Research On The Optimal Operation Styles And The Correlative Brain Plasticity Mechanism Of Contralater C7 Transferring On Brachial Plexus Avulsion

Introduction:Total brachial plexus avulsion is a devastating injury. Contralateral C7 transfer is a safe and reliable operation to treat this injury. The traditional procedure, however, only uses C7 nerve root to neurotize one single nerve amongst the major nerves of the affected upper extremity. Only one type of peripheral nerve is repaired, so, which yield very limited recovery. How to make better use of the abundant nerve fibers of C7 to neurotize more recipient nerves and restore more function is the goal of this study. And the another goal of the research is to investigate brain plastisity following C7 transfer and facilitate regain of independent movement of the affected limb. Clarification of the relationship between brain plasticity and brachial plexus nerve injury and regeneration will enrich the theoretic basis of C7 transfer and also provide guidelines for postoperative rehabilitation to facilitate recovery of independent movement.Part oneThe optimal operation styles nerve transfer of the healthy side C7 nerve root:an experimental studyObjective How to make better use of the abundant nerve fibers of C7 to neurotize more recipient nerves and restore more function is the goal of this study. The other object of the study is to research which one is most suitable operation plan under variety surgical procedure . This study is of clinical significance in that it investigates the outcome of nerve regeneration under various surgical procedures and reveals the most suitable operation plan.Method In this research, 105 adult SD rats were randomly divided into 7 groups from A to G , and left was experiment side. Several new surgical procudurse were designed to improve the function result after the healthy side C7 root transfer using Experimental rat models , which is based on the traditional treatment. The new management options consist of dividing the proximal end of the ulnar nerve into twobranch; one branch is transferred to the median nerve and the other is transferred to the median nerve or radial nerve. The effect of double branch of the surial nerve grafting was also compared with the use of dividing branch of ulnar nerve in the treatment of root avulsion of the brachial plexus. New types surgical procudurse rat models of brachial plexus avulsion were devised to compare the effect of tradition contralateral C7 root transfer. Behavioral analysis of grasping test and grooming test and pawprinting test were carried out by weekly observation at the beginning of the first postoperative month. The latent period and maximum amplitude of evoked motor action potential of the target muscle, number of regenerating myelinated nerve fibers, cross-sectional area and wet weight of the target muscle , and twitch and tetanic tensions of the target musle were measured at three postoperative intervals with 5 in each after operation was tested, electrophysiological of the recipient nerves and functional assessment of target muscles will be carried out to evaluate reinnervation effectiveness of different procedures and to explore which one is the most suitable style.Result As the postoperative interval prolonged, the function of the affected limb was recovery gradually. The best average behavioral results of grasping test and grooming test were observed from A, C, B, E groups and D, C, B groups in decending order. As for pawprinting test, there is no significant difference in E, F, G group. And there was sign of the active finger flexion and elbow flexion 2 months after the operation in groups of repairing median nerve and musculcutaneous nerve . Contrasted with group A, the grasping force was significant difference in the 2 months postoperatively in B^ C> E groups (P<0.05) , but there is no significant difference in the 3months and 6 months(P>0.05). There were no significant differences in B, C> D groups onset of discernible function of the grooming test. The latent period and maximum amplitude and twitch and maximum tetanic muscle contractile tension, muscle wet weight of reinnervated biceps and flexor carpal radials muscle and triceps, numbers of the myelinated nerve fibers distal to the nerve coaptation site of median nerve and musculcutaneous nerve and radial nerve were explored. The results show: there were no significant difference in the 2 months and 3 months (P>0.05) in A> B> C > E groups. However, there were significant difference in the 6months postoperatively compare A,C groups with B,E groups (P<0.05) . The average behavioral results of A,C groups are better than B,E groups. As for musculocutaneous , there were significant difference in the 2 months and 3 months postoperativelycompare B, C, D groups with control groups (PO.05, yet, there were no significant difference in the 6 months (P>0.05) in B>C\D groups and the control groups. As for radial nerve, there were no significant difference in the 2 months, 3 months,6 months (P>0.05) in E, F, G groups. On the contrary, there were significant difference in the 2 months, 3 months, 6 months postoperatively compare E, F, G groups with control groups (P<0.05) . There were no significant impairments of sensory and movement taken placed in the healthy side limb. Above all, the results indicated that there were enough regenerating nerve fibers in the double neurotization procedure models and nerve regeneration in double neurotization group is as good as single neurotization.ConclusionK healthy side C7 root transfer is safe and reliable procudure to manage the brachial plexus avulsion.2> healthy side C7 root contains enough nerve fibers to provide sufficient regeneration for two or more destination nerves.3 C7 root double-neurotization at same time has the advantage of restoring more function and get good effects as the tradition style.4 above all, The best average results were observed in group C. it implicates its future clinical application in treatment of severe brachial plexus avulsion.Part two:Research on anatomic study and clinical application of contralateral C7 transfer to two recipient nerves at the same timeObjective 1 > To provide reliable anatomical basis for more effective and reasonable ues of the medial forearm cutaneous nerve and the ulnar nerve as the graft for healthy side C7 transfer.2, another goal of this study is to investigate how to make better use of the abundant nerve fibers of C7 to neurotize more recipient nerves and restore more function .Method 1 > To observe the branches and course of the medial forearm cutaneous nerve and ulnar nerve. The study was done in 8 fixed and 3 fresh adult cadavers. The medial forearm cutaneous nerve and the branch and the blood supplyvessels was carefully dissected in the upper limb. And the course of the ulnar nerve was also dissected and followed.2 > Based on the traditional procedure, we design a new surgical procudure to improve the functional results after contralateral C7 transfer, one procedures the ulnar nerve is splited and sutured to median nerve and radial nerve by the end to end neurorraphy. In contrast to this technique, the other procedure of C7 transfer via ulnar and sural nerve graft to neurotize two recipient nerves is also devised. 8 patients with total brachial plexus root injury were reviewed at an average of 14 months (range from 14 months to 24 months )after the healthy side C7 transfer. The average time between the injury and the second time operation was 9 months .Result 1 % the medial forearm cutaneous nerve and the ulnar nerve are originated from lower trunk of the brachial plexus and travels (26. 5 + 3. 4) cm long to the elbow joint. The medial forearm cutaneous nerve and ulnar nerve are relatively stable and close each other and can be removed easily in the same incision.the results of median nerve: 3 of the 6 patients obtained M3 recovery and 2 patients had M2 recovery and 1 patient had MO recovery of the wrist and finger flexors. 3 patients obtained S2 and 2 patients obtained SI and 1 patient had SO recovery in the median nerve area. The results of radial nerve: 2 of the 4 patients obtained M2 and 1 patient had M1 recovery of the wrist and finger extensors and 1 patient had M1 recovery of the elbow extensors . 1 patients obtained S2 and 1 patient had SI and 2 patients had SO recovery in the radial nerve area. The result of musculcutaneous : 2 patients had M2 recovery of the biceps . Two patient with C7 transfer via ulnar and sural nerve graft to neurotize median nerve and musculocutaneous nerve obtained M3 recovery of the wrist and finger flexors and M3 recovery of the elbow joint flexors . No motor or sensory deficits related to the healthy side were noted clinically in all patients.Conclusion1 > The medial forearm cutaneous nerve and the ulnar nerve can be as nerve graft for contralateral C7 transfer to treat brachial plexus injury.2 > It is an efficient method for treatment of root avulsion of brachial plexus by C7 root double-neurotization at same time when the donor nerve is limited. It has the advantage of restoring more functionpart threeThe study of brain plasticity on patients with or without healthy side C7 nerveroot transfer by using fMRIObjective The aim of this study was to investigate the relation between the functional rehabilitation and the brain plasticity by applying functional magnetic resonance imaging(fMRI) to map the somatotopic organization of the primary motor cortex using brachial plexus avulsion and voluntary movements of the upper extremity movementThis study also aims to investigate brain plastisity following C7 transfer and facilitate regain of independent movement of the affected limb, and to improve the postoperative rehabilitation and the patient life qualityMethod 10 healthy right handedness volunteers were employed in this study. Motor task consisted of repetitive simple movements of the hands,elbows and foots. fMRI examinations were performed with superconduct 3.0T MR scanner and echo-planer imaging sequence was used. The maps of the most significant voxel of activation area in the whole brain motor related structures was recorded and the statistic analysis of variance was used for values of size and signal intensiy as well as the axis of the Talairach coordinates. Healthy volunteers and brachial plexus avulsion patients were employed in this study. To analysis the signal change of the primary motor cortex of the brachial plexus nerve root avulsion were surgically treated by transferring healthy C7 nerve root to impaired median nerve through bridged ulnar nerve. Statistical significance of fMRI signal changes were observed within contralateral primary motor cortex in all subjects and movement conditions, larger gradually in the following re-examination with time increase.Result In all subjects, The significient activation was predominantly in the contralateral motor areas include primary sensorimotor cortex, lateral premotor, parietal and supplementary motor areas. While the nonprimary motor areas were activated to be more extensive and to be seen in more subjects during the non-dominant hand task than during dominant hand task. Statically significant MR signal changes were observed within contralateral primary motor cortex in all subjectsand movement conditions. The pattern of functional activity in Ml region followed a topographic representation: hand ^ Elbow movements activated area located in order ? Statistic analysis indicated that there were significant differences between both hands. Activation of contralateral M1: The value of activation differed in the three groups. The difference is significient between A and B , That indicates the extent becomes also larger after nerve transfer. Activiation of Ipsilateral Ml : The value of activation differed in the three groups. The difference is significient between A and B,C . That means the intensity becomes transient stronger after nerve transfer. The number of activated pixels differed in the three groups. The difference is significient between C and anyone of A, C. That indicates the extent becomes also transient larger after nerve transfer. To analysis the signal change of the primary motor cortex of the brachial plexus nerve root avulsion were surgically treated by transferring healthy C7 nerve root to repaired median nerve through bridged ulnar nerve. Statistical significance of fMRI signal changes were observed within contralateral primary motor cortex in all subjects and movement conditions. Conclusion1 ^ fMRI is capable of mapping of the motor cortex in different tasks in subjects and can provide qualitive and quantitative information on functional research o2 > functional magnetic resonance imaging provide guidelines for postoperative rehabilitation to facilitate recovery of independent movement and improve life quality. fMRI can provide a valuable tool for the judgment of the effect of treatment on the recovery with peripheral nerve injury.3 -. The functional recovery was due to brain plasticity and positional doing exercise after operation.The study has shown the clinical significance between the the brain plasticity and peripheral nerve regeneration and the extremity functional rehabilitation. The function reorganization of the brain come true successfully following C7 transfer, and the affected limb can dominate only by the contralateral hemisphere ultimately.Part four...