Ari A. Pedrozo

Neurocisticercose: diagnóstico tomográfico em pacientes neurológicos

Neurocysticercosis (NC) is the most common parasitic disease of the central nervous system and accounts for a significant proportion of morbidity and mortality, in special epilepsy. The authors reviewed 3093 computed tomography scans out of 2554 randomized neurological patients evaluated during a one year period. Most patients (77.3%) were living in Curitiba, Parana, Brazil. 1821 (58.9%) CT scans were normal. NC was diagnosed in 236 patients based on tomographic criteria; the sex ratio was F:M 1.6:1. 219 (92.8%) patients had the inactive form of NC: 195 (89%) had only isolated intraparenchymal calcifications, and 24 calcifications plus hydrocephalus. Active forms were observed in 14 patients: 8 with degenerating cysts, 4 with viable cysts, 1 with intraventricular cyst, and 1 with racemose form. Three patients had both forms, active (cysts) and inactive (calcifications). The most common clinical finding among patients with tomographic diagnosis of NC was headache alone (35.5%), followed by epilepsy (20.9%). There is a potential role of NC as a causal factor of epilepsy in most of our patients, but surely not in all of them. On the other hand, the finding of inactive NC (calcifications without hydrocephalus and/or meningitic reaction) in patients with headache is probably fortuitous in most cases. In fact, the occasional finding of isolated calcifications in general population is not quite rare, as it was observed in 3.3% of another series of 973 patients with head trauma submitted to CT scan and without epilepsy previous history. The presence of CT findings compatible with NC, especially calcifications, must be carefully correlated with the clinical context in each case. Only then, an unequivocal cause-effect with all its medical and epidemiological implications role can be established.Neurocysticercosis (NC) is the most common parasitic disease of the central nervous system and accounts for a significant proportion of morbidity and mortality, in special epilepsy. The authors reviewed 3093 computed tomography scans out of 2554 randomized neurological patients evaluated during a one year period. Most patients (77.3%) were living in Curitiba, Paraná, Brazil. 1821 (58.9%) CT scans were normal. NC was diagnosed in 236 patients based on tomographic criteria; the sex ratio was F:M 1.6:1. 219 (92.8%) patients had the inactive form of NC: 195 (89%) had only isolated intraparenchymal calcifications, and 24 calcifications plus hydrocephalus. Active forms were observed in 14 patients: 8 with degenerating cysts, 4 with viable cysts, 1 with intraventricular cyst, and 1 with racemose form. Three patients had both forms, active (cysts) and inactive (calcifications). The most common clinical finding among patients with tomographic diagnosis of NC was headache alone (35.5%), followed by epilepsy (20.9%). There is a potential role of NC as a causal factor of epilepsy in most of our patients, but surely not in all of them. On the other hand, the finding of inactive NC (calcifications without hydrocephalus and/or meningitic reaction) in patients with headache is probably fortuitous in most cases. In fact, the occasional finding of isolated calcifications in general population is not quite rare, as it was observed in 3.3% of another series of 973 patients with head trauma submitted to CT scan and without epilepsy previous history. The presence of CT findings compatible with NC, especially calcifications, must be carefully correlated with the clinical context in each case. Only then, an unequivocal cause-effect with all its medical and epidemiological implications role can be established.

Estereoscopia aplicada à neuroanatomia: estudo comparativo entre as técnicas de filtro de cores e de polarização

The need of didactic material is increasing in medical science nowadays. The lack of anatomical specimens, and the toxicity of conservators, have originated an intense search for alternative ways of demonstrating the human anatomy. As a solution for this difficulty, three-dimensional (3-D) images may be used, facilitating the learning process. This study aims at comparing and describing two techniques of reproduction of bi-dimensional images into three dimensions, which is called stereoscopy. The methods evaluated are filter of colors (anaglyphic) and polarized light. Techniques were analyzed for clearness and 3-D effect. Fourteen images were evaluated by 5 people, with scores ranging from 0 to 4. Total mean scores of polarized light was superior compared to the anaglyphic technique. Both methods use the codification of the image, which means separation and exclusivity with each eye seeing its corresponding image. After several photographic essays and gradual adaptation to a better technique, based on optical physics, photography and neuroanatomical knowledge, we concluded that both techniques are suitable means for production of 3-D images. The best technique, however, considering the final quality of image was polarized light, which did not alter the natural color of the specimen, conserving clearness of images with lower cost.

Comparison of MRI-guided and ventriculography-based stereotactic surgery for Parkinson's disease

Stereotactic surgery for Parkinsons disease can be performed using different neuroimaging methods. Ventriculography has been used to locate the coordinates of the structures close to the third ventricle. Although it has several potential disadvantages related to the intraventricular injection of iodine contrast, it is considered a precise method. Computed tomography and magnetic resonance imaging have been used in some centers. In order to compare their efficacy, 50 stereotactic thalamotomies for Parkinsons disease were performed using either ventriculography (VE) (25) or magnetic resonance imaging (MRI) (25). In 14 out of 25 VE procedures, computed tomography (CT-scan) was also used and showed a significant mean difference of coordinate Y and Z. The clinical results employing either VE or MRI were similar, with 80% abolition of tremor in the VE group, and 84% in the MRI group, after a follow up period of at least 3 months. Another 12% of VE and 16% of MRI group showed significant improvement of tremor. Complication rate was 4% in both groups. MRI-guided stereotactic thalamotomy in Parkinsons disease has shown good clinical results, comparable to VE-guided stereotaxis.

Acoustic neurinomas: diagnosis and treatment

We present our experience with 83 patients with acoustic neurinomas (January 1988 to November 1996); 81 patients underwent surgery and 2 patients with intracanalicular neurinomas received conservative therapy due to their advanced age (1 case) and patients option (1 case). The surgical approach was retrosigmoid/transmeatal and the goal was total removal in one procedure with preservation of facial and cochlear nerves. Radical removal of lesion was attempted in 79 cases and it was possible in 77 patients. Subtotal tumor resection was planned in 2 cases. Facial nerve function (grades I to III, House and Brackman) was preserved in 90% and hearing in 58% of those with preoperative hearing. Three patients died due to postoperative complications. Early diagnosis of acoustic neurinomas is the most important factor in the prognosis and is one of the most important conquest of neurophysiology and modern neuroimaging. The management of these patients still present many controversial points. This article presents the diagnostic procedures used for acoustic neurinomas, the advantages and disadvantages of the different surgical approaches and the alternative management of these lesions.

Brainstem cysticercosis simulating cystic tumor lesion. A case report.

Os autores relatam o caso de paciente masculino de 37 anos com cisticerco unico no tronco cerebral (ponte) removido cirurgicamente com sucesso. Cirurgia tem sido indicada em neurocisticercose nos pacientes com hidrocefalia e/ou lesoes cisticas com importante efeito de massa. As lesoes localizadas no tronco cerebral ou medula espinhal podem ter indicacao cirurgica por duas razoes: (1) diagnostico; e (2) tratamento. O emprego de drogas cisticidas pode ser considerada uma alternativa terapeutica em certos casos. Contudo, o risco de desenvolvimento de complicacoes decorrentes da destruicao dos cistos situados em areas criticas do sistema nervoso central deve ser considerado.

Cirurgia estereotáxica guiada para angiomas cavernosos

Intracerebral cavernous angiomas may cause hemorrhage, epileptic seizures and neurological deficits. The diagnosis of these lesions became easier with the advent of the magnetic resonance image (MRI). Radical resection is the treatment of choice. Due to frequent subcortical or deep location, image-guided techniques, such as stereotactic-guided surgery, offer many advantages as smaller skin incision and craniotomy, less brain manipulation with consequently lower morbidity. We present a series of nine cavernous angiomas treated by stereotactic-guided radical surgical resection. The diagnosis was done by MRI and confirmed by pathologic studies in all cases. Mean age of patients was 30 years old (range 20-54 years). Postoperative morbidity occurred in two cases: one patient had a convulsion on the third postoperative day and the other presented dysphasia and hemiparesis on the second postoperative day, both with total recovery. Total resection of the lesion was possible in all cases with no neurological deficit.

Saphenous vein graft bypass in the treatment of giant cavernous sinus aneurysms: report of two cases

Two cases of giant intracavernous aneurysms treated by high flow bypass with saphenous vein graft between the external carotid artery (ECA) and branches of the middle cerebral artery (MCA) are presented. Very often these aneurysms are unclippable because they are fusiform or have a large neck. Occlusion of the internal carotid artery (ICA) is the treatment of choice in many cases. This procedure has however a high risk of brain infarction. Revascularization of the brain by extra-intracranial anastomosis between the superficial temporal artery (STA) and branches of the MCA is frequently performed. This procedure provides however a low flow bypass and brain infarction may occur. We report two cases of giant cavernous sinus aneurysms treated by high flow bypass and endovascular balloon occlusion of the ICA. Immediate high flow revascularization of MCA branches was achieved and the patients showed no ischemic events. Follow-up of 8 and 14 months after operation shows patency of the venous graft and no neurological deficits. Angiographic control examination showed complete aneurysm occlusion in both cases.

Middle cerebral artery revascularization: anatomical studies and considerations on the anastomosis site

In the surgical management of skull base lesions and vascular diseases such as giant aneurysms, involvement of the internal carotid artery may require the resection or the occlusion of the vessel. The anastomosis of the external carotid artery and the middle cerebral artery with venous graft may be indicated to re-establish the blood flow. To determine the best suture site in the middle cerebral artery, an anatomical study was carried out. Fourteen cerebral hemispheres were analysed after the injection of red latex into the internal carotid artery. The superior and inferior trunk of the main division of the middle cerebral artery have more than 2 mm of diameter. They are superficial allowing an anastomosis using a venous graft. The superior trunk has a disadvantage, it gives rise to branches for the precentral and post-central giri. The anastomosis with the inferior trunk presents lower risk of neurological deficit even though the angular artery originates from it.

Cirurgia estereotáctica para processos expansivos intracranianos: diagnóstico e tratamento

Os autores apresentam serie 50 pacientes submetidos a cirurgia estereotactica para processos expansivos intracranianos. Em 12 casos realizou-se um procedimento terapeutico: resseccao tumoral guiada em 5 pacientes e aspiracao do conteudo da lesao nos outros 7. Neste estudo confirmam-se a grande precisao e a baixa morbidade relacionadas com as tecnicas estereotacticas. A tomografia computadorizada e a ressonância magnetica determinam com acuracia as coordenadas estereotacticas, mas em certos casos a estereo-angiografia cerebral deve ser realizada. As resseccoes tumorais guiadas por estereotaxia permitem o tratamento de lesoes cerebrais profundas ou em areas funcionais anteriormente consideradas como inoperaveis. A literatura pertinente e discutida.

Hemorragia subaracnóidea perimesencefálica não-aneurismática: apresentação de caso e revisão de literatura

A 42 year-old man with subarachnoid hemorrhage was admitted in our Service (Hunt & Hess grade II). CT-scan disclosed predominantly perimesencephalic subarachnoid hemorrhage. Digital subtraction angiographic study did not disclose either cerebral aneurysm or any other potential site of intracranial bleeding. The evolution was uneventful. A DSA was repeated one month later and was negative. Four months later, the patient was asymptomatic. The authors review the literature and emphasize the importance in recognizing this benign clinical form of nonaneurysmatic subarachnoid hemorrhage.A 42 year-old man with subarachnoid hemorrhage was admitted in our Service (Hunt & Hess grade II). CT-scan disclosed predominantly perimesencephalic subarachnoid hemorrhage. Digital subtraction angiographic study did not disclose either cerebral aneurysm or any other potential site of intracranial bleeding. The evolution was uneventful. A DSA was repeated one month later and was negative. Four months later, the patient was asymptomatic. The authors review the literature and emphasize the importance in recognizing this benign clinical form of nonaneurysmatic subarachnoid hemorrhage.Os autores apresentam um caso de hemorragia subaracnoidea perimesencefalica nao aneurismatica em um paciente masculino de 42 anos, com excelente evolucao clinica. E realizada revisao da literatura, sendo apresentados aspectos clinicos e neurorradiologicos desta entidade benigna.