Articles: sciatic-neuropathy-pathology.
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Longitudinally oriented microstructures are essential for a nerve scaffold to promote significant regeneration of injured peripheral axons across nerve gaps. Extensive attention has been devoted to develop scaffolds with inner structures mimicking the nerve-guiding basal lamina microchannels in autografts. However, to date, little information has been obtained about scaffolds with similar inner microstructures, and the efficacy of such scaffolds in bridging peripheral nerve gaps in vivo has never been examined. ⋯ We evaluated the efficacy of the CCH scaffold to bridge a 15-mm-long sciatic nerve defect in rats using a combination of morphological and functional techniques. The in vivo animal study showed that the CCH scaffold achieved nerve regeneration and functional recovery equivalent to that of an autograft, without the exogenous delivery of regenerative agents or cell transplantation. These findings demonstrate that CCH scaffolds may be used as alternatives to nerve autografts for peripheral nerve regeneration.
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Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi · Jul 2009
[Peripheral anti-hyperalgesic effect and neurotoxicologic screening of amitriptyline and bupivacaine on sciatic nerve blockade chronically on neuropathic pain in rats].
To investigate whether the peripheral administration of amitriptyline and bupivacaine produces anti-hyperalgesic effect and to screen the neurotoxicological effect on sciatic nerve blockade in a rat model of neuropathic pain. ⋯ Repeated sciatic nerve blockade with 0.5% amitriptyline has peripheral anti-hyperalgesic effects on neuropathic pain of rats. No morphological evidence of neurotoxicity in the sciatic nerve of rats is observed in 0.5% amitriptyline.
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We applied diffusion tensor tractography (DTT), a recently developed MRI technique that reveals the microstructures of tissues based on its ability to monitor the random movements of water molecules, to the visualization of peripheral nerves after injury. The rat sciatic nerve was subjected to contusive injury, and the data obtained from diffusion tensor imaging (DTI) were used to determine the tracks of nerve fibers (DTT). The DTT images obtained using the fractional anisotropy (FA) threshold value of 0.4 clearly revealed the recovery process of the contused nerves. ⋯ The FA values of the peripheral nerves were more strongly correlated with axon-related (axon density and diameter) than with myelin-related (myelin density and thickness) parameters, supporting the theories that axonal membranes play a major role in anisotropic water diffusion and that myelination can modulate the degree of anisotropy. Moreover, restoration of the FA value at the lesion epicenter was strongly correlated with parameters of motor and sensory functional recovery. These correlations of the FA values with both the histological and functional changes demonstrate the potential usefulness of DTT for evaluating clinical events associated with Wallerian degeneration and the regeneration of peripheral nerves.
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Acta neurochirurgica · Jan 2009
Case ReportsSciatic cross-over in patients with peroneal and tibial intraneural ganglia confirmed by knee MR arthrography.
A predictable mechanism and stereotypic patterns of peroneal intraneural ganglia are being defined based on careful analysis of MRIs. Peroneal and tibial intraneural ganglia extending from the superior tibiofibular joint which extend to the level of the sciatic nerve have been observed leading to the hypothesis that sciatic cross-over could exist. Such a cross-over phenomenon would allow intraneural cyst from the peroneal nerve by means of its shared epineurial sheath within the sciatic nerve to cross over to involve the tibial nerve, or vice versa from a tibial intraneural cyst to the peroneal nerve. ⋯ This study provides direct in vivo proof of the nature of sciatic cross-over theorized by critical review of MRIs and/or experimental dye injections done in cadavers. This study is important in clarifying the potential paths of propagation of intraneural cysts at points of major bifurcation.
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The objective of this study was to evaluate the accuracy of magnetic resonance imaging (MRI) in the diagnosis of the piriformis muscle syndrome (PMS). ⋯ In piriformis muscle syndrome, MRI may demonstrate signal abnormalities of the sciatic nerve as well as its relationship with the normal and abnormal piriformis muscle.