel-Lindau disease

Objetivo: Apresentar os achados associados à doença de von Hippel-Lindau em pacientes portadores de hemangioblastoma do sistema nervoso central, aparentemente esporádico, submetidos a rastreamento (screening)em um centro neurocirúrgico de referência.Métodos:Na base de dados do Instituto Nacional de Neurologia e Neurocirurgia da Cidade do México foram identificados todos os pacientes com diagnóstico histológico confirmado de hemangioblastomado sistema nervoso central entre janeiro de 1980 e agosto de 2000.Os arquivos médicos, radiológicos e patológicos desses pacientes foram revisados retrospectivamente. Destes, 25 pacientes assintomáticos concordaram em submeter-se ao rastreamento, por meio de exame físico, ultra-sonografia e tomografia axial computadorizada de abdômen,ressonância magnética cranioespinhal e exame oftalmológico.Resultados: 32 por cento dos pacientes apresentaram policistose, 16 por cento, hemangioblastomas múltiplos e 12 por cento, carcinomas viscerais. Segundo os critérios de Neumann, logrou-se estabelecer o diagnóstico clínico da doença de von Hippel-Lindau em 60 por cento dos casos. Conclusão:A presença de lesões assintomáticas nos portadores da doença de von Hippel-Lindau assinala a falta de sensibilidade do exame clínico, fazendo-se necessário o rastreamento de todo paciente portador de hemangioblastomas do sistema nervoso central.

Trigeminal neuralgia secondary to arteriovenous malformations of the posterior fossa.

BACKGROUND: Trigeminal neuralgia secondary to a posterior fossa AVM has been seldom reported in the literature. Most of the cases have been published on a case report basis, and there is not a general agreement about the best way of treatment. METHODS: In this work, we analyze our experience with 5 cases of TN secondary to a posterior fossa AVM, treated at the Division of Neurosurgery from the National Institute of Neurology and Neurosurgery, "Manuel Velasco Suarez," Mexico City, Mexico, from January 1985 to December 2004. RESULTS: Trigeminal neuralgia associated with an AVM occurred in 1.3% of 375 brain AVMs and 9.8% of 37 posterior fossa AVMs. All had received drug therapy unsuccessfully, and 2 of them underwent a percutaneous thermocoagulation without solving the neuralgia. In 4 patients, a microvascular decompression was completed with excellent results. CONCLUSIONS: Even when different ways of treatment have been reported, it seems that percutaneous procedures (glycerol injection, thermocoagulation, or microcompression of the gasserian ganglia) give variable clinical results. The reported experience and our own results support the microvascular decompression of the trigeminal nerve as the best treatment whenever the total excision of the AVM cannot be accomplished.

Von Hippel-Lindau disease germline mutations in Mexican patients with cerebellar hemangioblastoma.

OBJECT: Central nervous system (CNS) hemangioblastomas are benign vascular tumors arising either sporadically or as a manifestation of von Hippel-Lindau (VHL) disease, a hereditary cancer syndrome. The authors studied a series of patients with CNS hemangioblastomas and their families to identify germline mutations in the VHL tumor suppressor gene and to establish a predictive testing and screening protocol. METHODS: Patients admitted between 2002 and 2004 to the Instituto Nacional de Neurología y Neurocirugía for hemangioblastoma were prospectively enrolled, together with their at-risk family members. The authors performed the molecular analysis of the VHL gene by using polymerase chain reaction and direct genetic sequencing. All asymptomatic mutation carriers underwent genetic counseling and tumor surveillance. Ninety-eight individuals were tested for VHL mutations--23 symptomatic and 75 asymptomatic individuals belonging to 16 families. Seven of the families had definite clinical criteria of VHL disease, five had sporadic hemangioblastoma, and four had CNS hemangioblastoma combined with minor visceral signs. Molecular genetic testing identified five germline mutations in six of the definite VHL families (sensitivity 85%), but none in the possible VHL and sporadic hemangioblastoma cases; four of these mutations had been previously described and one is a novel mutation present in two unrelated families. After patients carrying the mutation were identified, they underwent clinical screening and asymptomatic VHL-related lesions were identified in 43%. CONCLUSIONS: Genetic testing for mutations in the VHL gene is crucial in patients with CNS hemangioblastoma. The prompt identification of patients carrying the genetic mutation allows for a multidisciplinary screening protocol to decrease morbidity and mortality rates in these patients, while avoiding costly and invasive procedures for noncarriers.

Cerebellopontine angle cysticercus and concurrent vascular compression in a case of trigeminal neuralgia.

The authors present the case of a 59-year-old woman with an 8 months history of lancinating pain and hyphestesia on the right side of the face along with hearing impairment. She had poor tolerance to carbamazepine. A non-enhancing cystic image was observed at the right cerebellopontine angle on magnetic resonance imaging. The patient underwent surgery. Through a right retromastoid minicraniectomy and under microscopic magnification the VII and VIII cranial nerve complex was found involved by multiple adhesions around a cysticercus. After the cyst was removed a loop of the anteroinferior cerebellar artery was identified compressing the V right nerve at its root entry zone. Decompression was performed by the insertion of a Teflon implant. The postoperative course was uneventful and trigeminal neuralgia (TN) disappeared after surgery. Five previous cases of cranial nerve hyperactive dysfunction syndromes, four of trigeminal neuralgia and one of hemifacial spasm associated to cerebellopontine angle cysticercosis are briefly commented. We suggest that in some of these cases microvascular compression was probably present, and during surgery of cerebellopontine angle cysticercus by either trigeminal neuralgia or hemifacial spasm, vascular compression must be carefully searched and treated when found.

Intracranial aneurysms associated with unsuspected aortic coarctation.

Intracranial aneurysms (IAs) are found more often in patients with aortic coarctation (AC) than in the general population and aneurysm rupture occurs much earlier in the lives of these patients when there is coexistent AC. The diagnosis of AC is frequently made only after a serious cerebrovascular complication has developed. The aim of this paper is to call attention to AC in patients presenting with aneurysmal subarachnoid hemorrhage. The literature is reviewed, the key clinical features are highlighted, and the proposed pathogenesis of this association is discussed. The authors present clinical information and imaging data obtained in three young patients with ruptured IAs that were associated with initially unnoticed AC. Abnormal results of cardiovascular examinations led the authors to consider an underlying AC, which was later confirmed by aortography. These aneurysms were successfully treated prior to correction of the ACs. The diagnosis of AC should be considered in adolescent and young adult patients presenting with IAs.