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.
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 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.
Objective To study the effect of olfactory ensheathingcells(OECs) transplantation on protecting spinal cord and neurons after peripheral nerve injury. Methods Fifty-five SD rats were randomly divided into blank group (n=5), experimental group (n=25) and control group (n=25). The right sciatic nerves of all the rats were transected. The proximal end was embedded in muscle and treated with OECs (experimental group) and DMEM (control group). No treatment was given to the blank group. The rats were sacrificed 1, 2, 3, 7, and 14 days after the transplantation, the related neurons were observed with histological and TUNEL methods. Results After sciatic nerves were transected, death of neurons occurred in spinal cord and ganglion. One, 2, 3 days after treatment, the neuron survival rate in experimental group was 98.4％±6.5%，97.6％±6.5%，95.2％±6.7% respectively. The neuron survival rate in control group was 97.8％±6.7%，97.4％±6.4%，94.3％±6.8% 1, 2, and 3 days after treatment respectively. There was no significant difference between experimental group and control group. Seven and 14 days after treatment, the neuron survival rate in experimental group was 92.4％±8.9%，87.7％±9.4% respectively. The neuron survival rate in control group was 87.4％±8.6%，83.4％±8.5% 7 and 14 days after treatment respectively. There was significant difference between experimental group and control group. On 1st and 2nd day, no apoptosis was seen in spinal cord anterior horn of the rats in both experimental group and control group. On 3rd, 7th, and 14th day, the apoptosis index of spinal cord anterior horn motoneuron in experimental rats were lower（1.2±0.8，1.4±0.6，4.1±1.3） than that in the control group（2.1±1.1，3.1±1.1，6.1±1.8）（Plt;0.05）. One, 2, and 3 days after the operation, no ganglion neurons apoptosis was observed in all rats. On 7th day the apoptosis index of ganglion neurons in experimental group（2.10±0.32）were lower than thatin control group （4.40±0.56）（Plt;0.05）. On 14th day there was no significant difference in the apoptosis index of ganglion neurons between experimental group （4.30±1.80）and control group（6.70±2.50）(P＜0.05). Conclusion Apoptosis of neurons occur after peripheral nerve injury in spinal cord and ganglion. OECs transplantation is effective in preventing apoptosis.
Motor endplate is the structure connected between the nerve terminal and muscle fibre and plays a very important role in conducting nerve impulses to the target, therefore, systemical study of the sequential changes of the motor end-plate upon denervation is quite important.Ninety New Zealand rabbits were divided into nine groups from two weeks to nine months after denervation. Acetycholinesterase(AchE) was analyzed quantitatively to study the sequential changes of the motorendplates of tibialis anterior muscle. The results showed that there was no significant reduction of AchE at theend if one month after denervation, whereas a sharp reduction of AchE afterwards. AchE could not be stained after five month denervation.
Objective To explore effects of several immunosuppressants on cytokine expressions after repair for a sciatic nerve injury in a rat model. Methods The sciatic nerves of 42 rats were cut and suturedend to end. After operation, the rats were divided into 6 groups. Group A(n=9) was served as a control with no medicines given. Group B (n=9) was given methylprednisolone 20 mg/(kg·d) for 2 days. Groups C(n=9) and D(n=3) were given FK506 1 mg/(kg·d) for 2 weeks and 4 weeks respectively, and were given the same doses of methylprednisolone as Group B. Groups E and F were given CsA 2 mg/(kg·d) for 2 weeks and 4 weeks respectively, and were given the same doses of methylprednisolone as Group B. The sciaticnerves were sampled at 1, 2 and 4 weeks postoperatively. And immuneohistochemistry stainings of interleukin 1β(IL-1β)， tumor necrosis factor α(TNF-α), interferon γ(IFN-γ) and macrophage migration inhibitory factor(MIF) were performed. The staining results were compared and analyzed. Results The expression peaks of IL-1β and IFN-γ were found at the 1st week postoperatively in Group A. Then, the expression decreased rapidly at the 2nd week and disappeared at the 4th week. As for TNF-α and MIF, they were only found to have a low expression until the 1st week in Group A. In groups C-F, the expression peaks of IL-1β, TNF-α and IFN-γ were found at the 2nd week, while the expression peak of MIF was still at the 1st week, and the expression of all the cytokines extended to the 4th week. The expressions of these cytokines in Group B were just between the expression levels of Group A and Groups C-F. Conclusion Immunosuppressants can delay the expression peaks and significantly extend the expression time of IL-1β, TNF-α, IFN-γ and MIF after repair for a sciatic nerve injury in a rat model.
Objective To observe the effect of comprehensive rehabilitation in patients with peripheral nerve injuries after the Wenchuan earthquake. Methods A total of 24 cases of peripheral nerve injuries who were admitted to the Rehabilitation Center for Earthquake Victims of West China Hospital of Sichuan University were treated with comprehensive rehabilitation, including exercise therapy, acupuncture therapy, functional electrical stimulation, and occupational therapy (mainly sensory training and wearing orthosis). After 30 treatment sessions, patient motor and sensory function, upper limb functional activity, and electrodiagnostic parameters were evaluated. Meanwhile, concomitant injuries were also recorded. Results As for the recovery of motor and sensory functions, the effective rate was 41.66%. The difference in the scores of upper limb functional activities was statistically significant before and after treatment (Plt;0.01). As assessed by electromyogram and nerve conduction velocity, the response rate was 87.50%. Patients with more concomitant injuries were likely to have slower recovery. Conclusion Comprehensive rehabilitation is appropriate and effective for patients with peripheral nerve injuries after the Wenchuan earthquake.