Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia
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Meta Analysis Comparative Study
Hearing preservation rates after microsurgical resection of vestibular schwannoma.
Preservation of hearing is a major goal of surgery for patients with vestibular schwannoma (VS). We performed an analysis of the published literature on hearing outcome after microsurgery for VS. Our objective was to provide a comprehensive and unbiased description of published results. ⋯ Patients undergoing surgery via the MCF had better hearing outcomes on univariate analysis than those undergoing the RS approach (63% vs. 47%, p<0.0001). Multivariate analysis found that tumor size >1.5cm (odds ratio [OR] 2.81, 95% confidence interval [CI]=1.59-4.95, p<0.001), and the RS approach (OR 4.15, 95% CI=1.97-8.77, p<0.001) were independent significant risk factors for loss of serviceable hearing during VS surgery. Use of the MCF demonstrates superior hearing outcomes to the RS approach, even after correcting for the effect of the increased size of tumors addressed by the RS approach.
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Comparative Study
Sensitivity and specificity of in vivo diffusion-weighted MRI in acute spinal cord injury.
The aim of this study was to test the sensitivity and specificity of diffusion-weighted MRI for the detection of acute spinal cord injury. Forty female New Zealand white rabbits were randomly divided into four groups: the mild, moderate and severe injury groups, and the control (sham operation) group. Contusion of the spinal cord was induced using a weight-drop impactor. ⋯ The apparent diffusion coefficient values of the lesion were lower than those of adjacent unaffected regions in the mild and moderate injury groups, but higher than adjacent unaffected regions in the severe injury group. The histological findings were reliably correlated with the magnetic resonance findings. We found that DWI has a higher sensitivity, but a lower specificity, than conventional MRI for the detection of early pathological changes after contusive injury.
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Comparative Study
Vasospasm after subarachnoid hemorrhage in haptoglobin 2-2 mice can be prevented with a glutathione peroxidase mimetic.
Vasospasm after subarachnoid hemorrhage (SAH) is attributable to inflammation and oxidative stress associated with extracellular hemoglobin (Hb). Haptoglobin (Hp) binds free Hb and the Hp-Hb complex is cleared by macrophages, and the Hp-2 isoform of Hp is associated with more oxidative stress and more severe vasospasm. ⋯ We found that SAH induced significant vasospasm in Hp-2 mice (lumen patency reduced to 65.9%), but no vasospasm was seen in mice that received SYI-2074 after SAH (lumen patency of 98.7%). We conclude that vasospasm after SAH in Hp-2 mice can be prevented with SYI-2074, suggesting that oxidative stress contributes significantly to vasospasm.
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We compared the clinical and radiological results of posterior atlantoaxial fixation surgery using transarticular screws to those using a polyaxial screw-rod system in 55 patients with symptomatic atlantoaxial instability. Patients underwent posterior C1-C2 fixation: 28 patients (group 1) underwent C1-C2 transarticular screw fixation and 27 patients (group 2) underwent C1 lateral mass-C2 pedicle screw fixation. Patients were followed-up for at least 24 months. ⋯ One patient in group 2 had occipital neuralgia. One vertebral artery injury occurred during the screw placement in group 1 and another in group 2 during the muscle dissection. C1-C2 transarticular screw fixation and C1 lateral mass-C2 pedicle screw fixation both produced excellent results for stabilization of the atlantoaxial complex, but the radiological outcome tended to be superior in C1 lateral mass-C2 pedicle screw fixation.
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We aimed to identify the incidence, duration and causes of delayed emergence from anesthesia in patients with dystonia undergoing surgery for deep brain stimulation (DBS) placement. A retrospective review of patients with dystonia who underwent DBS placement was conducted and the following characteristics were noted: age, gender, comorbid conditions, American Society of Anesthesiologists classification, anesthetic agents used, amount of initial dose, amount of infusion dose, duration of the infusion and the time needed for emergence. Twenty-four patients underwent 33 DBS procedures for dystonia. ⋯ A possible cause of delayed emergence is excessive anesthetic potentiation of the low output pallidal state in dystonia which may depress the pallido-thalamo-cortical circuitry. Delayed emergence could also result from depression of the previously affected ventral pallidal inputs to the septo-hippocampal system that mediates general anesthesia and awareness. Complex neurotransmitter disturbances may also be involved.