Ipsilateral C7 Nerve Research Articles

The prerequisites and clinical outcomes of ipsilateral C7 nerve root transfer to the upper trunk for adult C5-C6 brachial plexus injuries.

Although ipsilateral C7 nerve transfer is used for the treatment of C5-C6 brachial plexus injuries, accurately evaluating the functional quality of the donor nerve (ipsilateral C7 nerve root) is difficult, especially when the C7 nerve root is slightly injured. The purpose of this study was to determine the indicators to evaluate the quality of the ipsilateral C7 nerve and assess the clinical outcomes of this procedure. This study employed the following three indicators to assess the quality of the ipsilateral C7 nerve: (1) the muscle strength and electrophysiological status of the latissimus dorsi, triceps brachii, and extensor digitorum communis; (2) the sensibility of the radial three digits, especially the index finger; and (3) the intraoperative appearance, feel and electrophysiological status of the ipsilateral C7 nerve root. Transfer of the ipsilateral C7 nerve root to the upper trunk was implemented only when the following three tests were conducted, the criteria were met, and the clinical outcomes were assessed in eight patients with C5-C6 brachial plexus injuries. Patients were followed-up for an average of 90 ± 42months. At the final follow-up, all eight patients achieved recovery of elbow flexion, with five and three patients scoring M4 and M3, respectively, according to the Medical Research Council scoring. The shoulder abduction range of motor recovery averaged 86 ± 47° (range, 30°-170°), whereas the shoulder external rotation averaged 51 ± 26° (range, 15°-90°). Ipsilateral C7 nerve transfer is a reliable and effective option for the functional reconstruction of the shoulder and elbow after C5-C6 brachial plexus injuries when the three prerequisites are met.

Preliminary results of posterior contralateral cervical 7 nerve transposition in the treatment of upper limb plegia after a stroke.

ObjectiveThis study aimed to explore a shorter and safer contralateral C7 transposition pathway for the treatment of central upper limb paralysis.MethodsFrom July 2018 to March 2019, 10 patients with central upper limb paralysis underwent posterior cervical 7 nerve transposition. The age of these patients ranged within 31–58 years old (average: 44 years old). These patients comprised of eight male patients and two female patients. Nine patients had cerebral hemorrhage, and one patient had a cerebral infarction. Furthermore, nine patients presented with spastic paralysis of the upper limbs and one patient presented with nonspastic paralysis. The duration of plegia before the operation ranged from 6 to 60 months (average: 26 months). The surgical procedure included transposition of the contralateral cervical 7 nerve root via a posterior vertebral approach under general anesthesia, and the distal part of the contralateral cervical 7 nerve was anastomosed with the proximal part of the ipsilateral cervical 7 nerve.ResultsThe length of the contralateral cervical 7 nerve was 5.16 ± 0.21 cm, which was directly anastomosed with the ipsilateral cervical 7 nerve. Neither case needed nerve transplantation. Most patients had temporary numbness in their healthy fingers, which all disappeared within three months. Up to now, the follow‐up results are as follows: The spasticity of the affected upper limbs in five patients is lower than that before the operation, the pain and temperature sensation of the affected upper limbs in six patients are better than before the operation.ConclusionThe distance of nerve transposition can be shortened by a posterior vertebral approach operation, where the contralateral C7 nerve can be anastomosed directly with the ipsilateral C7 nerve which may be effective for nerve regeneration and functional recovery. However, this conclusion still needs further research and verification.

Nerve transfer in the management of upper extremity paralysis after brachial plexus and central neurologic injuries: Experience of Huashan

Huashan Hospital receives the largest population of brachial plexus injury patients in China. Here, we presented our latest follow-up cases and newest strategies of nerve transfer in different types of brachial plexus injury, including both supra- and infra-clavicular injuries. The most challenging brachial plexus avulsion injuries (BPAI) involving partial (upper/lower) or global plexus will be mainly discussed. We will focus on optimized combination of nerve transfer strategies for perusing the best outcomes, especially the distal functions. In partial brachial plexus injury patients, several intra-brachial plexus donor nerves are utilized, such as brachialis branch of the musculocutaneous nerve, superior motor branch of the median nerve, partial ipsilateral C7 nerve. The extended applications of contralateral C7 nerve transfer and full-length phrenic nerve transfer will be specifically introduced. Moreover, special brachial plexus injury types with non-classical nerve transfer surgery are also included. As the central nervous system plays an important part in the rehabilitation process of peripheral nerve injury, we further explored the relationship between brachial plexus injury-repair (transfer) and brain reorganization. Based on our previous researches, the contralateral C7 nerve transfer shows the capacity of inducing the compensation potential of the intact hemisphere after unilateral central neurologic injury (e.g. cerebral palsy, traumatic brain injury, stroke). The contralateral C7 nerve transfer was thus used in treating hemiplegic upper extremities and applied in more than 50 patients. The preliminary results of these cases will also be presented.

Congenital subaxial cervical subluxation presenting as a bilateral Erb’s palsy: surgical management, rehabilitation, and outcome

Subaxial spine injuries during infancy are uncommon. We present the case of an infant referred to our brachial plexus clinic with proximal weakness of both arms noted immediately following a complicated breech delivery. Nerve conduction studies were consistent with bilateral proximal upper plexus injury; however, radiological evaluation revealed a C4-C5 subluxation and MRI features of bilateral C5 root avulsions. He was immobilized in a cervical-body orthosis and underwent open reduction and posterior C4-C5-C6 fixation at 10weeks age using luque rods, sublaminar wires, and rib graft. The spine was immobilized in a custom molded cervicothoracic brace for a total of 3months, and a home exercise program prescribed. Follow-up radiographic evaluation showed good posterior bony fusion by 2months but persistent bilateral proximal upper limb weakness with reduced compound motor action potential (CMAP) amplitudes of the axillary and musculocutaneous nerves. Bilateral supraclavicular exploration and C5 root neurotization using the ipsilateral C7 nerve roots were performed at 7months of age. Voluntary biceps activity followed by voluntary external rotation with gravity eliminated was noted within the next 2-3months. He progressed to develop near normal motor control of bilateral upper limbs within 1year. We wish to report this rare entity and our favorable outcome using a strategy of early spinal stabilization and neurotization repair to restore function following proximal nerve root injury.

The impact of different degrees of injured c7 nerve transfer: an experimental rat study.

Background:Ipsilateral C7 nerve transfer is an available procedure in C5C6 2-root avulsion injury of the brachial plexus. However, concomitant injury of a normal-looking C7 cannot be ruled out. The efficiency of a concomitant injury of C7 transfer was investigated.Methods:Forty-two Sprague-Dawley rats were randomly assigned to 5 groups. They all underwent a 2-stage procedure. In the first stage from dorsal spine approach, left C5 and C6 roots were avulsed and C7 was crushed with jeweler’s forceps with different degrees: group A (n = 6), C7 not injured; group B (n = 10), C7 crushed for 10 seconds; group C (n = 10), C7 crushed for 30 seconds; group D (n = 10), C7 doubly crushed for 60 seconds; and group E (n = 6), C7 transected and not repaired. Four weeks later in the second stage, the C7 was reexplored via volar approach, transected, and coapted to the musculocutaneous nerve. At 12 weeks following the nerve transfer, functional outcomes were assessed.Results:Grooming test, muscle weight, electromyography, and muscle tetanic contraction force all showed that the biceps muscles were significantly worse in group C (moderate crush) and group D (severe crush). Group B (mild crush) and group A (uninjured) showed no difference. Group E (C7 cut and not repaired) was the worst.Conclusions:An injured but grossly normal-looking ipsilateral C7 can be used as a motor source but with variable results. The result is directly proportional to the severity of injury, potentially implying that better results will be achieved when longer regeneration time is allowed.

End‐to‐side neurotization with different donor nerves for treating brachial plexus injury: An experimental study in a rat model

End-to-side neurotization is currently used to treat brachial plexus injury, but it is not clear which donor nerve yields the best outcome. We performed experiments to determine the optimal donor nerve. A total of 66 male Sprague-Dawley rats were assigned to 1 of 3 groups. Group A was the control group. In Group B, the phrenic nerve was used as the donor, while the ipsilateral C7 nerve root served as the donor in Group C. The epineurial window was used in end-to-side neurorrhaphy. Behavioral observations, histology, electrophysiology, and fluorescence retrotracing were performed postoperatively. Fluorescence retrotracing confirmed nerve regeneration in both Groups B and C upon end-to-side neurotization. The outcome of Group B was superior to that of Group C. Use of the phrenic nerve as the donor nerve yielded a better outcome than use of the ipsilateral C7 nerve root.

Total ipsilateral C7 root neurotization to the upper trunk for isolated C5-C6 avulsion in obstetrical brachial plexus palsy: a preliminary technical report

C5-C6 root avulsion in obstetrical brachial plexus palsy (OBPP) is a rare injury with poor prognosis usually associated with breech delivery. The treatment is challenging and requires high microsurgical skills. The triple nerve transfer (spinal accessory nerve, ulnar fascicles, and triceps long or lateral head branch) represents the gold standard treatment. The total ipsilateral C7 nerve root neurotization is a promising technique, which has never been described in OBPP. The total ipsilateral C7 nerve root is used as a neurotizer transferred to the upper trunk as an alternative method to other intra- or extra-plexual reconstruction techniques. During brachial plexus surgical exploration, an intraoperative neurostimulation was performed to confirm the integrity of C7 and the lesion of C5 and C6. The entire C7 nerve root and the upper trunk are cut. The C7 root was transferred to the upper trunk with a fibrin sealant. This technique was easily performed with a single approach and avoided intercalated nerve grafts. The C7 nerve root provided a large number of nerve fibers with an adequate diameter to be transferred to the upper trunk. We illustrated this technique with a typical case of a child at 8 years of follow-up. The total ipsilateral transfer of the C7 root to the upper trunk is a viable alternative procedure for newborns with C5-C6 avulsion.

Effect of Ipsilateral C7 Nerve Root Transfer on Restoration of Rat Upper Trunk Muscle and Nerve Function After Brachial Plexus Root Avulsion

The effects of ipsilateral cervical nerve root transfer on the restoration of the rat upper trunk muscle and nerve brachial plexus root avulsion were studied. After simulated root avulsion of the upper trunk brachial plexus, 120 rats were randomly divided into 4 groups: (A) ipsilateral C7 root transfer group; (B) Oberlin group; (C) phrenic nerve group; and (D) no axillary nerve restoration group. At 3, 6, and 12 weeks postoperatively, Ochiai score, Barth feet overreaching test, Terzis grooming test, and indices of neurotization were determined in 10 rats from each group. Twelve weeks postoperatively, nearly all the behavioral, neuroelectrophysiological, and histological outcomes of the axillary nerve and deltoid muscle and some of the indices of musculocutaneous nerve and biceps brachii function in the ipsilateral C7 group were superior to those in the other 3 groups. No significant difference was found between the ipsilateral C7 group and the other 3 groups in recovery rate of wet biceps muscle weight. No significant difference was found between the ipsilateral C7 group and the Oberlin group in the recovery of the axillary nerve compound muscle action potential and biceps brachii cell size. No significant difference was found between the ipsilateral C7 group and the phrenic nerve and no axillary nerve restoration groups in amplitude recovery rate of musculocutaneous nerve compound muscle action potential. No significant difference was found between the ipsilateral C7 and the Oberlin groups in the early recovery of musculocutaneous nerve compound muscle action potential, but recovery was significantly better in the ipsilateral C7 group at 12 weeks. Ipsilateral C7 root transfer can improve the quality of restoration of muscle and nerve function in the rat upper trunk after brachial plexus root avulsion.

Microanatomical study on the functional origin and direction of the thoracodorsal nerve from the trunks of brachial plexus

Ipsilateral C7 nerve root transfer or neurotization has been used for the repair of brachial plexus avulsions. In this procedure, the ipsilateral C7 nerve root is used as a donor nerve and is implanted into the damaged nerve of the brachial plexus in order to reinnervate distal muscles. However, this procedure may result in unintended injury to the thoracodorsal nerve, which receives motor fascicles form the cervical nerves of C6, C7, and C8, but mainly from C7. Damage to the thoracodorsal nerve ultimately results in weakness or paralysis of the latissimus dorsi muscle, which it innervates. In the present study, 20 adult cadaveric brachial plexus specimens and 3 fresh specimens were dissected using microscopy. The origin and direction of motor fascicles from the three trunks of the brachial plexus to the thoracodorsal nerve were investigated. Motor fiber counts of C7 and the thoracodorsal nerve were also performed. Several observations can be made: (1) The origin of the thoracodorsal nerve can be divided into three types: Type A, the thoracodorsal nerve originated from the superior and middle trunks; Type B, the thoracodorsal nerve originated from the inferior and middle trunks; and Type C, the thoracodorsal nerve originated from all three trunks. (2) More than 52% of the motor fibers in the thoracodorsal nerve originated in the C7 nerve root. (3) Motor fascicles from C7 to the thoracodorsal nerve were mostly localized in the posterior-internal part of C7 at the trunk-division boundary. In conclusion, we suggest that: (1) Because of variation in the origin of the thoracodorsal nerve, electromyography should be routinely performed intraoperatively during C7 nerve root transfer to determine the origin type and avoid thoracodorsal fascicle injury. (2) Preservation of the posterior-internal part of C7 (selective C7 transfer) can protect thoracodorsal nerve fascicles from damage and prevent postoperative dysfunction of the latissimus dorsi muscle.

An experimental study on outcome of ipsilateral C7 nerve root transfer to repair the root avulsion of the brachial plexus

To experimentally compare the treatment outcome of the injured upper limb of the root avulsion of C5 and C6 of the brachial plexus repaired by ipsilateral C7 nerve root transfer and other three multiple nerve transfers. One hundred and twenty SD rats of simulated C5 and C6 root avulsion randomly divided into 4 groups, and 30 each underwent various combined nerve transfers. Group A: the ipsilateral C7 root transferred to the upper trunk of brachial plexus and the spinal accessory nerve to the suprascapular nerve; Group B: partial fascicles of the ulnar nerve transferred to the biceps branch (Oberlin's procedure), the spinal accessory to the suprascapular and branches to the triceps long head to the axillary nerve; Group C: the phrenic transferred to the musculocutaneous, cervical plexus motor branches to the lower trunk (axillary nerve) of brachial plexus and the spinal accessory nerve to the suprascapular nerve; Group D: the phrenic transferred to the musculocutaneous and the spinal accessory nerve to the suprascapular nerve. Neurotization outcomes were evaluated at 3, 6 and 12 weeks postoperatively by comparing changes of behavioral tests (Ochiai clinical scores, Barth Foot-fault test and Terzis grooming test), neurophysiological investigations and muscular histology. At 3 weeks after operation, no significant difference was found between Group A and other three control groups in the three behavioral evaluations. Neurophysiologic investigations of the axillary nerve showed that Group A was superior to the other three groups. Muscular histological outcome of the axillary nerve and deltoid muscle showed that Group A was superior to the Group C and D, while no significant difference was found between Group A and B. Except that the thruput of regenerating medullated musculocutaneous nerve fibers of Group A was superior to Group C, neurophysiological and histological outcome of the musculocutaneous nerve and biceps showed that no significant difference was found between Group A and other three groups. At 12 weeks postoperatively, nearly all the behavioral, neurophysiological and histological determination showed that Group A was superior to the other three groups. Ipsilateral C7 transfer to the upper trunk of brachial plexus combined with the spinal accessory nerve to the suprascapular nerve is found to be significantly effective on treatment of the root avulsion of C5 and C6 of the brachial plexus.

Clinical application of ipsilateral C7 nerve root transfer for treatment of C5 and C6 avulsion of brachial plexus.

We applied a nerve transfer, using the ipsilateral C7 nerve root to treat the C5 and C6 root avulsion of the brachial plexus. Four patients with C5 and C6 preganglionic injury were operated on with this new technique from 1998-2000. Transfer of the spinal accessory nerve to the suprascapular nerve was simultaneously done in 2 these patients. After a follow-up of 1-2.5 years, the muscle strength of elbow flexors recovered to M4 (Lovett) in all cases, shoulder abduction of >90 degrees with external rotation of 30-40 degrees was gained in two cases, and that of 15-45 degrees with no external rotation in the other two cases. No remarkable impairment was found in all C7-innervated muscles except for decrease of muscle power of 1 grade (Lovett) in the short run. This new technique shows promise as an efficacious and safe treatment for C5 and C6 root avulsion of the brachial plexus. However, it should be applied prudently when incomplete injuries of the lower trunk are involved.