Peripheral nerve injuries (PNIs) remain a significant clinical problem, producing permanent motor-sensory deficits and diminishing patient's quality of life. Neurotrophic growth factors, a family of biomolecules, support neuronal survival and regeneration. Among them, Brain-Derived Neurotrophic Factor (BDNF) emerged as a key modulator of neurogenesis and neuroregeneration within the peripheral nervous system. This systematic review evaluates and summarises animal-based evidence on BDNF-based therapies used in peripheral nerve injury (PNI). A literature search in PubMed, EMBASE, Scopus, and Web of Science with the latest results from 10th of October 2024 to identify animal-based studies evaluating the effects of BDNF-based therapies used in PNI. Of 785 records, 40 articles met the inclusion criteria, encompassing 1887 rats and 430 mice or rabbits across various injury models. Gathered studies heterogenicity precluded meta-analysis, but most reports showed superior axonal regeneration, myelination, and functional recovery in BDNF-based therapies compared to control groups. The benefits were most significant with multimodal strategies, including multiple neurotrophins and stem cells. Combined therapies involving multiple neurotrophic growth factors, BDNF, and stem cell therapies showed the most significant improvement in functional outcomes and histological parameters of injured nerves. These results suggest that BDNF-based therapies hold promise for effective PNI treatment.

Purpose: The true incidence of radial nerve birth injury remains unknown due to presentation overlap with obstetric brachial plexus injury. These injuries may present with discrete clinical signs including palpable nodules or ecchymosis over the posterolateral arm and typically have favorable prognoses without surgical intervention. This study aimed to characterize patient presentations, recovery trajectories, and global management experiences for radial nerve birth injuries at a tertiary paediatric brachial plexus service. Methods: A retrospective single centre review of all patients with radial nerve birth injury between 2016 and 2024. Patients were identified from clinical coding as well as from clinic attendance. A literature review was conducted not limited by time or language. Results: Thirteen patients were identified with radial nerve birth injury with 14 affected limbs. Six (43%) affected limbs were right sided; eight (61.5%) were female. Median age at diagnosis by the specialist centre was 60 days (range 1-185 days). Four (29%) limbs had ecchymosis on the arm and five (36%) had a palpable nodule. Median time to recovery, as determined by a health care professional at the tertiary centre, was 162 days (90-824 days). All patients were offered physiotherapy; no child required surgery. A further 98 cases were identified from the global literature and only one patient required surgery, making an incomplete recovery. Conclusion: It is important to consider isolated radial nerve injuries when referring and assessing a child for obstetric brachial plexus injuries, particularly in the presence of ecchymosis or a palpable nodule on the posterolateral arm. Radial nerve birth injury has a good recovery trajectory by 6 months of age with physiotherapy alone. It is useful to ensure that all patients are assessed using a common evaluative tool, such as the Active Movement Scale, to ensure comparison between global work.

Background: Targeted muscle reinnervation (TMR) is a relatively new treatment for neuroma/phantom limb pain and for improving prosthetic functional outcomes. TMR uses coaptation of major peripheral nerves to recipient motor branches to expendable muscle targets.(1,2) This case demonstrates the first application of immediate TMR for acute upper limb amputation at Waikato Hospital. Case: We were presented with a 20-year-old otherwise well, male engineer. The patient suffered a farm machinery accident with multi-segmental crush/avulsion amputation of the non-dominant forearm. Within 3hours from time of injury, the patient was undergoing a multi-specialty team replantation of the limb. Unfortunately, on day 9 following replant, infection was noted. The limb was deemed non salvageable on day 11. Following multi-consultant review, a trans-humeral amputation to allow adequate stump closure and healing was chosen. Treatment/Outcome: The amputation was performed with immediate TMR. Via anterior approach the median nerve was transferred onto the nerve to short head of biceps and the ulnar nerve onto the nerve to brachialis. Via the posterior approach the radial nerve was transferred onto the branches to lateral head of triceps. The patient was discharged day 5 with minimal analgesia requirements. At the 2week follow-up the wound was well healed, without reports of neuroma/phantom limb pain. Conclusion: With established improved outcomes in pain and prosthetic use/function for patients and our positive case experience, we should consider immediate TMR for our patients undergoing upper limb amputation. References 1. Hagiga, A., Aly, M., Gumaa, M., etal. (2023). Targeted muscle reinnervation in managing post-amputation related pain: A systematic review and meta-analysis. Pain practice : the official journal of World Institute of Pain, 23(8), 922–932. 2. Le, E.L.H., Iorio, M.L. & Greyson, M.A. Targeted muscle reinnervation in upper extremity amputations. Eur J Orthop Surg Traumatol 34, 3717–3725 (2024).