Brachial Plexus Injuries - Review of the Anatomy and the Treatment Options

Promotive effect of skin precursor-derived Schwann cells on brachial plexus neurotomy and motor neuron damage repair through milieu-regulating secretome

Brachial plexus injury (BPI) with motor neurons (MNs) damage still remain poor recovery in preclinical research and clinical therapy, while cell-based therapy approaches emerged as novel strategies. Previous work of rat skin precursor-derived Schwann cells (SKP-SCs) provided substantial foundation for repairing peripheral nerve injury (PNI). Given that, our present work focused on exploring the repair efficacy and possible mechanisms of SKP-SCs implantation on rat BPI combined with neurorrhaphy post-neurotomy. Results indicated the significant locomotive and sensory function recovery, with improved morphological remodeling of regenerated nerves and angiogenesis, as well as amelioration of target muscles atrophy and motor endplate degeneration. Besides, MNs could restore from oxygen-glucose-deprivation (OGD) injury upon SKP-SCs-sourced secretome treatment, implying the underlying paracrine mechanisms. Moreover, rat cytokine array assay detected 67 cytokines from SKP-SC-secretome, and bioinformatic analyses of screened 32 cytokines presented multiple functional clusters covering diverse cell types, including inflammatory cells, Schwann cells, vascular endothelial cells (VECs), neurons, and SKP-SCs themselves, relating distinct biological processes to nerve regeneration. Especially, a panel of hypoxia-responsive cytokines (HRCK), can participate into multicellular biological process regulation for permissive regeneration milieu, which underscored the benefits of SKP-SCs and sourced secretome, facilitating the chorus of nerve regenerative microenvironment. Furthermore, platelet-derived growth factor-AA (PDGF-AA) and vascular endothelial growth factor-A (VEGF-A) were outstanding cytokines involved with nerve regenerative microenvironment regulating, with significantly elevated mRNA expression level in hypoxia-responsive SKP-SCs. Altogether, through recapitulating the implanted SKP-SCs and derived secretome as niche sensor and paracrine transmitters respectively, HRCK would be further excavated as molecular underpinning of the neural recuperative mechanizations for efficient cell therapy; meanwhile, the analysis paradigm in this study validated and anticipated the actions and mechanisms of SKP-SCs on traumatic BPI repair, and was beneficial to identify promising bioactive molecule cocktail and signaling targets for cell-free therapy strategy on neural repair and regeneration.

Mapping Motor Neuroplasticity after Successful Surgical Brachial Plexus Reconstruction Using Navigated Transcranial Magnetic Stimulation (nTMS)

Brachial plexus reconstruction (BPR) consists of the complex surgical restoration of nerve structures. To further understand the underlying motor cortex changes and evaluate neuroplasticity after a successful surgery, we performed a navigated transcranial magnetic stimulation (nTMS) study mapping the postoperative motor representation of the formerly plegic arm. We conducted a prospective nTMS study mapping the musculocutaneous nerve as a representative, prominent target of BPR including a patient (n = 8) and a control group (n = 10). Measurements like resting motor threshold (RMT), cortical motor area location, and size were taken. Mathematical analysis was performed using MATLAB 2022, statistical analysis was performed using SPSS 26, and nTMS mapping was performed using the Nexstim NBS 5.1 system. Mapping was feasible in seven out of eight patients. Median RMT on the affected hemisphere was 41% compared to 50% on the unaffected hemisphere and they were 37% and 36% on the left and right hemispheres of the control group. The motor area location showed a relocation of bicep brachii representation at the middle precentral gyrus of the corresponding contralateral hemisphere. Motor area size was increased compared to the control group and the patient's unaffected, ipsilateral hemisphere. Understanding cortical reorganization is important for potential future treatments like therapeutic nTMS. The issue of motor neuroplasticity in patients with brachial plexus lesions is worth exploring in further studies.

Excision of Giant Chronic Expanding Hematoma of the Thorax Caused by Rib Fractures after Proton Radiotherapy for Lung Cancer

Chronic expanding hematoma (CEH) is defined as a hematoma that gradually expands over months to years. An 82-year-old female underwent proton radiotherapy for left upper lobe lung cancer 10 years previously. Two years after the therapy, a hematoma developed from the left 3rd to 5th dorsal rib fractures and gradually expanded, causing contraction of the left shoulder. Transcatheter arterial embolization was performed; however, the hematoma continued to expand with thrombocytopenia, and the platelet was decreased to 4.2 × 104/μL. Computed tomography showed a 17.2 × 14.0 × 10.0 cm mass between the left scapula and left dorsal ribs. The CEH of the thorax was completely excised with combined resection of the 3rd to 5th ribs, while the brachial plexus was preserved. Postoperatively, the platelet completely recovered and she could raise her left arm. A complete excision with surrounding organs preserved is the strategy used in the treatment of CEH of the thorax.

Evaluation and Diagnostic-Treatment Approaches of Brachial Plexus Injuries in Adults

Background

Brachial plexus injury (BPI), as one of the most devastating injuries in adults, has various negative consequences such as profound functional impairment, debilitating pain, significant mental health consequences, and economic impacts. We aimed to review the evaluation and diagnostic-treatment Approaches of BPI in adults through a review study.

Methods

An electronic literature search was completed in Google Scholar, Springer, PubMed, and Science Direct databases from 1980 to 2023. Various keywords related to the purpose such as Brachial plexus, surgical strategy, adult were used.

Results

1.2% of people with multiple traumas had BPIs. BPI is more common in young adult males. For brachial plexus palsy, preoperative evaluation of nerve root avulsion is helpful in surgical planning. . EMG is useful in confirming a diagnosis, localizing the lesion level, estimating the extent of axon loss, and determining whether the lesion is complete. There are different options available for BPI, such as coordinating care, rehabilitation and psychosocial support. In recent times, significant advancements have been made in surgical techniques for nerve repairs.

Conclusion

Although it is often not possible to prevent damage to the brachial plexus, it is possible to reduce the risk of further problems after the injury by taking some measures.

Beyond the Knife-Reviewing the Interplay of Psychosocial Factors and Peripheral Nerve Lesions

Peripheral nerve injuries are a common clinical problem. They not only affect the physical capabilities of the injured person due to loss of motor or sensory function but also have a significant impact on psychosocial aspects of life. The aim of this work is to review the interplay of psychosocial factors and peripheral nerve lesions. By reviewing the published literature, we identified several factors to be heavily influenced by peripheral nerve lesions. In addition to psychological factors like pain, depression, catastrophizing and stress, social factors like employment status and worker's compensation status could be identified to be influenced by peripheral nerve lesions as well as serving as predictors of functional outcome themselves, respectively. This work sheds a light not only on the impact of peripheral nerve lesions on psychosocial aspects of life, but also on the prognostic values of these factors of functional outcome. Interdisciplinary, individualized treatment of patients is required to identify patient at risk for adverse outcomes and provide them with emotional support when adapting to their new life situation.