Vitamin D and Its Potential Interplay With Pain Signaling Pathways
About 50 million of the U.S. adult population suffer from chronic pain. It is a complex disease in its own right for which currently available analgesics have been deemed woefully inadequate since ~20% of the sufferers derive no benefit. Vitamin D, known for its role in calcium homeostasis and bone metabolism, is thought to be of clinical benefit in treating chronic pain without the side-effects of currently available analgesics. A strong correlation between hypovitaminosis D and incidence of bone pain is known. However, the potential underlying mechanisms by which vitamin D might exert its analgesic effects are poorly understood. In this review, we discuss pathways involved in pain sensing and processing primarily at the level of dorsal root ganglion (DRG) neurons and the potential interplay between vitamin D, its receptor (VDR) and known specific pain signaling pathways including nerve growth factor (NGF), glial-derived neurotrophic factor (GDNF), epidermal growth factor receptor (EGFR), and opioid receptors. We also discuss how vitamin D/VDR might influence immune cells and pain sensitization as well as review the increasingly important topic of vitamin D toxicity. Further in vitro and in vivo experimental studies will be required to study these potential interactions specifically in pain models. Such studies could highlight the potential usefulness of vitamin D either alone or in combination with existing analgesics to better treat chronic pain.
Sensory ganglionopathies (SG) are a rare heterogenous subgroup of neuropathies characterized by primary involvement of sensory neurons in dorsal root ganglions (DRGs) resulting in a distinctive clinical presentation. The onset is usually subacute or chronic with asymmetric, non –length-dependent sensory impairment and ataxia (when large-fiber neurons affected) and/or positive sensory symptoms such as burning pain, hyperesthesia and allodynia (when small-medium size neurons affected) with relatively well-preserved muscle strength.
Conclusion: SGB is effective in reducing the requirement of intraoperative propofol and fentanyl as well as decreasing opioid requirement in the postoperative period in patients with CRPS type II undergoing surgery.
Conclusion: Tetrapanax papyriferus and hederagenin relieved sciatica by reducing inflammation levels, inhibiting p38 MAPK phosphorylation, and decreasing the levels of dorsal root ganglion proteins. PMID: 32617100 [PubMed]
We report four cases of effective analgesia for intractable secondary headache resistant to medical management with high thoracic ESP blocks. In each case, the ESP block provided instant pain relief. We suggest that the findings of this case series indicate that the ESP block may be a useful intervention in patients with severe secondary headache or posterior cervical pain where conventional therapies have limited success, though more studies are necessary. PMID: 32606918 [PubMed]
Conditions: Low Back Pain; Pain Measurement; Chronic Pain; Analgesia, Epidural; Clinic, Pain Interventions: Procedure: Fluoroscopically guided lumbar medial branch nerve radiofrequency denervation.; Procedure: Fluoroscopically guided lumbar facet joint injection.; Procedure: Fluoroscopically guided lumbar epidural corticosteroid injection.; Procedure: Fluoroscopically guided caudal epidural c orticosteroid injection.; Procedure: Fluoroscopically guided pulsed radiofrequency of the lumbar dorsal root ganglion.; Procedu...
ConclusionsOur results suggest that DRGS applied with stimulation parameters within typical clinical ranges predominantly activates A β‐mechanoreceptors. In general, varying clinically controllable parameters affects the number of Aβ‐mechanoreceptors activated, although longer pulse widths can increase Aδ‐neuron activation. Our data support several Neuromodulation Appropriateness Consensus Committee guidelines on the clin ical implementation of DRGS.
AbstractObjectivesTraumatic peripheral nerve injuries (PNI) often result in severe neuropathic pain which typically becomes chronic, is recalcitrant to common analgesics, and is associated with sleep disturbances, anxiety, and depression. Pharmacological treatments proven to be effective against neuropathic pain are not well tolerated due to side effects. Neuromodulative interventions such as peripheral nerve or spinal cord stimulation have generated mixed results and may be limited by reduced somatotopic specificity. Dorsal root ganglion (DRG) stimulation may be more effective in this etiology.Materials and MethodsTwenty ...
ConclusionsThis study suggests a significant, clinically relevant effect of DRG stimulation on neuropathic pain, but also demonstrates substantial problems with maintenance and revision of currently available systems. Consequently, treatment with equipment marketed specifically for DRG stimulation is currently paused in Denmark.
Conclusions: Concomitant use of bilateral SPG block with general anesthesia is an effective and safe alternative technique to scalp blockade for obtundation of hemodynamic responses due to noxious stimulus during craniotomy surgeries.
ConclusionsThese data demonstrates the possibility of sensitization of vestibular nucleus neurons to impair vestibular function after CM, and anti-CGRP treatment to restore vestibular dysfunction in patients with CM.