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Handbook of Clinical Neurology 2024The femoral and obturator nerves both arise from the L2, L3, and L4 spinal nerve roots and descend into the pelvis before emerging in the lower limbs. The femoral... (Review)
Review
The femoral and obturator nerves both arise from the L2, L3, and L4 spinal nerve roots and descend into the pelvis before emerging in the lower limbs. The femoral nerve's primary function is knee extension and hip flexion, along with some sensory innervation to the leg. The obturator nerve's primary function is thigh adduction and sensory innervation to a small area of the medial thigh. Each may be injured by a variety of potential causes, many of them iatrogenic. Here, we review the anatomy of the femoral and obturator nerves and the clinical features and potential etiologies of femoral and obturator neuropathies. Their necessary investigations, including electrodiagnostic studies and imaging, their prognosis, and potential treatments, are discussed in this chapter.
Topics: Humans; Obturator Nerve; Peripheral Nervous System Diseases; Femoral Nerve; Femoral Neuropathy
PubMed: 38697739
DOI: 10.1016/B978-0-323-90108-6.00007-7 -
Neuromodulation : Journal of the... Feb 2024Functional gastrointestinal disorders (FGIDs) are common, and they severely impair an individual's quality of life. The mechanism of pathogenesis and the effective... (Review)
Review
INTRODUCTION
Functional gastrointestinal disorders (FGIDs) are common, and they severely impair an individual's quality of life. The mechanism of pathogenesis and the effective treatments for FGIDs remain elusive. Neuromodulation-a relatively new treatment-has exhibited a good therapeutic effect on FGIDs, although there are different methods for different symptoms of FGIDs.
MATERIALS AND METHODS
We used PubMed to review the history of neuromodulation for the treatment of FGIDs and to review several recently proposed neuromodulation approaches with improved effects on FGIDs.
CONCLUSION
Electroacupuncture, transcutaneous electroacupuncture, transcutaneous auricular vagal nerve stimulation, sacral nerve stimulation (SNS) (which relies on vagal nerve stimulation), and gastric electrical stimulation (which works through the modulation of slow waves generated by the interstitial cells of Cajal), in addition to the noninvasive neurostimulation alternative approach method of SNS-tibial nerve stimulation and transcutaneous electrical stimulation (which is still in its infancy), are some of the proposed neuromodulation approaches with improved effects on FGIDs. This review has discussed some critical issues related to the selection of stimulation parameters and the underlying mechanism and attempts to outline future research directions backed by the existing literature.
Topics: Humans; Quality of Life; Transcutaneous Electric Nerve Stimulation; Gastrointestinal Diseases; Vagus Nerve Stimulation; Spinal Nerves
PubMed: 37690016
DOI: 10.1016/j.neurom.2023.08.001 -
Science Translational Medicine Oct 2023Hyperexcitability in sensory neurons is known to underlie many of the maladaptive changes associated with persistent pain. Chemogenetics has shown promise as a means to...
Hyperexcitability in sensory neurons is known to underlie many of the maladaptive changes associated with persistent pain. Chemogenetics has shown promise as a means to suppress such excitability, yet chemogenetic approaches suitable for human applications are needed. PSAM-GlyR is a modular system based on the human α7 nicotinic acetylcholine and glycine receptors, which responds to inert chemical ligands and the clinically approved drug varenicline. Here, we demonstrated the efficacy of this channel in silencing both mouse and human sensory neurons by the activation of large shunting conductances after agonist administration. Virally mediated expression of PSAM-GlyR in mouse sensory neurons produced behavioral hyposensitivity upon agonist administration, which was recovered upon agonist washout. Stable expression of the channel led to similar reversible suppression of pain-related behavior even after 10 months of viral delivery. Mechanical and spontaneous pain readouts were also ameliorated by PSAM-GlyR activation in acute and joint pain inflammation mouse models. Furthermore, suppression of mechanical hypersensitivity generated by a spared nerve injury model of neuropathic pain was also observed upon activation of the channel. Effective silencing of behavioral hypersensitivity was reproduced in a human model of hyperexcitability and clinical pain: PSAM-GlyR activation decreased the excitability of human-induced pluripotent stem cell-derived sensory neurons and spontaneous activity due to a gain-of-function Na1.7 mutation causing inherited erythromelalgia. Our results demonstrate the contribution of sensory neuron hyperexcitability to neuropathic pain and the translational potential of an effective, stable, and reversible humanized chemogenetic system for the treatment of pain.
Topics: Humans; Mice; Animals; Neuralgia; Sensory Receptor Cells; Mutation; Ganglia, Spinal
PubMed: 37792955
DOI: 10.1126/scitranslmed.adh3839 -
Neuroscience Bulletin Jun 2024Cancer-induced bone pain (CIBP) is a type of ongoing or breakthrough pain caused by a primary bone tumor or bone metastasis. CIBP constitutes a specific pain state with... (Review)
Review
Cancer-induced bone pain (CIBP) is a type of ongoing or breakthrough pain caused by a primary bone tumor or bone metastasis. CIBP constitutes a specific pain state with distinct characteristics; however, it shares similarities with inflammatory and neuropathic pain. At present, although various therapies have been developed for this condition, complete relief from CIBP in patients with cancer is yet to be achieved. Hence, it is urgent to study the mechanism underlying CIBP to develop efficient analgesic drugs. Herein, we focused on the peripheral mechanism associated with the initiation of CIBP, which involves tissue injury in the bone and changes in the tumor microenvironment (TME) and dorsal root ganglion. The nerve-cancer and cancer-immunocyte cross-talk in the TME creates circumstances that promote tumor growth and metastasis, ultimately leading to CIBP. The peripheral mechanism of CIBP and current treatments as well as potential therapeutic targets are discussed in this review.
Topics: Humans; Bone Neoplasms; Cancer Pain; Animals; Tumor Microenvironment; Ganglia, Spinal
PubMed: 37798428
DOI: 10.1007/s12264-023-01126-6 -
Molecular Metabolism Dec 2023Interoception plays an important role in homeostatic regulation of energy intake and metabolism. Major interoceptive pathways include gut-to-brain and adipose tissue-to... (Review)
Review
Interoception plays an important role in homeostatic regulation of energy intake and metabolism. Major interoceptive pathways include gut-to-brain and adipose tissue-to brain signaling via vagal sensory nerves and hormones, such as leptin. However, signaling via spinal sensory neurons is rapidly emerging as an additional important signaling pathway. Here we provide an in-depth review of the known anatomy and functions of spinal sensory pathways and discuss potential mechanisms relevant for energy balance homeostasis in health and disease. Because sensory innervation by dorsal root ganglia (DRG) neurons goes far beyond vagally innervated viscera and includes adipose tissue, skeletal muscle, and skin, it is in a position to provide much more complete metabolic information to the brain. Molecular and anatomical identification of function specific DRG neurons will be important steps in designing pharmacological and neuromodulation approaches to affect energy balance regulation in disease states such as obesity, diabetes, and cancer.
Topics: Humans; Sensory Receptor Cells; Vagus Nerve; Obesity; Adipose Tissue; Ganglia, Spinal
PubMed: 37806487
DOI: 10.1016/j.molmet.2023.101817 -
Handbook of Clinical Neurology 2024This chapter covers axillary and musculocutaneous neuropathies, with a focus on clinically relevant anatomy, electrodiagnostic approaches, etiologic considerations, and... (Review)
Review
This chapter covers axillary and musculocutaneous neuropathies, with a focus on clinically relevant anatomy, electrodiagnostic approaches, etiologic considerations, and management principles. Disorders of the lateral antebrachial cutaneous nerve, a derivative of the musculocutaneous nerve, are also reviewed. We emphasize the importance of objective findings, including the physical examination and electrodiagnostic evaluation in confirming the isolated involvement of each nerve which, along with the clinical history, informs etiologic considerations. Axillary and musculocutaneous neuropathies are both rare in isolation and most frequently occur in the setting of trauma. Less commonly encountered etiologies include external compression or entrapment, neoplastic involvement, or immune-mediated disorders including neuralgic amyotrophy, postsurgical inflammatory neuropathy, multifocal motor neuropathy, vasculitic neuropathy, and multifocal chronic inflammatory demyelinating polyradiculoneuropathy.
Topics: Humans; Peripheral Nervous System Diseases; Musculocutaneous Nerve; Axilla; Electrodiagnosis
PubMed: 38697736
DOI: 10.1016/B978-0-323-90108-6.00004-1