Objective To review the advances of functional electrical stimulation(FES) in treatment of peripheral nerve injuries. Methods By index of recent literature, the measures of stimulation, the mechanisms of FES and unsolved problems were evaluated and analyzed. Results Great advances have been made in the treatment of peripheral nerve injuries. It can not only enhance the regeneration of injured peripheral nerve, but also prevent muscular atrophy. Conclusion FES is an effective treatment for peripheral nerve injuries.
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 explore the regularity of the change of S-100 protein in degenerative nerve after different pathological brachial plexus injuries. METHODS Eighty SD rats were randomly divided into two groups, right C5, C6 preganglionic injury, and postganglionic injury. The distribution and content of S-100 protein in distal degenerative nerve were detected after 1, 2, 3 and 6 months of injury by immunohistochemical methods. RESULTS The S-100 protein was mainly distributed along the axons. The S-100 protein positive axons of each time interval decreased after operation, with significant difference from normal nerves (P lt; 0.01). There was no statistically significant difference among 1, 2, 3 and 6 months group (P gt; 0.05). The S-100 protein stain of postganglionic group was negative. CONCLUSION In preganglionic injury, the functional expression of Schwann’s cells in the distal stump keeps at a certain level and for a certain period. Since Schwann’s cell has inductive effect on nerve regeneration, it suggests that the distal nerve stump in preganglionic injury can be used as nerve grafts.
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.
Objective To observe the delaying effect of neural stem cell (NSC) transplantation on denervated muscle atrophy after peri pheral nerve injury, and to investigate its mechanism. Methods NSCs were separated from the spinal cords of green fluorescent protein (GFP) transgenic rats aged 12-14 days mechanically and were cultured and induced to differentiate in vitro. Thirty-two F344 rats, aged 2 months and weighed (180 ± 20) g, were randomized into two groups (n=16 per group). The animal models of denervated musculus triceps surae were establ ished by transecting right tibial nerve and commom peroneal nerve 1.5 cm above the knee joints. In the experimental and the control group, 5 μL of GFP-NSCsuspension and 5 μL of culture supernatant were injected into the distal stump of the tibial nerve, respectivel. The generalcondition of rats after operation was observed. At 4 and 12 weeks postoperatively, the wet weight of right musculus tricepssurae was measured, the HE staining, the Mallory trichrome staining and the postsynaptic membrane staining were adopted for the histological observation. Meanwhile, the section area of gastrocnemius fiber and the area of postsynaptic membrane were detected by image analysis software and statistical analysis. Results The wounds in both groups of animals healed by first intension, no ulcer occurred in the right hind l imbs. At 4 and 12 weeks postoperatively, the wet weight of right musculus triceps surae was (0.849 ± 0.064) g and (0.596 ± 0.047) g in the experimental group, respectively, and was (0.651 ± 0.040) g and (0.298 ± 0.016) g in the control group, respectively, showing a significant difference (P lt; 0.05). The fiber section area of the gastrocnemius was 72.55% ± 8.12% and 58.96% ± 6.07% in the experimental group, respectively, and was 50.23% ± 4.76% and 33.63% ± 4.41% in the control group, respectively. There were significant differences between them (P lt; 0.05). Mallory trichrome staining of muscle notified that there was more collagen fiber hyperplasia of denervated gastrocnemius in the control group than that in the experimental group at 4 and 12 weeks postoperatively. After 12 weeks of operation, the area of postsynaptic membrane in the experimental group was (137.29 ± 29.14) μm2, which doubled that in the control group as (61.03 ± 11.38) μm2 and was closer to that in normal postsynaptic membrane as (198.63 ± 23.11) μm2, showing significant differences (P lt; 0.05). Conclusion The transplantation in vivo of allogenic embryonic spinal cord NSCs is capable of delaying denervated muscle atrophy and maintaining the normal appearance of postsynaptic membrane, providing a new approach to prevent and treat the denervated muscle atrophy cl inically.
Objective To recover the loss of the shoulder and elbow function after superior trunks injury of brachial plexus through multi ple nerves branch transfer simultaneously near the nerve entering points of reci pient nerves. Methods Four male patients (aged 21-39 years) with superior trunks injury of brachial plexus were treated from February to September 2007. All cases were injured in the traffic accident, left side in 1 case and right side in 3 cases, resulting in the loss of shoulder abduction, shoulder extorsion, shoulder l ift and elbow flexion, and the increase of muscle strength of shoulder shrug, elbow extension and finger flexion to above or equal to 4th grade. Patients were hospital ized 3-11 months afterinjury. Electromyography showed that the functions of accessory nerve, ulnar nerve and the branch to long head of tricepsbrachii were good, but the function of median nerve was injured partially. The following multiple donor nerves transfer were performed under general anaesthesia, namely from posterior approach accessory nerve to suprascapular nerve, from triceps to axillary nerve, from the partial branch of ulnar nerve to the biceps and/or brachial is muscular branch of musculocutaneous nerve. Results All incisions healed by first intention. One case suffered postoperative numbness on the ulnar side of hand and was symptomatically rel ieved after expectant treatment, while 3 cases had no manifestation of the motor and sensory functional injury related to donor nerve. All patients were followed up for 7-12 months. All patients regained the shoulder abduction and the elbow flexion 3-4 months after operation and electromyography showed that there was the regenerative potential in 3 recipient muscles. The shoulder abduction, elbow flexion and the muscle strength of the patients was 30-65°, 90-120° and 3-4 grade, respectively, 6-7 months after operation. Twelve months after operation, the first patient’s shoulder abduction, external rotation, superduction and elbow flexion almost returned to normal, and his shape of triangular muscle and biceps muscle were nearly normal. Conclusion Adopting donor nerves with similar functions to conduct the multiple donor nerves transfer in cord level has the advantages of l ittle functional loss at the donor sites, and fast and sound functional recovery at the reci pient sites. It is especially suitable for the superior trunks injury patient with delayed treatment and for the patient with the great risk in supraclavicular exploration, providing a new approach for treating superior trunks injury of brachial plexus.