Current understanding of nociplastic pain

Yeong-Min Yoo,Kyung-Hoon Kim 대한통증학회 2024 The Korean Journal of Pain Vol.37 No.2

Nociplastic pain by the “International Association for the Study of Pain” is defined as pain that arises from altered nociception despite no clear evidence of nociceptive or neuropathic pain. Augmented central nervous system pain and sensory processing with altered pain modulation are suggested to be the mechanism of nociplastic pain. Clinical criteria for possible nociplastic pain affecting somatic structures include chronic regional pain and evoked pain hypersensitivity including allodynia with after-sensation. In addition to possible nociplastic pain, clinical criteria for probable nociplastic pain are pain hypersensitivity in the region of pain to non-noxious stimuli and presence of comorbidity such as generalized symptoms with sleep disturbance, fatigue, or cognitive problems with hypersensitivity of special senses. Criteria for definitive nociplastic pain is not determined yet. Eight specific disorders related to central sensitization are suggested to be restless leg syndrome, chronic fatigue syndrome, fibromyalgia, temporomandibular disorder, migraine or tension headache, irritable bowel syndrome, multiple chemical sensitivities, and whiplash injury; non-specific emotional disorders related to central sensitization include anxiety or panic attack and depression. These central sensitization pain syndromes are overlapped to previous functional pain syndromes which are unlike organic pain syndromes and have emotional components. Therefore, nociplastic pain can be understood as chronic altered nociception related to central sensitization including both sensory components with nociceptive and/or neuropathic pain and emotional components. Nociplastic pain may be developed to explain unexplained chronic pain beyond tissue damage or pathology regardless of its origin from nociceptive, neuropathic, emotional, or mixed pain components.

통증의 생리

신홍기 한양대학교 의과대학 2003 한양의대 학술지 Vol.23 No.1

통증의 외과적 치료

김영수 한양대학교 의과대학 2003 한양의대 학술지 Vol.23 No.1

Neuropathic pain feature in cancer-induced bone pain: does it matter? a prospective observational study

Nantthasorn Zinboonyahgoon,Choopong Luansritisakul 대한통증학회 2023 The Korean Journal of Pain Vol.36 No.2

Background: Cancer-induced bone pain (CIBP) is considered to have both nociceptive and neuropathic components. However, the prevalence, risk factors, and impact of the neuropathic components are yet poorly understood. Methods: We estimate the prevalence of neuropathic pain (NP) features in patients with CIBP at a tertiary care pain clinic setting using the Douleur Neuropathique 4 questionnaire and evaluate their associated factors and their impact after 4 weeks of treatment using the Brief Pain Inventory questionnaire and the Edmonton Symptom Assessment System. Results: A total of 133 patients were recruited. The estimated prevalence of NP was 30.8% (95% confidence interval: 23.6%–39.1%). Initially, the patients with NP had significantly higher average pain scores (6.00 vs. 5.05, P = 0.006), higher total interference scores (5.84 vs. 4.89, P = 0.033), and symptom distress scores (35.88 vs. 26.52, P = 0.002). After 4 weeks of treatment, patients in both groups reported significantly decreased pain intensity and improved quality of life. However, the patients with NP still reported significantly higher average pain (4.61 vs. 3.58, P = 0.048), trending toward higher total interference scores (3.52 vs. 2.99, P = 0.426), and symptom distress scores (23.30 vs. 20.77, P = 0.524). From multivariate analysis, the independent risk factors for NP were younger age, pain in the extremities, and higher average pain scores. Conclusions: NP are common in patients with CIBP. These conditions negatively affect pain intensity and the patient’s quality of life before and after treatment.

All about pain pharmacology: what pain physicians should know

김경훈,Hyo-Jung Seo,Salahadin Abdi,Billy Huh 대한통증학회 2020 The Korean Journal of Pain Vol.33 No.2

From the perspective of the definition of pain, pain can be divided into emotional and sensory components, which originate from potential and actual tissue dam-age, respectively. The pharmacologic treatment of the emotional pain component includes antianxiety drugs, antidepressants, and antipsychotics. The anti-anxiety drugs have anti-anxious, sedative, and somnolent effects. The antipsychotics are effective in patients with positive symptoms of psychosis. On the other hand, the sensory pain component can be divided into nociceptive and neuropathic pain. Non-steroidal anti-inflammatory drugs (NSAIDs) and opioids are usually applied for somatic and visceral nociceptive pain, respectively; anticonvulsants and antide-pressants are administered for the treatment of neuropathic pain with positive and negative symptoms, respectively. The NSAIDs, which inhibit the cyclo-oxygenase pathway, exhibit anti-inflammatory, antipyretic, and analgesic effects; however, they have a therapeutic ceiling. The adverse reactions (ADRs) of the NSAIDs include gas-trointestinal problems, generalized edema, and increased bleeding tendency. The opioids, which bind to the opioid receptors, present an analgesic effect only, with-out anti-inflammatory, antipyretic, or ceiling effects. The ADRs of the opioids start from itching and nausea/vomiting to cardiovascular and respiratory depression, as well as constipation. The anticonvulsants include carbamazepine, related to sodium channel blockade, and gabapentin and pregabalin, related to calcium blockade. The antidepressants show their analgesic actions mainly through inhibiting the reuptake of serotonin or norepinephrine. Most drugs, except NSAIDs, need an up-dose titration period. The principle of polypharmacy for analgesia in case of mixed components of pain is increasing therapeutic effects while reducing ADRs, based on the origin of the pain.

Antimicrobial therapies for chronic pain (part 1): analgesic mechanisms

Eric J. Wang,Jay Karri,Nuj Tontisirin,Steven P. Cohen 대한통증학회 2023 The Korean Journal of Pain Vol.36 No.3

There is increasing evidence that the relationship between chronic pain and infections is complex and intertwined. Bacterial and viral infections can cause pain through numerous mechanisms such as direct tissue damage and inflammation, the induction of excessive immunologic activity, and the development of peripheral or central sensitization. Treating infections might relieve pain by attenuating these processes, but a growing body of literature suggests that some antimicrobial therapies confer analgesic effects, including for nociceptive and neuropathic pain symptoms, and affective components of pain. The analgesic mechanisms of antimicrobials are indirect, but might be conceptualized into two broad categories: 1) the reduction of the infectious burden and associated pro-inflammatory processes; and 2) the inhibition of signaling processes (e.g., enzymatic and cytokine activity) necessary for nociception and maladaptive neuroplastic changes via off-target effects (unintended binding sites). For the former, there is evidence that symptoms of chronic low back pain (when associated with Modic type 1 changes), irritable bowel syndrome, inflammatory bowel disease, chronic pelvic pain, and functional dyspepsia might be improved after antibiotic treatment, though significant questions remain regarding specific regimens and dose, and which subpopulations are most likely to benefit. For the latter, there is evidence that several antimicrobial classes and medications exert analgesic effects independent of their reduction of infectious burden, and these include cephalosporins, ribavirin, chloroquine derivatives, rapalogues, minocycline, dapsone, and piscidin-1. This article aims to comprehensively review the existing literature for antimicrobial agents that have demonstrated analgesic efficacy in preclinical or clinical studies.

A novel excisional wound pain model for evaluation of analgesics in rats

( Sergio Parra ),( Vaidehi J. Thanawala ),( Ajay Rege ),( Heather Giles ) 대한통증학회 2021 The Korean Journal of Pain Vol.34 No.2

Background: Management of pain from open wounds is a growing unmet healthcare need. However, the models available to study pain from wounds or to develop analgesics for the patients suffering from them have primarily relied on incisional models. Here, we present the first characterized and validated model of open wound pain. Methods: Unilateral full-skin excisional punch biopsy wounds on rat hind paws were evaluated for evoked pain using withdrawal responses to mechanical and thermal stimulation, and spontaneous pain was measured using hind paw weight distribution and guarding behavior. Evaluations were done before wounding (baseline) and 2-96 hours post-wounding. The model was validated by testing the effects of buprenorphine and carprofen. Results: Pain responses to all tests increased within 2 hours post-wounding and were sustained for at least 4 days. Buprenorphine caused a reversal of all four pain responses at 1 and 4 hours post-treatment compared to 0.9% saline (P < 0.001). Carprofen decreased the pain response to thermal stimulation at 1 (P ≤ 0.049) and 4 hours (P < 0.011) post-treatment compared to 0.9% saline, but not to mechanical stimulation. Conclusions: This is the first well-characterized and validated model of pain from open wounds and will allow study of the pathophysiology of pain in open wounds and the development of wound-specific analgesics.

골담초 메탄올 추출물의 진통 효과

박진석,차동석,전훈 한국생약학회 2016 생약학회지 Vol.47 No.1

Caragana sinica (Leguminosae) is a plant, which has been used as a traditional medicine for the treatment of lots of diseases including neuralgia, goat, hypertension and eczema. However, scientific studies of C. sinica in pharmacological aspects are not carried out. In this study, the anti-nociceptice effect of methanolic extract of C. sinica (MCS) was evaluated using various pain models. Our data represented that MCS significantly delayed the latency time under central pain condition which are arose from thermal stimuli, indicating MCS possess analgesic potential against central nociception. In addition, MCS showed strong and dose-dependent anti-nociceptive activities on acetic acid-induced peripheral pain, compared to positive control such as indomethacin. Further combination studies using naloxone, a non-selective opioid receptor antagonist, have revealed that analgesic activity of MCS was not changed in the presence of naloxone, indicating MCS exerts anti-nociceptive activity independent of opioid receptor. These results suggest that MCS may be an effective medicine in managing pain.

산청목 메탄올 추출물의 진통 효과

서현원,전훈,박경재,곽귀희,임준상,김대근,임재윤,차동석,권진,오찬호 한국생약학회 2013 생약학회지 Vol.44 No.2

Acer tegmentosum which is belongs to Aceraceae has been widely used as a traditional medicine for the treatment of lots of diseases including pain management. In this study, we evaluated the anti-nocicepitve effects of methanolic extract of A. tegmentosum (MAT) in mice using various pain models. MAT presented strong and dose-dependent anti-nociceptive activities on thermal nociception models such as tail-immersion test and hot plate test. Moreover, acetic acid-induced chemical nociception was signigicantly reduced by MAT treatment. We could confirm MAT's central and peripheral analgesic properties by formalin test. We also found that the pre-treatment of opioid receptor antagonist did not alter the MAT's anti-nociception, suggesting opioid receptor is not involved in analgesic activity of MAT. Based on our results, we could conclude that MAT may be possibly used as an anti-nociceptive agent for the treatment of various nociceptive pains.

곤달비 메탄올 추출물의 진통 효과

차동석,전훈 한국생약학회 2013 생약학회지 Vol.44 No.1

Ligularia stenocephala has been widely used as a traditional medicine for the treatment of lots of diseases such as asthma, arthritis, and jaundice. In this study, we evaluated the anti-nocicepitve activities of methanolic extract of L. stenocephala (MLS) using various pain models including thermal nociception as well as chemical nociception methods. MLS showed significant increase in latency time in the tail immersion test and hot-plate test. In addition, the number of acetic acidinduced abdominal constrictions was decreased by MLS. MLS also attenuated paw licking time in the formalin test. The combination test using naloxone revealed that the anti-nociceptive properties of MLS was not associated with opioid receptor activation. The present results demonstrate that MLS may possibly used as valuable analgesic agent for the treatment of nociceptive pain.