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Nature Communications Sep 2020Peripheral sensory neurons regenerate their axon after nerve injury to enable functional recovery. Intrinsic mechanisms operating in sensory neurons are known to...
Peripheral sensory neurons regenerate their axon after nerve injury to enable functional recovery. Intrinsic mechanisms operating in sensory neurons are known to regulate nerve repair, but whether satellite glial cells (SGC), which completely envelop the neuronal soma, contribute to nerve regeneration remains unexplored. Using a single cell RNAseq approach, we reveal that SGC are distinct from Schwann cells and share similarities with astrocytes. Nerve injury elicits changes in the expression of genes related to fatty acid synthesis and peroxisome proliferator-activated receptor (PPARα) signaling. Conditional deletion of fatty acid synthase (Fasn) in SGC impairs axon regeneration. The PPARα agonist fenofibrate rescues the impaired axon regeneration in mice lacking Fasn in SGC. These results indicate that PPARα activity downstream of FASN in SGC contributes to promote axon regeneration in adult peripheral nerves and highlight that the sensory neuron and its surrounding glial coat form a functional unit that orchestrates nerve repair.
Topics: Animals; Axons; Cell Proliferation; Fatty Acid Synthases; Female; Humans; Male; Mice; Mice, Inbred C57BL; Nerve Regeneration; Neuroglia; PPAR alpha; Peripheral Nerve Injuries; Peripheral Nerves; Sensory Receptor Cells; Signal Transduction
PubMed: 32994417
DOI: 10.1038/s41467-020-18642-y -
Journal of Cellular Physiology Apr 2019Peripheral nerve physiology and regeneration has been observed and investigated in literature but surgical applications to reconstruct and restore motor or sensory... (Review)
Review
Peripheral nerve physiology and regeneration has been observed and investigated in literature but surgical applications to reconstruct and restore motor or sensory functions are still in a developmental phase. The peripheral nerve progresses slowly and incompletely compared with other tissues, it may provoke separations of the nerve stumps and the axonal proliferation of the conduits is restricted to 30 mm. Recent surgical attempts to treat proximal nerve injures include direct nerve restoration, transfer, and autografting measures with favorable results. Moreover, studies are suggesting that engineering tissue tubes maybe as effective as nerve grafting to restore separations of more than 4 cm toward optimal nerve repair.
Topics: Amnion; Animals; Guided Tissue Regeneration; Humans; Nerve Regeneration; Neural Prostheses; Neurosurgical Procedures; Peripheral Nerve Injuries; Peripheral Nerves; Recovery of Function; Tissue Engineering; Treatment Outcome; Wound Healing
PubMed: 30206940
DOI: 10.1002/jcp.27299 -
Acta Anaesthesiologica Scandinavica Sep 2015Ultrasound guidance is now a standard nerve localization technique for peripheral nerve block (PNB). Ultrasonography allows simultaneous visualization of the target... (Review)
Review
BACKGROUND
Ultrasound guidance is now a standard nerve localization technique for peripheral nerve block (PNB). Ultrasonography allows simultaneous visualization of the target nerve, needle, local anesthetic injectate, and surrounding anatomical structures. Accurate deposition of local anesthetic next to the nerve is essential to the success of the nerve block procedure. Due to limitations in the visibility of both needle tip and nerve surface, the precise relationship between needle tip and target nerve is unknown at the moment of injection. Importantly, nerve injury may result both from an inappropriately placed needle tip and inappropriately placed local anesthetic. The relationship between the block needle tip and target nerve is of paramount importance to the safe conduct of peripheral nerve block.
METHODS
This review summarizes the evolution of nerve localization in regional anesthesia, characterizes a problem faced by clinicians in performing ultrasound-guided nerve block, and explores the potential technological solutions to this problem.
RESULTS
To date, technology newly applied to PNB includes real-time 3D imaging, multi-planar magnetic needle guidance, and in-line injection pressure monitoring. This review postulates that optical reflectance spectroscopy and bioimpedance may allow for accurate identification of the relationship between needle tip and target nerve, currently a high priority deficit in PNB techniques.
CONCLUSIONS
Until it is known how best to define the relationship between needle and nerve at the moment of injection, some common sense principles are suggested.
Topics: Humans; Nerve Block; Peripheral Nerves; Ultrasonography, Interventional
PubMed: 25997933
DOI: 10.1111/aas.12544 -
Progress in Neurological Surgery 2015Peripheral nerve stimulation (PNS) has been in use for over 50 years to treat patients suffering from chronic pain who have failed conservative treatments. Despite this... (Review)
Review
Peripheral nerve stimulation (PNS) has been in use for over 50 years to treat patients suffering from chronic pain who have failed conservative treatments. Despite this long history, the devices being used have changed very little. In fact, current PNS technology was developed specifically for spinal cord stimulation. The use of technology developed for other applications in PNS has led to an unnecessary number of device complications and the limited adoption of this promising therapy. The following chapter provides an overview of PNS technology throughout the years, outlining both the benefits and limitations. We will briefly explore the electrophysiology of PNS stimulation, with an emphasis on technology and indication-specific devices. Finally, design and technical requirements of an ideal PNS device will be discussed.
Topics: Animals; Electric Stimulation Therapy; Electrodes; Humans; Pain Management; Peripheral Nerves; Transcutaneous Electric Nerve Stimulation
PubMed: 26394391
DOI: 10.1159/000434651 -
Wiener Medizinische Wochenschrift (1946) Jun 2019Artificial and non-artificial nerve grafts are the gold standard in peripheral nerve reconstruction in cases with extensive loss of nerve tissue, particularly where... (Review)
Review
Artificial and non-artificial nerve grafts are the gold standard in peripheral nerve reconstruction in cases with extensive loss of nerve tissue, particularly where a direct end-to-end suture or an autologous nerve graft is inauspicious. Different materials are marketed and approved by the US Food and Drug Administration (FDA) for peripheral nerve graft reconstruction. The most frequently used materials are collagen and poly(DL-lactide-ε-caprolactone). Only one human nerve allograft is listed for peripheral nerve reconstruction by the FDA. All marketed nerve grafts are able to demonstrate sufficient nerve regeneration over small distances not exceeding 3.0 cm. A key question in the field is whether nerve reconstruction on large defect lengths extending 4.0 cm or more is possible. This review gives a summary of current clinical and experimental approaches in peripheral nerve surgery using artificial and non-artificial nerve grafts in short and long distance nerve defects. Strategies to extend nerve graft lengths for long nerve defects, such as enhancing axonal regeneration, include the additional application of Schwann cells, mesenchymal stem cells or supporting co-factors like growth factors on defect sizes between 4.0 and 8.0 cm.
Topics: Humans; Nerve Regeneration; Peripheral Nerve Injuries; Peripheral Nerves; Schwann Cells; Transplantation, Homologous; United States
PubMed: 30547373
DOI: 10.1007/s10354-018-0675-6 -
The Journal of the American Academy of... Aug 2023Undertreated digital nerve injuries may result in sensory deficits and pain. Early recognition and treatment will optimize outcomes, and providers should maintain a high...
Undertreated digital nerve injuries may result in sensory deficits and pain. Early recognition and treatment will optimize outcomes, and providers should maintain a high index of suspicion when assessing patients with open wounds. Acute, sharp lacerations may be amenable to direct repair while avulsion injuries or delayed repairs require adequate resection and bridging with nerve autograft, processed nerve allograft, or conduits. Conduits are most appropriate for gaps less than 15 mm, and processed nerve allografts have demonstrated reliable outcomes across longer gaps.
Topics: Humans; Peripheral Nerves; Peripheral Nerve Injuries; Finger Injuries; Transplantation, Autologous; Plastic Surgery Procedures; Allografts
PubMed: 37205873
DOI: 10.5435/JAAOS-D-23-00255 -
Diabetes Aug 2023Diabetes peripheral neuropathy (DPN) is commonly asymptomatic in the early stage. However, once symptoms and obvious defects appear, recovery is not possible. Diagnosis... (Review)
Review
Diabetes peripheral neuropathy (DPN) is commonly asymptomatic in the early stage. However, once symptoms and obvious defects appear, recovery is not possible. Diagnosis of neuropathy is based on physical examinations, questionnaires, nerve conduction studies, skin biopsies, and so on. However, the diagnosis of DPN is still challenging, and early diagnosis and immediate intervention are very important for prevention of the development and progression of diabetic neuropathy. The advantages of MRI in the diagnosis of DPN are obvious: the peripheral nerve imaging is clear, the lesions can be found intuitively, and the quantitative evaluation of the lesions is the basis for the diagnosis, classification, and follow-up of DPN. With the development of magnetic resonance technology, more and more studies have been conducted on detection of DPN. This article reviews the research field of MRI in DPN.
Topics: Humans; Diabetic Neuropathies; Peripheral Nerves; Magnetic Resonance Imaging; Nerve Conduction Studies; Diabetes Mellitus, Type 2
PubMed: 37471598
DOI: 10.2337/db22-0912 -
International Journal of Molecular... May 2023In peripheral nerve injuries (PNI) with substance loss, where tensionless end-to-end suture is not achievable, the positioning of a graft is required. Available options... (Review)
Review
In peripheral nerve injuries (PNI) with substance loss, where tensionless end-to-end suture is not achievable, the positioning of a graft is required. Available options include autografts (e.g., sural nerve, medial and lateral antebrachial cutaneous nerves, superficial branch of the radial nerve), allografts (Avance; human origin), and hollow nerve conduits. There are eleven commercial hollow conduits approved for clinical, and they consist of devices made of a non-biodegradable synthetic polymer (polyvinyl alcohol), biodegradable synthetic polymers (poly(DL-lactide-ε-caprolactone); polyglycolic acid), and biodegradable natural polymers (collagen type I with/without glycosaminoglycan; chitosan; porcine small intestinal submucosa); different resorption times are available for resorbable guides, ranging from three months to four years. Unfortunately, anatomical/functional nerve regeneration requirements are not satisfied by any of the possible alternatives; to date, focusing on wall and/or inner lumen organization/functionalization seems to be the most promising strategy for next-generation device fabrication. Porous or grooved walls as well as multichannel lumens and luminal fillers are the most intriguing options, eventually also including the addition of cells (Schwann cells, bone marrow-derived, and adipose tissue derived stem cells) to support nerve regeneration. This review aims to describe common alternatives for severe PNI recovery with a highlight of future conduits.
Topics: Animals; Humans; Swine; Sciatic Nerve; Polyesters; Peripheral Nerves; Prostheses and Implants; Peripheral Nerve Injuries; Polyglycolic Acid; Nerve Regeneration
PubMed: 37298122
DOI: 10.3390/ijms24119170 -
Hand Clinics May 2016The restoration of shoulder function after brachial plexus injury represents a significant challenge facing the peripheral nerve surgeons. This is owing to a combination... (Review)
Review
The restoration of shoulder function after brachial plexus injury represents a significant challenge facing the peripheral nerve surgeons. This is owing to a combination of the complex biomechanics of the shoulder girdle, the multitude of muscles and nerves that could be potentially injured, and a limited number of donor options. In general, nerve transfer is favored over tendon transfer, because the biomechanics of the musculotendinous units are not altered. This article summarizes the surgical techniques and clinical results of nerve transfers for restoration of shoulder function.
Topics: Brachial Plexus; Humans; Nerve Transfer; Peripheral Nerve Injuries; Peripheral Nerves; Range of Motion, Articular; Recovery of Function; Shoulder; Shoulder Injuries; Shoulder Joint
PubMed: 27094888
DOI: 10.1016/j.hcl.2015.12.004 -
Hand Clinics May 2015This article provides an overview of the management of traumatic peripheral nerve injuries. It examines the basic pathophysiology of peripheral nerve injuries, along... (Review)
Review
This article provides an overview of the management of traumatic peripheral nerve injuries. It examines the basic pathophysiology of peripheral nerve injuries, along with the clinical presentation, diagnostic work-up, and treatment options and outcomes for the various classifications of traumatic peripheral nerve injuries.
Topics: Humans; Peripheral Nerve Injuries; Peripheral Nerves
PubMed: 25934193
DOI: 10.1016/j.hcl.2015.01.007