The evaluation of the effects of steroid treatment on the tumor and peritumoral edema by DWI and MR spectroscopy in brain tumors

Objective To investigate the effects of dexamethasone on brain tumor and peritumoral edema by different sequences of magnetic resonance imaging (MRI). Materials and methods MRI was performed in 28 patients with brain tumor. Patients were divided into the 3 groups based on the histological diagnosis; Group I: high-grade glial tumor, Group II: low-grade glial tumor, and Group III: brain metastasis. The measurements of peritumoral edema volume and apparent diffusion coefficient (ADC) values were performed while the peak areas of cerebral metabolites were measured by spectroscopy in groups I and II. The changes in edema volumes, ADC values and cholin/creatine peak areas were compared. Results The volume of peritumoral edema was decreased in groups I and II, but increased in group III after dexamethasone treatment. These changes were not statistically significant for 3 groups. ADC value was decreased in group I and increased in groups II and III. Changes in ADC values were statistically significant. Cholin/creatine peak areas were decreased after dexamethasone in groups I and II, but these changes were also not significant. Conclusion Dexamethasone has no significant effect on the volume of peritumoral edema in glial tumor and metastasis. Moreover, dexamethasone increases the fluid movements in low grade gliomas and metastases, decreases in high grade gliomas. However, more comprehensive clinical studies are needed to show the effects of dexamethasone on brain tumors and peritumoral edema

The Use of Neuronavigation and Intraoperative Imaging in Spinal Stabilization Surgery

AIM: Misplacement of pedicle screw is the serious complication of spinal surgeries. Intraoperative imaging techniques and navigation systems are currently in use for the prevention of this complication. The aim of this study was to document the results of our experience with the navigation and intraoperative imaging technique and to share our experience with our colleagues. MATERIAL and METHODS: Between 2011 and 2014, one hundred and two patients underwent instrumented spinal surgery while using intraoperative computed tomography (iCT) and a navigation system. All patients had a CT scan performed no more than three days postoperatively to confirm adequate placement of the screws. The accuracy of pedicle screw placement was assessed by postoperative CT scan. Pedicle violations were graded according to an established classification system. RESULTS: In the 36-month period, a total of 610 screws in 102 patients were evaluated. Stabilization surgery was performed in the lumbosacral region in 51 (50%) patients, lumbar region in 35 (34.31%) patients, cervical region in 5 (4.9%) patients, thoracolumbar region in 7 (6.86%) patients and thoracic region in 4 (3.92%) patients. Of the 610 screws, 396 (64.91%) were placed in lumbar, 66 (10.81%) in thoracic, 106 (17.37%) in sacral and 42 (6.8%) in cervical vertebrae. Of the 610 screws, 599 screws (98.18%) were placed without a breach. Grade 1 breaches occurred in 8 screws (1.31%), Grade 2 breaches occurred in 2 screws (0.32%), and Grade 3 breaches in 1 screw (0.16%). No dural defect or neurological deficit occurred after the surgeries. CONCLUSION: The use of an ICT scan associated with a navigation system increases the accuracy of pedicle screw placement. This system protects the surgical team from fluoroscopic radiation exposure and the patient from the complications of screw misplacement and repeated surgeries

Expression of Sigma-Class Glutathione-S-Transferase in Fetal and Pediatric Filum Terminale Samples: A Comparative Study

Background and objectives: The pathophysiology of tethered cord syndrome (TCS) in children is not well elucidated. An inelastic filum terminale (FT) is the main factor underlying the stretching of the spinal cord in TCS. Our study aimed to investigate the expression of glutathione-S-transferase (GST) in children and fetal FT samples in order to understand the relationship between this enzyme expression and the development of TCS. Materials and Methods: FT samples were obtained from ten children with TCS (Group 1) and histological and immunohistochemical examinations were performed. For comparison, FT samples from fifteen normal human fetuses (Group 2) were also analyzed using the same techniques. Statistical comparison was made using a Chi-square test. Results: Positive GST-sigma expression was detected in eight (80%) of 10 samples in Group 1. The positive GST-sigma expression was less frequent in nine (60%) of 15 samples from Group 2. No statistically significant difference was detected between the two groups (p = 0.197). Conclusions: Decreased FT elasticity in TCS may be associated with increased GST expression in FT. More prospective studies are needed to clarify the mechanism of the GST–TCS relationship in children