Aggressive management of orbital meningeal melanocytoma.

OBJECTIVE: Meningeal melanocytoma generally occurs in the posterior fossa. Orbital manifestation is rarely encountered. METHODS: A thirty-five year-old man presented with progressive proptosis of his right eye. Computed tomography (CT) and Magnetic Resonance Imaging (MRI) of the brain showed an expansive intraconal mass lesion occupying the superior orbital compartment, the entire orbital apex, and the optic foramen. Histological analysis and Immunohistochemical staining for S-100 and HMB-45 monoclonal antibodies confirmed melanocytoma. FINDINGS: Microsurgical removal was accomplished through a fronto-orbital craniotomy. Chemotherapy and irradiation followed the initial intervention. The patient returned for follow up two years after surgery, complaining of headache and right visual loss. A subfrontal tumor with massive edema was found on follow up CT scan. INTERPRETATION: Meningeal melanocytomas are rare benign pigmented tumors of the central nervous system. They are predominant in the posterior fossa and spinal cord and frequently mistaken for melanomas, especially on frozen sections. Orbital presentation is rare. The natural history is poorly defined.

Delayed minimally invasive cranioplasty.

Minimally invasive cranioplasty is presented. Stereolithography is a new technology applied for the manufacture of custom-made cranial prosthesis that can provide an accurate reproduction of difficult anatomical contours of large cranial defects. The pre-operative development of perfect-fit prostheses permits a significant decrease in the operative time, in the overall costs of surgery, as well as on the rate of complications observed in patients with large cranial defects. At the end, this paper reviews the current concepts of application of engineering into medicine.

Neurocognitive assessment before and after cranioplasty.

OBJECTIVE: This paper addresses the possible value of neurocognitive tests on the evaluation of patients before and after cranioplasty for large cranial defects. METHODS: In a single patient with a large corrected cranial defect a detailed neurocognitive analysis was performed utilizing the EXIT interview and Cognistat before and after surgery. Planning and development of the surgical prosthesis were based on the pre-operative reconstruction of the head CT and on pre-operative pictures of the patient. Xenon-CT anatomical and quantitative cerebral blood flow (CBF) analysis was performed before and periodically after cranioplasty. FINDINGS: A significant improvement in major cognitive functions was observed after surgery. INTERPRETATION: Cognistat is a detailed neuropsychological battery that permits a better assessment of patients in diverse neurological conditions. The EXIT interview gives a better rapid assessment of cognition not provided by other methods, such as the mini-mental status examination (MMSE). The utilization of these techniques permits a better understanding of long-term outcomes for patients with diverse neurological conditions, including post-cranioplasty patients.

Unusual brain metastases from papillary thyroid carcinoma: case report.

OBJECTIVE AND IMPORTANCE: Brain metastases from papillary carcinoma of the thyroid gland are unusual. No consensus regarding management has yet been reached. We report a case, review the current literature, and explain our approach on the basis of clinical, pathological, and radiological data. CLINICAL PRESENTATION: A 33-year-old woman presented with signs of intracranial hypertension. The diagnostic evaluation included chest tomography, head computed tomography, brain magnetic resonance imaging with and without contrast enhancement, total-body scanning, and cerebral scintigraphy. Multiple supratentorial lesions and one right cerebellopontine angle lesion were observed. Histopathological analysis of the surgical specimen confirmed papillary carcinoma of the thyroid gland. INTERVENTION: A ventriculoperitoneal shunt was placed and a right suboccipital craniotomy was performed, with complete removal of the cerebellopontine angle tumor. Total-brain irradiation with 40 Gy/lesion followed the initial operation. One year after surgery, the patient presented with signs of increased intracranial pressure. A new left frontal lobe lesion with massive peritumoral edema was identified on magnetic resonance imaging scans. The edema was treated clinically and a left frontal craniotomy was performed, with complete resection of the tumor. The patient is currently faring well, with residual expressive aphasia. CONCLUSION: Surgery followed by radiotherapy seems to be a good alternative for the treatment of this specific type of metastasis. Thorough clinical and radiological evaluation, followed by genetic analysis of the surgical specimen, particularly with respect to the potential for tumor invasion under specific conditions, is recommended. The information obtained contributes to better management and better overall long-term outcomes for these patients.

Biomechanical properties of calvarium prosthesis.

There are many materials available for the reconstruction of calvarial defects. Even though their biomaterial properties are well known, the biomechanical properties as part of the calvarium have not been investigated. In this article, calvarial implants are reviewed with their historic development into modern cranioplasty. Materials for trephined skulls are classified by their category. Individual parameters to describe their mechanical properties are collected and revealed in detail. The laboratory testing methodology for cranioplasty material is introduced to understand each parameter. At last, we discuss an engineering technique to look into the implant behavior. Since there is no standard goal for the biomechanical and biomaterial point of view for cranioplasty, this article suggests the finite element method for evaluation of the implant behavior and the degree of damage upon the impact injury.

The neurochemical basis for the applications of the greater omentum in neurosurgery.

The omentum has been utilized in neurosurgery for over 30 years. However, the anatomical and physiological bases for its applications have not been described in great detail. In this paper, we will review the current status of the omentum applications for the management of central nervous system disorders.

Syndrome of the trephined: theory and facts.

The pathophysiology behind "the syndrome of the trephined" has been under investigation over the past 50 years. Research related to barometric pressure, cellular metabolism, cerebrospinal fluid (CSF) dynamics, and the vasculature have attempted to decipher the mechanism of disease. These subjects are discussed in five papers along with specific topics related to the syndrome. The symptoms experienced after craniectomy, the resolution of symptoms with cranioplasty as well as CSF, cerebral blood flow, and metabolic studies are presented, respectively, with a review of the theories.

Technological advances in the surgical management of trigeminal neuralgia.

For years, many controversies have arisen on the surgical management of trigeminal neuralgia and neuropathy. The purpose of this paper is to review most of the current surgical techniques for the management of trigeminal neuralgia and present our position on the current management of these situations.

Microsurgical anatomy of the short central artery.

We studied the origin, length, external diameter, disposition, branching patterns and the perforators of short central artery in the circle of Willis in eighty fresh, unfixed cerebral hemispheres (40 brains). We also examined the relationship of the short central artery, the recurrent artery of Heubner, and M1 perforators to the anterior perforated substance, caudate and putamen. The short central artery arises at 5.2 +/- 3.36 mm from the origin of the anterior cerebral artery, hidden and overlapped by the internal carotid artery bifurcation. The recurrent artery of Heubner arises distally to the origin of the short central artery. Four main anatomical variations were found: 1. Presence of short central artery and recurrent artery of Heubner (37.5%). 2. Isolated presence of the short central artery (27.5%). 3. Isolated presence of the recurrent artery of Heubner (21.25%). 4. Absence of short central artery and recurrent artery of Heubner (13.75%). Two different branching patterns were observed: 1. 2-4 straight perforators from the short central artery, perforators from the recurrent artery of Heubner and lenticulostriate from the most medial portion of the M1, in 42 of 80 hemispheres (52.5%). 2. 8-10 perforators from only short central artery in 10 of 80 hemispheres (12.5%) with absent or hypoplastic recurrent artery of Heubner and lenticulostriates from M1 and M2.

Stereolithography for posterior fossa cranioplasty.

Posterior fossa cranioplasty has been suggested for improvement of neurological symptoms following craniectomy. However, there is no particular recommendation in the literature about techniques for prosthesis manufacture and implantation. We report our experience using rapid prototyping technology and stereolithography for pre-surgical implant design and production of cranioplasties.

The use of high power drills for laminectomy in spinal stenosis: technical report.

High power drill systems are being used for cervical and lumbar spinal stenosis surgeries. The use and comparative analysis of several systems are presented.

Cranioplasty: cosmetic or therapeutic?

Cranioplasty is among the oldest surgical procedures. Trauma, infections, tumors and compression caused by brain edema are some of the reasons for the removal of bone. The indications for cranioplasty after resolution of the primary process that led to the bone defect were never well defined, and many were the "cosmetic" indications for cranioplasty. However, there are many theories suggesting that an underlying physiological alteration may occur which may require the correction of the bone defect; many patients improve after surgery. We discuss the physiopathological basis of the "syndrome of the trephined" and try to achieve a better understanding of the present status of cranioplasty and its possible therapeutic role.

Transporte mucociliar: implicacoes clinicas e metodos de estudo / Mucociliary transport: clinicals implications and methods of study

O transporte mucociliar desempenha um papel de extrema importancia na homeostase do individuo, uma vez que ele e responsavel pela eliminacao de impurezas e de microorganismos inalados juntamente com o ar inspirado. Considerando-se que as doencas respiratorias, principalmente as de carater infeccioso, sao importante causa de morte na populacao e que as alteracoes no transporte mucociliar tem papel fundamental na genese dessas doencas, justifica-se a escolha do tema dessa monografia. Com a finalidade de tornar mais clara a exposicao das alteracoes do transporte mucociliar nas entidades clinicas apresentadas (bronquite cronica, fibrose cistica, asma e cancer do pulmao), fizemos uma breve revisao dos mecanismos de batimento ciliar e regulacao da producao de muco. Ressaltamos, tambem, os principais metodos de estudo do transporte mucociliar, devido ao fato de serem eles pouco conhecidos, apesar de sua crucial importancia.