Estudo de traumatismo craniencefálico experimental em ratos com aparelho de impacto cortical controlado

Objetivo: Desenvolver um modelo de impacto cortical controlado (pneumático) para traumatismo craniencefálico experimental em ratos, sem exposição do encéfalo. Métodos: Com base em relatos da literatura, foi construído um modelo de impacto cortical pneumático, sendo testado em 30 ratos, com análise histopatológica de todos os animais. Resultados: Os resultados da análise histopatológica baseada na contagem de neurônios lesados por campo demonstraram a eficiência do modelo na produção de lesão traumática. Conclusão: Esse modelo para reprodução experimental de traumatismo craniencefálico poderá oferecer, por meio de metodologia reproduzível e clinicamente relevante, situações patológicas causadas por forças mecânicas em lesões traumáticas cranianas.

Prognostic Value of Intraventricular Bleeding in Spontaneous Intraparenchymal Cerebral Hemorrhage of Small Volume: A Prospective Cohort Study

BACKGROUND:

The literature is controversial on whether intraventricular bleeding has a negative impact on the prognosis of spontaneous intracerebral hemorrhage. Nevertheless, an association between intraventricular bleeding and spontaneous intracerebral hemorrhage volumes has been consistently reported.

OBJECTIVE:

To evaluate the prognostic value of intraventricular bleeding in deep intraparenchymal hypertensive spontaneous hemorrhage with a bleeding volume <30 cm3.

METHODS:

Of the 320 patients initially evaluated, 33 met the inclusion criteria and were enrolled in this prospective study. The volume of intraparenchymal hemorrhage was calculated by brain computed tomography (CT) image analysis, and the volume of intraventricular bleeding was calculated by the LeRoux scale. Clinical data, including neurological complications, were collected daily during hospitalization. Neurological outcome was evaluated 30 days after the event by using the Glasgow outcome scale. Patients were assigned to 1 of 3 groups according to intraventricular bleeding: Control, no intraventricular bleeding; LR 1, intraventricular bleeding with LeRoux scale scores of 1 to 8; or LR 2, intraventricular bleeding with LeRoux scale scores >8.

RESULTS:

There were no significant differences among groups concerning age, mean blood pressure, and time from onset to brain CT scan. Patients with greater intraventricular bleeding presented lower initial Glasgow coma scale scores, increased ventricular index and width of temporal horns, increased number of clinical and neurological complications, and longer hospitalization. Furthermore, their relative risk for unfavorable clinical outcome was 1.9 (95% confidence interval 1.25-2.49).

CONCLUSION:

Intraventricular bleeding with a LeRoux scale score >8 appears to have a negative effect on deep spontaneous intraparenchymal cerebral hemorrhage of small volume.

Evaluation of arthrodesis and cervical alignment in the surgical results of cervical discectomy using polymethylmetacrylate

BACKGROUND AND OBJECTIVES

Surgical treatment of cervical radiculopathy with or without myelopathy is a controversy issue, although anterior discectomy is the most common form of treatment.

METHOD

We present the evaluation of the arthrodesis' rate and cervical alignment in 48 patients with cervical degenerative disease (CDD) submitted to anterior cervical discectomy with interposition of polymethylmetacrylate (PMMA). Odom and Nürick scales were used to evaluation of functional status before and after surgery. Cervical spine X-rays were used to access arthrodesis and alignment, at least 2 years after the procedure.

RESULTS

Excellent and good results (Odom I and II) were obtained in 91% of the patients with radiculopathy and in 69% of those with myelopathy. Using the chi square test of independence (1% of significance), there was no association between excellent and good clinical results with the presence of arthrodesis verified in cervical X-rays. The presence of cervical alignment had association with good results, whereas the misalignment was associated with unfavorable outcomes. Two patients died: one cervical hematoma and other from graft migration with cord compression.

CONCLUSIONS

Cervical alignment was more important than fusion to achieve good surgical results in CDD.

Regional cooling for reducing brain temperature and intracranial pressure

OBJECTIVE

To evaluate the effectiveness of regional cooling for reducing brain temperature (BrTe) and intracranial pressure (ICP) in patients where conventional clinical treatment has failed.

METHOD

Regional cooling was carried out using ice bags covering the area of the craniectomy (regional method) in 23 patients. The BrTe and ICP were determined using a fiber optic sensor. Thirteen patients (56.52%) were female. The ages ranged from 16 to 83 years (mean of 48.9). The mean APACHE II score was 25 points (11-35). The patients were submitted, on mean, to 61.7 hours (20-96) of regional cooling.

RESULTS

There was a significant reduction in mean BrTe (p<0.0001--from 37.1 degrees C to 35.2 degrees C) and mean ICP (p=0.0001--from 28 mmHg to 13 mmHg).

CONCLUSION

Our results suggest that mild brain hypothermia induced by regional cooling was effective in the control of ICP in patients who had previously undergone decompressive craniectomy.

Transitional lumbosacral vertebrae and low back pain: diagnostic pitfalls and management of Bertolotti's syndrome

OBJECTIVE

Bertolotti's syndrome is a spine disorder characterized by the occurrence of a congenital lumbar transverse mega-apophysis in a transitional vertebral body that usually articulates with the sacrum or the iliac bone. It has been considered a possible cause of low back pain.

METHOD

We analyzed the cases of Bertolotti's syndrome that failed clinical treatment and reviewed the literature concerning this subject.

RESULTS

Five patients in our series had severe low back pain due to the neo-articulation and two of them were successfully submitted to surgical resection of the transverse mega-apophysis. Taking into account the clinical and surgical experience acquired with these cases, we propose a diagnostic-therapeutic algorithm.

CONCLUSION

There is still no consensus about the most appropriate therapy for Bertolotti's syndrome. In patients in whom the mega-apophysis itself may be the source of back pain, surgical resection may be a safe and effective procedure.

Parallel transverse-sigmoid sinus harboring dural arteriovenous malformation. How to differentiate the pathological and normal sinus in order to treat and preserve patency and function

An unusual case of dural arteriovenous malformation (DAVM) harboring a parallel transverse-sigmoid sinus (TSS) is presented. The patient had a 2-year history of left-sided pulsatile tinnitus in the left ear refractory to medical management. Angiography demonstrated a DAVM involving the left TSS. Super-selective transvenous dural sinus occlusion of the DAVM situated at the pathological compartment of the TSS provided cure. We were able to spare the normal compartment providing anatomical venous drainage from this system.

Selective hypothermia: an experimental study on traumatic brain injury in rats

OBJECTIVE: To evaluate the efficiency of selective hypothermia in the treatment of the traumatic brain injury in rats. METHOD: After the trauma produced for the model of cortical impact, a small craniectomy in the right frontoparietal region was carried through; after the procedure the animals had been divided in two groups of 15 each. Group A, without treatment with hypothermia (control group) and group B, treated with selective hypothermia for a period to 5 to 6 hours. After this time all the animals were sacrificed, their brains had been removed and histopathological analysis was carried through. RESULTS: Comparison between both groups was done using the counting of neurons injured for field. Counting in the control group n=15 had an average of 70.80 neurons injured for field against an average of 21.33 neurons injured for field in group B (submitted to the treatment with hypothermia), with n=15 also. The difference was statiscally significant. CONCLUSION: Based in the quantification of the neurons injured for field, the effectiveness of the treatment with selective hypothermia was demonstrated.

Comparison between posterior lumbar fusion with pedicle screws and posterior lumbar interbody fusion with pedicle screws in adult spondylolisthesis

The purpose of this study was to compare patients with lumbar spondylolisthesis submitted to two different surgical approaches, and evaluate the results and outcomes in both groups. In a two-year period, 60 adult patients with lumbar spondylolisthesis, both isthmic and degenerative, were submitted to surgery at the Biocor Institute, Brazil. All patients were operated on by the same surgeon (FLRD) in a single institution, and the results were analyzed prospectively. Group I comprised the first 30 consecutive patients that were submitted to a posterior lumbar spinal fusion with pedicle screws (PLF). Group II comprised the last 30 consecutive patients submitted to a posterior lumbar interbody fusion procedure (PLIF) with pedicle screws. All patients underwent foraminotomy for nerve root decompression. Clinical evaluation was carried out using the Prolo Economic and Functional Scale and the Rolland-Morris and the Oswestry questionnaire. Mean age was 52.4 for Group I (PLF), and 47.6 for Group II (PLIF). The mean follow-up was 3.2 years. Both surgical procedures were effective. The PLIF with pedicle screws group presented better clinical outcomes. Group I presented more complications when compared with Group II. Group II presented better results as indicated in the Prolo Economic and Functional Scale.

[Inhibition of peridural fibrosis after laminectomy using biological sheet in rat model]

The prevention of fibrosis after lumbar and thoracic laminectomies by avoiding herniation of muscular tissue was studied using Wistar-EPM rats with a biological membrane made of decorticated bone of bovine material. The rats were sacrificed after eight, sixteen and twenty four weeks and the material was sent to anatomopathological study. This membrane proved to be biocompatible and its efficacy was seen by allowing formation of bone and preventing muscular tissue invasion of the epidural space and avoiding adherences.

[Post-traumatic temporal lobe lesions: surgical decision making based on CT scan findings]

BACKGROUND

The indication for surgical treatment of post-traumatic parenchymal lesions in the temporal lobe remains controversial.

OBJECTIVE

We reviewed the tomographic parameters that might be useful in making surgical decisions.

METHOD

The tomographic findings of 69 patients were analyzed in a retrospective manner considering: 1) the effects of the lesion (classified into 4 variables: midline shift, status of the cisterns, status of the ventricles, and status of the peripheral sulci); and 2) the characteristics of the lesion: anterior, posterior or anteroposterior location (as defined by a coronal plane tangent to the cerebral peduncles) and its mediolateral diameter.

RESULTS

When none or only one of the aforementioned variables was found to be altered, conservative treatment was instituted (22 out of 38 lesions). In two cases, all four variables were altered, and surgery was performed in both. Anterior, anteroposterior and posterior lesions measuring 21, 23 and 28 mm in diameter, respectively, had a 50% chance of surgical removal.

CONCLUSION

Amongst the patients who underwent surgical intervention, the more anterior the location of the temporal lobe lesion, the smaller the diameter.

Pathophysiology of posttraumatic temporal lobe lesions

BACKGROUND

Posttraumatic parenchymal lesions in the temporal lobe may cause neurologic deterioration. An analysis was made of the natural evolution of this type of lesion, with emphasis on its 2 components: hemorrhage (hyperdense on computed tomography [CT]), and edema and necrosis (hypodense on CT). The clinical repercussions were studied, and the factors that might influence such evolution were investigated.

METHODS

Forty head-injured patients with temporal lobe lesions admitted within 12 hours after the injury were selected in a prospective manner. Computed tomography scans were systematically repeated within the first 36 hours and at 7 and 30 days postinjury. Factors such as interval between injury and the first CT scan, age, velocity of the injury, alcohol consumption, coagulation abnormalities, and the presence of decompressive measures were compared between the patients that had enlargement of the hemorrhage and those who did not. Increase in hypodensity was compared with that in hyperdensity.

RESULTS

Fourteen patients showed enlargement of the hemorrhage. In all cases but one, the interval between injury and admission was 3 hours or less. Other factors had no statistical significance as predisposing causes for such enlargement. In approximately half of the cases, the hypodense component increased in the first 36 hours and continued increasing until the end of the first week. Evolution of the hypodense component was not dependent on behavior of the hemorrhage, surgical drainage, or diameter of the hemorrhagic lesion.

CONCLUSIONS

The natural evolution of the hyperdense component of temporal lobe lesions was to enlarge within the first few hours after the injury. Edema and necrosis developed more slowly and with no significant clinical manifestations.

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.

Chordoid meningioma: report of two cases

We present CT scan, MRI and histopathologic findings of two patients harboring a rare type of meningioma. In the first case, a 52 year-old male patient, a large parasellar mass invading the cavernous sinus, infiltrating the infratemporal fossa and extending as low as C2 was founded. The tumor was isointense on T1, enhanced strongly with gadolinium injection, and was hyperintense on T2. In the second case, a 19-year-old male patient, a large high density temporal right mass was disclosed by CT scan. Both patients were taken to surgery. In the first case, only a partial removal was possible to be accomplished due to a severe intra operative bleeding. In the second case, the tumor was totally removed. Both showed characteristic pathologic findings of a meningioma resembling a chordoma. Meningioma is a relatively common intracranial tumor, occurring most frequently in adults, showing a wide variety of growth patterns. We described a pattern that had a peculiar chordoma-like appearance. The pathological findings and the differential diagnosis from chordoma are discussed.

Malignant transformation of pleomorphic xanthoastrocytoma: case report

We report a case of a pleomorphic xantoastrocytoma which manifested itself as a cystic isodense lesion in the right fronto-temporal lobe in a 26 year-old woman. It appeared as a soft yellow tumor with cystic cavities on surgery. Five months after this surgery, the patient was submitted to a new operation, which revealed a friable tumor, easily differentiated from the normal parenchyma, with cystic components. The histopathological examination demonstrated pleomorphic xanthoastrocytoma with malignant transformation. Histologically, the tumor at first procedure was composed of pleomorphic astrocytes with multinucleated and foamy cells. A rare case of malignant transformation in pleomorphic xanthoastrocytoma is presented, discussed and illustrated in this paper.

[Management of odontoid fractures using anterior screw fixation: analysis of 15 cases]

A retrospective analysis of the results of 15 patients with odontoid fractures type II P and II N, according to Roy-Camille's classification is presented. They were operated on by an anterior approach and direct fixation of the odontoid process through a screw. There were 13 men and 2 women, the age ranging from 14 to 74 years. The follow up period was from 6 to 36 months (mean 20 months). There was only one complication related to the surgical technique: one screw was misplaced and it was necessary another surgery to replace it. There were no deaths in this series. There were no screw breakdown and the fusion rate was 94%. We propose, based on this study, that the classification of Roy-Camille for odontoid fractures should be always used, since it proposes one surgical approach for each type of fracture. The results of this series show that this technique is useful and has advantages over another modalities of treatment. The correct diagnosis of the type of fracture and an appropriate selection of patients are the main elements to achieve good results.

Tratamento cirúrgico das fraturas do odontóide tipo II com parafuso anterior: análise de 15 casos

Apresentamos estudo retrospectivo dos resultados de 15 pacientes consecutivos, com fratura do odontóide tipo II P (fratura com traço oblíquo e deslocamento posterior) e II N (fratura com traço horizontal na base do odontóide), segundo a classificação de Roy-Camille , que foram submetidos a fixação anterior direta do odontóide com parafuso. A série é composta por 13 homens e 2 mulheres, com idade variando entre 14 a 74 anos e período de acompanhamento de 6 a 36 meses (média 20 meses). Tivemos apenas uma complicação relacionada com a técnica cirúrgica: um parafuso mal posicionado necessitando de uma reoperação para ser reposicionado. Não houve óbito. Não houve saída nem quebra de parafuso. Obteve-se 94% de fusão óssea. Propomos que seja utilizada a classificação de Roy-Camille na seleção dos casos cirúrgicos de fraturas do odontóide, pois ela fornece uma abordagem cirúrgica específica para cada tipo de fratura.

Regional mild hypothermia in the protection of the ischemic brain

Objective: To demonstrate that mild hypothermia can be a protective element when an ischemic onset occurs in rabbit brains. Methods: A rabbit model of focal ischemia was used to test the protection provided by mild hypothermia regionally produced by means of the placement of ice bag on the scalp of a hemicranium which has had previously its bone removed. Twenty New Zealand White rabbits were divided into two groups as follows: (A) a control group where an ischemic lesion was produced by coagulation of the middle cerebral artery and (B) a brain protected group where mild hypothermia was provided during 80 to 100 minutes after the same ischemic lesion. The brains slices were stained with 2,3,5-Triphenyletrazolium (TTC). The sections were photographed with a digital camera and the infarct volume was measured through a computer program. Results: The average of infarct volume was 70.53 mm³ in the control group. In the protected group, the average of infarct volume was 41,30 mm³ only in five animals. Five animals of this group did not demonstrate macroscopically and microscopically infarct area. Conclusions: We concluded that mild hypothermia regionally produced may protect ischemic brains of rabbits.

Cavernoma gigante: relato de dois casos

Angiomas cavernosos ou hemangiomas ou ainda cavernomas são malformações do sistema nervoso central, classificadas como lesões cerebrais vasculares ocultas, frequentemente assintomáticas, sendo relativamente raras. Definidas histologicamente como massas compactas cavernosas ou canais sinusoidais de vários tamanhos, com paredes finas no interior do parênquima cerebral e sem intervenção do tecido glial. Podem ocorrer em qualquer faixa etária inclusive em neonatos. Na maioria das vezes são lesões de tamanho reduzido, localizadas no interior do parênquima encefálico. Angiograficamente não mostram alterações com circulação patológica, podendo mesmo não ser diagnosticados pela tomografia, sendo o exame ideal para o seu diagnóstico a ressonância magnética de crânio. Os cavernomas são lesões histologicamente benignas mas, dependendo de sua localização, podem trazer grandes transtornos neurológicos e ser irressecáveis. A exérese cirúrgica da lesão é o tratamento de escolha se a lesão for única e em localização favorável e estiver desencadeando sintomatologia neurológica prejudicial ao paciente. Apresentamos dois casos de cavernomas gigantes que apresentaram boa evolução após ressecção cirúrgica completa. Descritos como gigantes, foram encontrados apenas três casos individuais na literatura .

[Giant cavernous angioma: report of two cases]

Cavernous angiomas or haemangiomas or yet cavernomas are malformations of the central nervous system classified as occult vascular brain lesions. These rare lesions are clinically silent. They are defined by the presence of abnormally large vascular cavities or sinusoids channels of variable size, with sharp walls, located inside but not invading the brain parenchyma. They can occur at any age, including the neonatal period. Most of the small lesions are located inside the brain parenchyma. No abnormal circulation can be demonstrated in angiography and CT scan can be helpful for diagnosis only in rare occasions. Magnetic resonance is the best exam to demonstrate the lesion. Despite the benign character some lesions may cause neurologic dysfunction when their removal may be difficult. Complete extirpation is the best treatment if the lesion is favorable located and is causing neurological dysfunction. Two cases of giant cavernomas with good outcome after total removal are present. Only three cases of giant cavernomas were reported in the literature.

[TSH pituitary adenoma: case report]

We describe a rare case of thyroid-stimulating hormone-secreting pituitary adenoma in a patient with a clinical picture of hyperthyroidism, that developed bitemporal hemianopsia after four years of a known thyroid dysfunction. CT scan showed a pituitary tumor considered grade 2 and stage C according to Hardy-Vezina and Wilson. Treatment was surgical, initially by a transsphenoidal approach, in which only a biopsy was possible. The patient was then submitted to an orbital-pterional craniotomy with sub-total resection of the tumor. Complementary treatment was indicated with radiotherapy.

[Actinomycosis of the central nervous system: a rare complication of cervicofacial actinomycosis]

Central nervous system actinomycosis is a rare but treatable chronic suppurative bacterial infection. The case of a young immunocompetent male with actinomycosis of the CNS is presented. The abscess originated from a primary cervico-facial infection and was located in the left parasellar region. After excision of the mass, that showed Actinomyces colonies, the patient was treated with intravenous Penicillin for 42 days followed by oral administration of the drug for 30 days. After surgery the patient was left with mild sequelae that had improved by the last follow-up, 7 months later. A new CT scan at that time revealed no residual disease or recurrence. The early diagnosis of cerebral actinomycosis relies essentially on a clinical suspicion. Hence it is imperative to be aware of the natural history of this infection and its various modes of presentation.