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.

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.

Brachial plexus palsy caused by halo traction before posterior correction in patients with severe scoliosis

Objective: To explore the clinical features and treatment results of brachial plexus palsy caused by halo traction before posterior correction in patients with severe scoliosis.Methods: A total of 300 cases of severe scoliosis received halo traction before posterior correction in our department from July 1997 to November 2004. Among them, 7 cases were complicated with brachial plexus palsy.The average Cobb angle was 110° (range, 90°-135°).Diagnoses were made as idiopathic scoliosis in 1 case,congenital scoliosis in 3 cases, and neuromuscular scoliosis in 3 cases. Additionally, diastematomyelia and tethered cord syndrome were found in 3 cases and thoracolumbar kyphosis in 2 cases. Weight of traction was immediately reduced when the patient developed any abnormal neurological symptoms in the upper extremity, and rehabilitation training was undertaken. Simultaneously,neurotrophic pharmacotherapy was applied, and the neurological function restoration of the upper limbs and the recovery time were documented.Results: Traction was used for an average of 3.5 weeks (range, 2-6 weeks) before spinal fusion for these 7 patients. The average traction weight was 8 kg, which was 19% on average (range, 13%-26%) of the average body weight (40.2 kg). These 7 patients had long and thin body configuration with a mean height of 175 cm. The duration between symptoms of brachial plexus paralysis and the diagnosis was 1-3 hours. All of these 7 patients presented various degrees of numbness in the ulnar side of the hand and forearm. Median nerve paresis was found in 3 cases and ulnar nerve paresis in 4 cases. Complete recovery of the neurological function had been achieved by the end of three months.Conclusions: The clinical features of brachial plexus palsy caused by halo traction include median nerve paresis,ulnar nerve paralysis, and numbness in the ulnar side of the hand and forearm, which may be due to the injury of the inferior part of the brachial plexus, i.e. , damage of Cs and T1 nerve roots. Complete recovery of neurological function can be expected when the patient is kept under careful observation for recognizing this complication as soon as possible, then immediately reducing or removing the traction weight, and adopting rehabilitation training and neurotrophic pharmaceutical treatment.