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Cold Spring Harbor Perspectives in... Feb 2020The vagus nerve plays an important role in maintaining physiological homeostasis, which includes reflex pathways that regulate cardiac function. The link between vagus... (Review)
Review
The vagus nerve plays an important role in maintaining physiological homeostasis, which includes reflex pathways that regulate cardiac function. The link between vagus nerve activity and the high-frequency component of heart rate variability (HRV) has been well established, correlating with vagal tone. Recently, vagus nerve stimulation (VNS) has been investigated as a therapeutic for a multitude of diseases, such as treatment-resistant epilepsy, rheumatoid arthritis, Crohn's disease, and asthma. Because of the vagus nerve's innervation of the heart, VNS has been identified as a potential therapy for cardiovascular disorders, such as cardiac arrest, acute myocardial infarction, and stroke. Here, we review the current state of preclinical and clinical studies, as well as the potential application of VNS in relation to the cardiovascular system.
Topics: Animals; Cardiovascular Diseases; Cardiovascular System; Heart Rate; Humans; Vagus Nerve; Vagus Nerve Stimulation
PubMed: 31109966
DOI: 10.1101/cshperspect.a034173 -
Hand Clinics Aug 2013Peripheral nerve injuries are common conditions, with broad-ranging groups of symptoms depending on the severity and nerves involved. Although much knowledge exists on... (Review)
Review
Peripheral nerve injuries are common conditions, with broad-ranging groups of symptoms depending on the severity and nerves involved. Although much knowledge exists on the mechanisms of injury and regeneration, reliable treatments that ensure full functional recovery are scarce. This review aims to summarize various ways these injuries are classified in light of decades of research on peripheral nerve injury and regeneration.
Topics: Animals; Axons; Cells, Cultured; Humans; Macrophages; Models, Animal; Models, Biological; Nerve Compression Syndromes; Nerve Fibers; Nerve Growth Factors; Nerve Regeneration; Neurons; Peripheral Nerve Injuries; Peripheral Nerves; Schwann Cells; Wallerian Degeneration
PubMed: 23895713
DOI: 10.1016/j.hcl.2013.04.002 -
Orthopaedics & Traumatology, Surgery &... Feb 2021At the elbow, the ulnar nerve (UN) may be the site of a static compression (by the cubital tunnel retinaculum and Osborne's ligament between the two heads of the flexor... (Review)
Review
At the elbow, the ulnar nerve (UN) may be the site of a static compression (by the cubital tunnel retinaculum and Osborne's ligament between the two heads of the flexor carpi ulnaris), or a dynamic compression, especially when the nerve is unstable (subluxation/dislocation outside the ulnar groove). The clinical basis for the diagnosis of ulnar neuropathy involves looking for subjective and objective signs of sensory and/or motor deficit in the ulnar nerve's territory in the hand, a pseudo-Tinel's sign, and doing manipulations to provoke UN irritation. The diagnosis is confirmed by electromyography and ultrasonography. In the early stages, patient education and elimination of flexion postures or repeated elbow flexion motions can provide relief. If this fails or signs of sensory and/or motor deficit are present, surgical treatment is proposed. If the nerve is stable, in-situ nerve decompression is typically done as the first-line treatment. If the nerve is unstable, anterior nerve transposition - generally subcutaneous - or more rarely, a medial epicondylectomy can be done. If surgical treatment fails, the patient's history is reviewed, and diagnostic tests can be repeated. Except in cases of a fibrotic scar, the main causes of failure are neuroma of a branch of the medial cutaneous nerve of the forearm, instability of the nerve and persistence of a compression point. In the latter two cases, surgical revision is justified and anterior nerve transposition or epicondylectomy can be proposed.
Topics: Cubital Tunnel Syndrome; Decompression, Surgical; Elbow; Humans; Neurosurgical Procedures; Ulnar Nerve; Ulnar Neuropathies
PubMed: 33321238
DOI: 10.1016/j.otsr.2020.102754 -
PM & R : the Journal of Injury,... May 2013Neuropathies that affect the lower limbs are often encountered after trauma or iatrogenic injury or by entrapment at areas of anatomic restriction. Symptoms may... (Review)
Review
Neuropathies that affect the lower limbs are often encountered after trauma or iatrogenic injury or by entrapment at areas of anatomic restriction. Symptoms may initially be masked by concomitant trauma or recovery from surgical procedures. The nerves that serve the lower extremities arise from the lumbosacral plexus, formed by the L2-S2 nerve roots. The major nerves that supply the lower extremities are the femoral, obturator, lateral femoral cutaneous, and the peroneal (fibular) and tibial, which arise from the sciatic nerve, and the superior and inferior gluteal nerves. An understanding of the motor and sensory functions of these nerves is critical in recognizing and localizing nerve injury. Electrodiagnostic studies are an important diagnostic tool. A well-designed electromyography study can help confirm and localize a nerve lesion, assess severity, and evaluate for other peripheral nerve lesions, such as plexopathy or radiculopathy.
Topics: Electrodiagnosis; Humans; Lower Extremity; Lumbosacral Plexus; Nerve Compression Syndromes; Risk Factors
PubMed: 23542774
DOI: 10.1016/j.pmrj.2013.03.029 -
Pain Physician Jul 2022The superior and middle cluneal nerves are sources of low back, buttock, and leg pain. These nerves are cutaneous branches of the lateral branches of the dorsal rami of... (Review)
Review
BACKGROUND
The superior and middle cluneal nerves are sources of low back, buttock, and leg pain. These nerves are cutaneous branches of the lateral branches of the dorsal rami of T11- S4. Pain arising from entrapment or dysfunction of one or more of these nerves is called "cluneal nerve syndrome." A clear understanding of the anatomy underlying cluneal nerve syndrome and its treatment has been hampered by the very small size of the cluneal nerves and their complex, varying anatomy. Because of differing methods and foci of investigation, the literature regarding cluneal nerves has been confusing and even contradictory.
OBJECTIVES
This paper provides a thorough critical literature review of cluneal nerve anatomy and implications for therapy.
STUDY DESIGN
A modified scoping review.
METHODS
The bibliographic trail of English language papers on the anatomy and treatment of cluneal nerve syndrome was used to resolve the contradictions that have appeared in some of the anatomic descriptions and, where applicable, to examine their implications for therapy.
RESULTS
Recent anatomic and surgical investigations confirm a wider than previously realized range of central nervous system origins of these peripheral nerves, explaining why cluneal nerve dysfunction can cause a wide array of symptoms, including low back, buttock, and/or leg pain or "pseudosciatica."
CONCLUSIONS
Cluneal nerve syndrome is characterized by a triad of pain, tender points, and relief with local anesthetic injections. The pain is a deep, aching, poorly localized low back pain with variable involvement of the buttocks and/or legs. Tender points are localized at the iliac crest or caudal to the posterior superior iliac spine. Muscle weakness and dermatomal sensory changes are absent in cluneal nerve syndrome. If the pain returns after injections, neuroablation, nerve stimulation, or surgical release may be needed.
Topics: Buttocks; Humans; Ilium; Low Back Pain; Nerve Compression Syndromes; Spinal Nerves
PubMed: 35793175
DOI: No ID Found -
BioMed Research International 2014Unlike other tissues in the body, peripheral nerve regeneration is slow and usually incomplete. Less than half of patients who undergo nerve repair after injury regain... (Review)
Review
Unlike other tissues in the body, peripheral nerve regeneration is slow and usually incomplete. Less than half of patients who undergo nerve repair after injury regain good to excellent motor or sensory function and current surgical techniques are similar to those described by Sunderland more than 60 years ago. Our increasing knowledge about nerve physiology and regeneration far outweighs our surgical abilities to reconstruct damaged nerves and successfully regenerate motor and sensory function. It is technically possible to reconstruct nerves at the fascicular level but not at the level of individual axons. Recent surgical options including nerve transfers demonstrate promise in improving outcomes for proximal nerve injuries and experimental molecular and bioengineering strategies are being developed to overcome biological roadblocks limiting patient recovery.
Topics: Animals; Humans; Nerve Regeneration; Peripheral Nerve Injuries; Peripheral Nerves; Plastic Surgery Procedures; Recovery of Function; Translational Research, Biomedical
PubMed: 25276813
DOI: 10.1155/2014/698256 -
Clinical Cancer Research : An Official... Aug 2022Perineural invasion (PNI), a common occurrence in oral squamous cell carcinomas, is associated with poor survival. Consequently, these tumors are treated aggressively....
PURPOSE
Perineural invasion (PNI), a common occurrence in oral squamous cell carcinomas, is associated with poor survival. Consequently, these tumors are treated aggressively. However, diagnostic criteria of PNI vary and its role as an independent predictor of prognosis has not been established. To address these knowledge gaps, we investigated spatial and transcriptomic profiles of PNI-positive and PNI-negative nerves.
EXPERIMENTAL DESIGN
Tissue sections from 142 patients were stained with S100 and cytokeratin antibodies. Nerves were identified in two distinct areas: tumor bulk and margin. Nerve diameter and nerve-to-tumor distance were assessed; survival analyses were performed. Spatial transcriptomic analysis of nerves at varying distances from tumor was performed with NanoString GeoMx Digital Spatial Profiler Transcriptomic Atlas.
RESULTS
PNI is an independent predictor of poor prognosis among patients with metastasis-free lymph nodes. Patients with close nerve-tumor distance have poor outcomes even if diagnosed as PNI negative using current criteria. Patients with large nerve(s) in the tumor bulk survive poorly, suggesting that even PNI-negative nerves facilitate tumor progression. Diagnostic criteria were supported by spatial transcriptomic analyses of >18,000 genes; nerves in proximity to cancer exhibit stress and growth response changes that diminish with increasing nerve-tumor distance. These findings were validated in vitro and in human tissue.
CONCLUSIONS
This is the first study in human cancer with high-throughput gene expression analysis in nerves with striking correlations between transcriptomic profile and clinical outcomes. Our work illuminates nerve-cancer interactions suggesting that cancer-induced injury modulates neuritogenesis, and supports reclassification of PNI based on nerve-tumor distance rather than current subjective criteria.
Topics: Head and Neck Neoplasms; Humans; Keratins; Mouth Neoplasms; Neoplasm Invasiveness; Neoplasm Staging; Peripheral Nerves; Prognosis; Retrospective Studies; Transcriptome
PubMed: 35819260
DOI: 10.1158/1078-0432.CCR-21-4543 -
American Journal of Respiratory and... May 2023Diaphragm neurostimulation consists of placing electrodes directly on or in proximity to the phrenic nerve(s) to elicit diaphragmatic contractions. Since its initial... (Review)
Review
Diaphragm neurostimulation consists of placing electrodes directly on or in proximity to the phrenic nerve(s) to elicit diaphragmatic contractions. Since its initial description in the 18th century, indications have shifted from cardiopulmonary resuscitation to long-term ventilatory support. Recently, the technical development of devices for temporary diaphragm neurostimulation has opened up the possibility of a new era for the management of mechanically ventilated patients. Combining positive pressure ventilation with diaphragm neurostimulation offers a potentially promising new approach to the delivery of mechanical ventilation which may benefit multiple organ systems. Maintaining diaphragm contractions during ventilation may attenuate diaphragm atrophy and accelerate weaning from mechanical ventilation. Preventing atelectasis and preserving lung volume can reduce lung stress and strain and improve homogeneity of ventilation, potentially mitigating ventilator-induced lung injury. Furthermore, restoring the thoracoabdominal pressure gradient generated by diaphragm contractions may attenuate the drop in cardiac output induced by positive pressure ventilation. Experimental evidence suggests diaphragm neurostimulation may prevent neuroinflammation associated with mechanical ventilation. This review describes the historical development and evolving approaches to diaphragm neurostimulation during mechanical ventilation and surveys the potential mechanisms of benefit. The review proposes a research agenda and offers perspectives for the future of diaphragm neurostimulation assisted mechanical ventilation for critically ill patients.
Topics: Humans; Respiration, Artificial; Diaphragm; Critical Illness; Positive-Pressure Respiration; Respiration
PubMed: 36917765
DOI: 10.1164/rccm.202212-2252CP