Igor de Castro

Transoral approach to the craniovertebral junction

The transoral approach provides a safe exposure to lesions in the midline and the ventral side of the craniovertebral junction. The advantages of the transoral approach are 1) the impinging bony pathology and granulation tissue are accessible only via the ventral route; 2) the head is placed in the extended position, thus decreasing the angulation of the brainstem during the surgery; and 3) surgery is done through the avascular median pharyngeal raphe and clivus. We analyzed the clinical effects of odontoidectomy after treating 38 patients with basilar invagination. The anterior transoral operation to treat irreducible ventral compression in patients with basilar invagination was performed in 38 patients. The patients ages ranged from 34 to 67 years. Fourteen patients had associated Chiari malformation and eight had previously undergone posterior decompressive surgery. The main indication for surgery was significant neurological deterioration. Symptoms and signs included neck pain, myelopathy, lower cranial nerve dysfunction, nystagmus and gait disturbance. Extended exposure was performed in 24 patients. The surgery was beneficial to the majority of patients. There was one death within 10 days of surgery, due to pulmonary embolism. Postoperative complications included two cases of pneumonia, three cases of oronasal fistula with regurgitation and one cerebrospinal fluid leak. In patients with marked ventral compression, the transoral approach provides direct access to the anterior face of the craniovertebral junction and effective means for odontoidectomy.

INTERNAL STRUCTURE OF THE CEREBRAL HEMISPHERES An introduction of fiber dissection technique

The aim of this study is to introduce the fiber dissection technique and its importance in the comprehension of the three-dimensional intrinsic anatomy of the brain. A total of twenty brain hemispheres were dissected. Using Kinglers technique we demonstrated the intrinsic structures of the brain. The supra lateral aspect of the brain as well as the medial aspect were presented. The most important fiber systems were demonstrated. The use and comprehension of new neuroimaging techniques demand a better understanding of this fascinating anatomy. The knowledge acquired with this technique will improve our understanding of critical pathways of the central nervous system.

The history of spinal surgery for disc disease: an illustrated timeline

This article presents the evolution in medical history which leads to the surgical treatment for ruptured discs. Only at the last century the precise diagnosis of a ruptured lumbar disc could be made after tremendous efforts of the many medical pioneers in the study of the spine. The experience gained with the lumbar spine was rapidly transferred to the cervical spine. We describe the evolution of the clinical and surgical aspects about ruptured discs in the lumbar and cervical spine. An illustrative timeline of the major events regarding the surgical treatment for ruptured disks is outlined in a straight forward manner. Our understandings of the relation between symptoms and signs and of that between anatomy and pathophysiology have led to more successful surgical treatment for this disease. Nowadays lumbar and cervical discectomies are the most frequent operations carried out by neurosurgeons. Our current care of patients with this kind of spinal disorders is based on the work of our ancient medical heroes.

Fixação occípito-cervical "inside-outside": relato técnico

The clinical knowledgement of biomechanics of atlantoaxial complex have been proved that progressive instability has a mandatory occurrence after anterior decompression of the craniocervical junction. We report the occipitocervical fixation so called inside-outside technique, originally described by Pait et al. appliedin in two patients whom underwent odontoidectomy. The occipitalcervical fixation technique consist in the use of a titanium rod bended according with occipital cervical angle placed and fixed laterally over the cervical spine. The rod is fixed to the occipital bone by mean of placement a screw which flat portion is positioned onto the epidural space. In the cervical spine the rod is attached to transarticular screws placed at the superolateral quadrant of the articular mass. In the axis the screw is introduced through the pars interarticularis finishing at the axis body or the lateral mass of the atlas. This technique proved to be safe and easily applied in the patients whom underwent this surgical procedure.

Posterior fossa craniotomy: technical report

The use of craniotomy to approach supratentorial lesions is quite well established in the literature. The use of craniotomy for posterior fossa approaches, however, is not well described. The aim of this article is to describe the technical aspects of this approach and to delineate the important landmarks. In our cases, posterior fossa craniotomies have been utilized for treat different pathologies. Additionally, the technique has not added any additional risk, and the cosmetic results have been excellent.

Adult hemispheric cerebellar medulloblastoma

Background: Medulloblastoma is an embryonal neoplasm and accounts for 1% of all adult intracranial tumors. It is associated with many familiar cancer syndromes, but there is no known cause for medulloblastoma. Many studies have documented differences between childhood and adult medulloblastomas in terms of location, proliferation, and apoptotic indices. There are four histological groups – classic and the variant forms (desmoplastic/nodular, anaplasic, and large cell). There are four major subgroups according to molecular configuration: wingless (WNT), sonic hedgehog (SHH), group 3, and group 4 with differences between them according to prognostic outcomes. Case Description: We present the case of a 19-year-old female who complained of headache and vomiting. On neurological exam, she was awake, conscious, and had mild truncal ataxia, dysmetria, and intentional tremor. Brain magnetic resonance imaging (MRI) showed an intra-axial left hemisphere cerebellar lesion causing midline shift tonsilar herniation. She was submitted for posterior fossa craniotomy and microsurgical resection of cerebellar tumor and then to 18 Gy adjuvant radiotherapy to the tumor bed and 23 Gy to the neuroaxis. Conclusion: This article briefly discusses the newest points in classification, diagnosis, and treatment of medulloblastoma. This case illustrates the diagnostic workup and treatment of a rare tumor in adults showing the importance of molecular and histological studies for the treatment and counseling of the patient. Medulloblastoma has different prognosis depending on the histological and molecular feature. Accessing these different features is essential to better plan the treatment as well as inform the patient regarding the disease and its prognosis.

Microsurgical coil removal after coiling a carotid bifurcation aneurysm

Department of Neurosurgery, Hospital de Força Aérea do Galeão, Rio de Janeiro RJ, Brazil; Department of Neurosurgery, University of Arkansas for Medical Sciences, Little Rock, USA; Department of Neurosurgery, Hospital São José do Avaí, Itaperuna RJ, Brazil; Chief of Department of Neurosurgery, Hospital de Força de Aérea do Galeão, Rio de Janeiro RJ, Brazil. Endovascular treatments have evolved rapidly in the past decade, and have become established as a treatment option for the management of cerebral aneurysms. Detachable coils represent a major technological advance in aneurysm treatment, although coils are not suitable for the treatment of all aneurysms. As the use of endovascular techniques, especially Guglielmi detachable coils, becomes more widespread, growing numbers of patients will require surgical intervention after endovascular treatment of their intracranial aneurysms. Despite the advances in endovascular technology, all techniques can be associated with treatment failures and serious complications. Increasingly, these patients will present to neurovascular centers for evaluation and further management, including those for whom endovascular treatment was completely unsuccessful, those who have been partially treated, and those who require surgery to deal with a complication of an endovascular treatment. The former group will simply undergo surgery and present no new challenge to the neurosurgeon. However, the latter two groups will require surgical clipping of aneurysms that were previously coiled. This report describes surgical coil removal in a patient with a large carotid bifurcation aneurysm who had undergone coiling, after which the coil mass protruded into the parent artery, obstructing the middle cerebral artery flow.

Compound osteosynthesis in the thoracic spine for treatment of vertebral metastases: technical report

Metastases to vertebrae often cause bone destruction leading to instability and neural compression. Anterior surgical approaches allow tumor resection and direct neural decompression. For patients with a short life expectancy, vertebral body replacement with methyl-methacrylate polymerized in situ can be used for load sharing in the axial plane. Screws hung from the rod into the corpectomy site are incorporated into the acrylic cement. The technique described in this article allows for immediate spinal stabilization and provides a protective environment for the neural elements. All the patients tolerated the procedure well and were able to ambulation without an orthoses.