Transposition of Branches of Radial Nerve Innervating Supinator to Posterior Interosseous Nerve for Functional Reconstruction of Finger and Thumb Extension in 4 Patients with Middle and Lower Trunk Root Avulsion Injuries of Brachial Plexus

This study aimed to investigate the reconstruction of the thumb and finger extension function in patients with middle and lower trunk root avulsion injuries of the brachial plexus. From April 2010 to January 2015, we enrolled in this study 4 patients diagnosed with middle and lower trunk root avulsion injuries of the brachial plexus via imaging tests, electrophysiological examinations, and clinical confirmation. Muscular branches of the radial nerve, which innervate the supinator in the forearm, were transposed to the posterior interosseous nerve to reconstruct the thumb and finger extension function. Electrophysiological findings and muscle strength of the extensor pollicis longus and extensor digitorum communis, as well as the distance between the thumb tip and index finger tip, were monitored. All patients were followed up for 24 to 30 months, with an average of 27.5 months. Motor unit potentials（MUP） of the extensor digitorum communis appeared at an average of 3.8 months, while MUP of the extensor pollicis longus appeared at an average of 7 months. Compound muscle action potential（CMAP） appeared at an average of 9 months in the extensor digitorum communis, and 12 months in the extensor pollicis longus. Furthermore, the muscle strength of the extensor pollicis longus and extensor digitorum communis both reached grade Ⅲ at 21 months. Lastly, the average distance between the thumb tip and index finger tip was 8.8 cm at 21 months. In conclusion, for patients with middle and lower trunk injuries of the brachial plexus, transposition of the muscular branches of the radial nerve innervating the supinator to the posterior interosseous nerve for the reconstruction of thumb and finger extension function is practicable and feasible.

OBSERVATION ON EFFECT OF POINT INJECTION AS THE MAIN TREATMENT FOR OBSTETRIC BRACHIAL PLEXUS PALSY

To discuss the best way of treatment for obstetric brachial plexus palsy （OBPP）. Method： The 102 cases of OBPP were randomized into two groups： the observation group （51 cases） and the control group （51 cases）. The observation group was treated by point injection with nerve growth factor （NGF）, acupuncture, and moxibustion. The control group was treated by acupuncture and moxibustion. Result： The result was compared after two courses of treatment. The curative rate of observation group was 35.3% and that of control group 11.8%. The curative and remarkably effective rate was 78.4% and 43.2% respectively. In the two-two comparison, the difference was significant （ P〈 0. 01 ）. Conclusion： The effect of NGF point injection as the main treatment for OBPP was good, worth spreading.

Supplementary motor area deactivation impacts the recovery of hand function from severe peripheral nerve injury

Although some patients have successful peripheral nerve regeneration,a poor recovery of hand function often occurs after peripheral nerve injury.It is believed that the capability of brain plasticity is crucial for the recovery of hand function.The supplementary motor area may play a key role in brain remodeling after peripheral nerve injury.In this study,we explored the activation mode of the supplementary motor area during a motor imagery task.We investigated the plasticity of the central nervous system after brachial plexus injury,using the motor imagery task.Results from functional magnetic resonance imaging showed that after brachial plexus injury,the motor imagery task for the affected limbs of the patients triggered no obvious activation of bilateral supplementary motor areas.This result indicates that it is difficult to excite the supplementary motor areas of brachial plexus injury patients during a motor imagery task,thereby impacting brain remodeling.Deactivation of the supplementary motor area is likely to be a serious problem for brachial plexus injury patients in terms of preparing,initiating and executing certain movements,which may be partly responsible for the unsatisfactory clinical recovery of hand function.

Transferrin receptor 1 plays an important role in muscle development and denervation-induced muscular atrophy

Previous studies demonstrate an accumulation of transferrin and transferrin receptor 1(TfR1) in regenerating peripheral nerves.However, the expression and function of transferrin and TfR1 in the denervated skeletal muscle remain poorly understood.In this study, a mouse model of denervation was produced by complete tear of the left brachial plexus nerve.RNA-sequencing revealed that transferrin expression in the denervated skeletal muscle was upregulated, while TfR1 expression was downregulated.We also investigated the function of TfR1 during development and in adult skeletal muscles in mice with inducible deletion or loss of TfR1.The ablation of TfR1 in skeletal muscle in early development caused severe muscular atrophy and early death.In comparison, deletion of TfR1 in adult skeletal muscles did not affect survival or glucose metabolism, but caused skeletal muscle atrophy and motor functional impairment, similar to the muscular atrophy phenotype observed after denervation.These findings suggest that TfR1 plays an important role in muscle development and denervation-induced muscular atrophy.This study was approved by the Institutional Animal Care and Use Committee of Beijing Institute of Basic Medical Sciences, China(approval No.SYXK 2017-C023) on June 1, 2018.