OBJECTIVE To investigate the effect of the emergent repair of peripheral nerve injury of the wrist. METHODS From July 1993 to December 1997, 17 cases were admitted, which 21 injured peripheral nerves were repaired emergently. Among them, there were 11 cases of median nerve injury, 2 cases of ulnar nerve injury and 4 cases of median and ulnar nerve injury. All the nerves were ruptured completely except one which was partially ruptured. The emergent operation was taken and the injured nerves were repaired by microsurgical technique. RESULTS Followed up 6 to 18 months after operation, 95.25% injured nerves had good outcome. CONCLUSION Because of the specific structure of the wrist, nerve injury at this part need to be repaired emergently. It can enhance the regeneration of the injured nerve, preserve the function of the intrinsic muscle of hand, and decrease the local adhesion.
Peripheral nerve injury (PNI) is a common neurological dysfunction. In clinical practice, autologous nerve transplantation is used to solve problems related to PNI, such as limited donor resources, neuroma formation and high donor incidence rate. Therefore, searching for new nerve regeneration materials has become a hot research topic. The decellularized extracellular matrix (dECM) hydrogel provides a scaffold for nerve regeneration by removing the cellular components in biological tissues, preserving the extracellular matrix, and is a potential therapeutic material for nerve regeneration. This article reviews the research progress of dECM hydrogel for PNI and looks forward to the clinical prospects of this research direction.
OBJECTIVE Following the delayed repair of peripheral nerve injury, the cell number of anterior horn of the spinal cord and its ultrastructural changes, motorneuron and its electrophysiological changes were investigated. METHODS In 16 rabbits the common peroneal nerves of both sides being transected one year later were divided into four groups randomly: the degeneration group and regeneration of 1, 3 and 5 months groups. Another 4 rabbits were used for control. All transected common peroneal nerves underwent epineural suture except for the degeneration group the electrophysiological examination was carried out at 1, 3 and 5 months postoperatively. Retrograde labelling of the anterior horn cells was demonstrated and the cells were observed under light and electronmicroscope. RESULTS 1. The number of labelled anterior horn cell in the spinal cord was 45% of the normal population after denervation for one year (P lt; 0.01). The number of labelled cells increased steadily from 48% to 57% and 68% of normal values at 1, 3 and 5 months following delayed nerve repair (P lt; 0.01). 2. The ultrastructure of the anterior horn cells of the recover gradually after repair. 3. With the progress of regeneration the latency become shortened, the conduction velocity was increased, the amplitude of action potential was increased. CONCLUSION Following delayed repair of injury of peripheral nerve, the morphology of anterior horn cells of spinal cord and electrophysiological display all revealed evidence of regeneration, thus the late repair of injury of peripheral nerve was valid.
Objective To study the functional change of nerve trunk after removing the partial bundles of ulnar nerve, to propose the concept of functional reserve of peripheral nerves and to investigate the functional reserve quantity of peripheral nerves. Methods Two hundred and twenty SD rats (male or female), aging 3 months and weighing 300-350 g, were randomized into the experimental group and the control group (n=110 per group). And the experimental group wassubdivided into group 1/8, group 1/4, group 1/3, group 1/2 and group 2/3 according to the resection portion (n=22 per group). In the experimental group, the section of the lowest level on ulnar nerve trunks was exposed, and a certain portion of its bundles was separated and cut, while in the control group the bundles were only separated without resection. The general condition of all rats was observed, and the motoneurons in cornu anterius medullae spinal is were detected at 1 week, 2 weeks and 2 months after operation. The neuro-electrophysiology and the function of dominated muscles were detected at 2 weeks, 2 months, 3 months, and 4 months after operation. Results All the rats survived without infection and obvious ulcer in the l imbs. The number of motoneurons in cornu anterius medullae spinal is in various experimental subgroups witnessed no obvious changes (P gt; 0.05). The superstructure changed obviously at the early postoperative stage in group 1/2 and group 2/3, but restored well at 2 months after operation. For the latent period of evoked potential, there was no significant difference between the various experimental subgroups and the control group at each time point (P gt; 0.05), but there was a significant difference among the various experimental subgroups when compared the time points of 2, 3 and 4 months to that of 2 weeks (P lt; 0.05) and no statistically significant difference at other time points (P gt; 0.05). For the wave ampl itude of evoked potential of motor nerves, the maximum wave ampl itude and the persistence time of the dominate muscle, there were significant differences between the various experimental subgroups and the control group at each time point (P lt; 0.05), and there were significant differences among the various experimental subgroups when comparing the time points of 2, 3 and 4 months to that of 2 weeks (P lt; 0.05) and no statistical significance at other time points (Pgt; 0.05). Conclusion The functional reserve of the ulnar nerve withoutcompromise accounts the 1/3 of the whole trunk diameter.
OBJECTIVE: To investigate the protective effect of tumor necrosis factor-alpha(TNF-alpha) on spinal motor neurons after peripheral nerve injury. METHODS: Twenty Wistar rats were divided into two groups, the right sciatic nerves of 20 Wistar rats were transected, the proximal stumps were inserted into a single blind silicone tube. 16 microliters of normal saline(NS) and TNF-alpha(30 U/ml) were injected into the silicone tubes. After 2 weeks, the 4th, 5th lumbar spinal cord were taken for examination. Enzyme histochemical technique and image analysis were used to show acetylcholinesterase(AChE) and nitric oxide synthase(NOS) activity of spinal motor neurons. RESULTS: The number of AChE and NOS staining neurons were 8.65 +/- 1.98 and 5.92 +/- 1.36 in the experimental group and 6.37 +/- 1.42 and 8.67 +/- 1.45 in the control group respectively, there were significant difference between the two groups(P lt; 0.01). CONCLUSION: It suggests that TNF-alpha has protective effect on motor neurons after peripheral nerve injury.
ObjectiveTo summarize the regulatory role of long non-coding RNA (lncRNA) in peripheral nerve injury (PNI) and neural regeneration.MethodsThe characteristics and mechanisms of lncRNA were summarized and its regulatory role in PNI and neural regeneration were elaborated by referring to relevant domestic and foreign literature in recent years.ResultsNeuropathic pain and denervated muscle atrophy are common complications of PNI, affecting patients’ quality of life. Numerous lncRNAs are upregulated after PNI, which promote the progress of neuropathic pain by regulating nerve excitability and neuroinflammation. Several lncRNAs are found to promote the progress of denervated muscle atrophy. Importantly, peripheral nerve regeneration occurs after PNI. LncRNAs promote peripheral nerve regeneration through promoting neuronal axonal outgrowth and the proliferation and migration of Schwann cells.ConclusionAt present, the research on lncRNA regulating PNI and neural regeneration is still in its infancy. The specific mechanism remains to be further explored. How to achieve clinical translation of experimental results is also a major challenge for future research.
To evaluate the value of clinical application of examination of fibrillation potential amplitude, 110 patients, 97 males and 13 females, were examined and only the maximum fibrillation potential amplitudes were recorded in 420 muscles. The results showed that there was no significant difference between sexes, ages and sides. However, significant difference was evident between the groups of different frequency (1+ to 4+). The fibrillation potential amplitude was maximum at 3 to 4 months after denervation and still remained at relatively high level for years in certain patients. No significant difference was showed between the time groups in incomplete nerve injuries. Surgery did not affect the course of fibrillation potential amplitude change. It was suggested that the muscle cells sustained their property for years after denervation in some patients, thus it might explain that satisfactory result could be obtained from operative repair in some late cases. The changes of fibrillation potential amplitude might indicate that the changes from muscle denervation was still reversible and might be more accurate than traditional method of examination.
ObjectiveTo study the expressions of microRNA-221 (miR-221) and the protein of phosphatase and tension protein homologue (PTEN) in the proximal and distal stumps after sciatic nerve injury in rats and their correlation with the repair of peripheral nerve injury, so as to provide a new target for clinical diagnosis of peripheral nerve injury.MethodsNinety-six male Sprague-Dawley rats of SPF grade were selected to establish sciatic nerve injury models. Twenty-four rats were sacrificed at 0 (immediately after operation), 1, 4, and 7 days after operation. The proximal and distal sciatic nerve fragments were taken under aseptic conditions. The expression of miR-221 was detected by real-time fluorescent quantitative PCR, and the expression of PTEN protein was detected by Western blot and immunofluorescent staining. The relationship between miR-221 and PTEN was verified by dual-luciferase reporter gene. At the same time, the ultrastructure of nerve stump was observed by transmission electron microscopy.ResultsThe results of real-time fluorescent quantitative PCR, Western blot, and immunofluorescence staining showed that the relative expression of miR-221 in the proximal and distal stumps increased gradually with time, and the relative expression of PTEN protein decreased gradually, and the differences between different time points after operation were significant (P<0.05). At 1, 4, and 7 days after operation, the relative expression of miR-221 in proximal stump was significantly higher than that in distal stump, and the relative expression of PTEN protein in proximal stump was significantly lower than that in distal stump (P<0.05). Dual-luciferase reporter gene suggested that PTEN was the target for miR-221. Transmission electron microscopy observation showed that the normal morphological structure was observed at 0 day after operation, and the proliferation of Schwann cells and degeneration of axons and myelin sheaths gradually increased with time. There was no significant difference between proximal and distal stumps at 1 day after operation. At 4 and 7 days, Schwann cells proliferated more in proximal stump than in distal stump, and the degeneration of axons and myelin sheaths was less.ConclusionAfter sciatic nerve injury in rats, the up-regulation of the miR-221 expression targets the down-regulation of PTEN expression, which results in the difference of expression levels of miR-221 and PTEN in proximal and distal stumps. This phenomenon may play a role in promoting nerve repair after peripheral nerve injury.
To observe the change of morphology and neuropeptide in the spinal neurons in order to clarify the functional state after injury of peripheral nerves is especially in the late stage. Sciatic nerves were cut with their proximal segments in the preparation of a model of peripheral nerve injury. Combination of horseradish peroxidase retrograde tracing immunohistochemistry and computer image analysis the changes in the morphometry of the perikarya of ventral horn neurons of the spinal cord, the quantitative changes of substance P (SP). Calcitonin gene-related peptide (CGRP) in dorsal horn and CGRP and choline acetyransferase (CHAT) in ventral horn of the spinal cord were examed. The results showd: (1) At the 3rd week after injury, swollen perikarya of the ventral horn neurons were observed, subseauently the swelling of perikarya was decreased tile the 6th week the neurons recovered to their normal size. At the 12th week the neurons were generally stable in their size, shortening of the dendrites was seen in 27% of the neurons. (2) The dendrites of the neurons progressively contracted till at the 12th week 53% of them were degenerated. The results of the 24th week were similar to the that at the 12th week. (3) CGRP in the ventral horn of the spinal cord was elevated to the highest point after 1 week of injury, that lasting for 4 weeks and 8 weeks later, the lever of CGRP returned to normal. From 20th to 24th week, there was no obvious changes of CHAT in the ventral horn of the spinal cord during observation. (4) SP went to the lowest point in the dorsal horn during 2-6 weeks, then recovered slowly, and beiny normal again after 16 weeks, however, CGRP was changed slightly. The results indicated that although a series of degenerating changes occurred in the neurons of the spinal cord during the late peripheral nerve injury, but the functional activity of the central meurons still was maintained at a certain level.
Objective To review researches of treatment of peripheral nerve injury with neuromuscular electrical stimulation (NMES) regarding mechanism, parameters, and cl inical appl ication at home and abroad. Methods The latest original l iterature concerning treatment of peri pheral nerve injury with NMES was extensively reviewed. Results NMES should be used under individual parameters and proper mode of stimulation at early stage of injury. It could promote nerve regeneration and prevent muscle atrophy. Conclusion NMES plays an important role in cl inical appl ication of treating peripheral nerve injury, and implantable stimulation will be the future.