Comparison of the effectiveness of ceftobiprole and vancomycin in a rabbit model of methicillin-resistant Staphylococcus aureus induced meningitis.

INTRODUCTION: Nosocomial meningitis may occur after procedures affecting the central nervous system or following traumatic injury. The causative infectious organism is commonly Staphylococcus aureus, a gram-positive bacterium. The aim of the present study was to compare the effectiveness of two antibacterial agents, ceftobiprole and vancomycin in an animal model of methicillin-resistant Staphylococcus aureus (MRSA) meningitis. METHOD: The strain of MRSA used was ATCC 43300. The animals were divided into three groups and infected intracisternally with MRSA. Controls received no antibiotherapy while the ceftobiprole group received 25 mg/kg and the vancomycin group received 20 mg/kg intravenously. Blood and cerebrospinal fluid (CSF) samples were collected at three time points. All animals were euthanased at 73 hours after start of treatment. RESULTS: There was a significant difference (p<0.05) between both treatment groups and the control animals at 24 hours (drug trough) and 73 hours (one hour after third dose) after start of treatment in terms of CSF bacterial levels. At 73 hours there was a significant difference in survival between the control group and the two treatment groups but no difference between the treated animal survival rates. CONCLUSION: In conclusion, intravenous treatment with ceftobiprole and vancomycin appears to be equally effective in a rabbit model of MRSA meningitis.

Dry-field maneuver for controlling the massive intraventricular bleeding during neuroendoscopic procedures.

PURPOSE: Massive hemorrhages pose a significant problem in intraventricular endoscopic surgeries. These hemorrhages have the potential to cause mortality and morbidity, particularly in excisional surgeries. Often, the bleeding can be controlled only by cauterization and liquid irrigation, due to the incongruity of the use of antihemorrhagic agents in the fluid. The final option to stop the massive bleeding is the dry-field maneuver. In this study, the effects and clinical results of the dry-field maneuver in bleeding control of a massive bleeding were investigated. METHODS: Dry-field maneuver was retrospectively studied in a patient population that had massive bleeding during intraventricular endoscopic procedures. RESULTS: Dry-field maneuver was used in seven patients. Four of these patients underwent some excisional surgery. The other two patients were operated for an endoscopic third ventriculostomy and one for intraventricular hemorrhage evacuation. It was observed that the hemorrhage in patients stopped rapidly after the dry-field maneuver. Moreover, there was no need for an antihemorrhagic material. CONCLUSION: Dry-field maneuver is an option for providing hemostasis, particularly, for a massive hemorrhage. It also has the potential to be used in elective surgeries because it improves the visual quality.

Ictal urinary urge: localization and lateralization value in a pediatric case.

BACKGROUND: Ictal urinary urge is a rare autonomic symptom usually lateralizing to the non-dominant hemisphere and localizing to the temporal lobe. CASE REPORT: A 12-year-old boy was referred with desire to void and contraction of the left arm. The history of the case revealed tickling and an unpleasant rising feeling in the stomach and sense of fear lasting for 1 year. He had been evaluated and treated several times with the diagnosis of gastroesophageal reflux and cystitis. His cranial MRI displayed an intra-axial mass formation on the right temporal lobe. Pathological findings were consistent with a low-grade glial mass. CONCLUSION: Ictal urinary urge has a considerable value both for localization and lateralization of seizures.

Two-stage approach in the management of thoracic neuroenteric cyst with spinal extension: thoracoscopic excision following dorsal laminectomy.

BACKGROUND: Neuroenteric cysts (NC) are rare pathologies and localized generally in posterior mediastinum or abdomen where they may extend to spinal canal through a vertebral defect. Isolated spinal lesions require dorsal/ventral laminectomy and thoracic ones thoracotomy or thoracoscopy. Posterolateral approach via thoracotomy is generally performed for lesions with both thoracic and spinal components. Minimal invasive excision of a thoracic NC with spinal extension in an infant is presented herein. CASE REPORT: A term female newborn with an antenatal (26th week) diagnosis of congenital diaphragmatic hernia (CDH) was admitted. On physical examination, she was normal except mild dyspnea and CDH were excluded on radiogram. Left parenchymal opacity necessitated thorax tomography that revealed lobulated cystic lesion (6 × 3.5 × 4.5 cm) in posterior mediastinum. MRI showed intraspinal extension of the lesion through a hemivertebrae (6th). Two-stage procedure was planned for suspected neuroenteric cyst. First, intraspinal component was excised with dorsal laminectomy and the connection was closed. Then, the thoracic component was excised thoracoscopically. Histopathological evaluation confirmed the diagnosis. Total parenteral nutrition and high dose somatostatin analog was needed due to transient left chylothorax on postoperative course. She was well and symptom-free in postoperative period. CONCLUSION: Neuroenteric cysts may lead to misdiagnoses in antenatal period. MRI is critical to show spinal and vertebral pathologies in suspected cases. Thoracoscopy may safely be performed for thoracic lesions with spinal extension in two-stage approach following closure of the connection and excision of the spinal component.

The identification of risk factors and outcomes of cerebrospinal fluid shunt infections caused by carbapenem-resistant gram-negative bacteria in children: a retrospective cohort.

OBJECTIVE: Cerebrospinal fluid (CSF) shunt infections caused by gram-negative bacteria are difficult to treat given the limited treatment options and the emergence of carbapenem-resistant (CR) strains. This study aimed to evaluate the demographic and clinical characteristics of children with CSF shunt and external ventricular drain (EVD) infections caused by gram-negative bacteria, to identify the risk factors for acquiring CR CSF shunt infections, and to report on the clinical outcomes of these infections. METHODS: A retrospective cohort study was designed to evaluate pediatric patients with CSF shunt and EVD infections caused by gram-negative bacteria between January 2013 and February 2023. RESULTS: A total of 64 episodes in 50 patients were evaluated. There were 45 (70.3%) CSF shunt infections and 19 (29.7%) EVD infections. The median (range) ages were 1.4 years (9 months-17.5 years) for CSF shunt infection patients and 4.2 years (1 month-17 years) for EVD infection patients. The most common isolated gram-negative bacteria species in CSF shunt infections were Pseudomonas spp. (12, 26.7%), followed by Escherichia coli (11, 24.4%), Klebsiella pneumoniae (9, 20%), and Enterobacter cloacae (5, 11.1%). In EVD infections, the most common isolated gram-negative bacteria species were Acinetobacter spp. (6, 31.6%), followed by Pseudomonas spp. (4, 21.1%) and E. coli (3, 15.8%). The carbapenem resistance rate was 26.3% (n = 5) in EVD infections and 26.2% (n = 11) in CSF shunt infections. When risk factors for carbapenem resistance were evaluated for CSF shunt infections, prior carbapenem treatment and a prolonged hospital stay > 7 days were risk factors for the CR group (p = 0.032 and p = 0.042, respectively). In definitive treatment, colistin was statistically more commonly used in the CR group (p = 0.049). When outcomes were evaluated, the 30-day mortality rate (18.2% vs 0%) was higher in the CR group, without a significant difference (p = 0.064). CONCLUSIONS: A prolonged hospital stay > 7 days and prior carbapenem exposure within 30 days were associated with CR shunt infections caused by gram-negative bacteria.

Daptomycin versus vancomycin in treatment of methicillin-resistant Staphylococcus aureus meningitis in an experimental rabbit model.

In this study, we aimed to compare the antibacterial activities of daptomycin and vancomycin in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) meningitis (induced by MRSA strain ATCC 43300) in an experimental rabbit meningitis model. After an 8-h period of treatment, bacterial counts decreased significantly in both treatment groups compared to the control group (P < 0.05). However, there was no statistically significant difference between treatment groups. Our results suggest that the antibacterial activity of daptomycin is similar to vancomycin for treatment in the experimental MRSA meningitis model in rabbits.

Vancomycin versus linezolid in the treatment of methicillin-resistant Staphylococcus aureus meningitis in an experimental rabbit model.

BACKGROUND: The aim of this study was to compare the antibacterial efficacy of vancomycin and linezolid in a rabbit model of methicillin-resistant Staphylococcus aureus (MRSA) meningitis. MATERIAL/METHODS: Meningitis was induced by intracisternal inoculation of ATCC 43300 strain. After 16 h incubation time and development of meningitis, the vancomycin group received vancomycin 20 mg/kg every 12 h. The linezolid-10 and linezolid-20 groups received linezolid in 10 and 20 mg/kg dosages every 12 h, respectively. The control group did not receive any antibiotics. Cerebrospinal fluid bacterial counts were measured at the end of 16-h incubation time and at the end of 24-h treatment. RESULTS: Bacterial counts were similar in all groups at 16 h. At the end of treatment the decrease in bacterial counts in the vancomycin group was approximately 2 logs higher than the linezolid-20 group (p>0.05) and approximately 4 logs higher than in the linezolid-10 group (p: 0.037) (Vancomycin group: -2.860 ± 4.495 versus Linezolid-20: -0.724 ± 4.360, versus Linezolid-10: 1.39 ± 3.37). Full or partial bacteriological response was higher in vancomycin versus linezolid-10 (p: 0.01), but not vancomycin versus linezolid-20 or linezolid-10 versus-linezolid-20 groups. CONCLUSIONS: Our results suggest that linezolid is not statistically inferior to vancomycin in the treatment of MRSA meningitis in an experimental rabbit model in 20 mg/kg q12 h dosage; however, it is inferior in 10 mg/kg q12 h dosage. Additional data should gathered to confirm these findings in advance of clinical trials to assess efficacy in humans.

Fenestration methods for Sylvian arachnoid cysts--endoscopy or microsurgery.

INTRODUCTION: Two different approaches to fenestration, endoscopic and microsurgical, are in use for Sylvian arachnoid cysts (SACs), the most frequent among intracranial arachnoid cysts. We presented the clinical data and compared our results, with regard to technique and clinical success, with either microsurgical or neuroendoscopic fenestration of SACs. MATERIALS AND METHODS: Twenty-nine patients who subjected to cysto-cisternostomy by the same team, using either of the two methods, were studied retrospectively. RESULTS: Thirteen patients underwent microsurgery, and 16 had endoscopic cysto-cisternostomy. No reoperation was needed in either of these groups, i.e., full clinical and radiological success was achieved in both. The complication rate was 23% in the microsurgery patients and 47% in the endoscopic surgery group, with no statistically significant difference. CONCLUSIONS: No relevant differences between the two methods are seen either in the published data or in our results. Adding our results to the published data, both techniques were reviewed in a discussion of the one that allows a better controlled or safer fenestration. We conclude that endoscopic fenestration of SACs is not superior to microsurgical cyst fenestration, and the latter seems safer.

Neuroendoscopic surgery in empty ventricular system under continuous gas infusion experimental study of pressure changes and complications.

INTRODUCTION: The most important limitations to endoscopic procedures in the ventricular system of the brain are due to the constraint of working inside a fluid. The evacuation of cerebrospinal fluid (CSF) from the ventricles is performed often in microsurgical interventions using a surgical microscope. This study aimed at studying the evacuation of CSF during neuroendoscopic surgery in animals while infusing gas to avoid ventricular collapse. MATERIALS AND METHODS: Hydrocephalus was provoked in five adult New Zealand rabbits by intracisternal injection of kaolin. Endoscopic intervention was performed later; fluid was given as a continuous infusion at constant speed into the CSF for 3 min. In the next stage, CSF was evacuated from the ventricles, which were infused with gas at a stable rate for the same amount of time. The intracranial pressure (ICP) of the rabbits was recorded during both operations. The animals were sacrificed and the brain subjected to pathology examination at the end of the experiment. RESULTS: Mean ICP value in the rabbit ventricle was 19.1 while working in CSF and 17.6 when working in air. The difference by a paired test was statistically significant for each individual rabbit except one. The ICP measurement, however, was never lower than the ambient pressure, even while working in continuous gas infusion. No epidural or subdural hematomas were found at autopsy. CONCLUSIONS: Endoscopic surgery is feasible in a ventricular system that has been insufflated with gas after CSF has been evacuated. During the experiment, however, steadily diminishing ICP values were measured. As a result, new devices, such as small-flow insufflators able to perform sensitive pressure adjustments are needed.

Linezolid in the treatment of methicillin-resistant staphylococcal post-neurosurgical meningitis: a series of 17 cases.

BACKGROUND: Linezolid is a bacteriostatic antibiotic with good cerebrospinal fluid penetration. The aim of this study was to evaluate the efficacy of linezolid in methicillin-resistant staphylococcal (methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus (MRCoNS)) meningitis. METHODS: We extracted data and outcomes for all adult patients (age > 18 y) with culture-proven MRSA or MRCoNS meningitis treated with linezolid between January 2006 and September 2010 in our hospital. Demographic, clinical, and laboratory data and predisposing factors, as well as information on response to treatment and outcome were obtained by regular visits. RESULTS: A total of 17 cases (9 MRCoNS, 7 MRSA, and 1 MRCoNS and MRSA mixed) fulfilled the inclusion criteria. All patients had hospital-acquired meningitis and had undergone neurosurgery. Cumulative microbiological success on day 5 was 88%. There was 1 staphylococcal meningitis-related death. There were no severe adverse events. CONCLUSIONS: Our experience with linezolid suggests that it can be an alternative for the treatment of MRCoNS- and MRSA-related meningitis.

Near-infrared camera for intraventricular neuroendoscopic procedures: in vitro comparison of the efficiency of near-infrared camera and visual light camera during bleeding.

PURPOSE: Bleeding is the most important problem in neuroendoscopic procedures. The visibility of the bleeding point for a long period of time is very crucial for the surgeon to stop the bleeding. In this study, the performances of a near-infrared camera (NIRC) and a visible light camera (VLC), which is widely used today, were compared in terms of the visibility duration of the bleeding point. METHODS: A bleeding point was generated in vitro, and it was monitored with VLC and NIRC (sensitive to 850-nm infrared light), which were connected to two identical telescope systems. This trial was repeated for 40 times using different telescope systems (Clarus neurochannel endoscopy and Storz Hopkins). The images were merged and analyzed digitally. RESULTS: Statistically, sharper brightness difference levels between bleeding point and background are achieved by NIRC than VLC. Analyses revealed that the bleeding point could be observed for a longer time with NIRC, when compared to VLC. CONCLUSION: NIRCs may provide very significant advantages against bleedings encountered during intraventricular operations.

Intraventricular migration of the bone dust. Is a second operation for removal necessary? Case report and review of the literature.

PURPOSE: As the number of endoscopic third ventriculostomy (E3V) operations increase, new rare complications are encountered. In this article, a complication caused by bone particles that migrated into the third ventricle will be described. Additionally, the methods of avoidance as well as the necessity of a new approach will be discussed. METHODS: After the video images of the first and second operations of a patient who was subjected to E3V twice were compared, it was discovered that one of the bone particles within the ventricle had occluded the ostium after the second operation. Most of the bones were removed and their pathological investigations were performed. RESULTS: Video images of the patient, surgical observations of the second operation, emergence of the time of dysfunction, and other similar cases in the literature were assessed, and it was concluded that the bones that localized intraventricularly were living tissues. DISCUSSION: Abandoning usage of bone dust for sealing burr holes is a solution to avoid this complication. In addition, it should be kept in mind that intraventricular bone particles might grow and lead to obstructions. If such particles are detected, removal of the bones in certain locations before formation of neovascularization can be an option.

Cerebro-spinal fluid shunt revisions, importance of the symptoms and shunt structure.

AIM: CSF shunt failure is still a frequent problem in children. This prospective study was designed for focusing symptoms and reasons of shunt failure. We also especially focused on the mechanical reasons of shunt failure. MATERIAL AND METHODS: We focused on the causes of shunt failures, and the symptoms and signs in patients who were operated for shunt malfunction between January 1, 2001 and December 31, 2005 in the neurosurgery department. All examination and operative data were collected prospectively. Evaluation of these data was with the chi-square and Fisher exact tests. RESULTS: After the evaluation of data on 111 patients and 153 revision procedures, the major symptoms in this group were vomiting (62.16%), somnolence (59.45%) and headache (48.64%). In the majority of the shunt revisions (115 operations, 75.2% of the all 153 procedures), one or more mechanical problems of the shunt systems were identified in surgery. CONCLUSION: Shunt failures in children sometimes appear with very unusual symptoms. Also, probable structural problems of the shunt systems seem very important for shunt failure according to patient characteristics and etiology of the hydrocephalus. A systematic approach including CT, shunt series and abdominal ultrasound is needed to rule out shunt malfunction.

Ceftaroline versus vancomycin in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) in an experimental MRSA meningitis model.

OBJECTIVES: The aim of this study was to compare the antibacterial activity of ceftaroline versus vancomycin in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) meningitis in an experimental rabbit meningitis model. METHODS: The antibacterial activity of ceftaroline was compared with vancomycin in the treatment of meningitis induced by MRSA strain ATCC 43300 in an experimental rabbit meningitis model. Quantitative cerebrospinal fluid (CSF) cultures were performed at the beginning of antibiotic treatment and 24h and 73h after the first antibiotic dose. Furthermore, in vitro time-kill data were investigated at 0, 2, 4, 6, 8, 12 and 24h in sterile human serum. RESULTS: The difference between the control group versus both treatment groups was significant when comparing the decrease in colony counts in CSF both at 24h and 73h after the first antibiotic dose (P<0.05). At the end of the experiment, there was a significant difference in survival between both the ceftaroline-treated group and the vancomycin-treated group versus the control group, but not between the two treatment groups. CONCLUSION: These results suggest that the antibacterial activity of both ceftaroline and vancomycin are similar in the treatment of MRSA meningitis in an experimental rabbit meningitis model.

Medulloblastoma: clinicopathologic evaluation of 42 pediatric cases.

PURPOSE: The aim of this study was to assess the prognostic value of MIB-1 and p53 in the pediatric medulloblastoma group. MATERIALS AND METHOD: Forty-two pediatric medulloblastoma cases diagnosed in a single institution during the past 10 years were evaluated. Follow-up data were available for 35 patients. RESULTS: The immunoreactivity of MIB-1 ranged from 10% to 95%; p53 immunoreactivity was found in five cases. Of the 35 patients with follow-up, 34 patients received a combination of chemotherapy and radiotherapy, while one received chemotherapy alone. The follow-up period ranged from 5 to 64 months. Of the 35 patients, 21 were alive without any evidence of recurrent disease, three were alive with evidence of recurrent disease and 11 died of disease during follow-up. The mean survival for these 11 patients was 21.9+/-10.4 months. Of the 35 cases, 16 had MIB-1 value of 25% or lower and 19 had a value of 26% or more. Of the 16 cases with low MIB-1 value, six died of disease; of the 19 cases with high MIB-1 value, five died of disease. The statistical difference between MIB-1 and prognosis was not significant. Three of the 35 (8.5%) cases were found to be positive with p53 protein; no correlation was observed between p53 immunoreactivity and prognosis. CONCLUSION: It appears that the MIB-1 value and p53 immunoreactivity have no relation with prognosis in pediatric medulloblastomas. However, it is convenient to support these findings with large series.

Atypical teratoid/rhabdoid tumor of the central nervous system: clinicopathologic and immunohistochemical features of four cases.

BACKGROUND: Atypical teratoid/rhabdoid tumor (AT/RT) is a rare aggressive infantile neoplasm of uncertain origin. This study was performed to assess the clinicopathologic and immunohistochemical features of four AT/RT cases. CASE REPORTS: Two cases were male and two were female, and their ages ranged from 8 to 103 months. Tumors were located in the cerebellum (two cases), frontoparietal lobe (one case), and third ventricle (one case). Histopathologically, the tumors were composed of rhabdoid cells and undifferentiated small cells mixed with epithelial or mesenchymal components. However, one of the tumors was composed predominantly of a mesenchymal component mimicking a sarcoma. Immunohistochemically, vimentin (4/4), epithelial membrane antigen (4/4), cytokeratin (3/4), smooth muscle actin (4/4), glial fibrillary acidic protein (4/4), S-100 (4/4), and synaptophysin (1/4) were positive in varying proportions, while desmin and INI-1 were negative in all the cases. All of the patients died within a mean of 14 months due to tumor progression despite the chemotherapy. Only one of our patients lived for 40 months after the diagnosis. In conclusion, AT/RTs are aggressive tumors. They can occur in a variety of locations, such as the third ventricle. Morphologically, a large spectrum can be seen, like predominantly sarcoma in appearance, but immunohistochemistry is helpful in the correct diagnosis.

Moxifloxacin versus ampicillin + gentamicin in the therapy of experimental Listeria monocytogenes meningitis.

OBJECTIVES: This study aimed to compare the antibacterial activity of moxifloxacin and ampicillin + gentamicin in the treatment of Listeria monocytogenes meningitis in a rabbit meningitis model. METHODS: Meningitis was induced by direct inoculation of a clinical strain isolated from an immunocompromised patient (10(7) cfu/mL) into the cisterna magna of New Zealand rabbits. After 16 h of incubation, rabbits were separated into four groups: moxifloxacin (M), ampicillin + gentamicin (A), ampicillin + gentamicin 2 (A2) and control (C). Group M received 20 mg/kg moxifloxacin at the end of the incubation time and 5 h later by intravenous (i.v.) route. Group A received ampicillin (30 mg/kg/h) and gentamicin (2.5 mg/kg/h) by i.v. route with continuous infusion for 8 h in 36 mL of 0.9% NaCl, group A2 received the same dosage of gentamicin and ampicillin in two different 36 mL 0.9% NaCl solutions and group C did not receive any treatment. Cerebrospinal fluid (CSF) samples (0.1-0.25 mL) were obtained 16 and 24 h after induction of meningitis. RESULTS: At the end of the 16 h of incubation, CSF bacterial counts were similar in all groups (P > 0.05). At the final stage of the study (24 h after induction of meningitis), bacterial counts in all treatment groups were significantly lower than the control group (P < 0.05). When the three treatment groups were compared, bacterial counts were found to be similar (P > 0.05). CONCLUSIONS: These data suggest that antibacterial activity of moxifloxacin is similar to ampicillin + gentamicin in the treatment of experimental L. monocytogenes meningitis of rabbits.

Melanotic progonoma of the skull in infancy.

INTRODUCTION: Melanotic progonoma or melanotic neuroectodermal tumor is a rare tumor in infancy. This lesion has to be considered in the differential diagnosis of benign or malignant lesions of calvarium. CASE REPORT: The authors present a case of a 4-month-old infant with left retroauricular mass. The patient had a subcutaneous mass that is fixed to the underlying skull. CT and MRI scans showed left occipitotemporal expansile mass. The tumor was removed by surgery. A tumor, brownish-black in color, was diagnosed as melanotic progonoma. The patient remained symptom-free for the last 2 years after complete surgery. DISCUSSION: Extracranial subcutaneous masses involving the skull are uncommon in infants. Benign or malignant lesions may occur as lumps on calvarium. Physical examination and some laboratory findings are helpful in the assessment of patient. Benign or malignant lesions can be differentiated by craniography, CT, or MRI scans, but exact diagnosis of melanotic progonoma is made by histopathology and immunostaining, as was in the presented case. Cranial vault progonomas have a better outcome by complete surgery. The tumors usually do not recur in long-term period.

Spinal meningeal melanocytoma. Report of two cases and review of the literature.

The authors report on two patients with spinal meningeal melanocytoma and review the literature on this lesion. One case is particularly interesting because of the lesion's thoracic intramedullary localization. Meningeal melanocytoma is a benign but locally aggressive lesion and is very rarely associated with spinal localizations. This patient presented with paraparesis. Clinical and radiological examinations suggested the possibility of an intramedullary solid tumor. Thoracic laminectomy, posterior myelotomy, and tumor resection were performed; the mass was totally removed. The patient suffered no additional neurological deficit. During a 3-year follow-up period in which radiotherapy was not performed, the lesion did not recur. Total excision of the tumor is the best therapeutic option.