RESUMO
OBJECTIVE: The suboccipital lateral or retrosigmoid approach is the main neurosurgical approach to the cerebellopontine angle (CPA). It is mainly used in the treatment of CPA tumors and vascular decompression of cranial nerves. A prospective study using navigation registered with anatomical landmarks in order to identify the transverse and sigmoid sinuses junction (TSSJ) was carried out in a series of 30 retrosigmoid craniotomies. The goal of this study was to determine the accuracy of this navigation technique and to establish the relationship between the location of the asterion and the TSSJ. METHODS: From March through November 2008, 30 patients underwent a retrosigmoid craniotomy for removal of CPA tumors or for surgical treatment of neurovascular syndromes. Magnetic resonance imaging (MRI) T1 sequences with gadolinium (FSPGR with FatSst, 1.5 T GE Signa) and frameless navigation (Vector vision, Brainlab) were used for surgical planning. Registration was performed using six anatomical landmarks. The position of the TSSJ indicated by navigation was the landmark to guide the craniotomy. The location of the asterion was compared with the position of the TSSJ. After craniotomy, the real TSSJ position was compared with the virtual position, as demonstrated by navigation. RESULTS: There were 19 cases of vestibular schwannomas, 5 petroclival meningiomas, 3 trigeminal neuralgias, 1 angioblastoma, 1 epidermoid cyst and 1 hemifacial spasm. In all cases, navigation enabled the location of the TSSJ and the emissary vein, with an accuracy flaw below 2 mm. The asterion was located directly over the TSSJ in only seven cases. One patient had a laceration of the sigmoid sinus during the craniotomy. CONCLUSIONS: Navigation using anatomical landmarks for registration is a reliable method in the localization of the TSSJ for retrosigmoid craniotomies and thereby avoiding unnecessary sinus exposure. In addition, the method proved to be fast and accurate. The asterion was found to be a less accurate landmark for the localization of the TSSJ using navigation.
Assuntos
Ângulo Cerebelopontino/cirurgia , Craniotomia/métodos , Neuronavegação/métodos , Osso Occipital/cirurgia , Cirurgia Assistida por Computador/métodos , Adulto , Idoso , Neoplasias Encefálicas/cirurgia , Ângulo Cerebelopontino/anatomia & histologia , Transtornos Cerebrovasculares/cirurgia , Fossa Craniana Posterior/anatomia & histologia , Fossa Craniana Posterior/irrigação sanguínea , Fossa Craniana Posterior/cirurgia , Neoplasias dos Nervos Cranianos/cirurgia , Cavidades Cranianas/anatomia & histologia , Cavidades Cranianas/cirurgia , Craniotomia/instrumentação , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Neuronavegação/instrumentação , Osso Occipital/anatomia & histologia , Cuidados Pré-Operatórios/instrumentação , Cuidados Pré-Operatórios/métodos , Estudos Prospectivos , Cirurgia Assistida por Computador/instrumentação , Adulto JovemRESUMO
Pedicle screws are widely used for instrumentation of the thoracolumbar spine. The anatomic studies performed in the last two decades, detailing the complex morphometry and three-dimensional anatomy of the thoracolumbar pedicles, have enabled the emergence of the so-called "free-hand" technique of pedicle screw placement based exclusively on anatomical parameters. However, in the thoracic spine, the benefits of pedicle screws have been tempered by its potential risks, such as, spinal canal violation, pedicle fracture, nerve root compression, and vascular lesions. Furthermore, the narrow and inconsistent shape of the thoracic pedicles, especially in spinal deformity, makes their placement technically challenging. In this article, the authors make a critical appraisal of current "state-of-art" of "free-hand" technique of pedicle instrumentation, analyzing its anatomical basis, surgical technique, present indications and limitations as well as the role of adjuvant image-guided and neurophysiological monitoring methods.
Assuntos
Parafusos Ósseos , Procedimentos Ortopédicos/instrumentação , Traumatismos da Medula Espinal/cirurgia , Fusão Vertebral/métodos , HumanosRESUMO
Creutzfeldt-Jakob disease (CJD) is a presenile dementia characterized by rapidly progressive mental deterioration, myoclonic jerking, and other less common neurological signs. Few autoctonous cases have been described in Brazil. A 54-year-old white woman, was admitted in our service with a month history of progressive, bilateral cortical blindness. After admission, she developed right partial motor seizures( right facial, upper and lower limbs), she became progressively aphasic( mixed aphasia). Seizures were controlled with phenytoin, but she developed choreoathetotic movements on her right dimidium, with partial control after introduction of chlorpromazine 25 mg q/d. She could no longer stand up or walk due to severe ataxia. The first EEG (October, 2001) showed left hemisphere severe seizure activity (status epilepticus partialis). She was delivered home with enteral nutrition, phenytoin, chlorpromazine and mepacrine 100 mg qd. The following laboratorial tests were negative or normal: blood series, platelets, ESR, kidney and liver function, copper, ceruloplasmin, VDRL, HIV, HTLV-1, lactate, and cerebral DSA (performed in other service).A spinal tap with normal opening pressure was perform and CSF examination was normal. CSF 14-3-3 protein was positive, CSF specific neuronal enolase 7.5 ng/ml(normal). Genetic study of PRNP gene did not disclosed any known mutation. A MRI (October, 2001) showed areas of hyperintense signal (T2 and FLAIR) without Gd-enhancement on T1, in the left temporal lobe and in both occipital lobes; basal ganglia have a normal appearance. DWI imaging showed bright areas at the same sites. An EEG (March, 2002) disclosed a periodical sharp triphasic waves pattern, suggestive of CJD. A second MRI (April, 2002) showed mild generalized atrophy, no ventricular dilatation, and the hyperintense sites disappeared. She remained clinically stable and under use of chlorpromazine and mepacrine until she died due to pulmonary complications on April, 2003.
Assuntos
Síndrome de Creutzfeldt-Jakob/diagnóstico , Imagem de Difusão por Ressonância Magnética/métodos , Antimaláricos/uso terapêutico , Antipsicóticos/uso terapêutico , Western Blotting , Síndrome de Creutzfeldt-Jakob/tratamento farmacológico , Síndrome de Creutzfeldt-Jakob/genética , Ecocardiografia , Eletroencefalografia , Evolução Fatal , Feminino , Humanos , Espectroscopia de Ressonância Magnética , Pessoa de Meia-Idade , Fenotiazinas/uso terapêutico , Proteína PrP 27-30/genética , Proteínas PrPC/genética , Quinacrina/uso terapêuticoRESUMO
A doença de Creutzfeldt-Jakob (CJD) é uma forma de demência pré-senil de rápida evolução, geralmente fatal em um ano. Casos autóctones no Brasil têm sido raramente descritos assim como achados de ressonância magnética. Mulher, natural de Ponta Grossa PR, branca , 54 anos , foi admitida no serviço em outubro de 2001 com quadro de amaurose bilateral cortical progressiva desde há 1 mês do internamento. Nunca viajou ao exterior e foi somente submetida a uma cirurgia de redução do estômago, para obesidade. História familial sem relato de casos semelhantes. Logo após o internamento a paciente desenvolveu quadro de disfasia mista, hemiparesia flácida direita, com movimentos coreoatetóticos e crises parciais motoras. Paciente evoluiu com quadro demencial progressivo; atualmente, acamada, torporosa, dependente de alimentação enteral, recebendo mepacrina, fenitoína e clorpromazina , estabilizando o quadro até final de maio de 2002. Exames laboratoriais negativos ou normais. Pesquisa de proteína 14-3-3 no líquor foi positiva; enolase-neurônio-específica no líquor foi normal. Estudo genético do gen PRNP não revelou mutação descrita anteriormente. EEG (23/10/2001) revelou intensa atividade irritativa hemisfério cerebral esquerdo. Estudo de ressonância magnética revelou áreas de hipersinal em T2 e FLAIR em regiões temporal esquerda e bioccipital; gânglios da base normal. Imagens de DWI mostraram hipersinal nas mesmas áreas.Outro EEG (15/03/2002) revelou padrão periódico de ondas trifásicas sugestivos de CJD. A paciente fez uso de mepacrina associado a clorpromazina com aparente estabilização do quadro, até seu óbito por complicações infecciosas pulmonares em abril de 2003.