Journal of neurosurgery
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Journal of neurosurgery · Feb 2014
ReviewMisdirection and guidance of regenerating axons after experimental nerve injury and repair.
Misdirection of regenerating axons is one of the factors that can explain the limited results often found after nerve injury and repair. In the repair of mixed nerves innervating different distal targets (skin and muscle), misdirection may, for example, lead to motor axons projecting toward skin, and vice versa-that is, sensory axons projecting toward muscle. In the repair of motor nerves innervating different distal targets, misdirection may result in reinnervation of the wrong target muscle, which might function antagonistically. ⋯ In this review the authors discuss these different factors and mechanisms that act along the pathway of the regenerating axon. The authors review recently developed evaluation methods that can be used to investigate the accuracy of regeneration after nerve injury and repair (including the use of transgenic fluorescent mice, retrograde tracing techniques, and motion analysis). In addition, the authors discuss new strategies that can improve in vivo guidance of regenerating axons (including physical guidance with multichannel nerve tubes and biological guidance accomplished using gene therapy).
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Journal of neurosurgery · Feb 2014
Case ReportsHistopathological assessment of fatal ipsilateral intraparenchymal hemorrhages after the treatment of supraclinoid aneurysms with the Pipeline Embolization Device.
Delayed ipsilateral intraparenchymal hemorrhage has been observed following aneurysm treatment with the Pipeline Embolization Device (PED). The relationship of this phenomenon to the device and/or procedure remains unclear. The authors present the results of histopathological analyses of the brain sections from 3 patients in whom fatal ipsilateral intracerebral hemorrhages developed several days after uneventful PED treatment of supraclinoid aneurysms. ⋯ These findings are suggestive of a potential association between intraprocedural foreign body emboli and post-PED treatment-delayed ipsilateral intraparenchymal hemorrhage.
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The sella turcica usually appears partially empty in MR images obtained from patients with chronic elevation of intracranial pressure. The authors measured the size of the sella turcica to determine if enlargement of the pituitary fossa explains the partially empty sella associated with pseudotumor cerebri. ⋯ Chronic elevation of intracranial pressure is associated with bony enlargement of the sella turcica. Enlargement of the sella turcica contributes to its partially empty appearance.
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Journal of neurosurgery · Feb 2014
Case ReportsAdvanced neuroimaging findings of pseudotumoral hemicerebellitis in an elderly male requiring surgical decompression.
Acute cerebellitis is an inflammatory process that usually affects bilateral cerebellar hemispheres in the pediatric population. Pseudotumoral hemicerebellitis is an extremely rare presentation in which unilateral cerebellar involvement mimics a tumor that can exert significant mass effect on the surrounding structures, which may require surgical intervention. ⋯ Advanced neuroimaging, including MR perfusion and MR spectroscopy, may be helpful in excluding other diagnoses. The authors present the case of pseudotumoral hemicerebellitis in the oldest documented patient, a 73-year-old man who required surgical decompression, and they provide a brief discussion of advanced neuroimaging findings.
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Journal of neurosurgery · Feb 2014
Assessment of the rate of spinal motor axon regeneration by choline acetyltransferase immunohistochemistry following sciatic nerve crush injury in mice.
The purpose of this study was to examine whether choline acetyltransferase (ChAT) staining can be used for assessing the rate of motor neuron regeneration at an early phase of axon outgrowth. ⋯ Our results suggest that measuring the length of motor axon outgrowth by ChAT immunostaining is reliable. ChAT staining provides a more convenient method for evaluating the rate of motor axon outgrowth in a mixed nerve.