967 resultados para PEDIATRIC NEUROSURGERY
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Epidural motor cortex stimulation (MCS) has been used for treating patients with neuropathic pain resistant to other therapeutic approaches. Experimental evidence suggests that the motor cortex is also involved in the modulation of normal nociceptive response, but the underlying mechanisms of pain control have not been clarified yet. The aim of this study was to investigate the effects of epidural electrical MCS on the nociceptive threshold of naive rats. Electrodes were placed on epidural motor cortex, over the hind paw area, according to the functional mapping accomplished in this study. Nociceptive threshold and general activity were evaluated under 15-min electrical stimulating sessions. When rats were evaluated by the paw pressure test, MCS induced selective antinociception in the paw contralateral to the stimulated cortex, but no changes were noticed in the ipsilateral paw. When the nociceptive test was repeated 15 min after cessation of electrical stimulation, the nociceptive threshold returned to basal levels. On the other hand, no changes in the nociceptive threshold were observed in rats evaluated by the tail-flick test. Additionally, no behavioral or motor impairment were noticed in the course of stimulation session at the open-field test. Stimulation of posterior parietal or somatosensory cortices did not elicit any changes in the general activity or nociceptive response. Opioid receptors blockade by naloxone abolished the increase in nociceptive threshold induced by MCS. Data shown herein demonstrate that epidural electrical MCS elicits a substantial and selective antinociceptive effect, which is mediated by opioids. (C) 2008 Elsevier B.V. All rights reserved.
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Aims: To investigate whether anterior thalamic nucleus (AN) lesions are protective against spontaneous recurrent seizures in the chronic phase of the pilocarpine model of epilepsy. Methods: Two groups of rats were treated with bilateral AN radiofrequency thalamotomies or sham surgery 2 weeks after pilocarpine-induced status epilepticus. After the lesions, animals were videotaped from the 2nd to the 8th week after status epilepticus (total 180 h). Results: During the 6 weeks of observation, no differences in the frequency of spontaneous seizures were found between animals that had bilateral AN lesions (n = 26; 3.1 +/- 0.6 seizures per animal) and controls (n = 25; 3.0 +/- 0.6 seizures per animal; p = 0.8). Conclusions: We conclude that AN thalamotomies were not effective in reducing the frequency of seizures during the chronic phase of the pilocarpine model of epilepsy. Copyright (C) 2009 S. Karger AG, Basel
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OBJECTIVE: Hypoglossal-facial neurorrhaphy has been widely used for reanimation of paralyzed facial muscles after irreversible proximal injury of the facial nerve. However, complete section of the hypoglossal nerve occasionally results in hemiglossal dysfunction and interferes with swallowing and speech. To reduce this morbidity, a modified technique with partial section of the hypoglossal nerve after mastoid dissection of the facial nerve (HFM) has been used. We report our experience with the HFM technique, retrospectively comparing the outcome with results of the classic hypoglossal-facial neurorrhaphy. METHODS: A retrospective review was performed in 36 patients who underwent hypoglossal-facial neurorrhaphy with the classic (n = 12) or variant technique (n = 24) between 2000 and 2006. Facial Outcome was evaluated with the House-Brackmann grading system, and tongue function was evaluated with a new scale proposed to quantify Postoperative tongue alteration. The results were compared, and age and time between nerve injury and surgery were correlated with the outcome. RESULTS: There was no significant difference between the two techniques concerning facial reanimation. A worse outcome of tongue function, however, was associated with the classic technique (Mann-Whitney U test; P < 0.05). When HFM was used, significant correlations defined by the Spearman test were identified between preoperative delay (p = 0.59; P = 0.002) or age (p = 0.42; P = 0.031) and results of facial reanimation evaluated with the House-Brackmann grading system. CONCLUSION: HFM is as effective as classic hypoglossal-facial neurorrhaphy for facial reanimation, and it has a much lower morbidity related to tongue function. Better results are obtained in younger patients and with a shorter interval between facial nerve injury and surgery.
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OBJECTIVE: The aim of this article is to describe the anatomy of the cavernous sinus and to provide a guide for use when performing surgery in this complex area. Clinical cases are used to illustrate routes to the cavernous sinus and its contents and to demonstrate how the cavernous sinus can be used as a pathway for exposure of deeper structures. METHODS: Thirty cadaveric cavernous sinuses were examined using X3 to X40 magnification after the arteries and veins were injected with colored silicone. Distances between the entrance of the oculomotor and trochlear nerves and the posterior clinoid process were recorded. Stepwise dissections (if the cavernous sinuses, performed to demonstrate the intradural and extradural routes, are accompanied by intraoperative photographs of those approaches. RESULTS: The anatomy of the cavernous sinus is complex because of the high density of critically important neural and vascular structures. Selective cases demonstrate how a detailed knowledge of cavernous sinus anatomy can provide for safer surgery with low morbidity. CONCLUSION: A precise understanding of the bony relationships and neurovascular contents of the cavernous sinus, together with the use of cranial base and microsurgical techniques, has allowed neurosurgeons to approach the cavernous sinus with reduced morbidity and mortality, changing the natural history of selected lesions in this region. Complete resection of cavernous sinus meningiomas has proven to be difficult and, in many cases, impossible without causing significant morbidity. However, surgical reduction of such lesions enhances the chances for success of subsequent therapy.
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Wolcott-Rallison syndrome (WRS, OMIM 226980) is a rare autosomal recessive disorder characterized by permanent neonatal diabetes mellitus, epiphyseal dysplasia, and other multisystemic clinical manifestations. We described two novel mutations in the EIF2AK3 gene in two consanguineous families with WRS from Brazil and Morocco. We have observed in case 1 a homozygous C > T replacement at base pair c.1192 at exon 7, generating a stop codon at position 398 (Gln398Stop). Both of his parents were found to be heterozygous for the mutation. We detected in both parents of case 2, a deceased Moroccan girl, a duplication of base pair c.851A at exon 5 (c.851dupA) leading to a frameshift and a stop codon at position 285 (p.Pro285AlafsX3). Both cases 1 and 2 had neonatal diabetes mellitus, multiple epiphyseal dysplasia, and growth delay, and presented episodes of acute hepatic dysfunction. Case 1 presented central hypothyroidism, developmental delay, and mild mental retardation. Case 2 presented a fatal episode of acute renal failure. The clinical phenotype associated with the syndrome can be variable, but a combination of infancy-onset diabetes mellitus, multiple epiphyseal dysplasia, and hepatic and/or renal dysfunction is the mainstay of diagnosis.
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Objective. We sought to evaluate the effects of immunosuppressant drugs (corticosteroid, cyclosporine [CsA], and tacrolimus [Tac]) on liver regeneration in growing animals submitted to 70% hepatectomy. Materials and Methods. Newborn and weaning rats were submitted to 70% hepatectomy receiving separately methylprednisolone, CsA, or Tac. All animals were sacrificed 24 hours after the procedure. The remnant liver lobes were subjected to histomorphometric analyses with determination of hepatocyte mitotic index. Results., Administration of immunosuppressants did not change the mitotic index of the regenerating liver in newborn animals. In weaning rats, methylprednisolone reduced the mitotic index (P = .01) and Tac caused a greater increase in this rate (P = .001). CsA had no effect on mitotic index. The number of hepatocyte mitoses in newborn animal livers was greater than that in weaning animal livers (P = .001). Conclusion. In situations in which intense, fast processes of liver regeneration are crucial, the advantages of the use of Tac must be considered, such as in pediatric transplant patients.
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The incidence of 21-hydroxylase deficiency (CYP21 D) congenital adrenal hyperplasia (CAH) in Brazil is purportedly one of the highest in the world (1:7,533). However, this information is not based on official data. The aim of this study was to determine the incidence of CYP21 D CAH in the state of Goias, Brazil, based on the 2005 results of government-funded mandatory screening. Of the live births during this period, 92.95% were screened by heel-prick capillary 17 alpha-hydroxyprogesterone (17-OHP). Of these, 82,343 were normal, 28 were at high risk for CAH and 232 at low risk for CAH. Eight cases, all from the high risk group, were confirmed. Eight asymptomatic children at 6-18 months of age still have high 17-OHP levels and await diagnostic definition. Based on the number of confirmed CYP21 D CAH cases among the 82,603 screened, the estimated annual incidence of the disease was 1:10,325, lower than the previously reported rate in Brazil.
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The regeneration and remodeling of the transplanted liver is the result of hepatocyte proliferation and apoptosis (programmed cell death). The purpose of this study was to verify the influence of immunosuppressants on the expression levels of genes: IL-6 (regulator of hepatocyte proliferation), pro-apoptotic (Bak and Bax) and anti-apoptotic (Bcl-Xl and Bcl-2). 36 newborn suckling rats (age 5-7 days, weight 6-10 g) were divided into four groups: hepatectomy, hepatectomy plus methylprednisolone, hepatectomy plus CsA and hepatectomy plus Tac. The same experiments were performed in 24 weaning rats (age 21-23 days, weight 30-50 g). The animals were killed one day after the hepatectomy and the remnant livers were analyzed. The livers of all animals exhibited histological changes of liver regeneration. The immunosuppressants did not promote any alteration on IL-6 gene expression levels. Methylprednisolone and CsA increased the expression levels of Bak gene in newborn rats. However, methylprednisolone and Tac promoted increased expression levels of Bcl-2 in all groups. We hypothesize that these effects explain the efficacy of these drugs on the treatment of acute and chronic liver rejection as the expression of Bcl-2 in cholangiocytes is decreased as a consequence of bile duct lesions.
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Objective: To compare clinical evaluation, electrophysiological investigation and magnetic resonance findings in assessing the severity of idiopathic carpal tunnel syndrome. Patients and methods: Seventy-four patients with idiopathic carpal tunnel syndrome were prospectively recruited. Clinical evaluation included symptoms severity score and two-point discrimination, sensory and motor nerve conduction velocities were determined by electroneuromyography and imaging parameters were obtained after wrist magnetic resonance. The Wilcoxon test was used to define the differences between measurements of median nerve area. The Pearson and Spearman correlation tests were used to determine the relationships between all the measured parameters. Results: Cross-sectional area of median nerve was smaller at hamate level than at radio-ulnar joint and pisiform levels (p < 0.001). With exception of median nerve area at hamate level, there was a lower degree of correlation between MRI parameters and findings obtained by clinical assessments and electrophysiological measurements. The median nerve area at hamate level correlated negatively with duration of symptoms, two-point discrimination, symptoms severity score and positively with sensory nerve conduction velocity (P < 0.01). Conclusion: In patients with idiopathic carpal tunnel syndrome, median nerve area measured by wrist magnetic resonance at hamate level may be considered as a valuable indicator to grading the severity of disease. (c) 2007 Elsevier B.V. All rights reserved.
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Backgound and Aims: Correct gene dosage of SOX3 is critical for the development of the hypothalamo-pituitary axis. Both overdosage of SOX3, as a result of gene duplication, and loss of function resulting from expansion of the first polyalanine (PA) tract are associated with variable degrees of hypopituitarism, with or without mental retardation. The aim of this study was to further investigate the contribution of SOX3 in the etiology of hypopituitarism and the mechanisms involved in the phenotypic variability. Methods: We screened 154 patients with congenital hypopituitarism and an undescended posterior pituitary for mutations in SOX3 and variability in the length of the first PA tract. In addition, 300 patients with variable septooptic dysplasia were screened for variability of the PA tract. Results: We report a novel 18-base pair deletion (p.A243_A248del6, del6PA) in a female patient with hypopituitarism resulting in a 2-fold increase in transcriptional activation in vitro, compared with wild-type SOX3. We also identified a previously reported seven-alanine expansion (p.A240_A241ins7, +7PA) in two male siblings with isolated GH deficiency and a distinct phenotype, in addition to the nonsynonymous variant p.R5Q in an unrelated individual; this appears to have no functional effect on the protein. In contrast to +7PA, del6PA maintained its ability to repress beta-catenin mediated transcription in vitro. Conclusion: This is the first study to report that PA tract deletions associated with hypopituitarism have functional consequences in vitro, possibly due to increased activation of SOX3 target genes. In addition, we have expanded the phenotypic spectrum associated with PA tract expansion (+7PA) mutations to include panhypopituitarism or isolated GH deficiency, with or without mental retardation. (J Clin Endocrinol Metab 96: E685-E690, 2011)
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OBJECTIVE: To describe the microsurgical anatomy, branches, and anatomic relationships of the posterior cerebral artery (PCA) represented in three-dimensional images. METHODS: Seventy hemispheres of 35 brain specimens were studied. They were previously injected with red silicone and fixed in 10% formalin for at least 40 days. Four of the studied specimens were frozen at -10 degrees to -15 degrees C for 14 days, and additional dissection was done with the Klingler`s fiber dissection technique at x6 to x40 magnification. Each segment of the artery was measured and photographed to obtain three-dimensional stereoscopic images. RESULTS: The PCA origin was in the interpeduncular cistern at the pontomesencephalic junction level in 23 specimens (65.7%). The PCA was divided into four segments: P1 extends from the PCA origin to its junction with the posterior communicating artery with an average length of 7.7 mm; P2 was divided into an anterior and posterior segment. The P2A segment begins at the posterior communicating artery and ends at the most lateral aspect of the cerebral peduncle, with an average length of 23.6 mm, and the P2P segment extends from the most lateral aspect of the cerebral peduncle to the posterior edge of the lateral surface of the midbrain, with an average length of 16.4 mm; P3 extends from the posterior edge of the lateral surface of the midbrain and ends at the origin of the parieto-occipital sulcus along the calcarine fissure, with an average length of 19.8 mm; and the P4 segment corresponds to the parts of the PCA that run along or inside both the parieto-occipital sulcus and the distal part of the calcarine fissure. CONCLUSIONS: To standardize the neurosurgical practice and knowledge, surgical anatomic classifications should be used uniformly and further modified according to the neurosurgical experience gathered. The PCA classification proposed intends to correlate its anatomic segments with their required microneurosurgical approaches.
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Background. Many resource-limited countries rely on clinical and immunological monitoring without routine virological monitoring for human immunodeficiency virus (HIV)-infected children receiving highly active antiretroviral therapy (HAART). We assessed whether HIV load had independent predictive value in the presence of immunological and clinical data for the occurrence of new World Health Organization (WHO) stage 3 or 4 events (hereafter, WHO events) among HIV-infected children receiving HAART in Latin America. Methods. The NISDI (Eunice Kennedy Shriver National Institute of Child Health and Human Development International Site Development Initiative) Pediatric Protocol is an observational cohort study designed to describe HIV-related outcomes among infected children. Eligibility criteria for this analysis included perinatal infection, age ! 15 years, and continuous HAART for >= 6 months. Cox proportional hazards modeling was used to assess time to new WHO events as a function of immunological status, viral load, hemoglobin level, and potential confounding variables; laboratory tests repeated during the study were treated as time-varying predictors. Results. The mean duration of follow-up was 2.5 years; new WHO events occurred in 92 (15.8%) of 584 children. In proportional hazards modeling, most recent viral load 15000 copies/mL was associated with a nearly doubled risk of developing a WHO event (adjusted hazard ratio, 1.81; 95% confidence interval, 1.05-3.11; P = 033), even after adjustment for immunological status defined on the basis of CD4 T lymphocyte value, hemoglobin level, age, and body mass index. Conclusions. Routine virological monitoring using the WHO virological failure threshold of 5000 copies/mL adds independent predictive value to immunological and clinical assessments for identification of children receiving HAART who are at risk for significant HIV-related illness. To provide optimal care, periodic virological monitoring should be considered for all settings that provide HAART to children.
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Objective. To assess health-related quality of life (HRQOL) in abatacept-treated children/adolescents with juvenile idiopathic arthritis (JIA). Methods. In this phase III, double-blind, placebo-controlled trial, subjects with active polyarticular course JIA and an inadequate response/intolerance to >= 1 disease-modifying antirheumatic drug (including biologics) received abatacept 10 mg/kg plus methotrexate (MTX) during the 4-month open-label period (period A). Subjects achieving the American College of Rheumatology Pediatric 30 criteria for improvement (defined ""responders"") were randomized to abatacept or placebo (plus MTX) in the 6-month double-blind withdrawal period (period B). HRQOL assessments included 15 Child Health Questionnaire (CHQ) health concepts plus the physical (PhS) and psychosocial summary scores (PsS), pain (100-mm visual analog scale), the Children`s Sleep Habits Questionnaire, and a daily activity participation questionnaire. Results. A total of 190 subjects from period A and 122 from period B were eligible for analysis. In period A, there were substantial improvements across all of the CHQ domains (greatest improvement was in pain/discomfort) and the PhS (8.3 units) and PsS (4.3 units) with abatacept. At the end of period B, abatacept-treated subjects had greater improvements versus placebo in all domains (except behavior) and both summary scores. Similar improvement patterns were seen with pain and sleep. For participation in daily activities, an additional 2.6 school days/month and 2.3 parents` usual activity days/month were gained in period A responders with abatacept, and further gains were made in period B (1.9 versus 0.9 [P = 0.033] and 0.2 versus -1.3 [P = 0.109] school days/month and parents` usual activity days/month, respectively, in abatacept-versus placebo-treated subjects). Conclusion. Improvements in HRQOL were observed with abatacept, providing real-life tangible benefits to children with JIA and their parents/caregivers.
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Objective: The aim of this paper is to study the respiratory muscle strength by evaluating the maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP) and lung volume before and 3 and 6 months after adenotonsillectomy. This is an interventional, before and after trial. It was set at the Department of Otolaryngology. University of Sao Paulo, School of Medicine. We included 29 children (6-13 years old), both genders, consecutively recruited from the waiting list for adenotonsillectomy. Children were submitted to maximal inspiratory pressures (MIP), maximal expiratory pressure (MEP) evaluation using an analog manovacuometer, lung volume, using incentive expirotometer and thoracic and abdominal perimeter using a centimeter tape. Children were evaluated in 3 different moments: 1 week before and 3 and 6 months after surgery. Results: MIP improved significantly 3 months (p < 0.001) after adenotonsillectomy and MEP did not change (p = 1). There were increases in lung volume (p = 000), chest (p = 0.017) and abdominal perimeter (p = 0.05). Six months after surgery, all parameters improved. MIP (p = 0), MEP (p = 0), lung volume (p = 0.02), chest (p = 0.034) and abdominal perimeter (p = 0.23). Conclusion: This study suggests that there was an improvement in respiratory muscular strength, once there was a significant improvement in maximal inspiratory pressure, lung volume and other parameters after adenotonsillectomy. (C) 2010 Elsevier Ireland Ltd. All rights reserved.
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Background/Purpose: Central venous catheterization is among the most common procedures performed by pediatric surgeons. Significant morbidity and even mortality can ensue from the widespread approach to the deep veins of the neck and femoral region. The external jugular vein (EJV) is a low-morbidity alternative for percutaneous catheterization in children, but it has yielded a low success rate in previous reports The authors show an improved success rate with this option. Methods: We performed an analysis of 33 patients` charts in which central venous catheterization using Seldinger technique through the EJV was attempted in 2005. Age, diagnosis, maneuvers used for success, fluoroscopy usefulness, and types of inserted catheters were evaluated. Results: The procedure was successful in 26 (78.8%) patients without complications. Diagnosis was neoplasia in almost half of the patients (42%). In half of the successful cases, body maneuvers were used, namely, twisting the head of the patient to the side of the vein and stretching the ipsilateral arm and shoulder. All but one procedure were completed under fluoroscopic guidance. In 6 (23%) patients, a long-term catheter was inserted. Conclusions: The EJV is an excellent option for central venous catheterization in children. The execution of simple maneuvers along with fluoroscopic assistance might allow for an improved success rate not only for short-term but also for long-term catheter insertion. (C) 2008 Elsevier Inc. All rights reserved.