1
|
Hung 洪瑋辰 WC, Chen 陳志成 CC, Yen 嚴震東 CT, Min 閔明源 MY. Presynaptic Enhancement of Transmission from Nociceptors Expressing Nav1.8 onto Lamina-I Spinothalamic Tract Neurons by Spared Nerve Injury in Mice. eNeuro 2024; 11:ENEURO.0087-24.2024. [PMID: 39256039 DOI: 10.1523/eneuro.0087-24.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 08/19/2024] [Accepted: 08/23/2024] [Indexed: 09/12/2024] Open
Abstract
Alteration of synaptic function in the dorsal horn (DH) has been implicated as a cellular substrate for the development of neuropathic pain, but certain details remain unclear. In particular, the lack of information on the types of synapses that undergo functional changes hinders the understanding of disease pathogenesis from a synaptic plasticity perspective. Here, we addressed this issue by using optogenetic and retrograde tracing ex vivo to selectively stimulate first-order nociceptors expressing Nav1.8 (NRsNav1.8) and record the responses of spinothalamic tract neurons in spinal lamina I (L1-STTNs). We found that spared nerve injury (SNI) increased excitatory postsynaptic currents (EPSCs) in L1-STTNs evoked by photostimulation of NRsNav1.8 (referred to as Nav1.8-STTN EPSCs). This effect was accompanied by a significant change in the failure rate and paired-pulse ratio of synaptic transmission from NRsNav1.8 to L1-STTN and in the frequency (not amplitude) of spontaneous EPSCs recorded in L1-STTNs. However, no change was observed in the ratio of AMPA to NMDA receptor-mediated components of Nav1.8-STTN EPSCs or in the amplitude of unitary EPSCs constituting Nav1.8-STTN EPSCs recorded with extracellular Ca2+ replaced by Sr2+ In addition, there was a small increase (approximately 10%) in the number of L1-STTNs showing immunoreactivity for phosphorylated extracellular signal-regulated kinases in mice after SNI compared with sham. Similarly, only a small percentage of L1-STTNs showed a lower action potential threshold after SNI. In conclusion, our results show that SNI induces presynaptic modulation at NRNav1.8 (consisting of both peptidergic and nonpeptidergic nociceptors) synapses on L1-STTNs forming the lateral spinothalamic tract.
Collapse
Affiliation(s)
- Wei-Chen Hung 洪瑋辰
- Department of Life Science, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
- Neurobiology and Cognitive Science Centre, National Taiwan University, Taipei 10617, Taiwan
| | | | - Cheng-Tung Yen 嚴震東
- Department of Life Science, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
- Neurobiology and Cognitive Science Centre, National Taiwan University, Taipei 10617, Taiwan
| | - Ming-Yuan Min 閔明源
- Department of Life Science, College of Life Science, National Taiwan University, Taipei 10617, Taiwan
- Neurobiology and Cognitive Science Centre, National Taiwan University, Taipei 10617, Taiwan
| |
Collapse
|
2
|
Jain A, Hakim S, Woolf CJ. Immune drivers of physiological and pathological pain. J Exp Med 2024; 221:e20221687. [PMID: 38607420 PMCID: PMC11010323 DOI: 10.1084/jem.20221687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 09/25/2023] [Accepted: 04/02/2024] [Indexed: 04/13/2024] Open
Abstract
Physiological pain serves as a warning of exposure to danger and prompts us to withdraw from noxious stimuli to prevent tissue damage. Pain can also alert us of an infection or organ dysfunction and aids in locating such malfunction. However, there are instances where pain is purely pathological, such as unresolved pain following an inflammation or injury to the nervous system, and this can be debilitating and persistent. We now appreciate that immune cells are integral to both physiological and pathological pain, and that pain, in consequence, is not strictly a neuronal phenomenon. Here, we discuss recent findings on how immune cells in the skin, nerve, dorsal root ganglia, and spinal cord interact with somatosensory neurons to mediate pain. We also discuss how both innate and adaptive immune cells, by releasing various ligands and mediators, contribute to the initiation, modulation, persistence, or resolution of various modalities of pain. Finally, we propose that the neuroimmune axis is an attractive target for pain treatment, but the challenges in objectively quantifying pain preclinically, variable sex differences in pain presentation, as well as adverse outcomes associated with immune system modulation, all need to be considered in the development of immunotherapies against pain.
Collapse
Affiliation(s)
- Aakanksha Jain
- F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Boston, MA, USA
| | - Sara Hakim
- F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Boston, MA, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Clifford J. Woolf
- F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Boston, MA, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
3
|
Mullins CF, Palumbo GJ, Harris S, Al-Kaisy O, Wesley S, Yearwood T, Al-Kaisy A. Effectiveness of combined dorsal root ganglion and spinal cord stimulation: a retrospective, single-centre case series for chronic focal neuropathic pain. PAIN MEDICINE (MALDEN, MASS.) 2024; 25:116-124. [PMID: 37738574 DOI: 10.1093/pm/pnad128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 09/07/2023] [Accepted: 09/18/2023] [Indexed: 09/24/2023]
Abstract
OBJECTIVE This case series retrospectively reviewed the outcomes in patients implanted with combined, synchronous dorsal root ganglion stimulation (DRGS) and spinal cord stimulation (SCS) connected to a single implantable pulse generator (IPG) in a tertiary referral neuromodulation centre in the United Kingdom. METHODS Twenty-six patients underwent a trial of DRGS+SCS for treating focal neuropathic pain between January 2016 and December 2019, with a follow-up in February 2022. A Transgrade approach was employed for DRGS. Patients were provided with 3 possible stimulation programs: DRGS-only, SCS-only, or DRGS+SCS. Patients were assessed for pain intensity, patients' global impression of change (PGIC), preferred lead(s) and complications. RESULTS Twenty patients were successful and went on for full implantation. The most common diagnosis was Complex Regional Pain Syndrome. After an average of 3.1 years follow-up, 1 patient was lost to follow-up, and 2 were non-responders. Of the remaining 17 patients, 16 (94%) continued to report a PGIC of 7. The average pain intensity at Baseline was 8.5 on an NRS scale of 0-10. At the last follow-up, the average NRS reduction overall was 78.9% with no statistical difference between those preferring DRGS+SCS (n = 9), SCS-only (n = 3) and DRGS-only (n = 5). The combination of DRGS+SCS was preferred by 53% at the last follow-up. There were no serious neurological complications. CONCLUSIONS This retrospective case series demonstrates the potential effectiveness of combined DRGS+SCS with sustained analgesia observed at an average follow-up of over 3 years. Implanting combined DRGS+SCS may provide programming flexibility and therapeutic alternatives.
Collapse
Affiliation(s)
- Cormac F Mullins
- Pain Management Department, Gassiot House, Guy's and St. Thomas' NHS Foundation Trust, London SE1 7EH, United Kingdom
- Department of Pain Medicine, South Infirmary Victoria University Hospital, Cork T12X23H, Ireland
| | - Gaetano Joseph Palumbo
- Pain Management Department, Gassiot House, Guy's and St. Thomas' NHS Foundation Trust, London SE1 7EH, United Kingdom
| | - Stephany Harris
- Pain Management Department, Gassiot House, Guy's and St. Thomas' NHS Foundation Trust, London SE1 7EH, United Kingdom
| | - Omar Al-Kaisy
- Pain Management Department, Gassiot House, Guy's and St. Thomas' NHS Foundation Trust, London SE1 7EH, United Kingdom
| | - Sam Wesley
- Pain Management Department, Gassiot House, Guy's and St. Thomas' NHS Foundation Trust, London SE1 7EH, United Kingdom
| | - Thomas Yearwood
- Pain Management Department, Gassiot House, Guy's and St. Thomas' NHS Foundation Trust, London SE1 7EH, United Kingdom
| | - Adnan Al-Kaisy
- Pain Management Department, Gassiot House, Guy's and St. Thomas' NHS Foundation Trust, London SE1 7EH, United Kingdom
| |
Collapse
|
4
|
Raolji S, Kumar P, Galor A. Ocular surface itch and pain: key differences and similarities between the two sensations. Curr Opin Allergy Clin Immunol 2023; 23:415-422. [PMID: 37490616 PMCID: PMC10529639 DOI: 10.1097/aci.0000000000000934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
PURPOSE OF REVIEW To review the pathophysiology and treatment of ocular itch and pain, encompassing nociceptive and neuropathic categories. RECENT FINDINGS Ocular itch and pain are sensations that arise from activation of ocular surface polymodal nerves. Nociceptive itch, commonly comorbid with ocular pain complaints, is mainly driven by a histamine-mediated type 1 hypersensitivity reaction. Beyond topical therapy, novel drug delivery systems are being explored to improve ocular residence time of nonsteroidal anti-inflammatory drugs (NSAIDs) and antihistamines. Nociceptive ocular pain can be driven by a variety of factors. Treatment focuses on addressing the causative sources of pain. Neuropathic ocular itch and pain are driven by nerve damage and dysfunction and as such, topical and oral neuromodulation have been explored as treatments. Oral neuromodulators include alpha 2 delta ligands, tricyclic antidepressants (TCAs), and low dose naltrexone. Novel therapies are being evaluated for both modalities such as difelikefalin (κ-opioid receptor agonist) for neuropathic itch and libvatrep (transient receptor potential vanilloid 1 antagonist) for neuropathic pain. SUMMARY Both ocular itch and pain can be driven by nociceptive and/or neuropathic mechanisms. Identifying contributors to abnormal ocular sensations is vital for precise medical care. Novel therapeutics for these conditions aim to improve patient outcomes and quality of life.
Collapse
Affiliation(s)
- Shyamal Raolji
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL
| | - Preet Kumar
- Florida Atlantic University Schmidt College of Medicine, Boca Raton, FL
| | - Anat Galor
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL
- Miami Veterans Administration Medical Center, 1201 NW 16th St, Miami, FL 33125
| |
Collapse
|
5
|
Smith PA. Neuropathic pain; what we know and what we should do about it. FRONTIERS IN PAIN RESEARCH 2023; 4:1220034. [PMID: 37810432 PMCID: PMC10559888 DOI: 10.3389/fpain.2023.1220034] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 09/05/2023] [Indexed: 10/10/2023] Open
Abstract
Neuropathic pain can result from injury to, or disease of the nervous system. It is notoriously difficult to treat. Peripheral nerve injury promotes Schwann cell activation and invasion of immunocompetent cells into the site of injury, spinal cord and higher sensory structures such as thalamus and cingulate and sensory cortices. Various cytokines, chemokines, growth factors, monoamines and neuropeptides effect two-way signalling between neurons, glia and immune cells. This promotes sustained hyperexcitability and spontaneous activity in primary afferents that is crucial for onset and persistence of pain as well as misprocessing of sensory information in the spinal cord and supraspinal structures. Much of the current understanding of pain aetiology and identification of drug targets derives from studies of the consequences of peripheral nerve injury in rodent models. Although a vast amount of information has been forthcoming, the translation of this information into the clinical arena has been minimal. Few, if any, major therapeutic approaches have appeared since the mid 1990's. This may reflect failure to recognise differences in pain processing in males vs. females, differences in cellular responses to different types of injury and differences in pain processing in humans vs. animals. Basic science and clinical approaches which seek to bridge this knowledge gap include better assessment of pain in animal models, use of pain models which better emulate human disease, and stratification of human pain phenotypes according to quantitative assessment of signs and symptoms of disease. This can lead to more personalized and effective treatments for individual patients. Significance statement: There is an urgent need to find new treatments for neuropathic pain. Although classical animal models have revealed essential features of pain aetiology such as peripheral and central sensitization and some of the molecular and cellular mechanisms involved, they do not adequately model the multiplicity of disease states or injuries that may bring forth neuropathic pain in the clinic. This review seeks to integrate information from the multiplicity of disciplines that seek to understand neuropathic pain; including immunology, cell biology, electrophysiology and biophysics, anatomy, cell biology, neurology, molecular biology, pharmacology and behavioral science. Beyond this, it underlines ongoing refinements in basic science and clinical practice that will engender improved approaches to pain management.
Collapse
Affiliation(s)
- Peter A. Smith
- Neuroscience and Mental Health Institute and Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| |
Collapse
|
6
|
Pang D, Ashkan K. Deep brain stimulation for phantom limb pain. Eur J Paediatr Neurol 2022; 39:96-102. [PMID: 35728428 DOI: 10.1016/j.ejpn.2022.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 03/25/2022] [Accepted: 05/23/2022] [Indexed: 11/29/2022]
Abstract
Phantom limb pain is a rare cause of chronic pain in children but it is associated with extremely refractory pain and disability. The reason for limb amputation is often due to treatment for cancer or trauma and it has a lower incidence compared to adults. The mechanism of why phantom pain exists remains uncertain and may be a result of cortical reorganisation as well as ectopic peripheral input. Treatment is aimed at reducing both symptoms as well as managing pain related disability and functional restoration. Neuromodulatory approaches using deep brain stimulation for phantom limb pain is reserved for only the most refractory cases. The targets for brain stimulation include the thalamic nuclei and motor cortex. Novel targets such as the anterior cingulate cortex remain experimental as cases of serious adverse effects such as seziures have limited their widespread uptake. A multidisciplinary approach is crucial to successful rehabilitation using a biopsychosocial pain management approach.
Collapse
Affiliation(s)
- David Pang
- Consultant in Pain Management, Pain Management Centre, INPUT St Thomas Hospital, London, SE1 7EH, UK.
| | - Keyoumars Ashkan
- Department of Neurosurgery, Kins's College Hospital NHS Foundation Trust, London, UK
| |
Collapse
|
7
|
Rigoard P, Roulaud M, Goudman L, Adjali N, Ounajim A, Voirin J, Perruchoud C, Bouche B, Page P, Guillevin R, Naudin M, Simoneau M, Lorgeoux B, Baron S, Nivole K, Many M, Maitre I, Rigoard R, David R, Moens M, Billot M. Comparison of Spinal Cord Stimulation vs. Dorsal Root Ganglion Stimulation vs. Association of Both in Patients with Refractory Chronic Back and/or Lower Limb Neuropathic Pain: An International, Prospective, Randomized, Double-Blinded, Crossover Trial (BOOST-DRG Study). MEDICINA (KAUNAS, LITHUANIA) 2021; 58:7. [PMID: 35056316 PMCID: PMC8780129 DOI: 10.3390/medicina58010007] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 12/01/2021] [Accepted: 12/15/2021] [Indexed: 12/25/2022]
Abstract
While spinal cord stimulation (SCS) is a well-established therapy to address refractory persistent spinal pain syndrome after spinal surgery (PSPS-T2), its lack of spatial selectivity and reported discomfort due to positional effects can be considered as significant limitations. As alternatives, new waveforms, such as burst stimulation and different spatial neural targets, such as dorsal root ganglion stimulation (DRGS), have shown promising results. Comparisons between DRGS and standard SCS, or their combination, have never been studied on the same patients. "BOOST DRG" is the first prospective, randomized, double-blinded, crossover study to compare SCS vs. DRGS vs. SCS+DRGS. Sixty-six PSPS-T2 patients will be recruited internationally in three centers. Before crossing over, patients will receive each stimulation modality for 1 month, using tonic conventional stimulation. After 3 months, stimulation will consist in switching to burst for 1 month, and patients will choose which modality/waveform they receive and will then be reassessed at 6 and 12 months. In addition to our primary outcome based on pain rating, this study is designed to assess quality of life, functional disability, psychological distress, pain surface coverage, global impression of change, medication quantification, adverse events, brain functional imaging and electroencephalography, with the objective being to provide a multidimensional insight based on composite pain assessment.
Collapse
Affiliation(s)
- Philippe Rigoard
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
- Department of Spine Surgery & Neuromodulation, Poitiers University Hospital, 86021 Poitiers, France;
- Pprime Institute UPR 3346, CNRS, ISAE-ENSMA, University of Poitiers, 86360 Chasseneuil-du-Poitou, France
| | - Manuel Roulaud
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
| | - Lisa Goudman
- Department of Neurosurgery, Universitair Ziekenhuis Brussel, 1090 Brussels, Belgium; (L.G.); (M.M.)
- STUMULUS Research Group, Vrije Universiteit Brussel, 1090 Brussels, Belgium
| | - Nihel Adjali
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
| | - Amine Ounajim
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
| | - Jimmy Voirin
- Department of Neurosurgery, Hopitaux Civils de Colmar, 68000 Colmar, France;
| | - Christophe Perruchoud
- Service of Anesthesiology and Pain Centre, University Hospital of Lausanne (CHUV), 1011 Lausanne, Switzerland;
| | - Bénédicte Bouche
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
- Department of Spine Surgery & Neuromodulation, Poitiers University Hospital, 86021 Poitiers, France;
| | - Philippe Page
- Department of Spine Surgery & Neuromodulation, Poitiers University Hospital, 86021 Poitiers, France;
| | - Rémy Guillevin
- Department of Radiology, Poitiers University Hospital, 86021 Poitiers, France; (R.G.); (M.N.)
- UMR CNRS 7348, DACTIM-MIS/LMA Laboratory, University of Poitiers, 86000 Poitiers, France
| | - Mathieu Naudin
- Department of Radiology, Poitiers University Hospital, 86021 Poitiers, France; (R.G.); (M.N.)
- UMR CNRS 7348, DACTIM-MIS/LMA Laboratory, University of Poitiers, 86000 Poitiers, France
| | - Martin Simoneau
- Department of Kinesiology, Faculty of Medicine, Laval University, Quebec, QC G1V 0A6, Canada;
- Centre Interdisciplinaire de Recherche en Réadaptation et Intégration Sociale (CIRRIS), Quebec, QC G1M 2S8, Canada
| | - Bertille Lorgeoux
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
| | - Sandrine Baron
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
| | - Kevin Nivole
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
| | - Mathilde Many
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
| | - Iona Maitre
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
| | - Raphaël Rigoard
- CEA Cadarache, Département de Support Technique et Gestion, Service des Technologies de l’Information et de la Communication, 13108 Saint-Paul-Lez-Durance, France;
| | - Romain David
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
- Department of Physical and Rehabilitation Medicine, Poitiers University Hospital, University of Poitiers, 86021 Poitiers, France
| | - Maarten Moens
- Department of Neurosurgery, Universitair Ziekenhuis Brussel, 1090 Brussels, Belgium; (L.G.); (M.M.)
- STUMULUS Research Group, Vrije Universiteit Brussel, 1090 Brussels, Belgium
| | - Maxime Billot
- PRISMATICS Lab (Predictive Research in Spine/Neuromodulation Management and Thoracic Innovation/Cardiac Surgery), Poitiers University Hospital, 86021 Poitiers, France; (M.R.); (N.A.); (A.O.); (B.B.); (B.L.); (S.B.); (K.N.); (M.M.); (I.M.); (R.D.); (M.B.)
| |
Collapse
|
8
|
Yeh HY, Lee JC, Chi HH, Chen CC, Liu Q, Yen CT. Longitudinal intravital imaging nerve degeneration and sprouting in the toes of spared nerve injured mice. J Comp Neurol 2021; 529:3247-3264. [PMID: 33880774 DOI: 10.1002/cne.25162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 02/26/2021] [Accepted: 04/14/2021] [Indexed: 12/19/2022]
Abstract
Neuropathic pain is pain caused by damage to the somatosensory nervous system. Both degenerating injured nerves and neighboring sprouting nerves can contribute to neuropathic pain. However, the mesoscale changes in cutaneous nerve fibers over time after the loss of the parent nerve has not been investigated in detail. In this study, we followed the changes in nerve fibers longitudinally in the toe tips of mice that had undergone spared nerve injury (SNI). Nav1.8-tdTomato, Thy1-GFP and MrgD-GFP mice were used to observe the small and large cutaneous nerve fibers. We found that peripheral nerve plexuses degenerated within 3 days of nerve injury, and free nerve endings in the epidermis degenerated within 2 days. The timing of degeneration paralleled the initiation of mechanical hypersensitivity. We also found that some of the Nav1.8-positive nerve plexuses and free nerve endings in the fifth toe survived, and sprouting occurred mostly from 7 to 28 days. The timing of the sprouting of nerve fibers in the fifth toe paralleled the maintenance phase of mechanical hypersensitivity. Our results support the hypotheses that both injured and intact nerve fibers participate in neuropathic pain, and that, specifically, nerve degeneration is related to the initiation of evoked pain and nerve sprouting is related to the maintenance of evoked pain.
Collapse
Affiliation(s)
- Han-Yuan Yeh
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Jye-Chang Lee
- Graduate Institute of Pharmacology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Han-Hsiung Chi
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Chih-Cheng Chen
- Institute of Biomedical Science, Academia Sinica, Taipei, Taiwan
| | - Qin Liu
- Department of Anesthesiology and the Center for the Study of Itch, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Chen-Tung Yen
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| |
Collapse
|
9
|
Tran EL, Crawford LK. Revisiting PNS Plasticity: How Uninjured Sensory Afferents Promote Neuropathic Pain. Front Cell Neurosci 2020; 14:612982. [PMID: 33362476 PMCID: PMC7759741 DOI: 10.3389/fncel.2020.612982] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 11/12/2020] [Indexed: 11/13/2022] Open
Abstract
Despite the widespread study of how injured nerves contribute to chronic pain, there are still major gaps in our understanding of pain mechanisms. This is particularly true of pain resulting from nerve injury, or neuropathic pain, wherein tactile or thermal stimuli cause painful responses that are particularly difficult to treat with existing therapies. Curiously, this stimulus-driven pain relies upon intact, uninjured sensory neurons that transmit the signals that are ultimately sensed as painful. Studies that interrogate uninjured neurons in search of cell-specific mechanisms have shown that nerve injury alters intact, uninjured neurons resulting in an activity that drives stimulus-evoked pain. This review of neuropathic pain mechanisms summarizes cell-type-specific pathology of uninjured sensory neurons and the sensory ganglia that house their cell bodies. Uninjured neurons have demonstrated a wide range of molecular and neurophysiologic changes, many of which are distinct from those detected in injured neurons. These intriguing findings include expression of pain-associated molecules, neurophysiological changes that underlie increased excitability, and evidence that intercellular signaling within sensory ganglia alters uninjured neurons. In addition to well-supported findings, this review also discusses potential mechanisms that remain poorly understood in the context of nerve injury. This review highlights key questions that will advance our understanding of the plasticity of sensory neuron subpopulations and clarify the role of uninjured neurons in developing anti-pain therapies.
Collapse
Affiliation(s)
- Emily L Tran
- Department of Pathobiological Sciences, University of Wisconsin-Madison School of Veterinary Medicine, Madison, WI, United States
| | - LaTasha K Crawford
- Department of Pathobiological Sciences, University of Wisconsin-Madison School of Veterinary Medicine, Madison, WI, United States
| |
Collapse
|
10
|
Hines K, Al Saiegh F, Mahtabfar A, Keppetipola KM, Matias CM, Wu C, Sharan A. Dorsal root ganglion stimulation for treatment of complex regional pain syndrome of the foot. ACTA ACUST UNITED AC 2020; 3:V8. [PMID: 36285272 PMCID: PMC9542308 DOI: 10.3171/2020.7.focvid2034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 07/01/2020] [Indexed: 11/22/2022]
Abstract
This is a case of a 54-year-old man presenting with complex regional pain syndrome (CRPS) type 1 of the right lower extremity, which was most debilitating in the plantar aspect of the right foot. The patient had prior treatment with thoracic spinal cord stimulation; however, the foot pain remained intractable. Given that his pain was predominantly in his foot and remained debilitating despite thoracic spinal cord stimulation, it was recommended that the patient undergo a trial of dorsal root ganglion (DRG) stimulation. The surgical technique for placement of dorsal root ganglion stimulators is demonstrated in this operative video. The video can be found here: https://youtu.be/_1xMxFZa6tU
Collapse
|
11
|
Parker J, Karantonis D, Single P. Hypothesis for the mechanism of action of ECAP-controlled closed-loop systems for spinal cord stimulation. Healthc Technol Lett 2020; 7:76-80. [PMID: 32754341 PMCID: PMC7353820 DOI: 10.1049/htl.2019.0110] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 05/06/2020] [Accepted: 05/15/2020] [Indexed: 01/14/2023] Open
Abstract
Advances in technology and improvement of efficacy for many neuromodulation applications have been achieved without understanding the relationship between the stimulation parameters and the neural activity which is generated in the nervous system. It is the neural activity that ultimately drives the therapeutic benefit and the advent of evoked compound action potential recording allows this activity to be directly measured and quantified. Closed-loop control adjusts the stimulation parameters to maintain a predetermined level of neural recruitment and has been shown to provide improved pain relief in individuals with spinal cord stimulators. However, no mechanism that relates more consistent neural recruitment to patient outcomes has been proposed. The authors propose a hypothesis that may explain the difference in efficacy between open- and closed-loop operational modes by considering the relationship between measured neural recruitment with hypothetical dose and side effect response curves. This provides a rational basis for directing clinical research and improving therapeutic systems.
Collapse
Affiliation(s)
- John Parker
- Saluda Medical Pty Ltd Artarmon, NSW, 2069, Australia.,Graduate School of Biomedical Engineering, University of New South Wales, Kensington, Australia
| | | | - Peter Single
- Saluda Medical Pty Ltd Artarmon, NSW, 2069, Australia
| |
Collapse
|
12
|
Esposito MF, Malayil R, Hanes M, Deer T. Unique Characteristics of the Dorsal Root Ganglion as a Target for Neuromodulation. PAIN MEDICINE 2020; 20:S23-S30. [PMID: 31152179 PMCID: PMC6544557 DOI: 10.1093/pm/pnz012] [Citation(s) in RCA: 114] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Objective The dorsal root ganglion (DRG) is a novel target for neuromodulation, and DRG stimulation is proving to be a viable option in the treatment of chronic intractable neuropathic pain. Although the overall principle of conventional spinal cord stimulation (SCS) and DRG stimulation—in which an electric field is applied to a neural target with the intent of affecting neural pathways to decrease pain perception—is similar, there are significant differences in the anatomy and physiology of the DRG that make it an ideal target for neuromodulation and may account for the superior outcomes observed in the treatment of certain chronic neuropathic pain states. This review highlights the anatomy of the DRG, its function in maintaining homeostasis and its role in neuropathic pain, and the unique value of DRG as a target in neuromodulation for pain. Methods A narrative literature review was performed. Results Overall, the DRG is a critical structure in sensory transduction and modulation, including pain transmission and the maintenance of persistent neuropathic pain states. Unique characteristics including selective somatic organization, specialized membrane characteristics, and accessible and consistent location make the DRG an ideal target for neuromodulation. Because DRG stimulation directly recruits the somata of primary sensory neurons and harnesses the filtering capacity of the pseudounipolar neural architecture, it is differentiated from SCS, peripheral nerve stimulation, and other neuromodulation options. Conclusions There are several advantages to targeting the DRG, including lower energy usage, more focused and posture-independent stimulation, reduced paresthesia, and improved clinical outcomes.
Collapse
Affiliation(s)
| | - Rudy Malayil
- St. Mary's Pain Relief Specialists, Huntington, West Virginia
| | | | - Timothy Deer
- The Spine and Nerve Center of the Virginias, Charleston, West Virginia, USA
| |
Collapse
|
13
|
Michels T. Peripheral Neuropathic Pain and Pain Related to Complex Regional Pain Syndrome with and without Fixed Dystonia - Efficient Therapeutic Approach with Local Anesthetics. Local Reg Anesth 2020; 13:11-16. [PMID: 32099453 PMCID: PMC6999782 DOI: 10.2147/lra.s229315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 12/17/2019] [Indexed: 11/28/2022] Open
Abstract
Peripheral Neuropathic Pain (PNP) as well as the Complex Regional Pain Syndrome (CRPS), also known as “Reflex Sympathetic Dystrophy”, or “Sudeck Dystrophy”, all of them have a poor prognosis. The numerous therapeutic offers are rarely accompanied by convincing success over a long duration of time. Even worse is the prognosis of a fixed dystonia which may develop in the extremities of PNP or CRPS patients. In literature a few cases are reported in which the often unbearable pain of those patients with or without a disabling dystonia disappeared immediately after the injection of local anesthetics (LAs) into the scars of a preceding trauma. This review evaluates publications concerning the neuropathological characteristics of fixed dystonia in PNP/CRPS patients and the electrophysiological processes of scar neuromas. The results of these evaluations support the understanding of the therapeutic successes and their immediate results reported above by the injection of LAs into triggering scars. Therapeutic options are discussed.
Collapse
Affiliation(s)
- Thomas Michels
- Internal Medicine, Hematology, Radiology, Natural Cure, Cologne (Köln) 50968, Germany
| |
Collapse
|
14
|
Shinoda M, Fukuoka T, Takeda M, Iwata K, Noguchi K. Spinal glial cell line-derived neurotrophic factor infusion reverses reduction of Kv4.1-mediated A-type potassium currents of injured myelinated primary afferent neurons in a neuropathic pain model. Mol Pain 2019; 15:1744806919841196. [PMID: 30868936 PMCID: PMC6463340 DOI: 10.1177/1744806919841196] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
High frequency spontaneous activity in injured primary afferents has been proposed as a pathological mechanism of neuropathic pain following nerve injury. Although spinal infusion of glial cell line-derived neurotrophic factor reduces the activity of injured myelinated A-fiber neurons after fifth lumbar (L5) spinal nerve ligation in rats, the implicated molecular mechanism remains undetermined. The fast-inactivating transient A-type potassium current (IA) is an important determinant of neuronal excitability, and five voltage-gated potassium channel (Kv) alpha-subunits, Kv1.4, Kv3.4, Kv4.1, Kv4.2, and Kv4.3, display IA in heterologous expression systems. Here, we examined the effect of spinal glial cell line-derived neurotrophic factor infusion on IA and the expression of these five Kv mRNAs in injured A-fiber neurons using the in vitro patch clamp technique and in situ hybridization histochemistry. Glial cell line-derived neurotrophic factor infusion reversed axotomy-induced reduction of the rheobase, elongation of first spike duration, and depolarization of the resting membrane potential. L5 spinal nerve ligation significantly reduced the current density of IA and glial cell line-derived neurotrophic factor treatment reversed the reduction. Among the examined Kv mRNAs, only the change in Kv4.1-expression was parallel with the change in IA after spinal nerve ligation and glial cell line-derived neurotrophic factor treatment. These findings suggest that glial cell line-derived neurotrophic factor should reduce the hyperexcitability of injured A-fiber primary afferents by IA recurrence. Among the five IA-related Kv channels, Kv4.1 should be a key channel, which account for this IA recurrence.
Collapse
Affiliation(s)
- Masamichi Shinoda
- 1 Department of Physiology, Nihon University School of Dentistry, Surugadai, Chiyoda-ku, Tokyo, Japan
| | - Tetsuo Fukuoka
- 2 Department of Anatomy and Neuroscience, Hyogo College of Medicine, Mukogawa-cho, Nishinomiya, Hyogo, Japan.,3 Fukuoka Clinic, Kasuga, Suita, Osaka, Japan
| | - Mamoru Takeda
- 4 Laboratory of Food and Physiological Sciences, Department of Life and Food Sciences, School of Life and Environmental Sciences, Azabu University, Fuchinobe, Chuo-ku, Sagamihara, Japan
| | - Koichi Iwata
- 1 Department of Physiology, Nihon University School of Dentistry, Surugadai, Chiyoda-ku, Tokyo, Japan
| | - Koichi Noguchi
- 2 Department of Anatomy and Neuroscience, Hyogo College of Medicine, Mukogawa-cho, Nishinomiya, Hyogo, Japan
| |
Collapse
|
15
|
Castro MVD, Silva MVRD, Chiarotto GB, Volpe BB, Santana MH, Malheiros Luzo ÂC, Oliveira ALRD. Reflex arc recovery after spinal cord dorsal root repair with platelet rich plasma (PRP). Brain Res Bull 2019; 152:212-224. [PMID: 31351157 DOI: 10.1016/j.brainresbull.2019.07.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 07/20/2019] [Accepted: 07/22/2019] [Indexed: 02/01/2023]
Abstract
Spinal dorsal roots can be affected by a wide range of lesions, leading to a significant loss of proprioceptive information transmission and greatly affecting motor behavior. In this context, the reimplantation of lesioned roots with platelet-rich plasma (PRP) may allow nerve regeneration. Therefore, the present study evaluated sensorimotor improvement following dorsal root rhizotomy and repair with PRP. For this purpose, female Lewis rats were subjected to unilateral rhizotomy (RZ) of the L4-L6 dorsal roots and divided into the following groups: (1) the unlesioned control group; (2) the group that underwent rhizotomy (RZ) without repair; and (3) the group that underwent RZ followed by root repair with PRP. PRP was obtained from human blood and characterized regarding platelet concentration, integrity, and viability. Reflex arc recovery was evaluated weekly for eight weeks by the electronic von Frey method. The spinal cords were processed 1 week postlesion to evaluate the in vivo gene expression of TNFα, TGF-β, BDNF, GDNF, VEGF, NGF, IL-4, IL-6, IL-13 by qRT-PCR and eight weeks postlesion to evaluate changes in the glial response (GFAP and Iba-1) and excitatory synaptic circuits (VGLUT1) by immunofluorescence. The results indicated that PRP therapy partially restores the paw withdrawal reflex over time, indicating the reentry of primary afferents from the dorsal root ganglia into the spinal cord without exacerbating glial reactivity. Additionally, the analysis of mRNA levels showed that PRP therapy has immunomodulatory properties. Overall, the present data suggest that the repair of dorsal roots with PRP may be considered a promising approach to improve sensorimotor recovery following dorsal rhizotomy.
Collapse
Affiliation(s)
- Mateus Vidigal de Castro
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Campinas, Sao Paulo, Brazil
| | - Moníze Valéria Ramos da Silva
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Campinas, Sao Paulo, Brazil
| | | | - Bruno Bosh Volpe
- Regional Center University of Espirito Santo do Pinhal, Espirito Santo do Pinhal, Sao Paulo, Brazil
| | - Maria Helena Santana
- Department of Engineering of Materials and Bioprocesses, School of Chemical Engineering, University of Campinas, Campinas, Sao Paulo, Brazil
| | | | | |
Collapse
|
16
|
Noh MC, Stemkowski PL, Smith PA. Long-term actions of interleukin-1β on K +, Na + and Ca 2+ channel currents in small, IB 4-positive dorsal root ganglion neurons; possible relevance to the etiology of neuropathic pain. J Neuroimmunol 2019; 332:198-211. [PMID: 31077855 DOI: 10.1016/j.jneuroim.2019.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 04/18/2019] [Accepted: 05/01/2019] [Indexed: 12/25/2022]
Abstract
Excitation of dorsal root ganglion (DRG) neurons by interleukin 1β (IL-1β) is implicated in the onset of neuropathic pain. To understand its mechanism of action, isolectin B4 positive (IB4+) DRG neurons were exposed to 100pM IL-1β for 5-6d. A reversible increase in action potential (AP) amplitude reflected increased TTX-sensitive sodium current (TTX-S INa). An irreversible increase in AP duration reflected decreased Ca2+- sensitive K+ conductance (BK(Ca) channels). Different processes thus underlie regulation of the two channel types. Since changes in AP shape facilitated Ca2+ influx, this explains how IL-1β facilitates synaptic transmission in the dorsal horn; thereby provoking pain.
Collapse
Affiliation(s)
- Myung-Chul Noh
- Department of Pharmacology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Patrick L Stemkowski
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Peter A Smith
- Department of Pharmacology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada; Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta T6G 2H7, Canada.
| |
Collapse
|
17
|
Suppression of neuropathic pain by selective silencing of dorsal root ganglion ectopia using nonblocking concentrations of lidocaine. Pain 2019; 160:2105-2114. [DOI: 10.1097/j.pain.0000000000001602] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
18
|
Morgalla MH, de Barros Filho MF, Chander BS, Soekadar SR, Tatagiba M, Lepski G. Neurophysiological Effects of Dorsal Root Ganglion Stimulation (DRGS) in Pain Processing at the Cortical Level. Neuromodulation 2018; 22:36-43. [PMID: 30561852 DOI: 10.1111/ner.12900] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 10/25/2018] [Accepted: 10/25/2018] [Indexed: 12/14/2022]
Abstract
OBJECTIVES Dorsal root ganglion stimulation (DRGS) has been used successfully against localized neuropathic pain. Nevertheless, the effects of DRGS on pain processing, particularly at the cortical level, remain largely unknown. In this study, we investigated whether positive responses to DRGS treatment would alter patients' laser-evoked potentials (LEP). METHODS We prospectively enrolled 12 adult patients with unilateral localized neuropathic pain in the lower limbs or inguinal region and followed them up for six months. LEPs were assessed at baseline, after one month of DRGS, and after six months of DRGS. Clinical assessment included the Numerical Rating Scale (NRS), Brief Pain Inventory (BPI), SF-36, and Beck Depression Inventory (BDI). For each patient, LEP amplitudes and latencies of the N2 and P2 components on the deafferented side were measured and compared to those of the healthy side and correlated with pain intensity, as measured with the NRS. RESULTS At the one- and six-month follow-ups, N2-P2 amplitudes were significantly greater and NRS scores were significantly lower compared with baseline (all p's < 0.01). There was a negative correlation between LEP amplitudes and NRS scores (rs = -0.31, p < 0.10). CONCLUSIONS DRGS is able to restore LEPs to normal values in patients with localized neuropathic pain, and LEP alterations are correlated with clinical response in terms of pain intensity.
Collapse
Affiliation(s)
| | - Marcos Fortunato de Barros Filho
- Department of Neurosurgery, University of Tuebingen, Tuebingen, Germany.,Applied Neurotechnology Laboratory, Department of Psychiatry and Psychotherapy, University of Tuebingen, Tuebingen, Germany.,Division of Functional Neurosurgery, School of Medicine, Universidade de São Paulo, São Paulo, Brazil
| | - Bankim Subhash Chander
- Department of Neurosurgery, University of Tuebingen, Tuebingen, Germany.,Applied Neurotechnology Laboratory, Department of Psychiatry and Psychotherapy, University of Tuebingen, Tuebingen, Germany
| | - Surjo Raphael Soekadar
- Applied Neurotechnology Laboratory, Department of Psychiatry and Psychotherapy, University of Tuebingen, Tuebingen, Germany.,Clinical Neurotechnology Laboratory, Neuroscience Research Center (NWFZ) & Department of Psychiatry and Psychotherapy, Charité - University Medicine Berlin, Berlin, Germany
| | - Marcos Tatagiba
- Department of Neurosurgery, University of Tuebingen, Tuebingen, Germany
| | - Guilherme Lepski
- Department of Neurosurgery, University of Tuebingen, Tuebingen, Germany.,Division of Functional Neurosurgery, School of Medicine, Universidade de São Paulo, São Paulo, Brazil
| |
Collapse
|
19
|
Michels T, Ahmadi S, Graf N. Treatment of peripheral pain with low-dose local anesthetics by epidermal, epithelial and periosteal application. Local Reg Anesth 2018; 11:129-136. [PMID: 30588085 PMCID: PMC6294063 DOI: 10.2147/lra.s151316] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Objectives The efficiency of local anesthetics (LAs) in the treatment of peripheral pain is commonly attributed to their capacity to block the axon conduction of sensory nerves. LAs even in non-blocking concentration suppress oscillations of the resting membrane potential. Spiking in sensory neurons is triggered by subthreshold membrane potential oscillations (SMPOs), which reach threshold and is maintained by depolarizing impulse after oscillations. The suppression of these oscillations abolishes sustained afferent discharge in sensory nerves without blocking the axon conduction. In a retrospective observational study, we examined if LAs in low concentration and very small quantities could reduce peripheral pain in patients. Design During a period of 2 years, a total of 127 consecutive patients, 43 with cervico-brachial, 12 with intercostal and 72 with lumbo-sciatic pain received an identical treatment, which consisted of LAs applied in 4–8 sessions on average to a fixed set of epidermal, epithelial and periosteal locations. The primary outcome was relief of symptoms measured by verbal analog scales at the end of therapy. Results At the end of therapy, 53 (41.7%) of all patients (127) had a complete remission (reduction of pain 100%). Twenty-three patients (18.1%) had a partial remission with >90% reduction of pain and 50 patients (39.4%) had a pain reduction of 30%–90%. One patient did not respond. Conclusion LAs in low concentration and small quantities proved to be highly efficient in the treatment of peripheral pain. An almost complete remission could be obtained in a majority of patients. Given the extent of pain reduction achieved, the method of application seems to be of major importance.
Collapse
Affiliation(s)
| | - Seifollah Ahmadi
- Institute of Physiology II, University of Bonn, 53115 Bonn, Germany
| | - Nicole Graf
- Graf Biostatistics, CH-8400 Winterthur, Switzerland
| |
Collapse
|
20
|
Zhang H, Kashihara T, Nakada T, Tanaka S, Ishida K, Fuseya S, Kawagishi H, Kiyosawa K, Kawamata M, Yamada M. Prostanoid EP4 Receptor-Mediated Augmentation of I h Currents in A β Dorsal Root Ganglion Neurons Underlies Neuropathic Pain. J Pharmacol Exp Ther 2018; 368:50-58. [PMID: 30409832 DOI: 10.1124/jpet.118.252767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 11/05/2018] [Indexed: 11/22/2022] Open
Abstract
An injury of the somatosensory system causes neuropathic pain, which is usually refractory to conventional analgesics, thus warranting the development of novel drugs against this kind of pain. The mechanism of neuropathic pain in rats that had undergone left L5 spinal nerve transection was analyzed. Ten days after surgery, these rats acquired neuropathic pain. The patch-clamp technique was used on the isolated bilateral L5 dorsal root ganglion neurons. The current-clamped neurons on the ipsilateral side exhibited significantly higher excitability than those on the contralateral side. However, only neurons with diameters of 40-50 μm on the ipsilateral side exhibited significantly larger voltage sags in response to hyperpolarizing current pulses than those on the contralateral side. Under the voltage clamp, only these neurons on the ipsilateral side showed a significantly larger density of an inward current at < -80 mV [hyperpolarization-activated nonselective cation (I h) current] with a rightward-shifted activation curve than that on the contralateral side. Ivabradine-an I h current inhibitor-inhibited I h currents in these neurons on both sides in a similar concentration-dependent manner, with an IC50 value of ∼3 μM. Moreover, the oral administration of ivabradine significantly alleviated the neuropathic pain on the ipsilateral side. An inhibitor of adenylyl cyclase or an antagonist of prostanoid EP4 receptors (CJ-023423) inhibited ipsilateral, but not contralateral I h, currents in these neurons. Furthermore, the intrathecal administration of CJ-023423 significantly attenuated neuropathic pain on the ipsilateral side. Thus, ivabradine and/or CJ-023423 may be a lead compound for the development of novel therapeutics against neuropathic pain.
Collapse
Affiliation(s)
- Hao Zhang
- Departments of Molecular Pharmacology (H.Z., T.K., T.N., H.K., K.K., M.Y.) and Anesthesiology and Resuscitology (H.Z., S.T., K.I., S.F., K.K., M.K.), Shinshu University School of Medicine, Matsumoto, Nagano, Japan
| | - Toshihide Kashihara
- Departments of Molecular Pharmacology (H.Z., T.K., T.N., H.K., K.K., M.Y.) and Anesthesiology and Resuscitology (H.Z., S.T., K.I., S.F., K.K., M.K.), Shinshu University School of Medicine, Matsumoto, Nagano, Japan
| | - Tsutomu Nakada
- Departments of Molecular Pharmacology (H.Z., T.K., T.N., H.K., K.K., M.Y.) and Anesthesiology and Resuscitology (H.Z., S.T., K.I., S.F., K.K., M.K.), Shinshu University School of Medicine, Matsumoto, Nagano, Japan
| | - Satoshi Tanaka
- Departments of Molecular Pharmacology (H.Z., T.K., T.N., H.K., K.K., M.Y.) and Anesthesiology and Resuscitology (H.Z., S.T., K.I., S.F., K.K., M.K.), Shinshu University School of Medicine, Matsumoto, Nagano, Japan
| | - Kumiko Ishida
- Departments of Molecular Pharmacology (H.Z., T.K., T.N., H.K., K.K., M.Y.) and Anesthesiology and Resuscitology (H.Z., S.T., K.I., S.F., K.K., M.K.), Shinshu University School of Medicine, Matsumoto, Nagano, Japan
| | - Satoshi Fuseya
- Departments of Molecular Pharmacology (H.Z., T.K., T.N., H.K., K.K., M.Y.) and Anesthesiology and Resuscitology (H.Z., S.T., K.I., S.F., K.K., M.K.), Shinshu University School of Medicine, Matsumoto, Nagano, Japan
| | - Hiroyuki Kawagishi
- Departments of Molecular Pharmacology (H.Z., T.K., T.N., H.K., K.K., M.Y.) and Anesthesiology and Resuscitology (H.Z., S.T., K.I., S.F., K.K., M.K.), Shinshu University School of Medicine, Matsumoto, Nagano, Japan
| | - Kenkichi Kiyosawa
- Departments of Molecular Pharmacology (H.Z., T.K., T.N., H.K., K.K., M.Y.) and Anesthesiology and Resuscitology (H.Z., S.T., K.I., S.F., K.K., M.K.), Shinshu University School of Medicine, Matsumoto, Nagano, Japan
| | - Mikito Kawamata
- Departments of Molecular Pharmacology (H.Z., T.K., T.N., H.K., K.K., M.Y.) and Anesthesiology and Resuscitology (H.Z., S.T., K.I., S.F., K.K., M.K.), Shinshu University School of Medicine, Matsumoto, Nagano, Japan
| | - Mitsuhiko Yamada
- Departments of Molecular Pharmacology (H.Z., T.K., T.N., H.K., K.K., M.Y.) and Anesthesiology and Resuscitology (H.Z., S.T., K.I., S.F., K.K., M.K.), Shinshu University School of Medicine, Matsumoto, Nagano, Japan
| |
Collapse
|
21
|
Devor M. Rethinking the causes of pain in herpes zoster and postherpetic neuralgia: the ectopic pacemaker hypothesis. Pain Rep 2018; 3:e702. [PMID: 30706041 PMCID: PMC6344138 DOI: 10.1097/pr9.0000000000000702] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 10/10/2018] [Indexed: 01/29/2023] Open
Abstract
INTRODUCTION Pain in herpes zoster (HZ) and postherpetic neuralgia (PHN) is traditionally explained in terms of 2 processes: irritable nociceptors in the rash-inflamed skin and, later, deafferentation due to destruction of sensory neurons in one virally infected dorsal root ganglion. OBJECTIVES AND METHODS Consideration of the evidence supporting this explanation in light of contemporary understanding of the pain system finds it wanting. An alternative hypothesis is proposed as a replacement. RESULTS This model, the ectopic pacemaker hypothesis of HZ and PHN, proposes that pain in both conditions is driven by hyperexcitable ectopic pacemaker sites at various locations in primary sensory neurons affected by the causative varicella zoster virus infection. This peripheral input is exacerbated by central sensitization induced and maintained by the ectopic activity. CONCLUSIONS The shift in perspective regarding the pain mechanism in HZ/PHN has specific implications for clinical management.
Collapse
Affiliation(s)
- Marshall Devor
- Department of Cell and Developmental Biology, Institute of Life Sciences, and Center for Research on Pain, The Hebrew University of Jerusalem, Jerusalem, Israel
| |
Collapse
|
22
|
Guha D, Shamji MF. The Dorsal Root Ganglion in the Pathogenesis of Chronic Neuropathic Pain. Neurosurgery 2018; 63 Suppl 1:118-126. [PMID: 27399376 DOI: 10.1227/neu.0000000000001255] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Affiliation(s)
| | - Mohammed F Shamji
- Department of Surgery and.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada.,Division of Neurosurgery, Toronto Western Hospital, Toronto, Ontario, Canada
| |
Collapse
|
23
|
Petersen BA, Nanivadekar AC, Chandrasekaran S, Fisher LE. Phantom limb pain: peripheral neuromodulatory and neuroprosthetic approaches to treatment. Muscle Nerve 2018; 59:154-167. [DOI: 10.1002/mus.26294] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2018] [Indexed: 12/11/2022]
Affiliation(s)
- Bailey A. Petersen
- Department of Bioengineering; University of Pittsburgh; 3520 Fifth Avenue, Pittsburgh Pennsylvania 15213 USA
| | - Ameya C. Nanivadekar
- Department of Bioengineering; University of Pittsburgh; 3520 Fifth Avenue, Pittsburgh Pennsylvania 15213 USA
| | - Santosh Chandrasekaran
- Department of Physical Medicine and Rehabilitation; University of Pittsburgh; Pittsburgh Pennsylvania USA
| | - Lee E. Fisher
- Department of Bioengineering; University of Pittsburgh; 3520 Fifth Avenue, Pittsburgh Pennsylvania 15213 USA
- Department of Physical Medicine and Rehabilitation; University of Pittsburgh; Pittsburgh Pennsylvania USA
| |
Collapse
|
24
|
Deer TR, Pope JE, Lamer TJ, Grider JS, Provenzano D, Lubenow TR, FitzGerald JJ, Hunter C, Falowski S, Sayed D, Baranidharan G, Patel NK, Davis T, Green A, Pajuelo A, Epstein LJ, Harned M, Liem L, Christo PJ, Chakravarthy K, Gilmore C, Huygen F, Lee E, Metha P, Nijhuis H, Patterson DG, Petersen E, Pilitsis JG, Rowe JJ, Rupert MP, Skaribas I, Sweet J, Verrills P, Wilson D, Levy RM, Mekhail N. The Neuromodulation Appropriateness Consensus Committee on Best Practices for Dorsal Root Ganglion Stimulation. Neuromodulation 2018; 22:1-35. [PMID: 30246899 DOI: 10.1111/ner.12845] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 05/03/2018] [Accepted: 05/29/2018] [Indexed: 12/21/2022]
Abstract
INTRODUCTION The Neuromodulation Appropriateness Consensus Committee (NACC) is dedicated to improving the safety and efficacy of neuromodulation and thus improving the lives of patients undergoing neuromodulation therapies. With continued innovations in neuromodulation comes the need for evolving reviews of best practices. Dorsal root ganglion (DRG) stimulation has significantly improved the treatment of complex regional pain syndrome (CRPS), among other conditions. Through funding and organizational leadership by the International Neuromodulation Society (INS), the NACC reconvened to develop the best practices consensus document for the selection, implantation and use of DRG stimulation for the treatment of chronic pain syndromes. METHODS The NACC performed a comprehensive literature search of articles about DRG published from 1995 through June, 2017. A total of 2538 article abstracts were then reviewed, and selected articles graded for strength of evidence based on scoring criteria established by the US Preventive Services Task Force. Graded evidence was considered along with clinical experience to create the best practices consensus and recommendations. RESULTS The NACC achieved consensus based on peer-reviewed literature and experience to create consensus points to improve patient selection, guide surgical methods, improve post-operative care, and make recommendations for management of patients treated with DRG stimulation. CONCLUSION The NACC recommendations are intended to improve patient care in the use of this evolving therapy for chronic pain. Clinicians who choose to follow these recommendations may improve outcomes.
Collapse
Affiliation(s)
| | | | - Tim J Lamer
- Division of Pain Medicine, Department of Anesthesiology, Mayo Clinic, Rochester, MN, USA
| | - Jay S Grider
- UKHealthCare Pain Services, Department of Anesthesiology, University of Kentucky College of Medicine, Lexington, KY, USA
| | | | | | - James J FitzGerald
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, UK.,Nuffield Department of Surgical Sciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Corey Hunter
- Ainsworth Institute of Pain Management, New York, NY, USA
| | - Steven Falowski
- Functional Neurosurgery, St. Lukes University Health Network, Bethlehem, PA, USA
| | - Dawood Sayed
- University of Kansas Medical Center, Kansas City, KS, USA
| | | | - Nikunj K Patel
- Institute of Clinical Neurosciences, Department of Neurosurgery, Southmead Hospital, University of Bristol, Bristol, UK
| | | | - Alex Green
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | | | | | - Michael Harned
- Department of Anesthesiology, University of Kentucky, Lexington, KY, USA
| | - Liong Liem
- St. Antonius Hospital, Nieuwegein, The Netherlands
| | | | | | | | - Frank Huygen
- Erasmus University Hospital, Rotterdam, The Netherlands
| | - Eric Lee
- Summit Pain Alliance, Santa Rosa, CA, USA
| | | | | | | | - Erika Petersen
- Department of Neurosurgery, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Julie G Pilitsis
- Neurosurgery and Neuroscience & Experimental Therapeutics, Albany Medical College, Albany, NY, USA
| | | | | | | | - Jennifer Sweet
- Case Western Reserve University, Stereotactic & Functional Neurosurgery, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | | | - Derron Wilson
- Goodman Campbell Brain and Spine, Indiana University School of Medicine Department of Neurological Surgery, Indianapolis, IN, USA
| | | | - Nagy Mekhail
- Evidence-Based Pain Management Research and Education, Cleveland Clinic, Cleveland, OH, USA
| |
Collapse
|
25
|
Dilute lidocaine suppresses ectopic neuropathic discharge in dorsal root ganglia without blocking axonal propagation: a new approach to selective pain control. Pain 2018. [DOI: 10.1097/j.pain.0000000000001205] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
26
|
|
27
|
Lin JJ, Lin Y, Zhao TZ, Zhang CK, Zhang T, Chen XL, Ding JQ, Chang T, Zhang Z, Sun C, Zhao DD, Zhu JL, Li ZY, Li JL. Melatonin Suppresses Neuropathic Pain via MT2-Dependent and -Independent Pathways in Dorsal Root Ganglia Neurons of Mice. Am J Cancer Res 2017; 7:2015-2032. [PMID: 28656058 PMCID: PMC5485420 DOI: 10.7150/thno.19500] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Accepted: 03/15/2017] [Indexed: 12/29/2022] Open
Abstract
Melatonin (Mel) and its receptors (MT1 and MT2) have a well-documented efficacy in treating different pain conditions. However, the anti-nociceptive effects of Mel and Mel receptors in neuropathic pain (NP) are poorly understood. To elucidate this process, pain behaviors were measured in a dorsal root ganglia (DRG)-friendly sciatic nerve cuffing model. We detected up-regulation of MT2 expression in the DRGs of cuff-implanted mice and its activation by the agonist 8-M-PDOT (8MP). Also, Mel attenuated the mechanical and thermal allodynia induced by cuff implantation. Immunohistochemical analysis demonstrated the expression of MT2 in the DRG neurons, while MT1 was expressed in the satellite cells. In cultured primary neurons, microarray analysis and gene knockdown experiments demonstrated that MT2 activation by 8MP or Mel suppressed calcium signaling pathways via MAPK1, which were blocked by RAR-related orphan receptor alpha (RORα) activation with a high dose of Mel. Furthermore, expression of nitric oxide synthase 1 (NOS1) was down-regulated upon Mel treatment regardless of MT2 or RORα. Application of Mel or 8MP in cuff-implanted models inhibited the activation of peptidergic neurons and neuro-inflammation in the DRGs by down-regulating c-fos, calcitonin gene-related peptide [CGRP], and tumor necrosis factor-1α [TNF-1α] and interleukin-1β [IL-1β]. Addition of the MT2 antagonist luzindole blocked the effects of 8MP but not those of Mel. In conclusion, only MT2 was expressed in the DRG neurons and up-regulated upon cuff implantation. The analgesic effects of Mel in cuff-implanted mice were closely associated with both MT2-dependent (MAPK-calcium channels) and MT2-independent (NOS1) pathways in the DRG.
Collapse
|
28
|
Pang D. Current experience of spinal neuromodulation in chronic pain: Is there a role in children and young people? Eur J Paediatr Neurol 2017; 21:56-66. [PMID: 27658771 DOI: 10.1016/j.ejpn.2016.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 06/20/2016] [Accepted: 07/02/2016] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Chronic pain in children has been an under-recognized problem compared to adult pain. The aim of management is to help children and their families cope with the symptoms rather than a cure. Current medical treatments to reduce pain intensity are often short lived, poorly tolerated or ineffective. RESULTS The use of electrical stimulation to treat pain is the current basis of modern Neuromodulation at the spinal cord and has been well established as spinal cord stimulation in adult practice. This involves placement of an epidural electrode connected to a subcutaneous implanted pulse generator. The electrode generates an electrical field at the dorsal columns of the spinal cord that inhibits pain pathways. Randomised controlled trials have demonstrated efficacy in neuropathic pain states such as the failed back surgery syndrome and complex regional pain syndrome. CONCLUSION Despite its initial expense, Spinal cord stimulation is a cost effective therapy in the long term and has the advantages of being a minimally invasive therapy and reversible.
Collapse
Affiliation(s)
- David Pang
- Pain Management and Neuromodulation Centre, St Thomas' Hospital, Westminster Bridge Road, London SE1 7EH, UK.
| |
Collapse
|
29
|
Norcini M, Sideris A, Adler SM, Hernandez LAM, Zhang J, Blanck TJJ, Recio-Pinto E. NR2B Expression in Rat DRG Is Differentially Regulated Following Peripheral Nerve Injuries That Lead to Transient or Sustained Stimuli-Evoked Hypersensitivity. Front Mol Neurosci 2016; 9:100. [PMID: 27803647 PMCID: PMC5068091 DOI: 10.3389/fnmol.2016.00100] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 09/26/2016] [Indexed: 12/30/2022] Open
Abstract
Following injury, primary sensory neurons undergo changes that drive central sensitization and contribute to the maintenance of persistent hypersensitivity. NR2B expression in the dorsal root ganglia (DRG) has not been previously examined in neuropathic pain models. Here, we investigated if changes in NR2B expression within the DRG are associated with hypersensitivities that result from peripheral nerve injuries. This was done by comparing the NR2B expression in the DRG derived from two modalities of the spared nerve injury (SNI) model, since each variant produces different neuropathic pain phenotypes. Using the electronic von Frey to stimulate the spared and non-spared regions of the hindpaws, we demonstrated that sural-SNI animals develop sustained neuropathic pain in both regions while the tibial-SNI animals recover. NR2B expression was measured at Day 23 and Day 86 post-injury. At Day 23 and 86 post-injury, sural-SNI animals display strong hypersensitivity, whereas tibial-SNI animals display 50 and 100% recovery from post-injury-induced hypersensitivity, respectively. In tibial-SNI at Day 86, but not at Day 23 the perinuclear region of the neuronal somata displayed an increase in NR2B protein. This retention of NR2B protein within the perinuclear region, which will render them non-functional, correlates with the recovery observed in tibial-SNI. In sural-SNI at Day 86, DRG displayed an increase in NR2B mRNA which correlates with the development of sustained hypersensitivity in this model. The increase in NR2B mRNA was not associated with an increase in NR2B protein within the neuronal somata. The latter may result from a decrease in kinesin Kif17, since Kif17 mediates NR2B transport to the soma’s plasma membrane. In both SNIs, microglia/macrophages showed a transient increase in NR2B protein detected at Day 23 but not at Day 86, which correlates with the initial post-injury induced hypersensitivity in both SNIs. In tibial-SNI at Day 86, but not at Day 23, satellite glia cells (SGCs) displayed an increase in NR2B protein. This study is the first to characterize of cell-specific changes in NR2B expression within the DRG following peripheral nerve injury. We discuss how the observed NR2B changes in DRG can contribute to the different neuropathic pain phenotypes displayed by each SNI variant.
Collapse
Affiliation(s)
- Monica Norcini
- Department of Anesthesiology, Perioperative Care and Pain Medicine, NYU Langone Medical Center, New York University, New York NY, USA
| | - Alexandra Sideris
- Department of Anesthesiology, Perioperative Care and Pain Medicine, NYU Langone Medical Center, New York University, New York NY, USA
| | - Samantha M Adler
- Department of Anesthesiology, Perioperative Care and Pain Medicine, NYU Langone Medical Center, New York University, New York NY, USA
| | - Lourdes A M Hernandez
- Department of Anesthesiology, Perioperative Care and Pain Medicine, NYU Langone Medical Center, New York University, New York NY, USA
| | - Jin Zhang
- Department of Anesthesiology, Perioperative Care and Pain Medicine, NYU Langone Medical Center, New York University, New York NY, USA
| | - Thomas J J Blanck
- Department of Anesthesiology, Perioperative Care and Pain Medicine, NYU Langone Medical Center, New York University, New YorkNY, USA; Department of Neuroscience and Physiology, NYU Langone Medical Center, New York University, New YorkNY, USA
| | - Esperanza Recio-Pinto
- Department of Anesthesiology, Perioperative Care and Pain Medicine, NYU Langone Medical Center, New York University, New YorkNY, USA; Department of Biochemistry and Molecular Pharmacology, NYU Langone Medical Center, New York University, New YorkNY, USA
| |
Collapse
|
30
|
HCN2 ion channels: basic science opens up possibilities for therapeutic intervention in neuropathic pain. Biochem J 2016; 473:2717-36. [DOI: 10.1042/bcj20160287] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 05/18/2016] [Indexed: 01/22/2023]
Abstract
Nociception — the ability to detect painful stimuli — is an invaluable sense that warns against present or imminent damage. In patients with chronic pain, however, this warning signal persists in the absence of any genuine threat and affects all aspects of everyday life. Neuropathic pain, a form of chronic pain caused by damage to sensory nerves themselves, is dishearteningly refractory to drugs that may work in other types of pain and is a major unmet medical need begging for novel analgesics. Hyperpolarisation-activated cyclic nucleotide (HCN)-modulated ion channels are best known for their fundamental pacemaker role in the heart; here, we review data demonstrating that the HCN2 isoform acts in an analogous way as a ‘pacemaker for pain’, in that its activity in nociceptive neurons is critical for the maintenance of electrical activity and for the sensation of chronic pain in pathological pain states. Pharmacological block or genetic deletion of HCN2 in sensory neurons provides robust pain relief in a variety of animal models of inflammatory and neuropathic pain, without any effect on normal sensation of acute pain. We discuss the implications of these findings for our understanding of neuropathic pain pathogenesis, and we outline possible future opportunities for the development of efficacious and safe pharmacotherapies in a range of chronic pain syndromes.
Collapse
|
31
|
Canavese F, Dimeglio A, Barbetta D, Galeotti M, Canavese B, Cavalli F. Radiologic and histological observations in experimental T1-T12 dorsal arthrodesis: A qualitative description of T1-T12 segment and other body parts involved, between prepubertal age and skeletal maturityxs. Indian J Orthop 2016; 50:558-566. [PMID: 27746501 PMCID: PMC5017180 DOI: 10.4103/0019-5413.189600] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND This experimental study provides a qualitative description and the morpho-structural features of the fusions taking place in the thoracic spine between prepubertal age and skeletal maturity. There is a lack of informations regarding the influence of partial or total dorso-thoracic vertebral arthrodesis on the development of the thoracic cage as well as its potential effects on different intra and extra-thoracic organs. This study admits the hypothesis that vertebral arthrodesis may have influence on other body areas and so, it intends to verify the possible secondary involvement of other body parts, such as intervertebral discs, cervical and thoracic spinal ganglia, sternocostal cartilage, ovaries and lungs. MATERIALS AND METHODS Fifty-four female New Zealand white rabbits were submitted to dorsal arthrodesis. The radiologic imaging and light microscopy histological pictures were taken and studied in all. Computed tomography (CT) scan measurements were performed in operated and sham operated rabbits at different time. Similarly, histological specimens of intervertebral discs, cervical and thoracic spinal ganglia, sternocostal cartilage, ovaries and lungs were analyzed at different times. The study ended at the age of 17-18 months. RESULTS Most rabbits had formed a fusion mass, which was only fibrous at first, then osteofibrous and finally, in the older subjects, structured in lamellar-osteon tissue. Intervertebral foramens were negatively involved in vertebral arthrodesis, as shown by CT scans. Intervertebral discs showed irregular aspects. The increase of atresic follicles and the reduction of primordial follicles in operated rabbits led to the hypothesis of a cause-effect relationship between arthrodesis and modified hormonal status. Dorsal root ganglia showed microscopic alterations in operated rabbits especially. CONCLUSIONS The process of fusion mass and bone formation, associated with the arthrodesis, involves at different degrees of the vertebral bodies, discs and intervertebral foramens, ganglia and spinal nerve roots.
Collapse
Affiliation(s)
- Federico Canavese
- Department of Pediatric Surgery, University Hospital Estaing, 1 Place Lucie et Raymond Aubrac, 63003 Clermont-Ferrand, France “University of Montpellier, 34000 Montpellier, France,Address for correspondence: Pr. Federico Canavese, Department of Pediatric Surgery, University Hospital Estaing, Service de Chirurgie Infantile, 1 Place Lucie et Raymond Aubrac, 63003 Clermont-Ferrand, France. E-mail:
| | - Alain Dimeglio
- Department of Pediatric Orthopedic Surgery, Saint Roch Hospital, 8 rue Marguerite, France,University of Montpellier, Faculty of Medicine, 2 Rue de l’Ecole de Medecine, 34000 Montpellier, France
| | - Davide Barbetta
- Department of Life Sciences, Animal Facility, University of Trieste, Via Valerio 28, 34127 Trieste, Italy
| | - Marco Galeotti
- Department of Food Science, University of Udine, Veterinary Pathology Section, Via Sondrio 2, 33100 Udine, Italy
| | - Bartolomeo Canavese
- Department of Food Science, University of Udine, Veterinary Pathology Section, Via Sondrio 2, 33100 Udine, Italy
| | - Fabio Cavalli
- Department of Radiology, Research Unit of Paleoradiology and Allied Sciences, University Hospital of Trieste, LTS, 34127 Trieste, Italy
| |
Collapse
|
32
|
Reversal of neurochemical alterations in the spinal dorsal horn and dorsal root ganglia by Mas-related gene (Mrg) receptors in a rat model of spinal nerve injury. Neurobiol Dis 2016; 91:274-83. [DOI: 10.1016/j.nbd.2016.03.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 03/12/2016] [Accepted: 03/21/2016] [Indexed: 12/17/2022] Open
|
33
|
Current status and future directions of botulinum neurotoxins for targeting pain processing. Toxins (Basel) 2015; 7:4519-63. [PMID: 26556371 PMCID: PMC4663519 DOI: 10.3390/toxins7114519] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 09/29/2015] [Accepted: 10/19/2015] [Indexed: 12/20/2022] Open
Abstract
Current evidence suggests that botulinum neurotoxins (BoNTs) A1 and B1, given locally into peripheral tissues such as skin, muscles, and joints, alter nociceptive processing otherwise initiated by inflammation or nerve injury in animal models and humans. Recent data indicate that such locally delivered BoNTs exert not only local action on sensory afferent terminals but undergo transport to central afferent cell bodies (dorsal root ganglia) and spinal dorsal horn terminals, where they cleave SNAREs and block transmitter release. Increasing evidence supports the possibility of a trans-synaptic movement to alter postsynaptic function in neuronal and possibly non-neuronal (glial) cells. The vast majority of these studies have been conducted on BoNT/A1 and BoNT/B1, the only two pharmaceutically developed variants. However, now over 40 different subtypes of botulinum neurotoxins (BoNTs) have been identified. By combining our existing and rapidly growing understanding of BoNT/A1 and /B1 in altering nociceptive processing with explorations of the specific characteristics of the various toxins from this family, we may be able to discover or design novel, effective, and long-lasting pain therapeutics. This review will focus on our current understanding of the molecular mechanisms whereby BoNTs alter pain processing, and future directions in the development of these agents as pain therapeutics.
Collapse
|
34
|
Obradović ALJ, Scarpa J, Osuru HP, Weaver JL, Park JY, Pathirathna S, Peterkin A, Lim Y, Jagodic MM, Todorovic SM, Jevtovic-Todorovic V. Silencing the α2 subunit of γ-aminobutyric acid type A receptors in rat dorsal root ganglia reveals its major role in antinociception posttraumatic nerve injury. Anesthesiology 2015; 123:654-67. [PMID: 26164299 PMCID: PMC4568754 DOI: 10.1097/aln.0000000000000767] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
BACKGROUND Neuropathic pain (NPP) is likely the result of repetitive high-frequency bursts of peripheral afferent activity leading to long-lasting changes in synaptic plasticity in the spinal dorsal horn. Drugs that promote γ-aminobutyric acid (GABA) activity in the dorsal horn provide partial relief of neuropathic symptoms. The authors examined how in vivo silencing of the GABA receptor type A (GABAA) α2 gene in dorsal root ganglia (DRG) controls NPP. METHODS After crush injury to the right sciatic nerve of female rats, the α2 GABAA antisense and mismatch oligodeoxynucleotides or NO-711 (a GABA uptake inhibitor) were applied to the L5 DRG. In vivo behavioral assessment of nociception was conducted before the injury and ensuing 10 days (n = 4 to 10). In vitro quantification of α2 GABAA protein and electrophysiological studies of GABAA currents were performed on acutely dissociated L5 DRG neurons at relevant time points (n = 6 to 14). RESULTS NPP postcrush injury of a sciatic nerve in adult female rats coincides with significant down-regulation of the α2 subunit expression in the ipsilateral DRG (approximately 30%). Selective down-regulation of α2 expression in DRGs significantly worsens mechanical (2.55 ± 0.75 to 5.16 ± 1.16) and thermal (7.97 ± 0.96 to 5.51 ± 0.75) hypersensitivity in crush-injured animals and causes development of significant mechanical (2.33 ± 0.40 to 5.00 ± 0.33) and thermal (10.80 ± 0.29 to 7.34 ± 0.81) hypersensitivity in sham animals (data shown as mean ± SD). Conversely, up-regulation of endogenous GABA via blockade of its uptake in DRG alleviates NPP. CONCLUSION The GABAA receptor in the DRG plays an important role in pathophysiology of NPP caused by sciatic nerve injury and represents promising target for novel pain therapies.
Collapse
Affiliation(s)
- Aleksandar LJ Obradović
- Department of Anesthesiology, University of Virginia Health System, Charlottesville, VA, USA
- Department of Physiology, University of Belgrade School of Pharmacy, Belgrade, Serbia
| | - Joseph Scarpa
- Department of Anesthesiology, University of Virginia Health System, Charlottesville, VA, USA
- Icahn Institute for Genomics and Multiscale Biology, Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Hari P Osuru
- Department of Anesthesiology, University of Virginia Health System, Charlottesville, VA, USA
| | - Janelle L Weaver
- Department of Anesthesiology, University of Virginia Health System, Charlottesville, VA, USA
| | - Ji-Yong Park
- Department of Anesthesiology, University of Virginia Health System, Charlottesville, VA, USA
- Department of Anesthesiology and Pain Medicine, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Sriyani Pathirathna
- Department of Anesthesiology, University of Virginia Health System, Charlottesville, VA, USA
| | - Alexander Peterkin
- Department of Anesthesiology, University of Virginia Health System, Charlottesville, VA, USA
| | - Yunhee Lim
- Department of Anesthesiology, University of Virginia Health System, Charlottesville, VA, USA
- Department of Anesthesiology and Pain Medicine, Sanggye Paik Hospital, College of Medicine, Inje University, Seoul, Republic of Korea
| | - Miljenko M Jagodic
- Department of Anesthesiology, University of Virginia Health System, Charlottesville, VA, USA
| | - Slobodan M Todorovic
- Department of Anesthesiology, University of Virginia Health System, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia Health System, Charlottesville, VA, USA
| | - Vesna Jevtovic-Todorovic
- Department of Anesthesiology, University of Virginia Health System, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia Health System, Charlottesville, VA, USA
| |
Collapse
|
35
|
Stemkowski PL, Noh MC, Chen Y, Smith PA. Increased excitability of medium-sized dorsal root ganglion neurons by prolonged interleukin-1β exposure is K(+) channel dependent and reversible. J Physiol 2015; 593:3739-55. [PMID: 26110238 PMCID: PMC4560594 DOI: 10.1113/jp270905] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 06/17/2015] [Indexed: 01/27/2023] Open
Abstract
KEY POINTS Neuropathic pain resulting from peripheral nerve injury is initiated and maintained by persistent ectopic activity in primary afferent neurons. Sciatic nerve injury increases the excitability of medium-sized dorsal root ganglion (DRG) neurons. Levels of the inflammatory cytokine interleukin 1β (IL-1β) increase and peak after 7 days. Five to six days of exposure of medium sized DRG neurons to 100 pm IL-1β promotes persistent increases in excitability which abate within 3-4 days of cytokine removal. This is associated with a profound attenuation of K(+) channel currents but only modest increases in function of cyclic nucleotide-sensitive hyperpolarization-activated channels (HCNs) and of voltage-gated Na(+) and Ca(2+) channel currents. It is unlikely, therefore, that direct interaction of IL-1β with DRG neurons is capable of initiating an enduring phenotypic shift in their electrophysiological properties that follows sciatic nerve injury. The findings also underline the importance of K(+) channel modulation in the actions of inflammatory mediators on peripheral neurons. ABSTRACT Chronic constriction injury of rat sciatic nerve promotes signs of neuropathic pain. This is associated with an increase in the level of interleukin 1β (IL-1β) in primary afferents that peaks at 7 days. This initial cytokine exposure has been proposed to trigger an enduring alteration in neuronal phenotype that underlies chronic hyper-excitability in sensory nerves, which initiates and maintains chronic neuropathic pain. We have shown previously that 5-6 days of exposure of rat dorsal root ganglia (DRGs) to 100 pm IL-1β increases the excitability of medium-sized neurons. We have now found using whole-cell recording that this increased excitability reverts to control levels within 3-4 days of cytokine removal. The effects of IL-1β were dominated by changes in K(+) currents. Thus, the amplitudes of A-current, delayed rectifier and Ca(2+) -sensitive K(+) currents were reduced by ∼68%, ∼64% and ∼36%, respectively. Effects of IL-1β on other cation currents were modest by comparison. There was thus a slight decrease in availability of high voltage-activated Ca(2+) channel current, a small increase in rates of activation of hyperpolarization-activated cyclic nucleotide-gated channel current (IH ), and a shift in the voltage dependence of activation of tetrodotoxin-sensitive sodium current (TTX-S INa ) to more negative potentials. It is unlikely, therefore, that direct interaction of IL-1β with DRG neurons initiates an enduring phenotypic shift in their electrophysiological properties following sciatic nerve injury. Persistent increases in primary afferent excitability following nerve injury may instead depend on altered K(+) channel function and on the continued presence of slightly elevated levels IL-1β and other cytokines.
Collapse
Affiliation(s)
- Patrick L Stemkowski
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, Canada, T2N 4N1
| | - Myung-Chul Noh
- Centre for Neuroscience and Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada, T6G 2H7
| | - Yishen Chen
- Centre for Neuroscience and Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada, T6G 2H7
| | - Peter A Smith
- Centre for Neuroscience and Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada, T6G 2H7
| |
Collapse
|
36
|
Neuralgia of the glossopharyngeal nerve in a patient with posttonsillectomy scarring: recovery after local infiltration of procaine-case report and pathophysiologic discussion. Case Rep Neurol Med 2015; 2015:560546. [PMID: 25960898 PMCID: PMC4415660 DOI: 10.1155/2015/560546] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 04/06/2015] [Indexed: 01/03/2023] Open
Abstract
We describe a patient with a three-year history of severe progressive left-sided glossopharyngeal neuralgia (GPN) that failed to adequately respond to various drug therapies. The application of lidocaine spray to the posterior pharyngeal wall provided no more than short-term relief. Apart from a large hypertrophic tonsillectomy scar on the left side all clinical and radiologic findings were normal. In terms of therapeutic local anaesthesia, the hypertrophic tonsillectomy scar tissue was completely infiltrated with the local anaesthetic (LA) procaine 1%. The patient has been almost completely pain-free ever since, and the lidocaine spray is no longer needed. Six weeks after the first treatment a repeat infiltration of the tonsillectomy scar led to the complete resolution of all symptoms. The patient has become totally symptom-free without the need to take any medication now for two and a half years. This is the first report of a successful therapeutic infiltration of a tonsillectomy scar using an LA in a patient with GPN that has been refractory to medical treatment for several years. A possible explanation may be that the positive feedback loop maintaining neurogenic inflammation is disrupted and “sympathetically maintained pain” resolved by LA infiltration.
Collapse
|
37
|
Deer TR, Mekhail N, Provenzano D, Pope J, Krames E, Leong M, Levy RM, Abejon D, Buchser E, Burton A, Buvanendran A, Candido K, Caraway D, Cousins M, DeJongste M, Diwan S, Eldabe S, Gatzinsky K, Foreman RD, Hayek S, Kim P, Kinfe T, Kloth D, Kumar K, Rizvi S, Lad SP, Liem L, Linderoth B, Mackey S, McDowell G, McRoberts P, Poree L, Prager J, Raso L, Rauck R, Russo M, Simpson B, Slavin K, Staats P, Stanton-Hicks M, Verrills P, Wellington J, Williams K, North R. The appropriate use of neurostimulation of the spinal cord and peripheral nervous system for the treatment of chronic pain and ischemic diseases: the Neuromodulation Appropriateness Consensus Committee. Neuromodulation 2015; 17:515-50; discussion 550. [PMID: 25112889 DOI: 10.1111/ner.12208] [Citation(s) in RCA: 319] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 01/07/2014] [Accepted: 02/28/2014] [Indexed: 02/02/2023]
Abstract
INTRODUCTION The Neuromodulation Appropriateness Consensus Committee (NACC) of the International Neuromodulation Society (INS) evaluated evidence regarding the safety and efficacy of neurostimulation to treat chronic pain, chronic critical limb ischemia, and refractory angina and recommended appropriate clinical applications. METHODS The NACC used literature reviews, expert opinion, clinical experience, and individual research. Authors consulted the Practice Parameters for the Use of Spinal Cord Stimulation in the Treatment of Neuropathic Pain (2006), systematic reviews (1984 to 2013), and prospective and randomized controlled trials (2005 to 2013) identified through PubMed, EMBASE, and Google Scholar. RESULTS Neurostimulation is relatively safe because of its minimally invasive and reversible characteristics. Comparison with medical management is difficult, as patients considered for neurostimulation have failed conservative management. Unlike alternative therapies, neurostimulation is not associated with medication-related side effects and has enduring effect. Device-related complications are not uncommon; however, the incidence is becoming less frequent as technology progresses and surgical skills improve. Randomized controlled studies support the efficacy of spinal cord stimulation in treating failed back surgery syndrome and complex regional pain syndrome. Similar studies of neurostimulation for peripheral neuropathic pain, postamputation pain, postherpetic neuralgia, and other causes of nerve injury are needed. International guidelines recommend spinal cord stimulation to treat refractory angina; other indications, such as congestive heart failure, are being investigated. CONCLUSIONS Appropriate neurostimulation is safe and effective in some chronic pain conditions. Technological refinements and clinical evidence will continue to expand its use. The NACC seeks to facilitate the efficacy and safety of neurostimulation.
Collapse
|
38
|
Schuelert N, Gorodetskaya N, Just S, Doods H, Corradini L. Electrophysiological characterization of spinal neurons in different models of diabetes type 1- and type 2-induced neuropathy in rats. Neuroscience 2015; 291:146-54. [PMID: 25686525 DOI: 10.1016/j.neuroscience.2015.02.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 01/15/2015] [Accepted: 02/03/2015] [Indexed: 10/24/2022]
Abstract
Diabetic polyneuropathy (DPN) is a devastating complication of diabetes. The underlying pathogenesis of DPN is still elusive and an effective treatment devoid of side effects presents a challenge. There is evidence that in type-1 and -2 diabetes, metabolic and morphological changes lead to peripheral nerve damage and altered central nociceptive transmission, which may contribute to neuropathic pain symptoms. We characterized the electrophysiological response properties of spinal wide dynamic range (WDR) neurons in three diabetic models. The streptozotocin (STZ) model was used as a drug-induced model of type-1 diabetes, and the BioBreeding/Worcester (BB/Wor) and Zucker diabetic fatty (ZDF) rat models were used for genetic DPN models. Data were compared to the respective control group (BB/Wor diabetic-resistant, Zucker lean (ZL) and saline-injected Wistar rat). Response properties of WDR neurons to mechanical stimulation and spontaneous activity were assessed. We found abnormal response properties of spinal WDR neurons in all diabetic rats but not controls. Profound differences between models were observed. In BB/Wor diabetic rats evoked responses were increased, while in ZDF rats spontaneous activity was increased and in STZ rats mainly after discharges were increased. The abnormal response properties of neurons might indicate differential pathological, diabetes-induced, changes in spinal neuronal transmission. This study shows for the first time that specific electrophysiological response properties are characteristic for certain models of DPN and that these might reflect the diverse and complex symptomatology of DPN in the clinic.
Collapse
Affiliation(s)
- N Schuelert
- Department of CNS Diseases Research, Boehringer Ingelheim Pharma GmbH & Co KG, 88397 Biberach, Germany.
| | - N Gorodetskaya
- Department of CNS Diseases Research, Boehringer Ingelheim Pharma GmbH & Co KG, 88397 Biberach, Germany
| | - S Just
- Department of CNS Diseases Research, Boehringer Ingelheim Pharma GmbH & Co KG, 88397 Biberach, Germany
| | - H Doods
- Department of CNS Diseases Research, Boehringer Ingelheim Pharma GmbH & Co KG, 88397 Biberach, Germany
| | - L Corradini
- Department of CNS Diseases Research, Boehringer Ingelheim Pharma GmbH & Co KG, 88397 Biberach, Germany
| |
Collapse
|
39
|
Malek N, Pajak A, Kolosowska N, Kucharczyk M, Starowicz K. The importance of TRPV1-sensitisation factors for the development of neuropathic pain. Mol Cell Neurosci 2015; 65:1-10. [PMID: 25662734 DOI: 10.1016/j.mcn.2015.02.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 01/20/2015] [Accepted: 02/02/2015] [Indexed: 12/17/2022] Open
Abstract
Transient receptor potential vanilloid type 1 (TRPV1), classically associated with transduction of high-temperature and low-pH pain, underlies pain hypersensitivity in neuropathic pain. The molecular regulation of TRPV1 channel activity is not yet fully understood. Therefore, we investigated factors regulating sensitisation of this receptor during development of neuropathic pain in a rat model of chronic construction injury (CCI) in the dorsal root ganglia (DRG). In the rat CCI model, elevated levels of pro-inflammatory cytokines (TNFα, IL-1β and IL-6) in DRG corresponded to development of neuropathic pain. We assessed the expression of known kinases influencing TRPV1 sensitisation at the mRNA and/or protein level. Protein kinase C ε (PKCε) showed the strongest upregulation at the mRNA and protein levels among all tested kinases. Co-expression of PKCε and TRPV1 in L5 DRG of CCI animals was high during the development of neuropathic pain. The number of neurons expressing PKCε increased throughout the experiment. We provide complex data on the expression of a variety of factors involved in TRPV1 sensitisation in a CCI model of neuropathic pain. Our study supports evidence for involvement of TRPV1 in the development of neuropathic pain, by showing increased expression of interleukins and kinases responsible for the channel sensitisation. TNFα and NGF seem to play a role in the transition from acute to neuropathic pain, while PKCε in its maintenance. Further studies might confirm their significance as novel targets for the treatment of neuropathic pain.
Collapse
Affiliation(s)
- Natalia Malek
- Laboratory of Pain Pathophysiology, Department of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12 Street, 31-343 Krakow, Poland.
| | - Agnieszka Pajak
- Laboratory of Pain Pathophysiology, Department of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12 Street, 31-343 Krakow, Poland.
| | - Natalia Kolosowska
- Laboratory of Pain Pathophysiology, Department of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12 Street, 31-343 Krakow, Poland.
| | - Mateusz Kucharczyk
- Laboratory of Pain Pathophysiology, Department of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12 Street, 31-343 Krakow, Poland.
| | - Katarzyna Starowicz
- Laboratory of Pain Pathophysiology, Department of Pain Pharmacology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12 Street, 31-343 Krakow, Poland.
| |
Collapse
|
40
|
Krames ES. The Dorsal Root Ganglion in Chronic Pain and as a Target for Neuromodulation: A Review. Neuromodulation 2014; 18:24-32; discussion 32. [DOI: 10.1111/ner.12247] [Citation(s) in RCA: 147] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 11/08/2013] [Accepted: 02/04/2014] [Indexed: 11/29/2022]
|
41
|
Fukuoka T, Miyoshi K, Noguchi K. De novo expression of Nav1.7 in injured putative proprioceptive afferents: Multiple tetrodotoxin-sensitive sodium channels are retained in the rat dorsal root after spinal nerve ligation. Neuroscience 2014; 284:693-706. [PMID: 25453779 DOI: 10.1016/j.neuroscience.2014.10.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 10/11/2014] [Accepted: 10/14/2014] [Indexed: 12/23/2022]
Abstract
Tetrodotoxin-sensitive (TTX-s) spontaneous activity is recorded from the dorsal roots after peripheral nerve injury. Primary sensory neurons in the dorsal root ganglion (DRG) express multiple TTX-s voltage-gated sodium channel α-subunits (Navs). Since Nav1.3 increases, whereas all other Navs decrease, in the DRG neurons after peripheral nerve lesion, Nav1.3 is proposed to be critical for the generation of these spontaneous discharges and the contributions of other Navs have been ignored. Here, we re-evaluate the changes in expression of three other TTX-s Navs, Nav1.1, Nav1.6 and Nav1.7, in the injured 5th lumbar (L5) primary afferent components following L5 spinal nerve ligation (SNL) using in situ hybridization histochemistry and immunohistochemistry. While the overall signal intensities for these Nav mRNAs decreased, many injured DRG neurons still expressed these transcripts at clearly detectable levels. All these Nav proteins accumulated at the proximal stump of the ligated L5 spinal nerve. The immunostaining patterns of Nav1.6 and Nav1.7 associated with the nodes of Ranvier were maintained in the ipsilateral L5 dorsal root. Interestingly, putative proprioceptive neurons characterized by α3 Na+/K+ ATPase-immunostaining specifically lacked Nav1.7 mRNA in naïve DRG but displayed de novo expression of this transcript following SNL. Nav1.7-immunoreactive fibers were significantly increased in the ipsilateral gracile nucleus where central axonal branches of the injured A-fiber afferents terminated. These data indicate that multiple TTX-s channel subunits could contribute to the generation and propagation of the spontaneous discharges in the injured primary afferents. Specifically, Nav1.7 may cause some functional changes in sensory processing in the gracile nucleus after peripheral nerve injury.
Collapse
Affiliation(s)
- T Fukuoka
- Department of Anatomy & Neuroscience, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan.
| | - K Miyoshi
- Department of Anatomy & Neuroscience, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - K Noguchi
- Department of Anatomy & Neuroscience, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| |
Collapse
|
42
|
Devor M, Vaso A, Adahan HM, Vyshka G. PNS origin of phantom limb sensation and pain: reply to letter to the editor regarding Foell et al., peripheral origin of phantom limb pain: is it all resolved? Pain 2014; 155:2207-2208. [PMID: 25168666 DOI: 10.1016/j.pain.2014.08.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 08/18/2014] [Accepted: 08/18/2014] [Indexed: 02/08/2023]
Affiliation(s)
- Marshall Devor
- Department of Cell & Developmental Biology, Institute of Life Sciences and Center for Research on Pain, The Hebrew University of Jerusalem, Jerusalem, Israel Pain and Rehabilitation Clinic, National Trauma Center, Trauma University Hospital and Galenus Clinic, Tirana, Albania Pain Rehabilitation Unit, Chaim Sheba Medical Center, Tel Hashomer, Israel Biomedical and Experimental Department, Faculty of Medicine, University of Medicine, Tirana, Albania
| | | | | | | |
Collapse
|
43
|
Diabetic-induced increased sodium channel activity attenuated by tetracaine in sensory neurons in vitro. Biochem Biophys Res Commun 2014; 453:296-301. [DOI: 10.1016/j.bbrc.2014.09.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 09/09/2014] [Indexed: 11/22/2022]
|
44
|
Benitez SU, Barbizan R, Spejo AB, Ferreira RS, Barraviera B, Góes AM, de Oliveira ALR. Synaptic plasticity and sensory-motor improvement following fibrin sealant dorsal root reimplantation and mononuclear cell therapy. Front Neuroanat 2014; 8:96. [PMID: 25249946 PMCID: PMC4158877 DOI: 10.3389/fnana.2014.00096] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 08/25/2014] [Indexed: 01/24/2023] Open
Abstract
Root lesions may affect both dorsal and ventral roots. However, due to the possibility of generating further inflammation and neuropathic pain, surgical procedures do not prioritize the repair of the afferent component. The loss of such sensorial input directly disturbs the spinal circuits thus affecting the functionality of the injuried limb. The present study evaluated the motor and sensory improvement following dorsal root reimplantation with fibrin sealant (FS) plus bone marrow mononuclear cells (MC) after dorsal rhizotomy. MC were used to enhance the repair process. We also analyzed changes in the glial response and synaptic circuits within the spinal cord. Female Lewis rats (6–8 weeks old) were divided in three groups: rhizotomy (RZ group), rhizotomy repaired with FS (RZ+FS group) and rhizotomy repaired with FS and MC (RZ+FS+MC group). The behavioral tests electronic von-Frey and Walking track test were carried out. For immunohistochemistry we used markers to detect different synapse profiles as well as glial reaction. The behavioral results showed a significant decrease in sensory and motor function after lesion. The reimplantation decreased glial reaction and improved synaptic plasticity of afferent inputs. Cell therapy further enhanced the rewiring process. In addition, both reimplanted groups presented twice as much motor control compared to the non-treated group. In conclusion, the reimplantation with FS and MC is efficient and may be considered an approach to improve sensory-motor recovery following dorsal rhizotomy.
Collapse
Affiliation(s)
- Suzana U Benitez
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas Campinas, Brazil
| | - Roberta Barbizan
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas Campinas, Brazil
| | - Aline B Spejo
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas Campinas, Brazil
| | - Rui S Ferreira
- Center for Studies of Venoms and Venomous Animals (CEVAP), University of Sao Paulo "Julio de Mesquita Filho," Botucatu, Brazil
| | - Benedito Barraviera
- Center for Studies of Venoms and Venomous Animals (CEVAP), University of Sao Paulo "Julio de Mesquita Filho," Botucatu, Brazil
| | - Alfredo M Góes
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais Belo Horizonte, Brazil
| | - Alexandre L R de Oliveira
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas Campinas, Brazil
| |
Collapse
|
45
|
Deer TR, Krames E, Mekhail N, Pope J, Leong M, Stanton-Hicks M, Golovac S, Kapural L, Alo K, Anderson J, Foreman RD, Caraway D, Narouze S, Linderoth B, Buvanendran A, Feler C, Poree L, Lynch P, McJunkin T, Swing T, Staats P, Liem L, Williams K. The Appropriate Use of Neurostimulation: New and Evolving Neurostimulation Therapies and Applicable Treatment for Chronic Pain and Selected Disease States. Neuromodulation 2014; 17:599-615; discussion 615. [DOI: 10.1111/ner.12204] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 01/14/2014] [Accepted: 02/07/2014] [Indexed: 12/20/2022]
Affiliation(s)
| | | | - Nagy Mekhail
- University of Kentucky-Lexington; Lexington KY USA
| | - Jason Pope
- Center for Pain Relief; Charleston WV USA
| | | | | | | | - Leo Kapural
- Carolinas Pain Institute at Brookstown; Wake Forest Baptist Health; Winston-Salem NC USA
| | - Ken Alo
- The Methodist Hospital Research Institute; Houston TX USA
- Monterey Technical Institute; Monterey Mexico
| | | | - Robert D. Foreman
- University of Oklahoma Health Sciences Center, College of Medicine; Oklahoma City OK USA
| | - David Caraway
- Center for Pain Relief, Tri-State, LLC; Huntington WV USA
| | - Samer Narouze
- Anesthesiology and Pain Medicine, Neurological Surgery; Summa Western Reserve Hospital; Cuyahoga Falls OH USA
| | - Bengt Linderoth
- Functional Neurosurgery and Applied Neuroscience Research Unit, Karolinska Institute; Karolinska University Hospital; Stockholm Sweden
| | | | - Claudio Feler
- University of Tennessee; Memphis TN USA
- Valley View Hospital; Glenwood Springs CO USA
| | - Lawrence Poree
- University of California at San Francisco; San Francisco CA USA
- Pain Clinic of Monterey Bay; Aptos CA
| | - Paul Lynch
- Arizona Pain Specialists; Scottsdale AZ USA
| | | | - Ted Swing
- Arizona Pain Specialists; Scottsdale AZ USA
| | - Peter Staats
- Premier Pain Management Centers; Shrewsbury NJ USA
- Johns Hopkins University; Baltimore MD USA
| | - Liong Liem
- St. Antonius Hospital; Nieuwegein The Netherlands
| | - Kayode Williams
- Johns Hopkins School of Medicine and Carey Business School; Baltimore MD USA
| |
Collapse
|
46
|
Pollema-Mays SL, Centeno MV, Apkarian AV, Martina M. Expression of DNA methyltransferases in adult dorsal root ganglia is cell-type specific and up regulated in a rodent model of neuropathic pain. Front Cell Neurosci 2014; 8:217. [PMID: 25152711 PMCID: PMC4126486 DOI: 10.3389/fncel.2014.00217] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Accepted: 07/17/2014] [Indexed: 11/13/2022] Open
Abstract
Neuropathic pain is associated with hyperexcitability and intrinsic firing of dorsal root ganglia (DRG) neurons. These phenotypical changes can be long lasting, potentially spanning the entire life of animal models, and depend on altered expression of numerous proteins, including many ion channels. Yet, how DRGs maintain long-term changes in protein expression in neuropathic conditions remains unclear. DNA methylation is a well-known mechanism of epigenetic control of gene expression and is achieved by the action of three enzymes: DNA methyltransferase (DNMT) 1, 3a, and 3b, which have been studied primarily during development. We first performed immunohistochemical analysis to assess whether these enzymes are expressed in adult rat DRGs (L4–5) and found that DNMT1 is expressed in both glia and neurons, DNMT3a is preferentially expressed in glia and DNMT3b is preferentially expressed in neurons. A rat model of neuropathic pain was then used to determine whether nerve injury may induce epigenetic changes in DRGs at multiple time points after pain onset. Real-time RT PCR analysis revealed robust and time-dependent changes in DNMT transcript expression in ipsilateral DRGs from spared nerve injury (SNI) but not sham rats. Interestingly, DNMT3b transcript showed a robust upregulation that appeared already 1 week after surgery and persisted at 4 weeks (our endpoint); in contrast, DNMT1 and DNMT3a transcripts showed only moderate upregulation that was transient and did not appear until the second week. We suggest that DNMT regulation in adult DRGs may be a contributor to the pain phenotype and merits further study.
Collapse
Affiliation(s)
- Sarah L Pollema-Mays
- Department of Physiology, Northwestern University Feinberg School of Medicine Chicago, IL, USA
| | - Maria V Centeno
- Department of Physiology, Northwestern University Feinberg School of Medicine Chicago, IL, USA
| | - A V Apkarian
- Department of Physiology, Northwestern University Feinberg School of Medicine Chicago, IL, USA
| | - Marco Martina
- Department of Physiology, Northwestern University Feinberg School of Medicine Chicago, IL, USA
| |
Collapse
|
47
|
Enhanced excitability of primary sensory neurons and altered gene expression of neuronal ion channels in dorsal root ganglion in paclitaxel-induced peripheral neuropathy. Anesthesiology 2014; 120:1463-75. [PMID: 24534904 DOI: 10.1097/aln.0000000000000176] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The mechanism of chemotherapy-induced peripheral neuropathy after paclitaxel treatment is not well understood. Given the poor penetration of paclitaxel into central nervous system, peripheral nervous system is most at risk. METHODS Intrinsic membrane properties of dorsal root ganglion neurons were studied by intracellular recordings. Multiple-gene real-time polymerase chain reaction array was used to investigate gene expression of dorsal root ganglion neuronal ion channels. RESULTS Paclitaxel increased the incidence of spontaneous activity from 4.8 to 27.1% in large-sized and from 0 to 33.3% in medium-sized neurons. Paclitaxel decreased the rheobase (nA) from 1.6 ± 0.1 to 0.8 ± 0.1 in large-sized, from 1.5 ± 0.2 to 0.6 ± 0.1 in medium-sized, and from 1.6 ± 0.2 to 1.0 ± 0.1 in small-sized neurons. After paclitaxel treatment, other characteristics of membrane properties in each group remained the same except that Aδ neurons showed shorter action potential fall time (ms) (1.0 ± 0.2, n = 10 vs. 1.8 ± 0.3, n = 9, paclitaxel vs. vehicle). Meanwhile, real-time polymerase chain reaction array revealed an alteration in expression of some neuronal ion channel genes including up-regulation of hyperpolarization-activated cyclic nucleotide-gated channel 1 (fold change 1.76 ± 0.06) and Nav1.7 (1.26 ± 0.02) and down-regulation of Kir channels (Kir1.1, 0.73 ± 0.05, Kir3.4, 0.66 ± 0.06) in paclitaxel-treated animals. CONCLUSION The increased neuronal excitability and the changes in gene expression of some neuronal ion channels in dorsal root ganglion may provide insight into the molecular and cellular basis of paclitaxel-induced neuropathy, which may lead to novel therapeutic strategies.
Collapse
|
48
|
Krames ES. The role of the dorsal root ganglion in the development of neuropathic pain. PAIN MEDICINE 2014; 15:1669-85. [PMID: 24641192 DOI: 10.1111/pme.12413] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND The dorsal root ganglion (DRG), in the not too distant past, had been thought of as a passive organ not involved in the development of abnormal aberrent neuropathic pain (NP), but merely metabolically "supporting" physiologic functions between the peripheral nervous system (PNS) and the central nervous system (CNS). New information regarding metabolic change within the DRG has dispelled this supportive passive role and suggests that the DRG is an active, not a passive, organ, in the process of the development of chronic pain. METHODS A review of the anatomic and physiologic literature utilizing PubMed and Google Scholar was performed to create a review of the anatomic and physiologic foundations for the development of NP after peripheral afferent fiber injury. CONCLUSIONS The DRG is as involved in the process of generating NP as is the nociceptor and the dorsal horn of the spinal cord.
Collapse
|
49
|
Kv2 dysfunction after peripheral axotomy enhances sensory neuron responsiveness to sustained input. Exp Neurol 2013; 251:115-26. [PMID: 24252178 PMCID: PMC3898477 DOI: 10.1016/j.expneurol.2013.11.011] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 10/21/2013] [Accepted: 11/07/2013] [Indexed: 12/16/2022]
Abstract
Peripheral nerve injuries caused by trauma are associated with increased sensory neuron excitability and debilitating chronic pain symptoms. Axotomy-induced alterations in the function of ion channels are thought to largely underlie the pathophysiology of these phenotypes. Here, we characterise the mRNA distribution of Kv2 family members in rat dorsal root ganglia (DRG) and describe a link between Kv2 function and modulation of sensory neuron excitability. Kv2.1 and Kv2.2 were amply expressed in cells of all sizes, being particularly abundant in medium-large neurons also immunoreactive for neurofilament-200. Peripheral axotomy led to a rapid, robust and long-lasting transcriptional Kv2 downregulation in the DRG, correlated with the onset of mechanical and thermal hypersensitivity. The consequences of Kv2 loss-of-function were subsequently investigated in myelinated neurons using intracellular recordings on ex vivo DRG preparations. In naïve neurons, pharmacological Kv2.1/Kv2.2 inhibition by stromatoxin-1 (ScTx) resulted in shortening of action potential (AP) after-hyperpolarization (AHP). In contrast, ScTx application on axotomized neurons did not alter AHP duration, consistent with the injury-induced Kv2 downregulation. In accordance with a shortened AHP, ScTx treatment also reduced the refractory period and improved AP conduction to the cell soma during high frequency stimulation. These results suggest that Kv2 downregulation following traumatic nerve lesion facilitates greater fidelity of repetitive firing during prolonged input and thus normal Kv2 function is postulated to limit neuronal excitability. In summary, we have profiled Kv2 expression in sensory neurons and provide evidence for the contribution of Kv2 dysfunction in the generation of hyperexcitable phenotypes encountered in chronic pain states. Kv2.1 and Kv2.2 are expressed in rat dorsal root ganglion neurons. Kv2 subunits are most abundant in myelinated sensory neurons. Kv2.1 and Kv.2 subunits are downregulated in a traumatic nerve injury pain model. Kv2 inhibition ex vivo allows higher firing rates during sustained stimulation. We conclude that Kv2 channels contribute to limiting peripheral neuron excitability.
Collapse
|
50
|
Pollema-Mays SL, Centeno MV, Ashford CJ, Apkarian AV, Martina M. Expression of background potassium channels in rat DRG is cell-specific and down-regulated in a neuropathic pain model. Mol Cell Neurosci 2013; 57:1-9. [PMID: 23994814 DOI: 10.1016/j.mcn.2013.08.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 07/30/2013] [Accepted: 08/12/2013] [Indexed: 10/26/2022] Open
Abstract
Neuropathic pain is associated with hyperexcitability of DRG neurons. Despite the importance of leakage potassium channels for neuronal excitability, little is known about their cell-specific expression in DRGs and possible modulation in neuropathic pain. Multiple leakage channels are expressed in DRG neurons, including TASK1, TASK3, TRESK, TRAAK, TWIK1, TREK1 and TREK2 but little is known about their distribution among different cell types. Our immunohistochemical studies show robust TWIK1 expression in large and medium size neurons, without overlap with TRPV1 or IB4 staining. TASK1 and TASK3, on the contrary, are selectively expressed in small cells; TASK1 expression closely overlaps TRPV1-positive cells, while TASK3 is expressed in TRPV1- and IB4-negative cells. We also studied mRNA expression of these channels in L4-L5 DRGs in control conditions and up to 4 weeks after spared nerve injury lesion. We found that TWIK1 expression is much higher than TASK1 and TASK3 and is strongly decreased 1, 2 and 4 weeks after neuropathic injury. TASK3 expression, on the other hand, decreases 1 week after surgery but reverts to baseline by 2weeks; TASK1 shows no significant change at any time point. These data suggest an involvement of TWIK1 in the maintenance of the pain condition.
Collapse
Affiliation(s)
- Sarah L Pollema-Mays
- Department of Physiology, Northwestern University Feinberg School of Medicine, 303 E Chicago Ave., Chicago, IL 60611, United States
| | | | | | | | | |
Collapse
|