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     

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.     

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.     

Regional donor nerves in the reinnervation of brachial plexus palsy due to upper spinal roots avulsion

The prognosis for surgical treatment in cases of upper brachial plexus palsy due to spinal roots avulsion is somewhat better than in cases of total palsy. The main reasons are better possibilities for surgical reinnervation using regional donors i.e. the medial pectoral and the thoracodorsal nerves, and a shorter time span for nerve regeneration. Regional donor nerves, alone or in combination with upper intercostals and/or the spinal accessory nerve, were used in 13 cases for the reinnervation of the musculocutaneous and/or the axillary nerves. The value of the regional donors is analysed and compared with that of the spinal accessory and intercostal nerves. The value is documented throughout the results of surgical treatment with a follow-up period of at least 18 months after surgery.     

Influence of species, age and weight on the establishment of a murine model of brachial plexus root avulsion

BACKGROUND: Animal models of brachial plexus root avulsion are required for the study of brachial plexus root injuries. The established ventral approach results in slight injuries, and is similar to mechanisms underlying human brachial plexus root avulsion.OBJECTIVE: To analyze the effects of weight, age, and species on the success rate of brachial plexus root avulsion, and to determine the perfect method for establishing models of brachial plexus root avulsion.DESIGN, TIME AND SETTING: A randomized, block design was performed at the Laboratory of Professor Lihua Zhou, Zhongshan School of Medicine, Sun Yat-sen University, China from June 2008 to June 2009.MATERIALS: Sprague Dawley (SD) rats, golden hamsters, and BALb/C mice were used in the present study.METHODS: All animals were randomly subjected to classical brachial plexus root avulsion and modified brachial plexus root avulsion.MAIN OUTCOME MEASURES: Success rate of brachial plexus root avulsion. RESULTS: The success rate of brachial plexus root avulsion was greater in the modified group than in the classical group (P＜0.01). Moreover, the difference was significant in 15-day-old SD rats, 5-week-old SD rats, and 3-month-old BALb/C mice (P＜0.01). The success rate of brachial plexus root avulsion was greater in the same weight, 15-day-old juvenile SD rats, than in the 3-month-old BALb/C mice (classical group, P＜0.01; modified group, P＜0.05). The success rate of brachial plexus root avulsion was significantly greater in 3-month-old golden hamsters than in 5-week-old SD rats in the classical group (P＜0.05). The success rate of brachial plexus root avulsion was significantly lower in the 15-day-old SD rats compared with the 5-week-old and 3-month-old SD rats in the classical group (P＜0.01). However, there was no significant difference in the success rate of brachial plexus root avulsion between various ages of SD rats in the modified group (P＞0.05).CONCLUSION: Modified surgery to induce brachial plexus root avulsion significantly increases the success rate of model establishment. Species, age, and weight affect the success rate of brachial plexus root avulsion, and species plays an important role in the success rate.     

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.     

Structure of the brachial plexus root and adjacent regions displayed by ultrasound imaging

Brachial plexuses of 110 healthy volunteers were examined using high resolution color Doppler ultrasound. Ultrasonic characteristics and anatomic variation in the intervertebral foramen, interscalene, supraclavicular and infraclavicular, as well as the axillary brachial plexus were investigated. Results confirmed that the normal brachial plexus on cross section exhibited round or elliptic hypoechoic texture. Longitudinal section imaging showed many parallel linear hypo-moderate echoes, with hypo-echo. The transverse processes of the seventh cervical vertebra, the scalene space, the subclavian artery and the deep cervical artery are important markers in an examination. The display rates for the interscalene, and supraclavicular and axillary brachial plexuses were 100% each, while that for the infraclavicular brachial plexus was 97%. The region where the normal brachial plexus root traversed the intervertebral foramen exhibited a regular hypo-echo. The display rate for the C 5-7 nerve roots was 100%, while those for C 8 and T 1 were 83% and 68%, respectively. A total of 20 of the 110 subjects underwent cervical CT scan. High-frequency ultrasound can clearly display the outline of the transverse processes of the vertebrae, which were consistent with CT results. These results indicate that high-frequency ultrasound provides a new method for observing the morphology of the brachial plexus. The C 7 vertebra is a marker for identifying the position of brachial plexus nerve roots.     

Valproic acid protects neurons and promotes neuronal regeneration after brachial plexus avulsion

Valproic acid has been shown to exert neuroprotective effects and promote neurite outgrowth in several peripheral nerve injury models. However, whether valproic acid can exert its beneficial effect on ...     

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.     

Ultrasound of the cervical roots and brachial plexus in neonates

Introduction: In this exploratory study we investigated whether ultrasound can visualize the neonatal cervical roots and brachial plexus. Methods: In 12 healthy neonates <2 days old, the neck region was studied unilaterally with ultrasound using a small‐footprint 15–7‐MHz transducer. Results: The C5–C8 nerve roots and brachial plexus could be imaged with sufficient delineation of the root exits to assess their integrity. The brachial plexus was more difficult to discern from the surrounding area in neonates compared with adults, especially in the interscalene region because of the smaller amount of connective tissue in and surrounding muscles and nerves. In addition, the large deposits of brown fat make for a different ultrasound appearance of the neonatal neck compared with adults. Conclusions: Ultrasound of the neonatal cervical nerve roots is feasible and may be used as a non‐invasive screening technique to assess nerve root integrity in obstetric brachial plexus injury. Muscle Nerve 51 : 35–41, 2015     

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。     

Electroacupuncture stimulation of the brachial plexus trunk on the healthy side promotes brain-derived neurotrophic factor mRNA expression in the ischemic cerebral cortex of a rat model of cerebral ischemia/reperfusion injury

A rat model of cerebral ischemia/reperfusion was established by suture occlusion of the left middle cerebral artery. In situ hybridization results showed that the number of brain-derived neurotrophic factor mRNA-positive cells in the ischemic rat cerebral cortex increased after cerebral ischemia/ reperfusion injury. Low frequency continuous wave electroacupuncture (frequency 2-6 Hz, current intensity 2 mA) stimulation of the brachial plexus trunk on the healthy (right) side increased the number of brain-derived neurotrophic factor mRNA-positive cells in the ischemic cerebral cortex 14 days after cerebral ischemia/reperfusion injury. At the same time, electroacupuncture stimulation of the healthy brachial plexus truck significantly decreased neurological function scores and alleviated neurological function deficits. These findings suggest that electroacupuncture stimulation of the brachial plexus trunk on the healthy (right) side can greatly increase brain-derived neurotrophic factor mRNA expression and improve neurological function.     

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.