Contralateral C7 transfer in adult plexopathies

Contralateral C7 Nerve Transfer for Stroke Recovery: New Frontier for Peripheral Nerve Surgery

Ischemic stroke remains a major cause of disability in the United States and worldwide. Following the large-scale implementation of stroke thrombectomy and the optimization of treatment protocols for acute stroke, the reduction in stroke-associated mortality has resulted in an increased proportion of stroke survivors, many of whom have moderate to severe disability. To date, the treatment of subacute and chronic stroke has remained a challenge. Several approaches, involving pharmacological interventions to promote neuroplasticity, brain stimulation strategies and rehabilitative interventions, are currently being explored at different stages of the translational spectrum, yet level 1 evidence is still limited. In a recent landmark study, surgical intervention using contralateral C7 nerve transfer, an approach used to treat brachial plexus injury, was implemented in patients with chronic stroke, demonstrating an added benefit to standard rehabilitation strategies, leading to improved motor performance and reduced spasticity. The procedure involved the transfer of the C7 nerve root and middle trunk from the uninjured extremity to the injured extremity using a short conduit that allows for faster regeneration and innervation of the injured upper extremity via the ipsilateral (contralesional) hemisphere. In this work, we review the rationale for using contralateral C7 nerve transfer in stroke, describe the surgical intervention with associated variations and limitations, and discuss the current evidence for the efficacy of this technique in ischemic stroke research.

Clinical Anatomy of Human Donor C7 Nerve Roots for Surgical Transfer in Patients with Spastic Arm Paralysis

BACKGROUND

Contralateral C7 (CC7) nerve transfer has successfully restored hand function in patients with spastic hemiplegia from chronic central nervous system injuries. However, little is known about the morphology and anatomy of the donor C7 nerve root in patients undergoing this procedure. This study quantified intraoperative measurements of donor C7 nerve roots during CC7 transfer surgery for spastic hemiplegia in patients treated at a high-volume center to describe observed anatomical variations for successful direct anastomosis.

METHODS

A database of images from 21 patients (2 females, 19 males) undergoing CC7 surgery was searched for photographic data that contained a standard ruler measuring donor C7 nerve root length after surgical sectioning and before transfer. Two independent observers analyzed these images and recorded C7 nerve root diameter, length, and branch lengths.

RESULTS

Mean (SD) values of donor C7 nerve measurements were length, 53.5 (8.0) mm; diameter, 5.1 (0.9) mm; branch length following surgical sectioning, 18.3 (6.3) mm. Right-sided donor C7 nerve roots yielded significantly longer branches compared with left-sided donor C7 nerve roots (P = 0.01). Other patient factors such as age, sex, or laterality of brain injury did not influence intraoperative anatomy.

CONCLUSIONS

We report detailed intraoperative measurements of the donor C7 root during CC7 nerve transfer for spastic hemiplegia. These findings describe existing variation in surgical C7 nerve root anatomy in patients undergoing this procedure and may serve as a general reference for the expected donor C7 length in successful direct anastomosis.

Contralateral C7 transfer to axillary and median nerves in rats with total brachial plexus avulsion

Background

Contralateral cervical 7 nerve (cC7) was used to repair two recipient nerves simultaneously for patients with total brachial plexus avulsion (TBPA).

Objective

To evaluate the effect of cC7 transfer to axillary and median nerves in rats with TBPA.

Methods

Eighty S-D rats were divided into 4 groups randomly on average. Group A: cC7-median nerve, Group B: cC7-axillary nerve, Group C: cC7-median and axillary nerves, Group D: TBPA without repair. The evaluation tools included behavioral tests, electromyogram (EMG), measurement of cross-sectional area of muscle fiber, nerve fiber count and gene expression assay.

Results

The effective rates of EMG were 90 and 70% in Flexor Carpi Radialis (FCR) in Group A and C, while 70 and 60% in deltoid (DEL) in Group B and C, respectively. In behavioral test, the differences of effective rates between groups were not significant. The mean cross-sectional area of FCR in Group A or C was significantly larger than that in Group D. Either the number of median or axillary nerve fibers in Group A, B or C was statistically more than that in Group D. No matter for FCR or DEL, there were no significant differences in the ratios of relative expression of Muscle Atrophy F-box(MAFBOX)and Muscle RING Finger 1(MURF1)among these groups.

Conclusion

Compared with cC7 transfer to median nerve, cC7 transfer to both median and axillary nerves did not affect median nerve recovery. The deltoid muscle also could be restored. The recovery proportion of axillary nerve was less than that of median nerve.

Contralateral C7 transfers: An innovative approach to improving peripheral neuropathic pain after traumatic brachial plexus injury with C5 rupture and avulsion of C6, C7, C8 and T1. A case series study

OBJECTIVES

Peripheral neuropathic pain is a common and disabling problem after traumatic brachial plexus injury with global plexopathy secondary to C5 rupture and avulsion of C6, C7, C8, and T1. The purpose of this paper is to evaluate restoration of sensation and pain levels before and after targeted muscle reinnervation to the hand using contralateral C7 nerve transfers in patients who have traumatic brachial plexus injuries with C5 rupture and avulsion of C6, C7, C8, and T1.

PATIENTS AND METHODS

This paper presents a retrospective review of the outcomes of the surgical management of 11 patients with global plexopathy with C5 rupture and avulsion from C6 to T1 roots. Ten of the patients had peripheral neuropathic pain. Mean follow-up was 6.9 years.

RESULTS

Sensory recovery to the median nerve territory was returned in 10 out of 11 patients. Pain and quality of life were improved in the majority.

CONCLUSION

Contralateral C7 nerve transfers may restore sensation to the median nerve territory with concurrent improvement in pain and some function in a limited number of patients for whom no other treatment options exist.

Motor and Sensory Cortical Changes after Contralateral Cervical Seventh Nerve Root (CC7) Transfer in Patients with Brachial Plexus Injuries

BACKGROUND

Previous animal studies demonstrated that the sensory and motor functions in ipsilesional upper limbs that had been reconstructed by CC7 transfer eventually associated with the contralesional brain cortices that had originally mediated the functions of the ipsilesional upper limbs before brachial plexus injury (BPI). Our hypothesis was that the same findings would be seen in humans.

METHODS

Four patients with total BPI treated with CC7 transfer were included. Changes in the locations of the activated areas in the primary motor (M1) and somatosensory (S1) cortices corresponding to the motor outputs to and sensory inputs from the ipsilesional limbs were investigated using functional near-infrared spectroscopy (fNIRS) 2-3 years and 6-7 years after surgery.

RESULTS

One patient was excluded from the evaluation of motor function after CC7 transfer. The motor and sensory functions of the ipsilesional upper limb in all patients were still controlled by the ipsilesional brain hemisphere 2-3 years after CC7 transfer. The reconstructed motions of the ipsilesional upper limbs correlated with the contralesional M1 in one patient and the bilateral M1s in another patient (both of whom demonstrated good motor recovery in the ipsilesional upper limbs) and with the ipsilesional M1 in a third patient with poor motor recovery in the ipsilesional upper limb. Sensory stimulation of the ipsilesional hands 6-7 years after CC7 transfer activated the contralesional S1 in two patients who achieved good sensory recovery in the ipsilesional hands but activated the ipsilesional S1 in the other two patients with poor sensory recovery of the ipsilesional hands.

CONCLUSIONS

Transhemispheric transposition of the activated brain cortices associated with the recovery of motor and sensory functions of the ipsilesional upper limbs was seen in patients with CC7 transfer as has been reported for animal models of CC7 transfer.

Retropharyngeal Contralateral C7 Nerve Transfer to the Lower Trunk for Brachial Plexus Birth Injury: Technique and Results

PURPOSE

Brachial plexus birth injuries with multiple nerve root avulsions present a particularly difficult reconstructive challenge because of the limited availability of donor nerves. The contralateral C7 has been described for brachial plexus reconstruction in adults but has not been well-studied in the pediatric population. We present our technique and results for retropharyngeal contralateral C7 nerve transfer to the lower trunk for brachial plexus birth injury.

METHODS

We performed a retrospective review. Any child aged less than 2 years was included. Charts were analyzed for patient demographic data, operative variables, functional outcomes, complications, and length of follow-up.

RESULTS

We had a total of 5 patients. Average nerve graft length was 3 cm. All patients had return of hand sensation to the ulnar nerve distribution as evidenced by a pinch test, unprompted use of the recipient limb without mirror movement, and an Active Movement Scale (AMS) of at least 2/7 for finger and thumb flexion; one patient had an AMS of 7/7 for finger and thumb flexion. Only one patient had return of ulnar intrinsic hand function with an AMS of 3/7. Two patients had temporary triceps weakness in the donor limb and one had clinically insignificant temporary phrenic nerve paresis. No complications were related to the retropharyngeal nerve dissection in any patient. Average follow-up was 3.3 years.

CONCLUSIONS

The retropharyngeal contralateral C7 nerve transfer is a safe way to supply extra axons to the severely injured arm in brachial plexus birth injuries with no permanent donor limb deficits. Early functional recovery in these patients, with regard to hand function and sensation, is promising.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic V.

Trial of Contralateral Seventh Cervical Nerve Transfer for Spastic Arm Paralysis

BACKGROUND

Spastic limb paralysis due to injury to a cerebral hemisphere can cause long-term disability. We investigated the effect of grafting the contralateral C7 nerve from the nonparalyzed side to the paralyzed side in patients with spastic arm paralysis due to chronic cerebral injury.

METHODS

We randomly assigned 36 patients who had had unilateral arm paralysis for more than 5 years to undergo C7 nerve transfer plus rehabilitation (18 patients) or to undergo rehabilitation alone (18 patients). The primary outcome was the change from baseline to month 12 in the total score on the Fugl-Meyer upper-extremity scale (scores range from 0 to 66, with higher scores indicating better function). Results The mean increase in Fugl-Meyer score in the paralyzed arm was 17.7 in the surgery group and 2.6 in the control group (difference, 15.1; 95% confidence interval, 12.2 to 17.9; P<0.001). With regard to improvements in spasticity as measured on the Modified Ashworth Scale (an assessment of five joints, each scored from 0 to 5, with higher scores indicating more spasticity), the smallest between-group difference was in the thumb, with 6, 9, and 3 patients in the surgery group having a 2-unit improvement, a 1-unit improvement, or no change, respectively, as compared with 1, 6, and 7 patients in the control group (P=0.02). Transcranial magnetic stimulation and functional imaging showed connectivity between the ipsilateral hemisphere and the paralyzed arm. There were no significant differences from baseline to month 12 in power, tactile threshold, or two-point discrimination in the hand on the side of the donor graft.

RESULTS

The mean increase in Fugl-Meyer score in the paralyzed arm was 17.7 in the surgery group and 2.6 in the control group (difference, 15.1; 95% confidence interval, 12.2 to 17.9; P<0.001). With regard to improvements in spasticity as measured on the Modified Ashworth Scale (an assessment of five joints, each scored from 0 to 5, with higher scores indicating more spasticity), the smallest between-group difference was in the thumb, with 6, 9, and 3 patients in the surgery group having a 2-unit improvement, a 1-unit improvement, or no change, respectively, as compared with 1, 6, and 7 patients in the control group (P=0.02). Transcranial magnetic stimulation and functional imaging showed connectivity between the ipsilateral hemisphere and the paralyzed arm. There were no significant differences from baseline to month 12 in power, tactile threshold, or two-point discrimination in the hand on the side of the donor graft.

CONCLUSIONS

In this single-center trial involving patients who had had unilateral arm paralysis due to chronic cerebral injury for more than 5 years, transfer of the C7 nerve from the nonparalyzed side to the side of the arm that was paralyzed was associated with a greater improvement in function and reduction of spasticity than rehabilitation alone over a period of 12 months. Physiological connectivity developed between the ipsilateral cerebral hemisphere and the paralyzed hand. (Funded by the National Natural Science Foundation of China and others; Chinese Clinical Trial Registry number, 13004466 .).

Good sensory recovery of the hand in brachial plexus surgery using the intercostobrachial nerve as the donor

OBJECTIVE

Restoration of the sensitivity to sensory stimuli in complete brachial plexus injury is very important. The objective of our study was to evaluate sensory recovery in brachial plexus surgery using the intercostobrachial nerve (ICBN) as the donor.

METHODS

Eleven patients underwent sensory reconstruction using the ICBN as a donor to the lateral cord contribution to the median nerve, with a mean follow-up period of 41 months. A protocol evaluation was performed.

RESULTS

Four patients perceived the 1-green filament. The 2-blue, 3-purple and 4-red filaments were perceptible in one, two and three patients, respectively. According to Highet's scale, sensation recovered to S3 in two patients, to S2+ in two patients, to S2 in six patients, and S0 in one patient.

CONCLUSION

The procedure using the ICBN as a sensory donor restores good intensity of sensation and shows good results in location of perception in patients with complete brachial plexus avulsion.

C8 cross transfer for the treatment of caudal brachial plexus avulsion in three dogs

OBJECTIVE

To evaluate the cervical nerve 8 cross-transfer technique (C8CT) as a part of surgical treatment of caudal brachial plexus avulsion (BPA) in the dog.

STUDY DESIGN

Case series.

ANIMALS

Client-owned dogs suspected to have caudal BPA based on neurological examination and electrophysiological testing (n = 3).

METHODS

The distal stump of the surgically transected contralateral C8 ventral branch (donor) was bridged to the proximal stump of the avulsed C8 ventral branch (recipient) and secured with 9-0 polypropylene suture under an operating microscope. A carpal panarthrodesis was performed on the injured limb after C8CT.

RESULTS

Surgical exploration confirmed avulsion of nerve roots C7, C8, and T1 in all cases. There was no evidence of an iatrogenic effect on the donor forelimb. Gradual improvement in function of the affected forelimb occurred in all dogs, with eventual recovery of voluntary elbow extension. Reinnervation was evident in EMG recordings 6 months postoperatively in all three dogs. Stimulation of the donor C8 ventral branch led to motor evoked potentials in the avulsed side triceps brachialis and radial carpus extensor muscles. Variable functional outcome was observed in the 3 dogs during clinical evaluation 3-4 years after surgery. Digital abrasion wounds, distal interphalangeal infectious arthritis, and self-mutilation necessitated distal phalanx amputation of digits 3 and 4 in 2 dogs.

CONCLUSION

C8CT provided partial reconnection of the donor C8 ventral branch to the avulsed brachial plexus in the 3 dogs of this series. Reinnervation resulted in active elbow extension and promoted functional recovery in the affected limb.

Surgical treatment for total root avulsion type brachial plexus injuries by neurotization: a prospective comparison study between total and hemicontralateral C7 nerve root transfer

PURPOSE

We conducted a clinical study to evaluate the effects of neurotization, especially comparing the total contralateral C7 (CC7) root transfer to hemi-CC7 transfer, on total root avulsion brachial plexus injuries (BPI).

METHODS

Forty patients who received neurotization for BPI were enrolled in this prospective study. Group 1 (n = 20) received hemi-CC7 transfer for hand function, while group 2 (n = 20) received total-CC7 transfer. Additional neurotization included spinal accessory, phrenic, and intercostal nerve transfer for shoulder and elbow function. The results were evaluated with an average of 6 years follow-up.

RESULTS

Group 1 had fewer donor site complications (15%) than group 2 (45%); group 2 had significantly better hand M3 and M4 motor function (65%) than group 1 (30%; P = 0.02). There was no difference in sensory recovery. Significantly, better shoulder function was obtained by simultaneous neurotization on both suprascapular and axillary nerves.

CONCLUSIONS

Total-CC7 transfer had better hand recovery but more donor complications than hemi-CC7. Neurotization on both supra-scapular and axillary nerves improved shoulder recovery.

Hemi-contralateral C7 transfer in traumatic brachial plexus injuries: outcomes and complications

BACKGROUND

In brachial plexus injuries with nerve root avulsions, the options for nerve reconstruction are limited. In select situations, half or all of the contralateral C7 (CC7) nerve root can be transferred to the injured side for brachial plexus reconstruction. Although encouraging results have been reported, CC7 transfer has not gained universal popularity. The purpose of this study was to critically evaluate hemi-CC7 transfer for restoration of shoulder function or median nerve function in patients with severe brachial plexus injury.

METHODS

A retrospective review of all patients with traumatic brachial plexus injury who had undergone hemi-CC7 transfer at a single institution during an eight-year period was performed. Complications were evaluated in all patients regardless of the duration of follow-up. The results of electrodiagnostic studies and modified British Medical Research Council (BMRC) motor grading were reviewed in all patients with more than twenty-seven months of follow-up.

RESULTS

Fifty-five patients with traumatic brachial plexus injury underwent hemi-CC7 transfer performed between 2001 and 2008 for restoration of shoulder function or median nerve function. Thirteen patients who underwent hemi-CC7 transfer to the shoulder and fifteen patients who underwent hemi-CC7 transfer to the median nerve had more than twenty-seven months of follow-up. Twelve of the thirteen patients in the shoulder group demonstrated electromyographic evidence of reinnervation, but only three patients achieved M3 or greater shoulder abduction motor function. Three of the fifteen patients in the median nerve group demonstrated electromyographic evidence of reinnervation, but none developed M3 or greater composite grip. All patients experienced donor-side sensory or motor changes; these were typically mild and transient, but one patient sustained severe, permanent donor-side motor and sensory losses.

CONCLUSIONS

The outcomes of hemi-CC7 transfer for restoration of shoulder motor function or median nerve function following posttraumatic brachial plexus injury do not justify the risk of donor-site morbidity, which includes possible permanent motor and sensory losses.

Adult peripheral nerve disorders: nerve entrapment, repair, transfer, and brachial plexus disorders

LEARNING OBJECTIVES

After reading this article, the participant should be able to: 1. Describe the pathophysiologic bases for nerve injury and how they apply to patient evaluation and management. 2. Recognize the wide variety of injury patterns and associated patient complaints and physical findings associated with peripheral nerve pathology. 3. Evaluate and recommend further tests to aid in defining the diagnosis. 4. Specify treatment options and potential risks and benefits.

SUMMARY

Peripheral nerve disorders comprise a gamut of problems, ranging from entrapment neuropathy to direct open traumatic injury and closed brachial plexus injury. The pathophysiology of injury defines the patient's symptoms, examination findings, and treatment options and is critical to accurate diagnosis and treatment. The goals of treatment include management of the often associated pain and improvement of sensory and motor function. Understanding peripheral nerve anatomy is critical to adopting novel nerve transfer procedures, which may provide superior options for a variety of injury patterns.

Comparison of nerve transfers and nerve grafting for traumatic upper plexus palsy: a systematic review and analysis

BACKGROUND

In treating patients with brachial plexus injury, there are no comparative data on the outcomes of nerve grafts or nerve transfers for isolated upper trunk or C5-C6-C7 root injuries. The purpose of our study was to compare, with systematic review, the outcomes for modern intraplexal nerve transfers for shoulder and elbow function with autogenous nerve grafting for upper brachial plexus traumatic injuries.

METHODS

PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials were searched for studies in which patients had surgery for traumatic upper brachial plexus palsy within one year of injury and with a minimum follow-up of twelve months. Strength and shoulder and elbow motion were assessed as outcome measures. The Fisher exact test and Mann-Whitney U test were used to compare outcomes, with an alpha level of 0.05.

RESULTS

Thirty-one studies met the inclusion criteria. Two hundred and forty-seven (83%) and 286 (96%) of 299 patients with nerve transfers achieved elbow flexion strength of grade M4 or greater and M3 or greater, respectively, compared with thirty-two (56%) and forty-seven (82%) of fifty-seven patients with nerve grafts (p < 0.05). Forty (74%) of fifty-four patients with dual nerve transfers for shoulder function had shoulder abduction strength of grade M4 or greater compared with twenty (35%) of fifty-seven patients with nerve transfer to a single nerve and thirteen (46%) of twenty-eight patients with nerve grafts (p < 0.05). The average shoulder abduction and external rotation was 122° (range, 45° to 170°) and 108° (range, 60° to 140°) after dual nerve transfers and 50° (range, 0° to 100°) and 45° (range, 0° to 140°) in patients with nerve transfers to a single nerve.

CONCLUSIONS

In patients with demonstrated complete traumatic upper brachial plexus injuries of C5-C6, the pooled international data strongly favors dual nerve transfer over traditional nerve grafting for restoration of improved shoulder and elbow function. These data may be helpful to surgeons considering intraoperative options, particularly in cases in which the native nerve root or trunk may appear less than optimal, or when long nerve grafts are contemplated.

Nerve reconstruction: A cohort study of 93 cases of global brachial plexus palsy

INTRODUCTION

Brachial plexus injury leading to flail upper limb is one of the most disabling injuries. Neglect of the injury and delay in surgeries may preclude reinnervation of the paralysed muscles. Currently for such injuries nerve transfers are the preferred procedures. We here present a series of 93 cases of global brachial plexus palsy treated with nerve transfers.

MATERIALS AND METHODS

Ninety-three cases of global palsies out of 384 cases of brachial plexus injury operated by the senior surgeon (AB) were selected. Age varied from 4 to 51 years with 63 patients in 20 to 40 age group and all patients having a minimum follow up of at least 1 year post surgery ranging up to 130 months. The delay before surgery ranged from 15 days to 16 months (mean 3.2 months). The aim of the surgery was to restore the elbow flexion, shoulder abduction, triceps function and wrist and finger flexion in that order of priority. The major nerve transfers used were spinal accessory to suprascapular nerve, intercostal to musculocutaneous nerve and pectoral nerves, contralateral C7 to median and radial nerves. Nerve stumps were used whenever available (30 patients).

RESULTS

Recovery of ≥ grade 3 power was noted in biceps in 73% (68/93) of patients, shoulder abduction in 89% (43/49), pectoralis major in 100% (8/8). Recovery of grade 2 triceps power was seen in 80% (12/16) patients with nerve transfer to radial nerve. Derotation osteotomies of humerus (n=13) and wrist fusion (n=14) were the most common secondary procedures performed to facilitate alignment and movements of the affected limb. Better results were noted in 59 cases where direct nerve transfers were done (without nerve graft).

CONCLUSION

Acceptable function (restoration of biceps power ≥3) can be obtained in more than two thirds (73%) of these global brachial plexus injuries by using the principles of early exploration and nerve transfer with rehabilitation.