Murilo S. Meneses

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.

Peritoneal dissemination from central neurocytoma: case report

OBJECTIVE Central neurocytoma is a low grade tumor of neuroglial origin and a relatively new histological entity. Only a few cases have been reported and its biological behavior is still uncertain. Some cases have shown an aggressive behavior (local recurrence, malignant dedifferentiation or CSF dissemination) and challenged the initial view of its relative benignity. A case of central neurocytoma with peritoneal dissemination is presented. CASE A six years-old boy with recurrent neurocytoma of III ventricle and left thalamus showed fast growth of tumor rest and ascites three and a half years after subtotal removal of the lesion. Tumor cells were identified in the ascitic fluid and implanted in the peritoneum. Chemotherapy was initiated immediately after diagnosis of peritoneal dissemination (etoposide, carboplatin, doxorubicin and cyclophosphamide). The patient developed metabolic imbalance and respiratory failure due to rapid formation of ascitic fluid and died 3 days after the diagnosis of peritoneal dissemination was established. CONCLUSION Central neurocytoma is a low grade tumor with low values of the proliferative index in the majority of cases. In spite of that, some tumors may present a very aggressive behavior and extraneural dissemination. Evaluation of proliferative index may be a guideline parameter for planning adjuvant therapies after surgical treatment in selected cases. Extraneural dissemination may occur in some cases specially in patients with ventriculoperitoneal shunt.

Primary filum terminale ependymoma: a series of 16 cases

Filum terminale ependymomas are slow growing tumors of the cauda equina with a high incidence in young adults. Although a complete microsurgical resection can lead to a cure, recurrence is not uncommon. Sixteen cases of filum terminale ependymomas treated at the Instituto de Neurologia de Curitiba were analyzed. Eleven patients were females and 5 males, their age ranging from 7 to 84 years. Symptoms and signs included lumbar pain (31.25%), radicular pain (56.25%) and neurological deficits (12.5%). In three cases, patients had previously undergone surgery in other hospitals. All were tested through MRI and were operated on. Two underwent a laminoplasty and 14 a laminectomy. The last 8 patients of this series had neuro-physiological monitoring during surgery. In all patients a total microsurgical resection was achieved. Histologically, 2 cases were cellular ependymomas and 14 cases myxopapillary ependymomas. There was no recurrence during a 2 to 84 month follow-up period.

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.

Syncope or epileptic fits? Some examples of diagnostic confounding factors

Syncope is a condition often misdiagnosed as epileptic seizures. However, the differential diagnosis between both conditions can be quite difficult, even for well-trained physicians. Four cases of epilepsy and/or syncope are reported, to exemplify this situation. Each case is discussed individually, and the confounding factors are analyzed.

Hot-water epilepsy , "warm-water epilepsy", or bathing epilepsy? Report of three cases and considerations regarding an old theme

Partial and generalized tonic-clonic reflex seizures related to hot water bathing have been described as temperature-related. We describe three cases of bathing epilepsy: a 28 year-old white male and a 30 year-old white female with spells triggered either by warm or hot water, and a 32 year-old female with spells triggered by hot water. The later two of the three cases presented localized epilepsy and a familial history of epilepsy. A complex tactile stimuli might play the most relevant role on seizure triggering, as well as water temperature with an additive effect over cutaneous stimulation.

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.

Bilateral oculomotor nerve palsies due to vascular conflict.

Departament of Neurosurgery, Instituto de Neurologia de Curitiba, Curitiba PR, Brazil; Department of Neurology, Instituto de Neurologia de Curitiba, Curitiba PR, Brazil; Neurological Clinic of Paraiba, Joao Pessoa PB, Brazil. Oculomotor nerve palsy is frequently caused by an aneurismal compression and diabetes mellitus. Brainstem infarction, cavernous sinus tumors and other intracranial lesions are well known causes of oculomotor palsy also. However, neurovascular conflict causing oculomotor nerve disturbances are rare. After the advent of high quality MRI and neuroimaging improvements, the diagnosis of such atypical neurovascular conflicts in symptomatic patients became quite simple. The case of a patient with bilateral oculomotor disorder with MRI imaging of the head showing a right oculomotor nerve compression by the right posterior cerebral artery and a left oculomotor nerve compression by the left superior cerebellar artery is reported and discussed.

Vagus nerve stimulation may be a sound therapeutic option in the treatment of refractory epilepsy

INTRODUCTION Refractory epilepsy accounts for 20 to 30% of epilepsy cases and remains a challenge for neurologists. Vagus nerve stimulation (VNS) is an option for palliative treatment. OBJECTIVE It was to study the efficacy and tolerability of VNS in patients implanted with a stimulator at the Curitiba Institute of Neurology (INC). METHODS A case study of six patients with refractory epilepsy submitted to a VNS procedure at the INC in the last four years was described and discussed. RESULTS Mean age at time of implantation was 29 years. Mean follow-up was 26.6 months. Seizure frequency decreased in all patients (40-50% (n=2) and ≥80% (n=4)). Three patients no longer required frequent hospitalizations. Two patients previously restricted to wheelchairs started to walk, probably because of improved mood. CONCLUSION In this population, VNS proved to be a sound therapeutic option for treating refractory epilepsy.