RESUMO -O autor relata sua experiência com sete pacientes portadores de cistos aracnóides tratados cirurgicamente, todos pela técnica neuroendoscópica. Dentre os pacientes, dois portadores de cistos suprasselares haviam sido submetidos a várias cirurgias de derivação do líquido cefalorraquiano e um portador de cisto temporal, a derivações externas de higroma subdural associado. Apenas neste caso a abordagem endoscópica não resultou em controle dos sintomas do paciente. O tempo de acompanhamento variou de um a nove anos. PALAVRAS-CHAVE: cisto aracnóide, neuroendoscopia. Intracranial arachnoid cysts: neuroendoscopic treatmentABSTRACT -The author reports the techniques and results of seven patients with intracranial arachnoid cysts treated surgically, all of them through neuroendoscopic approach. Two carriers of supraselar cysts had undergone several shunt surgeries, and another carrier of a temporal cyst undergone external drainage to treat an associated subdural higroma. Only in this case the endoscopic approach has not resulted in control of the symptoms of the patient. The follow up period extended from one to nine years.KEY WORDS: arachnoid cyst, neuroendoscopy.Os cistos aracnóides são coleções intraracnóides de líquido céfalo raquiano (LCR). São de natureza congênita e se formam graças a defeito valvular das membranas aracnóides que facilita a passagem do LCR para o interior do cisto e dificulta a saída 1 . Embora muitos podem constituir achados incidentais, outros podem causar sintomas por compressão do parênquima cerebral ou aumento da pressão intracraniana 2 . É conhecida a propensão de ocorrer hemorragias no interior dos cistos [3][4][5] . Desde o desenvolvimento dos modernos endoscópios, uma técnica minimamente invasiva foi disponibilizada para o tratamento destas lesões. O autor relata neste estudo sua experiência no tratamento de sete cistos aracnóides pela neuroendoscopia. CASUÍSTICADe 1987 a 1997 foram atendidos no Serviço de Neurocirurgia do Hospital Santa Genoveva 21 pacientes portadores de cistos aracnóides sob as mais variadas formas de apresentação. Dentre estes, um paciente no início da série, portador de cisto da placa quadrigêmina, foi submetido a cinco cirurgias dentre fenestrações e derivações cisto e ventrículo peritoneais. Outra paciente foi admitida na emergência com história de queda, sonolência e déficit motor. A tomografia axial computadorizada (TC) revelou imagem sugestiva de cisto aracnóide da fissura silviana e hematoma intraparenquimatoso com desvio de linha média, confirmados pela abordagem cirúrgica. Doze pacientes não receberam qualquer forma de tratamento e sete foram tratados por fenestrações sob técnica endoscópica. Estes últimos constituem o objeto deste relato (Tabela 1).
RESUMOEste artigo é um estudo laboratorial das características do fluxo e resistência de modelos de vários tipos de cateteres peritoneais, inclusive os disponíveis comercialmente. Utilizou-se uma bancada de testes que permitiu um controle preciso da pressão de perfusão do sistema. Os resultados demonstram que os cateteres comercialmente disponíveis não possuem resistência (Rout) significativa; o cateter aberto apresentou uma Rout que variou de 1,12 a 1,95 mmHg/ml/min, e o cateter com fendas de 10 mm apresentou uma Rout que variou de 1,22 a 1,26 mmHg/ml/min. Em humanos, os níveis considerados normais do elemento resistivo da dinâmica liquórica (Rout) é de até 3 mmHg/ml/min. Isso significa que os cateteres peritoneais testados reproduzem os valores dos elementos resistivos fisiológicos. Contudo, considerando-se a hipótese de Kajimoto, os cateteres de 8 mm e 9 mm possuem potencial para acrescentar o elemento resistivo adequado ao sistema de derivação. O cateter com fendas de 8 mm teve, em ∆P inicial de 5,15 mmHg, um fluxo de 2,11 ml/min e Rout de 2,45 mmHg/ml/min e, em ∆P sentado (14 mmHg), um fluxo de 9,96 ml/min e Rout de 1,41 mmHg/ml/min, representando um elemento resistivo adicional de 25% quando comparado ao cateter aberto tanto em ∆P inicial quanto em ∆P sentado . O cateter com fendas de 9 mm teve, em ∆P inicial de 4,05 mmHg, um fluxo de 1,93 ml/min e Rout de 2,1 mmHg/ml/min, e em ∆P sentado , um fluxo de 10,32 ml/min e Rout de 1,36 mmHg/ml/min, representando um elemento resistivo adicional de 7% em ∆P inicial e de 21% em ∆P sentado quando comparados com o cateter aberto. Assim, os cateteres de 8 mm e 9 mm mostraram potencial para contribuir como um elemento resistivo adicional para limitar o efeito sifão, e merecerão estudos futuros para se observar os efeitos hidrodinâmicos numa bancada de testes que inclua um sistema valvular. PALAVRAS-CHAVEHidrodinâmica das derivações liquóricas. Derivação ventriculoperitoneal. Efeito sifão. ABSTRACTHydrodynamic considerations on CSF shunts. Part I: the elusive role of peritoneal catheters Several peritoneal catheters were submitted to laboratorial tests for their hydrodynamic properties, under different levels of perfusion pressure.Peritoneal catheters with open end and those with 10 mm fenestrations have similar hydrodynamic properties. The open end catheter showe Rout between 1.12 and 1.95 mmHg/ml/min, and 10 mm fenestrations catheteres showed Rout between 1.22 and 1.26 mmHg/ml/min. The catheter with 8 mm fenestration had, at ∆P initial of 5.15 mmHg, a flow of 2.11 ml/min and Rout of 2.45 mmHg/ml/min, and for ∆P sitting (14 mmHg), a flow of 9,96 ml/min and Rout de 1.41 mmHg/ml/min, representing an additional resistive element of 25% for both ∆P initial and ∆P sitting when compared to open end catheter. The catheter with 9 mm fenestrations had, in ∆P initial of 4.05 mmHg, a flow of 1.93 ml/min and Rout of 2.1 mmHg/ml/min, and at ∆P sitting , a flow of 10.32 ml/min and Rout of 1.36 mmHg/ml/min, representing an additional resistive element of 7% at ∆P initial and 21% at ∆...
PURPOSE: To investigate the accuracy of 1.0T Magnetic Resonance Imaging (MRI) to measure the ventricular size in experimental hydrocephalus in pup rats. METHODS: Wistar rats were subjected to hydrocephalus by intracisternal injection of 20% kaolin (n=13). Ten rats remained uninjected to be used as controls. At the endpoint of experiment animals were submitted to MRI of brain and killed. The ventricular size was assessed using three measures: ventricular ratio (VR), the cortical thickness (Cx) and the ventricles area (VA), performed on photographs of anatomical sections and MRI. RESULTS: The images obtained through MR present enough quality to show the lateral ventricular cavities but not to demonstrate the difference between the cortex and the white matter, as well as the details of the deep structures of the brain. There were no statistically differences between the measures on anatomical sections and MRI of VR and Cx (p=0.9946 and p=0.5992, respectively). There was difference between VA measured on anatomical sections and MRI (p<0.0001). CONCLUSION: The parameters obtained through 1.0T MRI were sufficient in quality to individualize the ventricular cavities and the cerebral cortex, and to calculate the ventricular ratio in hydrocephalus rats when compared to their respective anatomic slice.
Abstract-Iron misregulation promotes oxidative stress and abnormally high iron levels have been found in the spinal cords of patients with ALS. The authors investigated whether HFE gene polymorphisms, linked to hemochromatosis, are associated with ALS using two independent populations of patients with sporadic ALS and controls (totaling 379 patients and 400 controls). They found that the H63D polymorphism is overrepresented in individuals with sporadic ALS (odds ratio 1.85, CI: 1.35 to 2.54). NEUROLOGY 2005;65:934-937 E.F. Goodall, BSc; M.J. Greenway, MB; I. van Marion, BSc; C.B. Carroll, PhD, MRCP;O. Hardiman, MD, FRCPI; and K.E. Morrison, DPhil, FRCP Many theories of ALS pathogenesis have been proposed, among them that of increased oxidative stress. Elevated levels of iron have been found in ALS spinal cord tissue, 1 and this may contribute to oxidative damage via the ability of iron to generate reactive oxygen species through the Fenton reaction.Iron homeostasis in humans is tightly controlled as both iron overload and deficiency have severe physiologic consequences. Hereditary hemochromatosis (HH) is a genetic disorder resulting in accumulation of unchelated iron in parenchymal tissues and organ damage. Two principal polymorphisms in the HFE gene, C282Y and H63D, have been identified as the cause of classic HH.2 Although the exact function of HFE is unknown, reports suggest a role in sensing body iron levels via its interaction with the transferrin receptor (TfR). 3 The most frequently identified polymorphism in HH is the C282Y variant, which disrupts cell surface expression of HFE and therefore the interaction with TfR.3 Another common HFE polymorphism is the lowly penetrant H63D, often occurring in HH patients with a heterozygous C282Y variant.2 Both of these polymorphisms in the heterozygous state have been reported in association with higher iron concentrations.Given the evidence of both oxidative stress and disrupted iron homeostasis in ALS, we investigated whether this disease is associated with the HFE polymorphisms. We report an association between the H63D polymorphism and ALS, suggesting that disrupted iron metabolism may be one factor that initiates or propagates motor neuron damage in ALS. Genotyping. DNA was extracted from venous blood samples according to standard protocols using NucleonII kits (Amersham). DNA (50 ng) from the Birmingham samples was amplified by PCR primers flanking the H63D and C282Y polymorphisms (Alta Bioscience, University of Birmingham, UK), as described by others. 4 The HFE polymorphisms were detected by restriction enzyme digestion with Rsa1 and Mbo1 for C282Y and H63D (New England Biolabs). DNA samples from six patients with HH known to be homozygous or heterozygous for the H63D and C282Y polymorphisms were amplified and digested as controls. DNAs from the Irish samples were amplified and genotyped using an alternative method.5 Consistency of genotyping was assessed by reanalysis of 10% of the Birmingham samples by this alternative method.Statistical analysis. The ob...
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