Journal of neurosurgery
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Journal of neurosurgery · Dec 2002
Clinical and electrophysiological expression of deafferentation pain alleviated by dorsal root entry zone lesions in rats.
The aims of this study were to construct an animal model of deafferentation of the spinal cord by brachial plexus avulsion and to analyze the effects of subsequent dorsal root entry zone (DREZ) lesions in this model. To this end, the authors measured the clinical and electrophysiological effects of total deafferentation of the cervical dorsal horn in rats and evaluated the clinical efficacy of cervical DREZ lesioning. ⋯ These results emphasize the role of the spinal dorsal horn in the genesis of deafferentation pain and suggest that dorsal horn deafferentation by cervical posterior rhizotomy in the rat provides a reliable model of chronic pain due to brachial plexus avulsion and its suppression by MDR.
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Journal of neurosurgery · Dec 2002
Case ReportsPainful neuromas: a potential role for a structural transmembrane protein, ankyrin G.
Severe nerve injury induces the formation of a neuroma. Some neuromas cause excruciating pain. Overexpression of Na+ channels leads to hyperexcitability and painful phenomena. Ankyrin G, a multifunctional transmembrane protein of the axolemma, might be a key protein in neuroma formation because it binds Na+ channels in the initial segments of a regenerating axon and links with neuronal cell adhesion molecules. The authors wanted to determine if ankyrin G could be detected in neuroma, and if present, whether there would be differences in distribution between nonpainful neuromas, painful neuromas, and normal nerve. ⋯ Altered regulation of ankyrin G after nerve injury may lead to hyperexcitability and painful phenomena via clustering of Na+ channels. A propensity to overexpress ankyrin G after peripheral nerve trauma may turn out to be a factor in the development of painful neuromas and neuropathic pain. The relevant literature regarding the importance of ankyrin G for nerve regeneration and nerve membrane remodeling is reviewed.
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Journal of neurosurgery · Dec 2002
Efficacy of gamma knife radiosurgery for nonfunctioning pituitary adenomas: a quantitative follow up with magnetic resonance imaging-based volumetric analysis.
The authors assessed the efficacy of gamma knife radiosurgery (GKS) for nonfunctioning pituitary adenomas (NPAs) by sequential quantitative determinations of tumor volume and neurological and endocrinological follow-up examinations. ⋯ Postoperative GKS for residual or recurrent small fragments of NPAs is effective and safe. With regard to the issues of radioprotection and therapeutic morbidity, it seems superior to fractionated radiotherapy. Quantification of tumor reduction is a valuable tool for documenting a therapeutic response and for identifying tumor recurrence. As part of a radiosurgical standard protocol, the follow-up examination for NPAs should include tumor volumetric analysis.
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Journal of neurosurgery · Dec 2002
Survival and pattern of failure in brain metastasis treated with stereotactic gamma knife radiosurgery.
Gamma knife radiosurgery (GKS) has become a well-established treatment modality in the management of selected patients with brain metastasis. The authors review the management patients with these tumors treated at a single center. ⋯ Gamma knife radiosurgery provided an excellent palliation with low incidence of toxicity. A Phase III prospective randomized trial is required to define the role of WBRT in combination with GKS.
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Journal of neurosurgery · Dec 2002
Genetic differences between neurocytoma and dysembryoplastic neuroepithelial tumor and oligodendroglial tumors.
Because of their histological similarities, it is occasionally difficult to differentiate neurocytoma and dysembryoplastic neuroepithelial tumor (DNT) from oligodendroglial tumors. This study was conducted to investigate genetic differences among these tumor types in terms of loss of heterozygosity on chromosomes 1p and 19q, and p53 gene mutation. ⋯ Despite histological similarities, central neurocytomas and DNTs are genetically distinct from oligodendroglial tumors. Examination for allelic loss on 1p and 19q and for p53 mutation can be useful for making this distinction.