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

Background

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.

Objective

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.

Methods

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.

Result

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.

Conclusion

The total ipsilateral transfer of the C7 root to the upper trunk is a viable alternative procedure for newborns with C5-C6 avulsion.     

Modified C7 neurotization for the treatment of obstetrical brachial plexus palsy

Contralateral C7 transfer is used rarely in infants with obstetrical brachial plexus palsy (OBPP). We aimed to determine the efficacy of contralateral C7 transfer to two different recipient nerves in infants with OBPP. Between 2001 and 2005, 9 infants with brachial plexus root avulsions underwent nerve reconstruction using a modified C7 neurotization technique. In this procedure, the contralateral C7 root was transferred to both the musculocutaneous nerve and the median nerve on the affected side. The strength of the biceps muscles increased to M3 or M4 in 7 patients and to M2 in 2 patients. The median nerve transfers led to regained motor function and strength of wrist and finger flexors with improvement to M3 or M4 in 5 patients. All patients showed notable gains of sensory function. Contralateral C7 transfer to two different recipient nerves is a feasible and efficient approach in infants with OBPP.     

Full-length phrenic nerve transfer as the treatment for brachial plexus avulsion injury to restore wrist and finger extension

Introduction: The functional restoration of wrist and finger extension after complete brachial plexus avulsion injury remains an unsolved problem. We conducted a prospective study to elucidate a new method for resolving this injury. Methods: Six patients with complete brachial plexus avulsion injury underwent a new surgical procedure in which the full‐length phrenic nerve was transferred to the medial portion of the radial nerve at the level of the latissimus dorsi insertion via endoscopic thoracic surgery. Results: In 5 patients, extensor carpi ulnaris and extensor carpi radialis strength recovered to Medical Research Council grade ≥M3, and in 4 patients extensor digitorum strength recovered to ≥M3. Conclusions: Neurotization of phrenic nerve to the medial portion of the radial nerve at the level of latissimus dorsi insertion is a feasible means of restoring wrist and finger extension in cases of complete brachial plexus avulsion injury. Muscle Nerve 45: 39–42, 2012     

Neurotization from Two Medial Pectoral Nerves to Musculocutaneous Nerve in a Pediatric Brachial Plexus Injury

Traumatic brachial plexus injuries can be devastating, causing partial to total denervation of the muscles of the upper extremities. Surgical reconstruction can restore motor and/or sensory function following nerve injuries. Direct nerve-to-nerve transfers can provide a closer nerve source to the target muscle, thereby enhancing the quality and rate of recovery. Restoration of elbow flexion is the primary goal for patients with brachial plexus injuries. A 4-year-old right-hand-dominant male sustained a fracture of the left scapula in a car accident. He was treated conservatively. After the accident, he presented with motor weakness of the left upper extremity. Shoulder abduction was grade 3 and elbow flexor was grade 0. Hand function was intact. Nerve conduction studies and an electromyogram were performed, which revealed left lateral and posterior cord brachial plexopathy with axonotmesis. He was admitted to Rehabilitation Medicine and treated. However, marked neurological dysfunction in the left upper extremity was still observed. Six months after trauma, under general anesthesia with the patient in the supine position, the brachial plexus was explored through infraclavicular and supraclavicular incisions. Each terminal branch was confirmed by electrophysiology. Avulsion of the C5 roots and absence of usable stump proximally were confirmed intraoperatively. Under a microscope, neurotization from the musculocutaneous nerve to two medial pectoral nerves was performed with nylon 8-0. Physical treatment and electrostimulation started 2 weeks postoperatively. At a 3-month postoperative visit, evidence of reinnervation of the elbow flexors was observed. At his last follow-up, 2 years following trauma, the patient had recovered Medical Research Council (MRC) grade 4+ elbow flexors. We propose that neurotization from medial pectoral nerves to musculocutaneous nerve can be used successfully to restore elbow flexion in patients with brachial plexus injuries.     

不同来源神经供体进行臂丛神经根性撕脱伤移位修复的疗效比较

目的分析不同来源神经供体进行臂丛神经根性撕脱伤移位修复的疗效,并探讨手术效果影响因素。方法选取2011-01—2017-12平顶山市第五人民医院骨科收治的行神经移位修复术治疗臂丛神经根性撕脱伤患者94例作为研究对象,分别行健侧颈7神经移位术(32例)、肋间神经移位术(30例)及膈神经移位术(32例),收集患者基本资料,并对患者术后患肢肘关节功能及肌力恢复情况进行评估。结果3组患者肘关节恢复达到良以上分别为膈神经组21例(65.6%),肋间神经组20例(66.7%),C7神经组23例(71.9%),3组患者术后肘关节功能恢复情况比较,差异无统计学意义(P>0.05)。术后膈神经组、肋间神经组,C7神经组肌力≥Ⅲ级的例数分别为25例(78.1%)、22例(73.3%)、25例(78.1%),3组患者术后患肢肌力恢复情况无显著性差异(P>0.05)。3组术后肘关节功能恢复的影响因素存在差异。(1)膈神经组术后肘关节功能恢复情况与年龄、损伤-手术时间、神经移植长度和功能锻炼时间等因素有关(P<0.05);(2)肋间神经组术后肘关节功能恢复情况与功能锻炼时间、损伤部位和神经移植长度等因素有关(P均<0.05);(3)C7神经组术后肘关节功能恢复情况与年龄、损伤-手术时间、神经移植长度等因素有关(P<0.05)。与3组患者术后肘关节功能恢复情况均有关的影响因素为神经移植长度。3组患者术后肌力恢复的影响因素存在差异。(1)膈神经组肌力恢复情况与患者年龄、损伤-手术时间、神经移植长度和功能锻炼时间等因素有关(P均<0.01);(2)肋间神经组肌力恢复情况与年龄、功能锻炼时间和神经移植长度等因素有关(P均<0.01);(3)颈7神经组肌力恢复情况与年龄、功能锻炼时间及损伤-手术时间等因素有关(P均<0.01)。结论3种供体神经移植修复臂丛神经根性撕脱伤效果相当,但术后效果的影响因素不尽相同,因此根据患者具体情况选择最优的治疗方式,有利于提高手术有效率。     

The phrenic nerve transfer in the treatment of a septuagenarian with brachial plexus avulsion injury: a case report

Phrenic nerve transfer has been a well-established procedure for restoring elbow flexion function in patients with brachial plexus avulsion injury. Concerning about probably detrimental respiratory effects brought by the operation, however, stirred up quite a bit of controversy. We present a case report of the successful application of phrenic nerve as donor to reinnervate the biceps in a septuagenarian with brachial plexus avulsion injury, not accompanied with significant clinical respiratory problem.     

Phrenic nerve transfer to the musculocutaneous nerve for the repair of brachial plexus injury: electrophysiological characteristics

Phrenic nerve transfer is a major dynamic treatment used to repair brachial plexus root avulsion. We analyzed 72 relevant articles on phrenic nerve transfer to repair injured brachial plexus that were indexed by Science Citation Index. The keywords searched were brachial plexus injury, phrenic nerve, repair, surgery, protection, nerve transfer, and nerve graft. In addition, we performed neurophysiological analysis of the preoperative condition and prognosis of 10 patients undergoing ipsilateral phrenic nerve transfer to the musculocutaneous nerve in our hospital from 2008 to 201 3 and observed the electromyograms of the biceps brachii and motor conduction function of the musculocutaneous nerve. Clinically, approximately 28% of patients had brachial plexus injury combined with phrenic nerve injury, and injured phrenic nerve cannot be used as a nerve graft. After phrenic nerve transfer to the musculocutaneous nerve, the regenerated potentials first appeared at 3 months. Recovery of motor unit action potential occurred 6 months later and became more apparent at 12 months. The percent of patients recovering ‘excellent' and ‘good' muscle strength in the biceps brachii was 80% after 18 months. At 12 months after surgery, motor nerve conduction potential appeared in the musculocutaneous nerve in seven cases. These data suggest that preoperative evaluation of phrenic nerve function may help identify the most appropriate nerve graft in patients with an injured brachial plexus. The functional recovery of a transplanted nerve can be dynamically observed after the surgery.     

Somatosensory evoked potentials from musculocutaneous nerve in the diagnosis of brachial plexus injuries

A technique for recording somatosensory evoked potentials using stimulation of musculocutaneous sensory nerve fibers proximal to the wrist has been used in 10 normal subjects and in 8 patients with traumatic lesions of proximal parts of the brachial plexus. The technique gave satisfactory evoked potentials in all normal subjects and provided useful information in patients with avulsion of the 5th and 6th cervical roots. The results were similar to those obtained by radial nerve stimulation. The results in 3 patients with upper trunk injuries and in 1 patient with avulsion of the 5th cervical root were unhelpful. In 2 patients with multiple cervical root avulsions the evoked potentials from cervical cord and contralateral scalp were absent and were attenuated at Erb's point. This is the first report where musculocutaneous nerve evoked potentials have been applied to a group of patients.     

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

Introduction: 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. Methods: 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. Results: 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. Conclusions: Use of the phrenic nerve as the donor nerve yielded a better outcome than use of the ipsilateral C7 nerve root. Muscle Nerve 50 : 67–72, 2014     

The breathing hand: obstetric brachial plexopathy reinnervation from thoracic roots?

It has been found that in cases of obstetric brachial plexopathy, injured phrenic nerve or C3/4/5 roots may sprout into the adjacent injured upper and middle trunks of the brachial plexus. This aberrant regeneration produces co-contraction of the diaphragm and proximal upper limb muscles. This phenomenon, referred to as respiratory synkinesis or "the breathing arm", may not be limited to the upper cervical roots. We present two cases, identified through electromyographic investigations, of respiratory synkinesis selectively affecting intrinsic hand muscles, and propose that upper thoracic roots and their intercostal nerves may also produce respiratory synkinesis, resulting in a "breathing hand." This novel brand of synkinesis indicates that obstetric brachial plexus neuropathies can have quite proximal nerve injury in all trunks. The findings in our patients may not be entirely unique. The time required to develop distal muscle synkinesis and the subtle nature of our findings may suggest that with time and the assistance of EMG the breathing hand may be more common. When considering brachial plexus surgery, the significance of respiratory synkinesis should not be overlooked as its presence indicates injury at a root or proximal trunk level and may come from either nerves destined for the diaphragm or for the intercostal muscles.     

Phrenic nerve conduction study in patients with traumatic brachial plexus palsy

Phrenic nerve conduction studies were performed to assess the ipsilateral nerve in 100 patients with traumatic brachial plexus palsy. Open exploration and intraoperative recordings of somatosensory evoked potentials and nerve action potentials were used to confirm the level of root lesions. The relationship between C-5 preganglionic root lesion and the functional integrity of the ipsilateral phrenic nerve was examined. The phrenic nerves were normal in 80 cases, partially injured in 7, and severely injured in 13. We found C-5 preganglionic root lesions in 13 (100%) patients with severely injured, 5 (71.4%) with partially injured, and 24 (30%) with normal phrenic nerves. This correlation suggests phrenic nerve conduction study is a useful tool in the diagnosis of C-5 preganglionic root lesions in patients with traumatic brachial plexopathy.     

Differentiation of endogenous neural stem cells in adult versus neonatal rats after brachial plexus root avulsion injury

An experimental model of brachial plexus root avulsion injury of cervical dorsal C5-6 was established in adult and neonatal rats.Real-time PCR showed that the levels of brain-derived neurotrophic factor,nerve growth factor and neurotrophin-3 in adult rats increased rapidly 1 day after brachial plexus root avulsion injury,and then gradually decreased to normal levels by 21 days.In neonatal rats,levels of the three neurotrophic factors were decreased on the first day after injury,and then gradually increased from the seventh day and remained at high levels for an extended period of time.We observed that greater neural plasticity contributed to better functional recovery in neonatal rats after brachial plexus root avulsion injury compared with adult rats.Moreover, immunohistochemical staining showed that the number of bromodeoxyuridine/nestin-positive cells increased significantly in the spinal cords of the adult rats compared with neonatal rats after brachial plexus root avulsion injury.In addition,the number of bromodeoxyuridine/glial fibrillary acidic protein-positive cells in adult rats was significantly higher than in neonatal rats 14 and 35 days after brachial plexus injury.Bromodeoxyuridine/β-tubulin-positive cells were not found in either adult or neonatal rats.These results indicate that neural stem cells differentiate mainly into astrocytes after brachial plexus root avulsion injury.Furthermore,the degree of neural stem cell differentiation in neonatal rats was lower than in adult rats.     

Nerve transfer helps repair brachial plexus injury by increasing cerebral cortical plasticity

In the treatment of brachial plexus injury, nerves that are functionally less important are transferred onto the distal ends of damaged crucial nerves to help recover neuromuscular function in the target region. For example, intercostal nerves are transferred onto axillary nerves, and accessory nerves are transferred onto suprascapular nerves, the phrenic nerve is transferred onto the musculocutaneous nerves, and the contralateral C7 nerve is transferred onto the median or radial nerves. Nerve transfer has become a major method for reconstructing the brachial plexus after avulsion injury. Many experiments have shown that nerve transfers for treatment of brachial plexus injury can help reconstruct cerebral cortical function and increase cortical plasticity. In this review article, we summarize the recent progress in the use of diverse nerve transfer methods for the repair of brachial plexus injury, and we discuss the impact of nerve transfer on cerebral cortical plasticity after brachial plexus injury.     

Measurement of cross‐sectional area of cervical roots and brachial plexus trunks

Introduction: The aim of this study was to determine normal reference values for cross‐sectional area (CSA) and the correlation between demographic factors and CSA in the cervical roots and brachial plexus trunks using ultrasonography. Methods: Ninety‐five age‐matched healthy individuals were studied. Ultrasonographic tests were performed via nerve tracing from the cervical root to the brachial plexus trunk. The CSA of each nerve was measured in the C5–8 ventral roots and brachial plexus (trunk level). Results: Normal values of each cervical root were: C5, 5.66 ± 1.02 mm²; C6, 8.98 ± 1.65 mm²; C7, 10.43 ± 1.86 mm²; and C8, 10.76 ± 2.02 mm². Values for the brachial plexus were: upper trunk, 16.70 ± 2.88 mm²; middle trunk, 14.01 ± 2.70 mm²; and lower trunk, 13.75 ± 2.57 mm². The side‐to‐side discrepancy was 11.91 ± 11.11%. Body mass index (BMI) and height correlated frequently with nerve CSA. Conclusions: These reference values may be helpful in investigating pathologies involving the cervical area. Muscle Nerve 46: 711–716, 2012     

Oberlin transfer and partial radial to axillary nerve neurotization to repair an explosive traumatic injury to the Brachial Plexus in a child: Case report

Purpose

Explosive injuries to the pediatric brachial plexus are exceedingly rare and as such are poorly characterized in the medical literature.

Methods

Herein, we describe an 8-year-old who was struck in the neck by a piece of shrapnel and suffered multiple vascular injuries in addition to a suspected avulsion of the cervical 5 and 6 ventral rami. The patient had a complete upper brachial plexus palsy and failed to demonstrate any clinical improvement at 6-months follow-up. He was taken to the operating from for a partial ulnar to musculocutaneous nerve neurotization as well as a partial radial to axillary nerve neurotization.

Results

The patient’s motor exam improved from a Medical Research Council scale 1 to 4+ for biceps brachii and 0 to 4 deltoid function with greater than 90° of shoulder abduction.

Conclusions

This outcome supports complex neurotization techniques as viable treatment options for persistent motor deficits following an upper brachial plexus injury in older, non-infant age, children.     

Direct anastomosis of contralateral CT nerve root transfer with affected-side inferior trunk for repair of brachial plexus avulsion injury

AIM： To observe the effect of direct anastomosis of contralateral C7 nerve root transferred through prespina route with affected-side infedor trunk for repair of brachial plexus avulsion injury, and investigate its feasibility. METHODS ： Two male patients, with the age of 24 and 41 years respectively, were retrieved. When admitted to the hospital, they were diagnosed as brachial plexus avulsion injury. They subjected the operation in the 252 Hospital of Chinese PLA in March 2006 and May 2006 respectively. The proximal end of contralateral C7 nerve root was dissociated to nerve root pore and the distal end was dissociated to anterior and posterior divisions of middle trunk. The injured C7 nerve root was widely dissociated to inferior trunk, medial cord, ulnar nerve and medial head of median nerve. When elbow and shoulder joints were in flexion, the injured C7 nerve root was directly anastomosed with contralateral C7 nerve root in the gap between affected-side cervical vagina vasorum and esophagus with no tensions. RESULTS： During 3 to 5 hours of operation, little hemorrhage was found, nerves were not used for connection. Dyspnea, hoarse voice and other complications did not appear, either. In the postoperative 7^th to 8^th months, electromyogram examination showed that the growth velocity of anastomosed nerve was normal. CONCLUSION ： Direct anastomosis of contralateral C7 nerve root transferred through prespinal route with affected-side inferior trunk can be used for repair of brachial plexus avulsion injury with satisfying therapeutic effects.     

Stability of motor endplates is greater in the biceps than in the interossei in a rat model of obstetric brachial plexus palsy

The time window for repair of the lower trunk is shorter than that of the upper trunk in patients with obstetric brachial plexus palsy. The denervated intrinsic muscles of the hand become irreversibly atrophic much faster than the denervated biceps. However, it is unclear whether the motor endplates of the denervated interosseous muscles degenerate more rapidly than those of the denervated biceps. In this study, we used a rat model of obstetric brachial plexus palsy of the right upper limb. C5–6 was lacerated distal to the intervertebral foramina, with concurrent avulsion of C7–8 and T1, with the left upper limb used as the control. Bilateral interossei and biceps were collected at 5 and 7 weeks. Immunofluorescence was used to assess the morphology of the motor endplates. Real-time quantitative polymerase chain reaction and western blot assay were used to assess mRNA and protein expression levels of acetylcholine receptor subunits(α, β and δ), rapsyn and β-catenin. Immunofluorescence microscopy showed that motor endplates in the denervated interossei were fragmented, while those in the denervated biceps were morphologically intact with little fragmentation. The number and area of motor endplates, relative to the control side, were significantly lower in the denervated interossei compared with the denervated biceps. mRNA and protein expression levels of acetylcholine receptor subunits(α, β and δ) were significantly lower, whereas β-catenin protein expression was higher, in the denervated interossei compared with the denervated biceps. The protein expression of rapsyn was higher in the denervated biceps than in the denervated interossei at 7 weeks. Our findings demonstrate that motor endplates of interossei are destabilized, whereas those of the biceps remain stable, in the rat model of obstetric brachial plexus palsy. All procedures were approved by the Experimental Animal Ethics Committee of Fudan University, China(approval No. DF-187) in January 2016.     

Histopathological basis of Horner's syndrome in obstetric brachial plexus palsy differs from that in adult brachial plexus injury

Although Horner's syndrome is usually taken as an absolute indicator of avulsions of the C8 and T1 ventral roots in adult brachial plexus injury, its pathological basis in obstetric brachial plexus palsy (OBPP) is unclear. We therefore examined the morphological mechanism for the presence of Horner's syndrome in brachial plexus injury in infants and adults. Some axons of sympathetic preganglionic neurons in T1 innervate the superior cervical ganglion via the C7 ventral root in infants but not in adults. Therefore, the presence of Horner's syndrome may relate in part to avulsion of the C7 root in OBPP. These findings suggest that Horner's syndrome in OBPP is not necessarily indicative of avulsions of the C8 and T1 roots, as it can occur with avulsion of the C7 root.     

The utility of various sensory nerve conduction responses in assessing brachial plexopathies

To determine which sensory nerve conduction studies (S-NCS) are helpful in detecting supraclavicular axon loss brachial plexopathies, we selected 53 cases (of 417 reviewed) in whom complicating factors were absent and which, by needle electrode examination findings, involved only a single “truncal” element (upper, middle, or lower) of the brachial plexus. Extensive S-NCS included: median, recording thumb (Med-D1), index (Med-D2), and middle fingers (Med-D3); ulnar, recording fifth finger (Uln-D5); dorsal ulnar cutaneous, recording dorsum of the hand (DUC); radial, recording base of thumb; and both medial and lateral antebrachial cutaneous (MABC, LABC), recording forearm. Except for the median sensory fibers, the “cord” elements traversed by the sensory fibers assessed during the S-NOS listed above are anatomically defined (i.e., the sensory fibers enter the brachial plexus at only one cord). In regard to the median sensory fibers, however, there are two possible pathways through the infraclavicular plexus: (1) the lateral cord and/or (2) the medial cord. Because the lower trunk is only accessible via the medial cord, any sensory fibers found to be traversing the lower trunk had to first traverse the medial cord. Similarly, those traversing the upper and middle trunks must first be a component of the lateral cord. The frequency that the various S-NCS responses were abnormal (unelicitable, below laboratory normal value, or ≤ 50% of the contralateral response) for a given brachial plexus element lesion was as follows: (1) upper trunk (UT): 25 of 26 Med-D1, 25 of 26 LABC, 15 of 26 radial, 5 of 26 Med-D2, 2 of 26 Med-D3; (2) middle trunk (MT): 1 of 1 Med-D3; (3) lower trunk (LT): 25 of 26 Uln-D5, 22 of 23 DUC, 11 of 17 MABC, 3 of 23 Med-D3. With lower trunk brachial plexopathies, both “routine” (Uln-D5) and “uncommon” (DUC; MABC) S-NCS are abnormal. With upper trunk brachial plexopathies, in contrast, only the “uncommon” S-NCS (Med-D1; LABC) are consistently affected. The “routine” median S-NCS recording digit 2 (Med-D2) is far less reliable than the median S-NCS recording digit 2 (Med-D1) in detecting upper trunk axon loss brachial plexopathies. Additionally, the various pathways traversed by the fibers contributing to the individual S-NCS responses can be predicted, an important point when the full extent of a brachial plexus lesion is sought. © 1995 John Wiley & Sons, Inc.     

Penile erectile dysfunction after brachial plexus root avulsion injury in rats

Our previous studies have demonstrated that some male patients suffering from brachial plexus injury, particularly brachial plexus root avulsion, show erectile dysfunction to varying degrees. However, the underlying mechanism remains poorly understood. In this study, we evaluated the erectile function after establishing brachial plexus root avulsion models with or without spinal cord injury in rats. After these models were established, we administered apomorphine （via a sub- cutaneous injection in the neck） to observe changes in erectile function. Rats subjected to simple brachial plexus root avulsion or those subjected to brachial plexus root avulsion combined with spinal cord injury had significantly fewer erections than those subjected to the sham operation. Expression of neuronal nitric oxide synthase did not change in brachial plexus root avulsion rats. However, neuronal nitric oxide synthase expression was significantly decreased in brachial plexus root avulsion ＋ spinal cord injury rats. These findings suggest that a decrease in neuronal nitric oxide synthase expression in the penis may play a role in erectile dysfunction caused by the combi- nation of brachial plexus root avulsion and spinal cord injury.