Journal of neurosurgery
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Journal of neurosurgery · Oct 2003
Inhibition of proteoglycan and type II collagen synthesis of disc nucleus cells by nicotine.
Systemic nicotine has been hypothesized to cause degeneration of the intervertebral disc which in turn decreases vascular supply to the disc through a cholinergic receptor-mediated process. Another possible mechanism may be through direct regulatory effects on disc cells. In this study, the authors tested the hypothesis that nicotine adversely affects nucleus pulposus cells by directly inhibiting proteoglycan synthesis and gene expression of type II collagen (Phase I study). They also assessed the hypothesis that nicotine inhibits the bone morphogenetic protein (BMP)-2-induced upregulation of extracellular matrix (Phase II study). ⋯ The results of this study raise the possibility that nicotine may contribute to the process of disc degeneration by a direct effect on the nucleus pulposus cells, possibly by antagonizing the effect of BMP-2.
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Journal of neurosurgery · Oct 2003
Changes in nerve root motion and intraradicular blood flow during intraoperative femoral nerve stretch test. Report of four cases.
It is not known whether changes in intraradicular blood flow (IRBF) occur during the femoral nerve stretch test (FNST) in patients with lumbar disc herniation. An FNST was conducted in patients with lumbar disc herniation to observe the changes in IRBF, and results were then compared with clinical features. ⋯ The intraoperative FNST showed that the hernia compressd the nerve roots and there was marked disturbance of gliding, which was reduced to only a few millimeters. During the test, IRBF decreased by 92.8 to 100% (96.9 +/- 3.7% [mean +/- standard error of the mean]).
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The purpose of this paper was to analyze outcomes in patients at the Louisiana State University Health Sciences Center (LSUHSC) who presented with contusion-stretch injuries to the axillary nerve. These injuries resulted from shoulder injury either with or without fracture/dislocation. Although recovery of deltoid function can occur spontaneously, this was not always the case. ⋯ Operative exploration of axillary contusion-stretch lesions is worthwhile in carefully selected cases. If indicated by inspection and intraoperative electrical studies, nerve repair can lead to useful function.
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Journal of neurosurgery · Oct 2003
Posterolateral percutaneous endoscopic lumbar foraminotomy for L5-S1 foraminal or lateral exit zone stenosis. Technical note.
The purpose of this study was to determine the efficacy and feasibility of posterolateral percutaneous endoscopic lumbar foraminotomy (PELF) for foraminal or lateral exit zone stenosis of the L5-S1 level in the awake patient. Twelve consecutive patients with L5-S1 foraminal stenosis and associated leg pain underwent PELF between May 2001 and July 2002. Under fluoroscopic guidance, posterolateral endoscopic foraminal decompression was performed using a bone reamer, endoscopic forceps, and a laser. ⋯ There was no complication. The PELF procedure provides a simple alternative for treating lumbar foraminal or lateral exit zone stenosis in selected cases. The authors found that the posterolateral endoscopic approach to the L5-S1 foramen was usually possible and that using a bone reamer to undercut the superior facet was effective.
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Journal of neurosurgery · Oct 2003
Sympathetic mechanisms in cerebral blood flow alterations induced by spinal cord stimulation.
Cervical spinal cord stimulation (SCS) has been found to augment cerebral blood flow (CBF) in a number of animal models, although the mechanisms underlying the cerebrovascular effects of SCS are poorly described. In this study, the authors examined the role of sympathetic tone in CBF alterations induced by SCS in rats. ⋯ Sympathetic tone plays a major role in SCS-induced increases in CBF. This effect seems to be mediated primarily by alpha1-adrenergic receptors. Systemic hypotension alone cannot explain the effects of sympathetic blockade on the SCS response. Clinical use of SCS in the treatment of cerebral ischemia should take alpha1-adrenergic receptor sympathetic tone into account.