OBJECTIVE: To investigate the variation of neurotrophic factors expression in spinal cord and muscle after root avulsion of brachial plexus. METHODS: Forty-eight Wistar rats were involved in this study and according to the observing time in 1st day, 1st week, 4th week, 8th week, and 12th week after avulsion, and the control, were divided into 6 groups. By immunohistochemical and hybridization in situ assays, the expression of nerve growth factor (NGF) on muscle, basic fibroblast growth factor(bFGF) and its mRNA on the neurons of corresponding spinal cord was detected. Computer image analysis system was used to calculate the result. RESULTS: After the root avulsion of brachial plexus occurred, expression of NGF increased and reached to the peak at the 1st day. It subsided subsequently but was still higher than normal control until the 12th week. While expression of bFGF and its mRNA increased in the neurons of spinal cord and reached to the peak at the 1st week. Then it dropped down and at the 12th week it turned lower than normal control. CONCLUSION: After root avulsion of brachial plexus, neurotrophic factors expression increase on target muscle and neurons of corresponding spinal cord. It maybe the autoregulation and may protect neuron and improve nerve regeneration.
Objective To study and compare the effect of end-to-end and end-to-side neurorrhaphy between the reci pient’s musculocutaneous nerve and the donor’s ulnar nerve, and to observe the regeneration of peri pheral nerve and muscle refection. Methods Sixty male SD rats (weighing 200-250 g) were randomized into 2 groups (n=30 per group), and made the musculocutaneous nerve injury model. In group A, the donor’s nerve was transected for end-to-end neurorrhaphy.In group B, an epineurial window was exposed and the distal end of the muscle branch of musculocutaneous nerve was sutured to the side of the ulnar nerve. Electromyography was performed, biceps wet weight ratio, muscle fiber cross-sectional area, and count of myel inated nerve fiber (CMF) were measured at 4 and 12 weeks postoperatively. The behavior changes of the rats were observed. Results At 4 weeks, the nerve conduction velocity (NCV) and the latency ampl itude (AMP) of group A were significantly higher than those of group B (P lt; 0.05); at 12 weeks, there was no significant difference in the NCV and AMP between groups A and B (P gt; 0.05). At 4 and 8 weeks, there was no significant difference in biceps wet weight ratio and muscle fiber cross-sectional area between groups A and B (P gt; 0.05). At 4 weeks, the CMF was 230.15 ± 60.25 in group A and 160.73 ± 48.77 in group B, showing significant difference (P lt; 0.05); at 12 weeks, it was 380.26 ± 10.01 in group A and 355.63 ± 28.51 in group B, showing no significant difference (P gt; 0.05). Conclusion Both end-to-end and end-to-side neurorrhaphy have consistent long-term effect in repair of brachial plexus upper trunk injury.
The results of nerve transposition for root avulsion of brachial plexas in 21 cases were reported. The methods of the nerve transposition were divided into four groups as followings: By transfer of phrenic nerve, accesory nerve, the motor branches of cervical plexus and intercostal nerves in cease; By transfer of phrenic nerve, accessory nerve and the motor branches of cervical plexus in 6 cases; By transfer of phrenic nerve and accessory nerve in 9 cases, and by transfer of phrenic nerve or the motor branches of cervical plexus or intercostal nerve in 5 cases. During operation, in 1 cases variation of the brachial plexus was found. Injury to the subclavian artery occurred in 4 cases and they were repaired, which is good for the blood circulation of the upper arm and nerve regeneration. Nineteen cases were followed up with good results. The overall excellent and good rate was 73.7%. It was considered that transposition of nerve should be a routine operation for the treatment of root avulsion of brachial plexus and the accompanied arterial injury should be repaired at the same time during operation, and the latter would be advantageous to enhance functional recovery of nerve.
Objective To review the recent development of extraplexal neurotization as a treatment for brachial plexus injuries. Methods Relevant literature was extensively reviewed.The new development, the advantages and disadvantages of extraplexal neurotization were comprehensively evaluated and analyzed. Results After many years of clinical research, great improvement in treatment of brachial plexus injuries was achieved. There were more donor nerves and better use of every donor nerve was made.Conclusion Extraplexal neurotization is an effective treatment for brachial plexus injuries.
Objective To explore the effect of spinal neural progenitor transplantation to the cervical spinal on treating brachial plexus injury with the reimplantation of the avulsed spinal roots. Methods Thebrachial plexusavulsed injury model was made on 54 rats and they were evenly divided into 3 groups: fresh group, chronic group, control group. The spinal neural progenitor was cultured and identified. Then 10 μl（1×105/μl）cells were labelled with BrdUand transplanted into the fresh group (15 rats survived, being model for 1 week) and the chronic group (14 rats survived, being model for 2 months). No cell was transplanted into the control group. Two months after the transplantation, therecovery of function of the injured limb was evaluated. Electrophysiologic study and immunohistochemical study of the injured limb were made. Results Spinal neural progenitors were isolated from the spine and became neural sphere. The neural spheres were differentiated into neurons and astrocytes. Fourteen rats out of 15 in the fresh group were recovered, 7 rats out of 14 in the chronic groupwere recovered, and 5 rats out of 12 in the control group were recovered. Immunohistochemical study indicated that the transplanted progenitors in fresh group survived and differentiated into the neural cells, and the transplanted progenitors in chronic group existed and did not differentiate well. Conclusion Transplanted spinal neural progenitors can promote the recovery of the brachial plexus injury with the reimplantation of the avulsed spinal root.
OBJECTIVE To observe the ultrastructural changes and number of satellite cells in different muscles with different denervation interval and investigate the mechanism of denervation atrophy. METHODS Muscles of different denervation interval were harvested, which were 6 biceps brachii and 6 abductor digiti minimi. The ultrastructure of the samples were observed under transmission electron microscope. The number of nucleus and satellite cells were counted to calculate the percentage content of satellite cells. RESULTS In early stage of denervation, the myofilament and sarcomere of the majority were well oriented. The nucleoli of some muscle cell nucleus were enlarged and pale. Vacuolarization was also seen in some mitochondria. There was no obvious proliferation of collagen fiber around myofibers. After denervation of half a year, rupture and disorientation of myofilament was seen. The nucleus became smaller, dark stained, and some of them were condensed. There was proliferation of fibroblasts, adipose cells and collagen fibers around myofibers. Motor endplate was not recognized one year after denervation. In the early stage of denervation, satellite cell percentage of the two muscles was relatively high. It then declined with time. One year after denervation, satellite cells were scarcely detected. Comparison of the curves for satellite cell declination in two muscles revealed that the declination of the abductor digiti minimi was faster than that of biceps brachii. Decrease of the former started 3 months after denervation, while the latter started after 6 months. CONCLUSION Disappearing of motor endplate and proliferation of collagen fibers are main factors that affect the treatment outcome in late cases. Decrease of satellite cell number is another cause. The correlation of less satellite cell in abductor digiti minimi and poorer recovery of hand intrinsic muscles indicates that increment of satellite cells in long-term denervated muscles may be one of the effective measures to improve treatment outcome.
Objective To investigate the quantity and distribution of motor fiber of rat’s C7 nerve root. Methods Motor fiber quantity and section area in the main nerves of the upper extremity and the fascicles of C7 in 30 SD rats were analyzed.Results Fascicles and certain amount (207) of motor fibers from the anterior division of C7 were distributed to musculocutaneous nerve and median nerve, the orientation of these fibers were not clear. The ones (323) from posterior division were to the axillary, radial, and dorsal thoracic nerves, thus the orientation of these fascicles was relatively definite. Conclusion Thedistribution of the motor fibers and fascicles in the divisions of C7 in rat is similar to human beings, so rat is a relatively good model for the study of selective C7 nerve root transfer.
【Abstract】 Objective To observe the distribution feature of nerve bundles in C7 nerve anterior and posterior division end. Methods The brachial plexus specimen was harvested from 1 fresh adult cadaver. After C7 nerve was confirmed, the distal end of anterior and posterior division was dissected and embedded by OCT. Then the samples were serially horizontally sliced with each 10 μm deep. After acetylcholinesterase (AChE) histochemical staining, the stain characteristics of different nerve fiber bundles were observed and amount of the nerve fiber bundles were counted under optic-microscope. At last, the imaging which were collected were three-dimensional (3-D) reconstructed by using Amira 4.1 software. Results There was no obvious difference in the stain between the anterior and posterior divisions. The running of the nerve fiber bundles were dispersive from proximal end of nerve to distal end of nerve. Nerve fiber bundles of anterior division were mainly sensor nerve fiber bundles, which located in medial side. Nerve fiber bundles of posterior division were mainly moter nerve fiber bundles, having no regularity in the distribution of nerve fiber bundles. The total number of nerve fiber bundles in distal end of anterior division was 7.85 ± 1.04, the number of motor nerve fiber bundles was 2.85 ± 0.36, and the number of sensor nerve fiber bundles was 5.13 ± 1.01. The total number of nerve fiber bundles in distal end of posterior division was 9.79 ± 1.53, the number of motor nerve fiber bundles was 6.00 ± 0.69, and the number of sensor nerve fiber bundles was 3.78 ± 0.94. There were significant differences in the numbers of motor and sensor nerve fiber bundles between anterior and posterior divisions (P lt; 0.05). The microstructure 3-D model was reconstructed based on serial slice through Amira 4.1. The intercross and recombination process of nerves bundles could be observed obviously. The nerve bundle distribution showed cross and combination. Conclusion Nerve fiber bundles of anterior division are mainly sensor nerve fiber bundles and locate in medial side. Nerve fiber bundles of posterior division are mainly motor nerve fiber bundles, which has no regularity in the distribution of nerve fiber bundles. The 3-D reconstruction can display the internal structure feature of the C7 division end.
Objective To analysis the electrophysiological dominance weight of the triceps brachii muscle/extensordigitorum communis muscle innervated by brachial plexus and to conclude its effect on the ipsilateral C7 transfer so as to offer electrophysiological data for the safety and indication of i psilateral C7 transfer. Methods From August 2007 to October 2007, 15 patients with complete brachial plexus nerve root avulsion received contralateral C7 transfer. There were 13 males and 2 females aged 18-49 years (28 years on average). Injury was caused by fall ing in 1 case, by crush in 2 cases and by traffic accident in 12 cases, involving left side in 8 cases and right side in 7 cases. The upper, middle and lower trunk of the brachial plexus were stimulated respectively, the compound muscle action potential (CMAP) at the triceps brachii muscle/extensor digitorum communis muscle was recorded, and then the electrophysiological dominance weight of the triceps brachii muscle/extensor digitorum communis muscle innervated by brachial plexus was confirmed according to the comparison of the ampl itude percentage of the CMAP by three trunks. The muscle strength of triceps brachii muscle/extensor digitorum communis muscle was evaluated and the electromyogram was taken 6 months after operation. Results All patients were followed up for 6 months. Concerning the electrophysiological dominance weight, the triceps brachii muscle was mainly innervated by uppermiddle trunk in 3 cases (20%), by middle-lower trunk in 3 cases (20%), by whole trunk in 7 cases (47%) and by middle trunk in 2 cases (13%). While the extensor digitorum communis muscle was mainly innervated by middle-lower trunk in 3 cases (20%), by whole trunk in 10 cases (67%) and by lower trunk in 2 cases (13%). Concerning the triceps brachii muscle, 2 patients got the muscle strength of 4 grade with recruitment simple phase at 1 month after operation and returned to normal at 3 month after operation, while 13 patients got the muscle strength of 5 grade with recruitment simple or mixed phase at 1 month after operation. Concerning the extensor digitorum communis muscle, the muscle strength and the recruitment phase of all 15 patients recovered to normal at 1 month after operation. Conclusion To patients with various kinds of electrophysiological dominance weight, the cutting of C7 does not substantially damage the triceps brachii muscle or extensor digitorum communis muscle, indicating that the ipsilateral C7 transfer is safe and feasible. However, it should be appl ied prudently for the patients with high dominance weight since it may result in the short-term decrease of triceps brachii muscle strength.
【Abstract】 Objective To investigate the feasibil ity of contralateral C7 nerve transfer via posterior spinal route fortreatment of brachial plexus root avulsion injury by anatomical study. Methods Ten cadaveric specimens of 7 men and3 women were selected, who had no obvious deformity and no tissue defect in neck neutral position. By simulating surgical exploration of brachial plexus injury, the length of contralateral C7 nerve root was elongated by dissecting its anterior and posterior divisions to the distal end, while the length of C7 nerve from the intervertebral foramen to the branching point and the length of the anterior and posterior divisions were measured. By simulating cervical posterior approach, the C7 vertebral plate and T1 spinous process were fully exposed; the hole was made near vertebral body; and the C7 nerve root lengths by posterior vertebra path to the contralateral upper trunk and lower trunk were measured. Results C7 nerve root length was (58.62 ± 8.70) mm; the length of C7 nerve root plus posterior or anterior division was (65.15 ± 9.11) mm and (70.03 ± 10.79) mm, respectively. By posterior spinal route, the distance was (72.12 ± 10.22) mm from the end of C7 nerve to the contralateral upper trunk of brachial plexus, and was (95.21 ± 12.50) mm to the contralateral lower trunk of brachial plexus. Conclusion Contralateral C7 nerve can be transferred to the contralateral side through posterior spinal route and it only needs short bridge nerve or no. The posterior spinal route can effectively prevent from neurovascular injury, so it might be the best surgery approach for the treatment of brachial plexus root avulsion injury.
