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Sample records for impairs neuropathic pain

  1. Neuropathic pain.

    PubMed

    Colloca, Luana; Ludman, Taylor; Bouhassira, Didier; Baron, Ralf; Dickenson, Anthony H; Yarnitsky, David; Freeman, Roy; Truini, Andrea; Attal, Nadine; Finnerup, Nanna B; Eccleston, Christopher; Kalso, Eija; Bennett, David L; Dworkin, Robert H; Raja, Srinivasa N

    2017-02-16

    Neuropathic pain is caused by a lesion or disease of the somatosensory system, including peripheral fibres (Aβ, Aδ and C fibres) and central neurons, and affects 7-10% of the general population. Multiple causes of neuropathic pain have been described and its incidence is likely to increase owing to the ageing global population, increased incidence of diabetes mellitus and improved survival from cancer after chemotherapy. Indeed, imbalances between excitatory and inhibitory somatosensory signalling, alterations in ion channels and variability in the way that pain messages are modulated in the central nervous system all have been implicated in neuropathic pain. The burden of chronic neuropathic pain seems to be related to the complexity of neuropathic symptoms, poor outcomes and difficult treatment decisions. Importantly, quality of life is impaired in patients with neuropathic pain owing to increased drug prescriptions and visits to health care providers, as well as the morbidity from the pain itself and the inciting disease. Despite challenges, progress in the understanding of the pathophysiology of neuropathic pain is spurring the development of new diagnostic procedures and personalized interventions, which emphasize the need for a multidisciplinary approach to the management of neuropathic pain.

  2. Neuropathic pain

    PubMed Central

    Colloca, Luana; Ludman, Taylor; Bouhassira, Didier; Baron, Ralf; Dickenson, Anthony H.; Yarnitsky, David; Freeman, Roy; Truini, Andrea; Attal, Nadine; Finnerup, Nanna B.; Eccleston, Christopher; Kalso, Eija; Bennett, David L.; Dworkin, Robert H.; Raja, Srinivasa N.

    2017-01-01

    Neuropathic pain is caused by a lesion or disease of the somatosensory system, including peripheral fibres (Aβ, Aδ and C fibres) and central neurons, and affects 7–10% of the general population. Multiple causes of neuropathic pain have been described and its incidence is likely to increase owing to the ageing global population, increased incidence of diabetes mellitus and improved survival from cancer after chemotherapy. Indeed, imbalances between excitatory and inhibitory somatosensory signalling, alterations in ion channels and variability in the way that pain messages are modulated in the central nervous system all have been implicated in neuropathic pain. The burden of chronic neuropathic pain seems to be related to the complexity of neuropathic symptoms, poor outcomes and difficult treatment decisions. Importantly, quality of life is impaired in patients with neuropathic pain owing to increased drug prescriptions and visits to health care providers, as well as the morbidity from the pain itself and the inciting disease. Despite challenges, progress in the understanding of the pathophysiology of neuropathic pain is spurring the development of new diagnostic procedures and personalized interventions, which emphasize the need for a multidisciplinary approach to the management of neuropathic pain. PMID:28205574

  3. Central Neuropathic Pain Syndromes.

    PubMed

    Watson, James C; Sandroni, Paola

    2016-03-01

    Chronic pain is common in patients with neurologic complications of a central nervous system insult such as stroke. The pain is most commonly musculoskeletal or related to obligatory overuse of neurologically unaffected limbs. However, neuropathic pain can result directly from the central nervous system injury. Impaired sensory discrimination can make it challenging to differentiate central neuropathic pain from other pain types or spasticity. Central neuropathic pain may also begin months to years after the injury, further obscuring recognition of its association with a past neurologic injury. This review focuses on unique clinical features that help distinguish central neuropathic pain. The most common clinical central pain syndromes-central poststroke pain, multiple sclerosis-related pain, and spinal cord injury-related pain-are reviewed in detail. Recent progress in understanding of the pathogenesis of central neuropathic pain is reviewed, and pharmacological, surgical, and neuromodulatory treatments of this notoriously difficult to treat pain syndrome are discussed.

  4. Neuropathic pain.

    PubMed

    Koltzenburg, M; Scadding, J

    2001-10-01

    Damage to peripheral nerves triggers a cascade of events in axotomized sensory neurones that are generally believed to be responsible for the generation of neuropathic pain. Recent data in animal models show that alterations in the properties of undamaged neurones that project into a damaged nerve can also play an important role. These new findings could explain some of the enigmatic clinical signs and symptoms of pain following nerve injury such as the spread of symptoms into areas not affected by the primary lesion. The basis by which uninjured nerves could be affected is a reduced supply of neurotrophic factors, an abnormal interaction in the Remak bundles of partially denervated Schwann cells and unmyelinated axons, or the byproducts of Wallerian degeneration.

  5. Neuropathic pain in leprosy.

    PubMed

    Raicher, Irina; Stump, Patrick Raymond Nicolas Andre Ghislain; Baccarelli, Rosemari; Marciano, Lucia H S C; Ura, Somei; Virmond, Marcos C L; Teixeira, Manoel Jacobsen; Ciampi de Andrade, Daniel

    2016-01-01

    Nerve impairment is a key clinical aspect of leprosy and may present the distribution of mononeuropathy or multiple nerve trunks, small cutaneous nerve fibers, and free nerve endings. The clinical range of leprosy is determined by individual cell-mediated immune response to infection that also may play a role in different types of pain syndromes in leprosy. Previous studies reported a high prevalence of neuropathic pain in leprosy. In an Ethiopian study with 48 patients, pure nociceptive pain was experienced by 43% of patients and pure neuropathic pain (NeP) by 11% of patients. In an Indian study, 21.8% of leprosy patients had pain with neuropathic characteristics. These rates underlie the need to develop tools for the early diagnosis and detection of infection and its complications, such as nerve damage and pain. In a larger sample with leprosy-associated NeP (n = 90), we have applied the Douleur Neuropathique en 4 questions (DN4) and found sensitivity = 97.1% and specificity = 57.9%. The high sensitivity of this tool in leprosy patients suggests that it could be a valuable tool to screen for neuropathic pain in this population and could be used as part of health care programs aimed at detecting, treating, and rehabilitating leprosy in endemic areas. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Managing Neuropathic Pain in Dogs

    PubMed Central

    Moore, Sarah A.

    2016-01-01

    Disorders of the somatosensory system such as neuropathic pain are common in people with chronic neurologic and musculoskeletal diseases, yet these conditions remain an underappreciated morbidity in veterinary patients. This is likely because assessment of neuropathic pain in people relies heavily on self-reporting, something our veterinary patients are not able to do. The development of neuropathic pain is a complex phenomenon, and concepts related to it are frequently not addressed in the standard veterinary medical curriculum such that veterinarians may not recognize this as a potential problem in patients. The goals of this review are to discuss basic concepts in the pathophysiology of neuropathic pain, provide definitions for common clinical terms used in association with the condition, and discuss pharmacological treatment options for dogs with neuropathic pain. The development of neuropathic pain involves key mechanisms such as ectopic afferent nerve activity, peripheral sensitization, central sensitization, impaired inhibitory modulation, and pathologic activation of microglia. Treatments aimed at reducing neuropathic pain are targeted at one or more of these mechanisms. Several drugs are commonly used in the veterinary clinical setting to treat neuropathic pain. These include gabapentin, pregabalin, amantadine, and amitriptyline. Proposed mechanisms of action for each drug, and known pharmacokinetic profiles in dogs are discussed. Strong evidence exists in the human literature for the utility of most of these treatments, but clinical veterinary-specific literature is currently limited. Future studies should focus on objective methods to document neuropathic pain and monitor response to therapy in veterinary patients. PMID:26942185

  7. Neuropathic Pain After Breast Surgery

    ClinicalTrials.gov

    2017-07-31

    Chronic Neuropathic Pain, Postoperative; Chronic Pain, Postoperative; Chronic Chemotherapy-induced Neuropathic Pain; Chronic Chemotherapy-induced Pain; Chronic Chemotherapy-induced Peripheral Neuropathy

  8. Neuropathic Pain After Lung Surgery

    ClinicalTrials.gov

    2017-05-30

    Chronic Neuropathic Pain, Postoperative; Chronic Pain, Postoperative; Chronic Chemotherapy-induced Neuropathic Pain; Chronic Chemotherapy-induced Pain; Chronic Chemotherapy-induced Peripheral Neuropathy

  9. Memantine (Namenda) for neuropathic pain.

    PubMed

    Rogers, Mailien; Rasheed, Atif; Moradimehr, Abdolali; Baumrucker, Steven J

    2009-01-01

    Neuropathic pain is common in the palliative care population; unless adequately treated, the pain can lead to chronic anxiety, depression, and social impairment. Many treatments have been proposed for neuropathic pain; however, it remains underdiagnosed, under-treated, and often requires long-term therapy with risk of adverse effects. Memantine (Namenda), an N-Methyl, D-aspartate receptor inhibitor currently marketed for the treatment of dementia, has been proposed as a medication for the treatment of neuropathic pain for its mechanism, safety, lack of serious adverse effects, and relatively rapid onset of action. However, clinical trials have not been promising so far and its routine use in neuropathic pain is not currently recommended.

  10. Impairment of adenylyl cyclase-mediated glutamatergic synaptic plasticity in the periaqueductal grey in a rat model of neuropathic pain

    PubMed Central

    Ho, Yu-Cheng; Cheng, Jen-Kun; Chiou, Lih-Chu

    2015-01-01

    Key points Long-lasting neuropathic pain has been attributed to elevated neuronal plasticity changes in spinal, peripheral and cortical levels. Here, we found that reduced neuronal plasticity in the ventrolateral periaqueductal grey (vlPAG), a midbrain region important for initiating descending pain inhibition, may also contribute to neuropathic pain. Forskolin- and isoproterenol (isoprenaline)-elicited EPSC potentiation was impaired in the vlPAG of a rat model of neuropathic pain induced by spinal nerve injury. Down-regulation of adenylyl cyclase–cAMP– PKA signalling, due to impaired adenylyl cyclase, but not phosphodiesterase, in glutamatergic terminals may contribute to the hypofunction of excitatory synaptic plasticity in the vlPAG of neuropathic rats and the subsequent descending pain inhibition, ultimately leading to long-lasting neuropathic pain. Our results suggest that drugs that activate adenylyl cyclase in the vlPAG have the potential for relieving neuropathic pain. Abstract Neuropathic pain has been attributed to nerve injury-induced elevation of peripheral neuronal discharges and spinal excitatory synaptic plasticity while little is known about the contribution of neuroplasticity changes in the brainstem. Here, we examined synaptic plasticity changes in the ventrolateral (vl) periaqueductal grey (PAG), a crucial midbrain region for initiating descending pain inhibition, in spinal nerve ligation (SNL)-induced neuropathic rats. In vlPAG slices of sham-operated rats, forskolin, an adenylyl cyclase (AC) activator, produced long-lasting enhancement of EPSCs. This is a presynaptic effect since forskolin decreased the paired-pulse ratio and failure rate of EPSCs, and increased the frequency, but not the amplitude, of miniature EPSCs. Forskolin-induced EPSC potentiation was mimicked by a β-adrenergic agonist (isoproterenol (isoprenaline)), and prevented by an AC inhibitor (SQ 22536) and a cAMP-dependent protein kinase (PKA) inhibitor (H89), but not by a

  11. New therapy for neuropathic pain.

    PubMed

    Mizoguchi, Hirokazu; Watanabe, Chizuko; Yonezawa, Akihiko; Sakurada, Shinobu

    2009-01-01

    Neuropathic pain is one of the worst painful symptoms in clinic. It contains nerve-injured neuropathy, diabetic neuropathy, chronic inflammatory pain, cancer pain, and postherpes pain, and is characterized by a tactile allodynia and hyperalgesia. Neuropathic pain, especially the nerve-injured neuropathy, the diabetic neuropathy, and the cancer pain, is opioid resistant pain. Since the downregulation of mu-opioid receptors is observed in dorsal spinal cord, morphine and fentanyl could not provide marked antihyperalgesic/antiallodynic effects in the course neuropathic pain states. The downregulation of mu-opioid receptors is suggested to be mediated through the activation of NMDA receptors. Moreover, at the neuropathic pain states, the increased expression of voltage-dependent Na+ channels and Ca2+ channels are observed. Based on the above information concerned with the pathophysiology of neural changes in neuropathic pain states, new drug treatments for neuropathic pain, using ketamine, methadone, and gabapentin, have been developed. These drugs show remarkable effectiveness against hyperalgesia and allodynia during neuropathic pain states. Oxycodone is a mu-opioid receptor agonist, which has different pharmacological profiles with morphine. The remarkable effectiveness of oxycodone for neuropathic pain provides the possibility that mu-opioid receptor agonists, which have different pharmacological profile with morphine, can be used for the management of neuropathic pain.

  12. Ocular neuropathic pain

    PubMed Central

    Rosenthal, Perry; Borsook, David

    2016-01-01

    As the biological alarm of impending or actual tissue damage, pain is essential for our survival. However, when it is initiated and/or sustained by dysfunctional elements in the nociceptive system, it is itself a disease known as neuropathic pain. While the critical nociceptive system provides a number of protective functions, it is unique in its central role of monitoring, preserving and restoring the optical tear film in the face of evaporative attrition without which our vision would be non-functional. Meeting this existential need resulted in the evolution of the highly complex, powerful and sensitive dry eye alarm system integrated in the peripheral and central trigeminal sensory network. The clinical consequences of corneal damage to these nociceptive pathways are determined by the type and location of its pathological elements and can range from the spectrum known as dry eye disease to the centalised oculofacial neuropathic pain syndrome characterised by a striking disparity between the high intensity of symptoms and paucity of external signs. These changes parallel those observed in somatic neuropathic pain. When seen through the neuroscience lens, diseases responsible for inadequately explained chronic eye pain (including those described as dry eye) can take on new meanings that may clarify long-standing enigmas and point to new approaches for developing preventive, symptomatic and disease-modifying interventions for these currently refractory disorders. PMID:25943558

  13. Translational investigation and treatment of neuropathic pain

    PubMed Central

    2012-01-01

    Neuropathic pain develops from a lesion or disease affecting the somatosensory system. Translational investigations of neuropathic pain by using different animal models reveal that peripheral sensitization, spinal and cortical plasticity may play critical roles in neuropathic pain. Furthermore, descending facilitatory or excitatory modulation may also act to enhance chronic pain. Current clinical therapy for neuropathic pain includes the use of pharmacological and nonpharmacological (psychological, physical, and surgical treatment) methods. However, there is substantial need to better medicine for treating neuropathic pain. Future translational researchers and clinicians will greatly facilitate the development of novel drugs for treating chronic pain including neuropathic pain. PMID:22400804

  14. Placebo, nocebo, and neuropathic pain.

    PubMed

    Vase, Lene; Skyt, Ina; Hall, Kathryn T

    2016-02-01

    Over the last decade, the apparent increase in placebo responses in randomized controlled trials (RCTs) of neuropathic pain have complicated and potentially limited development and availability of new effective pain medication. Placebo analgesia and nocebo hyperalgesia effects are well described in nociceptive and idiopathic pain conditions, but less is known about the magnitude and mechanisms of placebo and nocebo effects in neuropathic pain. In neuropathic pain, placebo treatments have primarily been used as control conditions for active agents under investigation in RCTs and these placebo responses are typically not controlled for the natural history of pain and other confounding factors. Recently, mechanistic studies that control for the natural history of pain have investigated placebo and nocebo effects in neuropathic pain in their own right. Large placebo analgesia but no nocebo hyperalgesic effects have been found, and the underlying mechanisms are beginning to be elucidated. Here we review placebo and nocebo effects and the underlying mechanisms in neuropathic pain and compare them with those of nociceptive and idiopathic pain. This allows for a novel discussion on how knowledge of psychological, neurobiological, and genetic factors underlying well-controlled placebo effects may help improve the information that can be obtained from and potentially restore the utility of RCTs.

  15. Placebo, nocebo, and neuropathic pain

    PubMed Central

    Vase, Lene; Skyt, Ina; Hall, Kathryn T.

    2016-01-01

    Over the last decade, the apparent increase in placebo responses in randomized controlled trials (RCTs) of neuropathic pain have complicated and potentially limited development and availability of new effective pain medication. Placebo analgesia and nocebo hyperalgesia effects are well described in nociceptive and idiopathic pain conditions, but less is known about the magnitude and mechanisms of placebo and nocebo effects in neuropathic pain. In neuropathic pain, placebo treatments have primarily been used as control conditions for active agents under investigation in RCTs and these placebo responses are typically not controlled for the natural history of pain and other confounding factors. Recently, mechanistic studies that control for the natural history of pain have investigated placebo and nocebo effects in neuropathic pain in their own right. Large placebo analgesia but no nocebo hyperalgesic effects have been found, and the underlying mechanisms are beginning to be elucidated. Here we review placebo and nocebo effects and the underlying mechanisms in neuropathic pain and compare them with those of nociceptive and idiopathic pain. This allows for a novel discussion on how knowledge of psychological, neurobiological, and genetic factors underlying well-controlled placebo effects may help improve the information that can be obtained from and potentially restore the utility of RCTs. PMID:26785162

  16. Gynecological Management of Neuropathic Pain

    PubMed Central

    TU, Frank F.; HELLMAN, Kevin; BACKONJA, Miroslav

    2011-01-01

    Obstetrician/gynecologists often are the initial management clinicians for pelvic neuropathic pain. While treatment may require comprehensive team management and consultation with other specialists, there a few critical and basic steps that can be performed on an office visit that offer the opportunity to significantly improve quality of life in this patient population. A key first step is a thorough clinical examination to physically map the pain site and identify potentially involved nerves. Only limited evidence exists on how best to manage neuropathic pain, but generally a combination of surgical, manipulative or pharmacological methods should be considered. Experimental methods for more precisely characterizing the nature of the nerve dysfunction exist to diagnose and treat neuropathic pain, but additional scientific evidence is needed to unanimously recommend these options. In the meantime, an approach adopted from guidelines of the International Association for Study of Pain tailored for gynecological pain is suggested. PMID:21777899

  17. Recommendations for neuropathic pain treatment.

    PubMed

    Demarin, Vida; Basić-Kes, Vanja; Zavoreo, Iris; Bosnar-Puretić, Marijana; Rotim, Kresimir; Lupret, Velimir; Perić, Mladen; Ivanec, Zeljko; Fumić, Lidija; Lusić, Ivo; Aleksić-Shihabis, Anka; Kovac, Biserka; Ivanković, Mira; Skobić, Helena; Maslov, Boris; Bornstein, Natan; Niederkorn, Kurt; Sinanović, Osman; Rundek, Tanja

    2008-09-01

    Damage to the somatosensory nervous system poses a risk for the development of neuropathic pain. Such an injury to the nervous system results in a series of neurobiological events resulting in sensitization of both the peripheral and central nervous system. The symptoms include continuous background pain (often burning or crushing in nature) and spasmodic pain (shooting, stabbing or "electrical"). The diagnosis of neuropathic pain is based primarily on the history and physical examination finding. Although monotherapy is the ideal approach, rational polypharmacy is often pragmatically used. Several classes of drugs are moderately effective, but complete or near-complete relief is unlikely. Antidepressants and anticonvulsants are most commonly used. Opioid analgesics can provide some relief but are less effective than for nociceptive pain; adverse effects may prevent adequate analgesia. Topical drugs and a lidocaine-containing patch may be effective for peripheral syndromes. Sympathetic blockade is usually ineffective except for some patients with complex regional pain syndrome.

  18. Emerging Treatments for Neuropathic Pain.

    PubMed

    Pessoa, Bruno L; Escudeiro, Gabriel; Nascimento, Osvaldo J M

    2015-12-01

    Neuropathic pain is a series of well-known conditions caused by diseases or lesions to the somatosensory system. Due to the better understanding of the pathophysiology of neuropathic pain, previously unexplored therapies have been used with encouraging results. As such, Acetyl-L-carnitine (ALC), Alpha-lipoic-acid (ALA), cannabinoids, Clonidine, EMA401, Botulinum Toxin type A, and new voltage-gated sodium channel blockers, can be cited. Furthermore, new modalities in neuromodulation such as high-frequency spinal cord stimulation, burst stimulation, dorsal root ganglion stimulation, transcranial direct current stimulation, and many others have been showing exciting results. Besides, changing paradigms may occur with the advent of optogenetics and a better understanding of epigenetic regulation. This article reviews the published literature on the treatment of NP. Despite the interesting results, randomized controlled trials are demanded for the majority of the therapies previously mentioned.

  19. The endocannabinoid system and neuropathic pain.

    PubMed

    Maldonado, Rafael; Baños, Josep Eladi; Cabañero, David

    2016-02-01

    The research of new therapeutic strategies for neuropathic pain represents a major current priority. Important drawbacks to advance in the development of these therapies are the limited translational value of the animal models now available and the elucidation of the complex neuronal and immune pathophysiological mechanisms underlying neuropathic pain. One of the neurotransmitter systems participating in neuropathic pain control that has recently raised a particular interest is the endocannabinoid system. This system is highly expressed in neurons and immune cells, and it plays a crucial role in the development of neuropathic pain. Preclinical studies have provided important findings, revealing the potential interest of the endocannabinoid system for the treatment of neuropathic pain. These studies have reported the analgesic effects of cannabinoid agonists in multiple neuropathic pain models, and they have identified specific targets within this system to develop more effective and safe analgesic compounds. However, further studies using more relevant neuropathic pain animal models are required to confirm these interesting results. Several clinical studies suggest that cannabinoids significantly reduced neuropathic pain, although most of these trials fail the required standards of quality. The different pain patient populations included in the systematic reviews also make it difficult to get adequate conclusions. Therefore, additional clinical trials that consider an adequate number of patients, the use active treatments as controls, and longer duration of administration are required to have an adequate profile of the effectiveness and safety of cannabinoids in neuropathic pain.

  20. mir-500-Mediated GAD67 Downregulation Contributes to Neuropathic Pain.

    PubMed

    Huang, Zhen-Zhen; Wei, Jia-You; Ou-Yang, Han-Dong; Li, Dai; Xu, Ting; Wu, Shao-Ling; Zhang, Xiao-Long; Liu, Cui-Cui; Ma, Chao; Xin, Wen-Jun

    2016-06-08

    Neuropathic pain is a common neurobiological disease involving multifaceted maladaptations ranging from gene modulation to synaptic dysfunction, but the interactions between synaptic dysfunction and the genes that are involved in persistent pain remain elusive. In the present study, we found that neuropathic pain induced by the chemotherapeutic drug paclitaxel or L5 ventral root transection significantly impaired the function of GABAergic synapses of spinal dorsal horn neurons via the reduction of the GAD67 expression. We also found that mir-500 expression was significantly increased and involved in the modulation of GAD67 expression via targeting the specific site of Gad1 gene in the dorsal horn. In addition, knock-out of mir-500 or using mir-500 antagomir rescued the GABAergic synapses in the spinal dorsal horn neurons and attenuated the sensitized pain behavior in the rats with neuropathic pain. To our knowledge, this is the first study to investigate the function significance and the underlying molecular mechanisms of mir-500 in the process of neuropathic pain, which sheds light on the development of novel therapeutic options for neuropathic pain. Neuropathic pain is a common neurobiological disease involving multifaceted maladaptations ranging from gene modulation to synaptic dysfunction, but the underlying molecular mechanisms remain elusive. The present study illustrates for the first time a mir-500-mediated mechanism underlying spinal GABAergic dysfunction and sensitized pain behavior in neuropathic pain induced by the chemotherapeutic drug paclitaxel or L5 ventral root transection, which sheds light on the development of novel therapeutic options for neuropathic pain. Copyright © 2016 the authors 0270-6474/16/366321-11$15.00/0.

  1. Neuropathic Pain after Spinal Surgery

    PubMed Central

    Lee, Jae Hyup; Song, Kwang-Sup; Hong, Jae-Young

    2017-01-01

    Neuropathic pain after spinal surgery, the so-called failed back surgery syndrome (FBSS), is a frequently observed troublesome disease entity. Although medications may be effective to some degree, many patients continue experiencing intolerable pain and functional disability. Only gabapentin has been proven effective in patients with FBSS. No relevant studies regarding manipulation or physiotherapy for FBSS have been published. Spinal cord stimulation (SCS) has been widely investigated as a treatment option for chronic neuropathic pain, including FBSS. SCS was generally accepted to improve chronic back and leg pain, physical function, and sleep quality. Although the cost effectiveness of SCS has been proved in many studies, its routine application is limited considering that it is invasive and is associated with safety issues. Percutaneous epidural adhesiolysis has also shown good clinical outcomes; however, its effects persisted for only a short period. Because none of the current methods provide absolute superiority in terms of clinical outcomes, a multidisciplinary approach is required to manage this complex disease. Further studies concerning the etiology, diagnosis, treatment, and cost effectiveness of FBSS are warranted to deepen our understanding of this condition. PMID:28874984

  2. Intrathecal ziconotide for neuropathic pain: a review.

    PubMed

    Rauck, Richard L; Wallace, Mark S; Burton, Allen W; Kapural, Leonardo; North, James M

    2009-01-01

    Neuropathic pain is a considerable burden that affects activities of daily living. The management of neuropathic pain can be challenging because of multiple etiologies and complex manifestations. Ziconotide is a nonopioid intrathecal (IT) analgesic option for patients with neuropathic pain refractory to conventional treatments. The objective of this article is to review the published literature on ziconotide for the treatment of neuropathic pain. Relevant publications were identified through searches of all years of 6 databases, which included PubMed, EMBASE, and CINAHL. Search terms used were ziconotide, SNX-111, MVIIA, Prialt, and neuropathic pain. Publications were included if ziconotide was intrathecally administered (either alone or in combination with other IT agents) to treat neuropathic pain of any etiology and if pain assessment was an outcome measure. Data extracted included study design, IT drug doses, pain outcome measures, and adverse events (AEs). Twenty-eight articles met the inclusion criteria: 5 were preclinical studies and 23 were clinical studies. In the preclinical studies, ziconotide demonstrated antiallodynic effects on neuropathic pain. Data from double-blind, placebo-controlled (DBPC) trials indicated that patients with neuropathic pain reported a mean percent improvement in pain score with ziconotide monotherapy that ranged from 15.7% to 31.6%. A low starting dose and slow titration of ziconotide resulted in an improved safety profile in the aforementioned trials. Common AEs associated with ziconotide include nausea and/or vomiting, dizziness, confusion, urinary retention, and somnolence. Evidence from DBPC trials, open-label studies, case series, and case studies suggests that ziconotide, as either monotherapy or in combination with other IT drugs, is a potential therapeutic option for patients with refractory neuropathic pain. Additional studies are needed to establish the long-term efficacy and safety of ziconotide for neuropathic pain.

  3. Chronic Neuropathic Pain: It's about the Rhythm.

    PubMed

    Alshelh, Zeynab; Di Pietro, Flavia; Youssef, Andrew M; Reeves, Jenna M; Macey, Paul M; Vickers, E Russell; Peck, Christopher C; Murray, Greg M; Henderson, Luke A

    2016-01-20

    The neural mechanisms underlying the development and maintenance of chronic neuropathic pain remain unclear. Evidence from human investigations suggests that neuropathic pain is associated with altered thalamic burst firing and thalamocortical dysrhythmia. Additionally, experimental animal investigations show that neuropathic pain is associated with altered infra-slow (<0.1 Hz) frequency oscillations within the dorsal horn and somatosensory thalamus. The aim of this investigation was to determine whether, in humans, neuropathic pain was also associated with altered infra-slow oscillations within the ascending "pain" pathway. Using resting-state functional magnetic resonance imaging, we found that individuals with orofacial neuropathic pain have increased infra-slow oscillatory activity throughout the ascending pain pathway, including within the spinal trigeminal nucleus, somatosensory thalamus, thalamic reticular nucleus, and primary somatosensory cortex. Furthermore, these infra-slow oscillations were temporally coupled across these multiple sites and occurred at frequencies similar to calcium waves in activated astrocytes. The region encompassing the spinal trigeminal nucleus also displayed increased regional homogeneity, consistent with a local spread of neural activity by astrocyte activation. In contrast, no increase in oscillatory behavior within the ascending pain pathway occurred during acute noxious stimuli in healthy individuals. These data reveal increased oscillatory activity within the ascending pain pathway that likely underpins increased thalamocortical oscillatory activity, a self-sustaining thalamocortical dysrhythmia, and the constant perception of pain. Significance statement: Chronic neuropathic pain is associated with altered thalamic firing and thalamocortical dysrhythmia. The mechanisms responsible for these changes remain unknown. In this study, we report in individuals with neuropathic pain increased oscillatory neural activity within the

  4. Analgesic Microneedle Patch for Neuropathic Pain Therapy.

    PubMed

    Xie, Xi; Pascual, Conrado; Lieu, Christopher; Oh, Seajin; Wang, Ji; Zou, Bende; Xie, Julian; Li, Zhaohui; Xie, James; Yeomans, David C; Wu, Mei X; Xie, Xinmin Simon

    2017-01-24

    Neuropathic pain caused by nerve injury is debilitating and difficult to treat. Current systemic pharmacological therapeutics for neuropathic pain produce limited pain relief and have undesirable side effects, while current local anesthetics tend to nonspecifically block both sensory and motor functions. Calcitonin gene related peptide (CGRP), a neuropeptide released from sensory nerve endings, appears to play a significant role in chronic neuropathic pain. In this study, an analgesic microneedle (AMN) patch was developed using dissolvable microneedles to transdermally deliver selective CGRP antagonist peptide in a painless manner for the treatment of localized neuropathic pain. Local analgesic effects were evaluated in rats by testing behavioral pain sensitivity in response to thermal and mechanical stimuli using neuropathic pain models such as spared-nerve injury and diabetic neuropathy pain, as well as neurogenic inflammatory pain model induced by ultraviolet B (UVB) radiation. Unlike several conventional therapies, the AMN patches produced effective analgesia on neuropathic pain without disturbing the normal nociception and motor function of the rat, resulting from the high specificity of the delivered peptide against CGRP receptors. The AMN patches did not cause skin irritation or systemic side effects. These results demonstrate that dissolvable microneedle patches delivering CGRP antagonist peptide provide an effective, safe, and simple approach to mitigate neuropathic pain with significant advantages over current treatments.

  5. The neurosurgical treatment of neuropathic facial pain.

    PubMed

    Brown, Jeffrey A

    2014-04-01

    This article reviews the definition, etiology and evaluation, and medical and neurosurgical treatment of neuropathic facial pain. A neuropathic origin for facial pain should be considered when evaluating a patient for rhinologic surgery because of complaints of facial pain. Neuropathic facial pain is caused by vascular compression of the trigeminal nerve in the prepontine cistern and is characterized by an intermittent prickling or stabbing component or a constant burning, searing pain. Medical treatment consists of anticonvulsant medication. Neurosurgical treatment may require microvascular decompression of the trigeminal nerve. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Neuropathic Pain in Children: Special Considerations

    PubMed Central

    Walco, Gary A.; Dworkin, Robert H.; Krane, Elliot J.; LeBel, Alyssa A.; Treede, Rolf-Detlef

    2010-01-01

    Neuropathic pain is relatively uncommon in children. Although some syndromes closely resemble those found in adults, the incidence and course of the condition can vary substantially in children, depending on developmental status and contextual factors. There are some neuropathic pain syndromes that are rare and relatively unique to the pediatric population. This article discusses the array of neuropathic pain conditions in children and available treatment strategies. Data are limited by small numbers and few randomized controlled trials. Research and clinical implications are discussed. PMID:20194147

  7. Ranolazine attenuates behavioral signs of neuropathic pain.

    PubMed

    Gould, Harry J; Garrett, Colleen; Donahue, Renee R; Paul, Dennis; Diamond, Ivan; Taylor, Bradley K

    2009-12-01

    Ranolazine modulates the cardiac voltage-gated sodium channel (NaV 1.5) and is approved by the FDA in the treatment of ischemic heart disease. Ranolazine also targets neuronal (NaV 1.7, 1.8) isoforms that are implicated in neuropathic pain. Therefore, we determined the analgesic efficacy of ranolazine in a preclinical animal model of neuropathic pain. Both intraperitoneal and oral administration of ranolazine dose-dependently inhibited the mechanical and cold allodynia associated with spared nerve injury, without producing ataxia or other behavioral side effects. These data warrant clinical investigation of the potential use of ranolazine in the treatment of neuropathic pain.

  8. AAPT Diagnostic Criteria for Central Neuropathic Pain.

    PubMed

    Widerström-Noga, Eva; Loeser, John D; Jensen, Troels Staehelin; Finnerup, Nanna Brix

    2017-06-27

    Central neuropathic pain, which is pain caused by a lesion or disease of the central somatosensory nervous system, is a serious consequence of spinal cord injury, stroke, multiple sclerosis, and other conditions affecting the central nervous system. A collaborative effort between the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks public-private partnership and the American Pain Society, the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks-American Pain Society Pain Taxonomy (AAPT) initiative, invited a working group to develop diagnostic criteria for central neuropathic pain. The criteria for central neuropathic pain that were developed expand upon existing criteria for neuropathic pain and the International Classification of Diseases 11th Revision draft criteria to ensure consistency. This article focuses on central neuropathic pain associated with spinal cord injury, stroke, and multiple sclerosis, but the AAPT framework can be extended to central pain due to other causes such as traumatic brain injury. The classification of central neuropathic pain is organized according to the AAPT multidimensional framework, specifically: 1) core diagnostic criteria, 2) common features, 3) common medical and psychiatric comorbidities, 4) neurobiological, psychosocial, and functional consequences, and 5) putative neurobiological and psychosocial mechanisms, risk factors, and protective factors. The AAPT chronic central neuropathic pain taxonomy provides a classification for central pain associated with spinal cord injury, stroke, and multiple sclerosis. The diagnostic criteria are organized according to the AAPT multidimensional framework, specifically: 1) core diagnostic criteria, 2) common features, 3) common medical and psychiatric comorbidities, 4) neurobiological, psychosocial, and functional consequences, and 5) putative neurobiological and psychosocial

  9. Neuropathic Pain in Patients with Sickle Cell Disease

    PubMed Central

    Brandow, Amanda M.; Farley, Rebecca A.; Panepinto, Julie A.

    2015-01-01

    Background Despite the suggestion of a neuropathic component to sickle cell disease (SCD) pain, there are minimal data on the systematic assessment of neuropathic pain in patients with SCD. Neuropathic pain is defined as pain primarily initiated by dysfunction of the peripheral or central nervous system. Procedure In a cross-sectional study, we used the painDETECT questionnaire, a one-page validated neuropathic pain screening tool, to determine the presence of neuropathic pain in patients with SCD and to evaluate the relationship between neuropathic pain, age, and gender. We hypothesized that 20% of patients with SCD will experience neuropathic pain and that neuropathic pain will be associated with older age and female gender. The completed painDETECT questionnaire yields a total score between 0–38 (≥19=definite neuropathic pain, 13–18=probable neuropathic pain, ≤12=no neuropathic pain). Scores ≥13 were designated as having evidence of neuropathic pain. Results A total of 56 patients participated. Median age was 20.3 years and 77% were female. We found 37% of patients had evidence of neuropathic pain. Age was positively correlated with total score [r=0.43; p=0.001] suggesting older patients experience more neuropathic pain. Females had higher mean total scores [13 vs 8.4; p=0.04]. Significantly more patients with neuropathic pain were taking hydroxyurea [90% vs 59%; p=0.015]. Despite 37% of patients experiencing neuropathic pain, only 5% were taking a neuropathic pain drug. Conclusions Neuropathic pain exists in SCD. Valid screening tools can identify patients that would benefit from existing and future neuropathic pain therapies and could determine the impact of these therapies. PMID:24167104

  10. Molecular Hydrogen Attenuates Neuropathic Pain in Mice

    PubMed Central

    Kawaguchi, Masanori; Satoh, Yasushi; Otsubo, Yukiko; Kazama, Tomiei

    2014-01-01

    Neuropathic pain remains intractable and the development of new therapeutic strategies are urgently required. Accumulating evidence indicates that overproduction of oxidative stress is a key event in the pathogenesis of neuropathic pain. However, repeated intra-peritoneal or intrathecal injections of antioxidants are unsuitable for continuous use in therapy. Here we show a novel therapeutic method against neuropathic pain: drinking water containing molecular hydrogen (H2) as antioxidant. The effect of hydrogen on neuropathic pain was investigated using a partial sciatic nerve ligation model in mice. As indicators of neuropathic pain, temporal aspects of mechanical allodynia and thermal hyperalgesia were analysed for 3 weeks after ligation. Mechanical allodynia and thermal hyperalgesia were measured using the von Frey test and the plantar test, respectively. When mice were allowed to drink water containing hydrogen at a saturated level ad libitum after ligation, both allodynia and hyperalgesia were alleviated. These symptoms were also alleviated when hydrogen was administered only for the induction phase (from day 0 to 4 after ligation). When hydrogen was administered only for the maintenance phase (from day 4 to 21 after ligation), hyperalgesia but not allodynia was alleviated. Immunohistochemical staining for the oxidative stress marker, 4-hydroxy-2-nonenal and 8-hydroxydeoxyguanosine, showed that hydrogen administration suppressed oxidative stress induced by ligation in the spinal cord and the dorsal root ganglion. In conclusion, oral administration of hydrogen water may be useful for alleviating neuropathic pain in a clinical setting. PMID:24941001

  11. Cytokines in Neuropathic Pain and Associated Depression.

    PubMed

    Lees, Justin G; Fivelman, Brett; Duffy, Samuel S; Makker, Preet G S; Perera, Chamini J; Moalem-Taylor, Gila

    2015-01-01

    Neuropathic pain occurs as a result of lesion or disease affecting the somatosensory nervous system and is present in a diverse set of peripheral and central pathologies such as nerve trauma, diabetic neuropathy, post-herpetic neuralgia, chemotherapy-induced peripheral neuropathy, spinal cord injury and multiple sclerosis. Debilitating symptoms including allodynia, hyperalgesia and spontaneous pain have a substantial negative impact on patients' quality of life. The currently available therapeutic treatments are generally ineffective and characterised by poor response rates. Accumulating evidence suggests that neuroinflammation and cytokine signalling play a critical role in neuropathic pain. Numerous experimental studies have demonstrated that certain pro-inflammatory cytokines are elevated in neuropathic pain conditions, and administration of these cytokines can elicit pain hypersensitivity in the absence of injury or disease. This phenomenon is also apparent in the 'sickness response', which encompasses a broad inflammatory response to disease and injury and involves a series of physiological and behavioural changes including pain hypersensitivity. Interestingly, the 'sickness response' is also similar in nature to some of the defining characteristics of the depressed state of affective disorder. In this review, we explore links that may relate the co-existence of depression in neuropathic pain patients with the activity of cytokines and discuss the role of several key pro-inflammatory and anti-inflammatory cytokines in neuropathic pain.

  12. Stem cell therapy for neuropathic pain treatment

    PubMed Central

    Siniscalco, D; Rossi, F; Maione, S

    2007-01-01

    Pain initiated or caused by a primary lesion or dysfunction in the nervous system is defined as neuropathic pain. About 75 -150 million people in the United States are suffering for chronic pain disorder. Neuropathic pain has a great impact on the human wellbeing. It is very debilitating and often has an associated degree of depression that contributes to decreasing the quality of life. Moreover, the management of chronic pain is costly to the health care system. Pain is a national healthcare priority in US: the United States Congress has declared the present decade (2001-2010) as the “Decade of Pain Control and Research”. Neuropathic pain is a very complex disease, involving several molecular pathways. Due to its individual character, its treatment is extremely difficult. Current available drugs are usually not acting on the several mechanisms underlying the generation and propagation of pain. Nowadays, pain research is focusing on newer molecular ways, such as stem cell therapy, gene therapy, and viral vectors for delivery of biologic anti-nociceptive molecules. These methods could provide a new therapeutic approach to neuropathic pain relief. PMID:24693013

  13. Symptom profiles differ in patients with neuropathic versus non-neuropathic pain.

    PubMed

    Dworkin, Robert H; Jensen, Mark P; Gammaitoni, Arnold R; Olaleye, David O; Galer, Bradley S

    2007-02-01

    The distinction between neuropathic and non-neuropathic pain reflects partially distinct mechanisms and patterns of treatment response. It was therefore hypothesized that patients with neuropathic and non-neuropathic pain have different profiles of symptoms and signs. To test this hypothesis, pain intensity, unpleasantness, quality, and spatial characteristics were examined in 618 patients with 1 of 3 peripheral neuropathic pain conditions (painful diabetic peripheral neuropathy, painful idiopathic sensory polyneuropathy, or postherpetic neuralgia), osteoarthritis pain, or low back pain. These assessments were conducted before treatment had begun in clinical trials of lidocaine patch 5% administered alone or with stable dosages of other analgesics. Patients with osteoarthritis pain and low back pain did not differ in their profile of pain quality and spatial characteristics and were combined to form a group of patients with non-neuropathic pain. In univariate analyses, patients with peripheral neuropathic pain reported significantly more intense hot, cold, sensitive, itchy, and surface pain and significantly less intense dull and deep pain than patients with non-neuropathic pain. In a multivariate analysis, the overall pattern of pain quality and spatial characteristics differed significantly between patients with neuropathic and non-neuropathic pain. In addition, specific pain quality and spatial characteristics improved the discrimination of patients with neuropathic and non-neuropathic pain in a logistic regression model that adjusted for demographic covariates and overall pain intensity and unpleasantness. The results indicate that the distinction between neuropathic and non-neuropathic pain is reflected in different profiles of pain quality and spatial characteristics and suggest that the assessment of patterns of pain symptoms might contribute to the identification of distinct pathophysiologic mechanisms and the development of mechanism-based treatment

  14. Dendritic spine dysgenesis in neuropathic pain.

    PubMed

    Tan, Andrew M; Waxman, Stephen G

    2015-08-05

    Neuropathic pain is a significant unmet medical need in patients with variety of injury or disease insults to the nervous system. Neuropathic pain often presents as a painful sensation described as electrical, burning, or tingling. Currently available treatments have limited effectiveness and narrow therapeutic windows for safety. More powerful analgesics, e.g., opioids, carry a high risk for chemical dependence. Thus, a major challenge for pain research is the elucidation of the mechanisms that underlie neuropathic pain and developing targeted strategies to alleviate pathological pain. The mechanistic link between dendritic spine structure and circuit function could explain why neuropathic pain is difficult to treat, since nociceptive processing pathways are adversely "hard-wired" through the reorganization of dendritic spines. Several studies in animal models of neuropathic pain have begun to reveal the functional contribution of dendritic spine dysgenesis in neuropathic pain. Previous reports have demonstrated three primary changes in dendritic spine structure on nociceptive dorsal horn neurons following injury or disease, which accompany chronic intractable pain: (I) increased density of dendritic spines, particularly mature mushroom-spine spines, (II) redistribution of spines toward dendritic branch locations close to the cell body, and (III) enlargement of the spine head diameter, which generally presents as a mushroom-shaped spine. Given the important functional implications of spine distribution, density, and shape for synaptic and neuronal function, the study of dendritic spine abnormality may provide a new perspective for investigating pain, and the identification of specific molecular players that regulate spine morphology may guide the development of more effective and long-lasting therapies.

  15. Orofacial neuropathic pain induced by oxaliplatin

    PubMed Central

    Ling, Jennifer; Erol, Ferhat; Viatchenko-Karpinski, Viacheslav; Kanda, Hirosato

    2017-01-01

    Neuropathic pain induced by chemotherapy drugs such as oxaliplatin is a dose-limiting side effect in cancer treatment. The mechanisms underlying chemotherapy-induced neuropathic pain are not fully understood. KCNQ2 channels are low-threshold voltage-gated K+ channels that play a role in controlling neuronal excitability. Downregulation of KCNQ2 channels has been proposed to be an underlying mechanism of sensory hypersensitivity that leads to neuropathic pain. However, it is currently unknown whether KCNQ channels may be downregulated by chemotherapy drugs in trigeminal ganglion neurons to contribute to the pathogenesis of chemotherapy-induced orofacial neuropathic pain. In the present study, mechanical sensitivity in orofacial regions is measured using the operant behavioral test in rats treated with oxaliplatin. Operant behaviors in these animals show the gradual development of orofacial neuropathic pain that manifests with orofacial mechanical allodynia. Immunostaining shows strong KCNQ2 immunoreactivity in small-sized V2 trigeminal ganglion neurons in controls, and the numbers of KCNQ2 immunoreactivity positive V2 trigeminal ganglion neurons are significantly reduced in oxaliplatin-treated animals. Immunostaining is also performed in brainstem and shows strong KCNQ2 immunoreactivity at the trigeminal afferent central terminals innervating the caudal spinal trigeminal nucleus (Vc) in controls, but the KCNQ2 immunoreactivity intensity is significantly reduced in oxaliplatin-treated animals. We further show with the operant behavioral test that oxaliplatin-induced orofacial mechanical allodynia can be alleviated by the KCNQ2 potentiator retigabine. Taken together, these findings suggest that KCNQ2 downregulation may be a cause of oxaliplatin-induced orofacial neuropathic pain and KCNQ2 potentiators may be useful for alleviating the neuropathic pain. PMID:28741430

  16. [Prevalence and aetiopathogenesis of neuropathic pain in elderly cancer patients].

    PubMed

    Cabezón-Gutiérrez, Luis; Custodio-Cabello, Sara; Khosravi-Shahi, Parham

    2016-01-01

    The prevalence of neuropathic pain is difficult to estimate as most studies evaluating chronic pain do not differentiate neuropathic from nociceptive pain. There are only a few studies of neuropathic pain in the elderly, specifically in the oncology population. This article is a non-systematic review of the relevant evidence on the prevalence and aetiopathogenesis of neuropathic cancer pain in the elderly. Copyright © 2015 SEGG. Published by Elsevier Espana. All rights reserved.

  17. Fear of pain in children and adolescents with neuropathic pain and complex regional pain syndrome.

    PubMed

    Simons, Laura E

    2016-02-01

    A significant proportion of children and adolescents with chronic pain endorse elevated pain-related fear. Pain-related fear is associated with high levels of disability, depressive symptoms, and school impairment. Because of faulty nerve signaling, individuals with neuropathic pain and complex regional pain syndrome may be more prone to develop pain-related fear as they avoid use of and neglect the affected body area(s), resulting in exacerbated symptoms, muscle atrophy, maintenance of pain signaling, and ongoing pain-related disability. Not surprisingly, effective treatments for elevated pain-related fears involve exposure to previously avoided activities to downregulate incorrect pain signaling. In the context of intensive interdisciplinary pain treatment of youth with neuropathic pain, decreasing pain-related fear is associated with improved physical and psychological functioning, whereas high initial pain-related fear is a risk factor for less treatment responsiveness. An innovative approach to targeting pain-related fear and evidence of a neural response to treatment involving decoupling of the amygdala with key fear circuits in youth with complex regional pain syndrome suggest breakthroughs in our ability to ameliorate these issues.

  18. Sodium channel blockers in neuropathic pain.

    PubMed

    Kalso, Eija

    2005-01-01

    Subtypes of tetrodotoxin resistant voltage-gated sodium channels are involved in the development of certain types of neuropathic pains. After nerve injury hyperexcitability and spontaneous firing develop at the site of injury and also in the dorsal root ganglion cell bodies. This hyperexcitability results at least partly from accumulation of sodium channels at the site of injury. The facts that these sodium channels seem to exist in peripheral nerves only and that they can be blocked at the resting state (use-dependent block) offer the possibility to develop drugs, which selectively block these damaged, overexcited nerves. At the moment no such drugs are available. However, some of the most potent drugs that are currently used to manage neuropathic pain e.g. amitriptyline and other tricyclic antidepressants, also block these channels in addition to having several other mechanisms of action. Also most anticonvulsants that are used to alleviate neuropathic pain are sodium channel blockers. Lidocaine, the prototype drug, has been shown to be effective in peripheral neuropathic pain. Its use is limited by the fact that it cannot be administered orally. An oral local anesthetic type sodium channel blocker, mexiletine is an antiarrhythmic agent that is effective in neuropathic pain. However, effective doses may be difficult to achieve because of adverse effects.

  19. The Pharmacological Therapy of Chronic Neuropathic Pain.

    PubMed

    Binder, Andreas; Baron, Ralf

    2016-09-16

    Chronic neuropathic pain, including painful peripheral polyneuropathy and post-herpetic neuralgia, affects 6.9-10% of the general population. In this article, we present current treatment recommendations on the basis of a selective review of the literature. Neuropathic pain does not respond consistently to classic non-opioid analgesic drugs and is better treated with co-analgesic, antidepressant, and anticonvulsant drugs and topical agents. Under certain conditions, however, neuropathic pain can be treated with opioids, even chronically. It was concluded in a large-scale m eta- analysis that tricyclic antidepressants, selective serotonin- norepinephrine reuptake inhibitors, and calcium-channel anticonvulsants are the drugs of first choice, with a number needed to treat (NNT) of 3.5-7.7 for a 50% reduction of pain. An analysis of all studies yielded an estimated publication bias of 10%. Treatment planning must include adequate consideration of the patient's age and comorbidities, concomitant medication, and potential side effects. Drugs are now chosen to treat neuropathic pain independently of the cause and symptoms of the pain. Topical agents are used only to treat peripheral neuropathy. The utility of a treatment approach based on the patient's symptoms and pathological mechanisms was recently demonstrated for the first time in a randomized trial. The goal of current research is to facilitate treatment planning on the basis of the clinical phenotype.

  20. [Non pharmacologic treatment of neuropathic pain].

    PubMed

    Guastella, Virginie; Mick, Gérard; Laurent, Bernard

    2008-02-01

    Nondrug treatments of neuropathic pain should always begin at the same time as pharmacologic treatment. There are three types of nondrug treatment for neuropathic pain: physical, surgical, and "psychocorporal" and psychotherapeutic treatment. Transcutaneous electrical nerve stimulation (TENS) is a simple physical treatment that strengthens local inhibitory controls and is indicated in focal neuropathic pain when upstream stimulation is possible for a superficial sensitive nerve trunk. Destructive surgery is represented today by "DREZotomy", destruction of nociceptive fibers and their dorsal root entry zones. It is indicated essentially in intractable pain due to plexus avulsion. Functional surgery is implanted electric stimulation--either spinal or central (encephalic)--of structures that exert inhibitory control on the pain pathways. Spinal stimulation is performed at the level of the posterior spinal cord and is indicated essentially in segmental mononeuropathies refractory to drug treatment. Central stimulation is performed at the motor cortex and is indicated for refractory central pain. "Psychocorporal" techniques (relaxation, sophrology, hypnosis) are useful to reduce anxiety and neurovegetative hypertonicity, both factors that aggravate neuropathic pain.

  1. Endomorphin-2 Inhibition of Substance P Signaling within Lamina I of the Spinal Cord Is Impaired in Diabetic Neuropathic Pain Rats

    PubMed Central

    Wan, Fa-Ping; Bai, Yang; Kou, Zhen-Zhen; Zhang, Ting; Li, Hui; Wang, Ya-Yun; Li, Yun-Qing

    2017-01-01

    Opiate analgesia in the spinal cord is impaired in diabetic neuropathic pain (DNP), but until now the reason is unknown. We hypothesized that it resulted from a decreased inhibition of substance P (SP) signaling within the dorsal horn of the spinal cord. To investigate this possibility, we evaluated the effects of endomorphin-2 (EM2), an endogenous ligand of the μ-opioid receptor (MOR), on SP release within lamina I of the spinal dorsal horn (SDH) in rats with DNP. We established the DNP rat model and compared the analgesic efficacy of EM2 between inflammation pain and DNP rat models. Behavioral results suggested that the analgesic efficacy of EM2 was compromised in the condition of painful diabetic neuropathy. Then, we measured presynaptic SP release induced by different stimulating modalities via neurokinin-1 receptor (NK1R) internalization. Although there was no significant change in basal and evoked SP release between control and DNP rats, EM2 failed to inhibit SP release by noxious mechanical and thermal stimuli in DNP but not in control and inflammation pain model. We also observed that EM2 decreased the number of FOS-positive neurons within lamina I of the SDH but did not change the amount of FOS/NK1R double-labeled neurons. Finally, we identified a remarkable decrease in MORs within the primary afferent fibers and dorsal root ganglion (DRG) neurons by Western blot (WB) and immunohistochemistry (IHC). Taken together, these data suggest that reduced presynaptic MOR expression might account for the loss of the inhibitory effect of EM2 on SP signaling, which might be one of the neurobiological foundations for decreased opioid efficacy in the treatment of DNP. PMID:28119567

  2. Imaging Biomarkers and the Role of Neuroinflammation in Neuropathic Pain

    PubMed Central

    Chang, Linda; Cooper, Mark S.; Clark, Vincent P.

    2013-01-01

    The papers from this thematic issue followed a translational research workshop, Imaging Neuroinflammation and Neuropathic Pain, that focused on the search for neuroimaging biomarkers to assess neuroinflammation associated with neuropathic pain. The topics covered in this issue include overviews of the historical and current knowledge regarding neuropathic pain, the potential mechanisms involved, the often under-recognized clinical presentations that can delay diagnosis, the various neuroimaging techniques that have been applied to evaluate neuropathic pain and neuroinflammation, to case series illustrating novel treatments of neuropathic pain. Furthermore, the use of telemedicine to disseminate knowledge and improve the diagnosis and treatment of pain syndromes is also discussed. PMID:23666404

  3. Concise Review: Stem Cell Therapies for Neuropathic Pain

    PubMed Central

    Fortino, Veronica R.; Pelaez, Daniel

    2013-01-01

    Neuropathic pain is a chronic condition that is heterogeneous in nature and has different causes. Different from and more burdensome than nociceptive pain, neuropathic pain more severely affects people's quality of life. Understanding the various mechanisms of the onset and progression of neuropathic pain is important in the development of an effective treatment. Research is being done to replace current pharmacological treatments with cellular therapies that will have longer lasting effects. Stem cells present an exciting potential therapy for neuropathic pain. In this review, we describe the neuroprotective effects of stem cells along with special emphasis on the current translational research using stem cells to treat neuropathic pain. PMID:23572051

  4. Update on pharmacotherapy guidelines for treatment of neuropathic pain.

    PubMed

    Wallace, J Mark

    2007-06-01

    Neuropathic pain encompasses a myriad of painful disease states that are often hard to treat, especially with one single medication. In the comprehensive treatment of neuropathic pain, the concept of complex polypharmacy is a rational approach, accompanied by physical and mental health therapies. Medications primarily used for neuropathic pain generally fall into the categories of anticonvulsants, antidepressants, opioids, and topical agents. Generally, most first-line medications used today show a response rate of approximately 30% to 50% reduction in pain in up to 50% of patients treated. There is no "gold standard" in regard to one medication for neuropathic pain. Some new medications have emerged during the past few years that help to augment the armamentarium of medications used in neuropathic pain. This paper reviews the definition of neuropathic pain and introduces the reader to the evidence-based literature on these new medications available for the treatment of neuropathic pain.

  5. Neuropathic orofacial pain: Facts and fiction.

    PubMed

    Baad-Hansen, Lene; Benoliel, Rafael

    2017-01-01

    Definition and taxonomy This review deals with neuropathic pain of traumatic origin affecting the trigeminal nerve, i.e. painful post-traumatic trigeminal neuropathy (PTTN). Symptomatology The clinical characteristics of PTTN vary considerably, partly due to the type and extent of injury. Symptoms involve combinations of spontaneous and evoked pain and of positive and negative somatosensory signs. These patients are at risk of going through unnecessary dental/surgical procedures in the attempt to eradicate the cause of the pain, due to the fact that most dentists only rarely encounter PTTN. Epidemiology Overall, approximately 3% of patients with trigeminal nerve injuries develop PTTN. Patients are most often female above the age of 45 years, and both physical and psychological comorbidities are common. Pathophysiology PTTN shares many pathophysiological mechanisms with other peripheral neuropathic pain conditions. Diagnostic considerations PTTN may be confused with one of the regional neuralgias or other orofacial pain conditions. For intraoral PTTN, early stages are often misdiagnosed as odontogenic pain. Pain management Management of PTTN generally follows recommendations for peripheral neuropathic pain. Expert opinion International consensus on classification and taxonomy is urgently needed in order to advance the field related to this condition.

  6. Diabetic neuropathic pain: Physiopathology and treatment

    PubMed Central

    Schreiber, Anne K; Nones, Carina FM; Reis, Renata C; Chichorro, Juliana G; Cunha, Joice M

    2015-01-01

    Diabetic neuropathy is a common complication of both type 1 and type 2 diabetes, which affects over 90% of the diabetic patients. Although pain is one of the main symptoms of diabetic neuropathy, its pathophysiological mechanisms are not yet fully known. It is widely accepted that the toxic effects of hyperglycemia play an important role in the development of this complication, but several other hypotheses have been postulated. The management of diabetic neuropathic pain consists basically in excluding other causes of painful peripheral neuropathy, improving glycemic control as a prophylactic therapy and using medications to alleviate pain. First line drugs for pain relief include anticonvulsants, such as pregabalin and gabapentin and antidepressants, especially those that act to inhibit the reuptake of serotonin and noradrenaline. In addition, there is experimental and clinical evidence that opioids can be helpful in pain control, mainly if associated with first line drugs. Other agents, including for topical application, such as capsaicin cream and lidocaine patches, have also been proposed to be useful as adjuvants in the control of diabetic neuropathic pain, but the clinical evidence is insufficient to support their use. In conclusion, a better understanding of the mechanisms underlying diabetic neuropathic pain will contribute to the search of new therapies, but also to the improvement of the guidelines to optimize pain control with the drugs currently available. PMID:25897354

  7. Spinal Cord Stimulation for Neuropathic Pain

    PubMed Central

    2005-01-01

    Executive Summary Objective The objective of this health technology policy assessment was to determine the effectiveness of spinal cord stimulation (SCS) to manage chronic intractable neuropathic pain and to evaluate the adverse events and Ontario-specific economic profile of this technology. Clinical Need SCS is a reversible pain therapy that uses low-voltage electrical pulses to manage chronic, intractable neuropathic pain of the trunk or limbs. Neuropathic pain begins or is caused by damage or dysfunction to the nervous system and can be difficult to manage. The prevalence of neuropathic pain has been estimated at about 1.5% of the population in the United States and 1% of the population in the United Kingdom. These prevalence rates are generalizable to Canada. Neuropathic pain is extremely difficult to manage. People with symptoms that persist for at least 6 months or who have symptoms that last longer than expected for tissue healing or resolution of an underlying disease are considered to have chronic pain. Chronic pain is an emotional, social, and economic burden for those living with it. Depression, reduced quality of life (QOL), absenteeism from work, and a lower household income are positively correlated with chronic pain. Although the actual number is unknown, a proportion of people with chronic neuropathic pain fail to obtain pain relief from pharmacological therapies despite adequate and reasonable efforts to use them. These people are said to have intractable neuropathic pain, and they are the target population for SCS. The most common indication for SCS in North America is chronic intractable neuropathic pain due to failed back surgery syndrome (FBSS), a term that describes persistent leg or back and leg pain in patients who have had back or spine surgery. Neuropathic pain due to complex regional pain syndrome (CRPS), which can develop in the distal aspect of a limb a minor injury, is another common indication. To a lesser extent, chronic intractable

  8. Neuropathic Pain: Central vs. Peripheral Mechanisms.

    PubMed

    Meacham, Kathleen; Shepherd, Andrew; Mohapatra, Durga P; Haroutounian, Simon

    2017-06-01

    Our goal is to examine the processes-both central and peripheral-that underlie the development of peripherally-induced neuropathic pain (pNP) and to highlight recent evidence for mechanisms contributing to its maintenance. While many pNP conditions are initiated by damage to the peripheral nervous system (PNS), their persistence appears to rely on maladaptive processes within the central nervous system (CNS). The potential existence of an autonomous pain-generating mechanism in the CNS creates significant implications for the development of new neuropathic pain treatments; thus, work towards its resolution is crucial. Here, we seek to identify evidence for PNS and CNS independently generating neuropathic pain signals. Recent preclinical studies in pNP support and provide key details concerning the role of multiple mechanisms leading to fiber hyperexcitability and sustained electrical discharge to the CNS. In studies regarding central mechanisms, new preclinical evidence includes the mapping of novel inhibitory circuitry and identification of the molecular basis of microglia-neuron crosstalk. Recent clinical evidence demonstrates the essential role of peripheral mechanisms, mostly via studies that block the initially damaged peripheral circuitry. Clinical central mechanism studies use imaging to identify potentially self-sustaining infra-slow CNS oscillatory activity that may be unique to pNP patients. While new preclinical evidence supports and expands upon the key role of central mechanisms in neuropathic pain, clinical evidence for an autonomous central mechanism remains relatively limited. Recent findings from both preclinical and clinical studies recapitulate the critical contribution of peripheral input to maintenance of neuropathic pain. Further clinical investigations on the possibility of standalone central contributions to pNP may be assisted by a reconsideration of the agreed terms or criteria for diagnosing the presence of central sensitization in humans.

  9. Topical medications for orofacial neuropathic pain.

    PubMed

    Bramwell, Bethany L

    2010-01-01

    The primary advantage of the treatment modalities discussed in this article is the potential to provide relief of neuropathic pain without the associated side effects of systemic therapies. By working closely with a dental practitioner to help formulate the best pharmaceutical therapy for patients, the compounding pharmacist has become an essential member of the healthcare team for practicing dentists.

  10. Anticytokine therapy in neuropathic pain management.

    PubMed

    Schäfers, Maria; Sommer, Claudia

    2007-11-01

    Cytokine activation or dysregulation is implied in a variety of painful disease states. Numerous experimental studies provide evidence that proinflammatory cytokines induce or facilitate neuropathic pain. Cytokine levels are rapidly and markedly upregulated in the peripheral nerves, dorsal root ganglia, spinal cord and in particular regions of the brain, after peripheral nerve injuries. Direct receptor-mediated actions on afferent nerve fibers as well as cytokine effects involving further mediators have been reported. Whereas direct application of exogenous proinflammatory cytokines induces pain, blockade of these cytokines or application of anti-inflammatory cytokines reduces pain behavior in most experimental paradigms. Cytokine measurements may identify patients at risk of developing chronic pain associated with their neuropathic conditions, as in the examples of peripheral neuropathies and postherpetic neuralgia. Anticytokine agents currently on the market are effective for the treatment of mostly inflammatory pain conditions, and are starting to be introduced for neuropathic pain states; however, their use is limited by potential life-threatening complications. Owing to the pleiotropy and redundancy of the cytokine system, the successful approach may not be inhibition of one particular cytokine but strategies shifting the balance between pro- and anti-inflammatory cytokines in properly selected patients. Agents that specifically target downstream signaling molecules may provide hope for safer and more specific therapies.

  11. Neuropathic sensory symptoms: association with pain and psychological factors

    PubMed Central

    Shaygan, Maryam; Böger, Andreas; Kröner-Herwig, Birgit

    2014-01-01

    Background A large number of population-based studies of chronic pain have considered neuropathic sensory symptoms to be associated with a high level of pain intensity and negative affectivity. The present study examines the question of whether this association previously found in non-selected samples of chronic pain patients can also be found in chronic pain patients with underlying pathology of neuropathic sensory symptoms. Methods Neuropathic sensory symptoms in 306 patients with chronic pain diagnosed as typical neuropathic pain, radiculopathy, fibromyalgia, or nociceptive back pain were assessed using the Pain DETECT Questionnaire. Two separate cluster analyses were performed to identify subgroups of patients with different levels of self-reported neuropathic sensory symptoms and, furthermore, to identify subgroups of patients with distinct patterns of neuropathic sensory symptoms (adjusted for individual response bias regarding specific symptoms). Results ANOVA (analysis of variance) results in typical neuropathic pain, radiculopathy, and fibromyalgia showed no significant differences between the three levels of neuropathic sensory symptoms regarding pain intensity, pain chronicity, pain catastrophizing, pain acceptance, and depressive symptoms. However, in nociceptive back pain patients, significant differences were found for all variables except pain chronicity. When controlling for the response bias of patients in ratings of symptoms, none of the patterns of neuropathic sensory symptoms were associated with pain and psychological factors. Conclusion Neuropathic sensory symptoms are not closely associated with higher levels of pain intensity and cognitive-emotional evaluations in chronic pain patients with underlying pathology of neuropathic sensory symptoms. The findings are discussed in term of differential response bias in patients with versus without verified neuropathic sensory symptoms by clinical examination, medical tests, or underlying pathology of

  12. Spinal cord stimulation for neuropathic pain: current perspectives

    PubMed Central

    Wolter, Tilman

    2014-01-01

    Neuropathic pain constitutes a significant portion of chronic pain. Patients with neuropathic pain are usually more heavily burdened than patients with nociceptive pain. They suffer more often from insomnia, anxiety, and depression. Moreover, analgesic medication often has an insufficient effect on neuropathic pain. Spinal cord stimulation constitutes a therapy alternative that, to date, remains underused. In the last 10 to 15 years, it has undergone constant technical advancement. This review gives an overview of the present practice of spinal cord stimulation for chronic neuropathic pain and current developments such as high-frequency stimulation and peripheral nerve field stimulation. PMID:25429237

  13. Multidimensional Neuropathic Pain Phenotypes after Spinal Cord Injury.

    PubMed

    Widerström-Noga, Eva; Felix, Elizabeth R; Adcock, James P; Escalona, Maydelis; Tibbett, Jacqueline

    2016-03-01

    Identifying clinical neuropathic pain phenotypes is a first step to better understand the underlying pain mechanisms after spinal cord injury (SCI). The primary purpose of the present study was to characterize multidimensional neuropathic pain phenotypes based on quantitative sensory testing (QST), pain intensity, and utilization of catastrophizing coping strategies. Thermal perception, thermal pain, and vibratory perception thresholds were assessed above and below the level of injury (LOI) in 101 persons with SCI and neuropathic pain, 18 persons with SCI and no neuropathic pain, and 50 able-bodied, pain-free controls. Cluster analysis of QST z-scores below the LOI, pain intensity ratings, and the Coping Strategies Questionnaire (CSQ) catastrophizing subscale scores in subjects with neuropathic pain resulted in two phenotypes: severe neuropathic pain (SNP) with greater pain intensity (7.39 ± 1.57) and thermal and vibratory sensitivity compared with the moderate neuropathic pain (MNP; 5.40 ± 1.43). A factor analysis including all CSQ subscales, the Neuropathic Pain Symptom Inventory (NPSI) total score, and thermal pain sensitivity above and below the LOI resulted in three factors: (1) adaptive pain coping including increasing activities, diverting attention, and reinterpreting pain sensations; (2) catastrophizing, neuropathic pain, and thermal sensitivity including greater NPSI total score, thermal pain sensitivity below the LOI, and catastrophizing; and (3) general pain sensitivity including greater thermal pain sensitivity above the LOI and lower catastrophizing. Our results suggest that neuropathic pain symptom severity post-SCI is significantly associated with residual spinothalamic tract function below the LOI and catastrophizing pain coping.

  14. An Epidemiological Study of Neuropathic Pain Symptoms in Canadian Adults

    PubMed Central

    VanDenKerkhof, Elizabeth G.; Mann, Elizabeth G.; Torrance, Nicola; Smith, Blair H.; Johnson, Ana; Gilron, Ian

    2016-01-01

    The reported prevalence of neuropathic pain ranges from 6.9% to 10%; however the only Canadian study reported 17.9%. The objective of this study was to describe the epidemiology of neuropathic pain in Canada. A cross-sectional survey was conducted in a random sample of Canadian adults. The response rate was 21.1% (1504/7134). Likely or possible neuropathic pain was defined using a neuropathic pain-related diagnosis and a positive outcome on the Self-Report Leeds Assessment of Neuropathic Symptoms and Signs pain scale (S-LANSS) or the Douleur Neuropathique 4 (DN4) Questions. The prevalence of likely neuropathic pain was 1.9% (S-LANSS) and 3.4% (DN4) and that of possible neuropathic pain was 5.8% (S-LANSS) and 8.1% (DN4). Neuropathic pain was highest in economically disadvantaged males. There is a significant burden of neuropathic pain in Canada. The low response rate and a slightly older and less educated sample than the Canadian population may have led to an overestimate of neuropathic pain. Population prevalence varies by screening tool used, indicating more work is needed to develop reliable measures. Population level screening targeted towards high risk groups should improve the sensitivity and specificity of screening, while clinical examination of those with positive screening results will further refine the estimate of prevalence. PMID:27445636

  15. Ziconotide infusion for severe chronic pain: case series of patients with neuropathic pain.

    PubMed

    Wermeling, Daniel P; Berger, Joseph R

    2006-03-01

    Ziconotide intrathecal infusion was recently approved by the United States Food and Drug Administration for the treatment of intractable severe chronic pain. Patients with neuropathic pain make up a significant population among those who experience chronic pain for which there are less than optimal pharmacotherapeutic options. Published clinical trials provide a global view of ziconotide efficacy and safety. A subset of patients in clinical trials obtained complete pain relief, a remarkable finding given the history of drug treatment for neuropathic pain. To provide more information regarding those who respond to ziconotide therapy, we discuss three patients with neuropathic pain who received ziconotide infusion. Two patients with longstanding neuropathic pain, one with complex regional pain syndrome (formerly known as reflex sympathetic dystrophy) of the leg and one with lumbar radiculitis, achieved temporary but complete pain relief from single 5- and 10-microg epidural test doses. In the third case, a patient with longstanding bilateral leg and foot neuropathic pain from acquired immunodeficiency syndrome and antiretroviral drug therapy achieved considerable pain relief from a long-term continuous intrathecal infusion. The patients who received a single dose had mild central nervous system adverse effects such as sedation, somnolence, nausea, headache, and lightheadedness. The patient who received the intrathecal infusion experienced mild-to-severe adverse effects depending on the rate of infusion; these effects included sedation, confusion, memory impairment, slurred speech, and double vision. This patient could sense impending adverse effects and made rate adjustments or suspended infusion to avert untoward symptoms. In all three cases, patients achieved considerable pain relief that was long-lasting and persisted well after dose administration or suspension of infusion.

  16. Morphine for chronic neuropathic pain in adults.

    PubMed

    Cooper, Tess E; Chen, Junqiao; Wiffen, Philip J; Derry, Sheena; Carr, Daniel B; Aldington, Dominic; Cole, Peter; Moore, R Andrew

    2017-05-22

    Neuropathic pain, which is caused by a lesion or disease affecting the somatosensory system, may be central or peripheral in origin. Neuropathic pain often includes symptoms such as burning or shooting sensations, abnormal sensitivity to normally painless stimuli, or an increased sensitivity to normally painful stimuli. Neuropathic pain is a common symptom in many diseases of the nervous system. Opioid drugs, including morphine, are commonly used to treat neuropathic pain. Most reviews have examined all opioids together. This review sought evidence specifically for morphine; other opioids are considered in separate reviews. To assess the analgesic efficacy and adverse events of morphine for chronic neuropathic pain in adults. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase for randomised controlled trials from inception to February 2017. We also searched the reference lists of retrieved studies and reviews, and online clinical trial registries. We included randomised, double-blind trials of two weeks' duration or longer, comparing morphine (any route of administration) with placebo or another active treatment for neuropathic pain, with participant-reported pain assessment. Two review authors independently extracted data and assessed trial quality and potential bias. Primary outcomes were participants with substantial pain relief (at least 50% pain relief over baseline or very much improved on Patient Global Impression of Change scale (PGIC)), or moderate pain relief (at least 30% pain relief over baseline or much or very much improved on PGIC). Where pooled analysis was possible, we used dichotomous data to calculate risk ratio (RR) and number needed to treat for an additional beneficial outcome (NNT) or harmful outcome (NNH). We assessed the quality of the evidence using GRADE and created 'Summary of findings' tables. We identified five randomised, double-blind, cross-over studies with treatment periods of four to

  17. Venlafaxine for neuropathic pain in adults.

    PubMed

    Gallagher, Helen C; Gallagher, Ruth M; Butler, Michelle; Buggy, Donal J; Henman, Martin C

    2015-08-23

    Neuropathic pain, which is caused by nerve damage, is increasing in prevalence worldwide. This may reflect improved diagnosis, or it may be due to increased incidence of diabetes-associated neuropathy, linked to increasing levels of obesity. Other types of neuropathic pain include post-herpetic neuralgia, trigeminal neuralgia, and neuralgia caused by chemotherapy. Antidepressant drugs are sometimes used to treat neuropathic pain; however, their analgesic efficacy is unclear. A previous Cochrane review that included all antidepressants for neuropathic pain is being replaced by new reviews of individual drugs examining chronic neuropathic pain in the first instance. Venlafaxine is a reasonably well-tolerated antidepressant and is a serotonin reuptake inhibitor and weak noradrenaline reuptake inhibitor. Although not licensed for the treatment of chronic or neuropathic pain in most countries, it is sometimes used for this indication. To assess the analgesic efficacy of, and the adverse effects associated with the clinical use of, venlafaxine for chronic neuropathic pain in adults. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) via The Cochrane Library, and MEDLINE and EMBASE via Ovid up to 14 August 2014. We reviewed the bibliographies of any randomised trials identified and review articles, contacted authors of one excluded study and searched www.clinicaltrials.gov to identify additional published or unpublished data. We also searched the meta-Register of controlled trials (mRCT) (www.controlled-trials.com/mrct) and the WHO International Clinical Trials Registry Platform (ICTRP) (apps.who.int/trialsearch/) for ongoing trials but did not find any relevant trials. We included randomised, double-blind studies of at least two weeks' duration comparing venlafaxine with either placebo or another active treatment in chronic neuropathic pain in adults. All participants were aged 18 years or over and all included studies had at least 10 participants

  18. Tramadol for neuropathic pain in adults.

    PubMed

    Duehmke, Rudolf Martin; Derry, Sheena; Wiffen, Philip J; Bell, Rae F; Aldington, Dominic; Moore, R Andrew

    2017-06-15

    This review is an update of a review of tramadol for neuropathic pain, published in 2006; updating was to bring the review in line with current standards. Neuropathic pain, which is caused by a lesion or disease affecting the somatosensory system, may be central or peripheral in origin. Peripheral neuropathic pain often includes symptoms such as burning or shooting sensations, abnormal sensitivity to normally painless stimuli, or an increased sensitivity to normally painful stimuli. Neuropathic pain is a common symptom in many diseases of the peripheral nervous system. To assess the analgesic efficacy of tramadol compared with placebo or other active interventions for chronic neuropathic pain in adults, and the adverse events associated with its use in clinical trials. We searched CENTRAL, MEDLINE, and Embase for randomised controlled trials from inception to January 2017. We also searched the reference lists of retrieved studies and reviews, and online clinical trial registries. We included randomised, double-blind trials of two weeks' duration or longer, comparing tramadol (any route of administration) with placebo or another active treatment for neuropathic pain, with subjective pain assessment by the participant. Two review authors independently extracted data and assessed trial quality and potential bias. Primary outcomes were participants with substantial pain relief (at least 50% pain relief over baseline or very much improved on Patient Global Impression of Change scale (PGIC)), or moderate pain relief (at least 30% pain relief over baseline or much or very much improved on PGIC). Where pooled analysis was possible, we used dichotomous data to calculate risk ratio (RR) and number needed to treat for an additional beneficial outcome (NNT) or harmful outcome (NNH), using standard methods. We assessed the quality of the evidence using GRADE and created 'Summary of findings' tables. We identified six randomised, double-blind studies involving 438 participants

  19. Altered Resting State in Diabetic Neuropathic Pain

    PubMed Central

    Cauda, Franco; Sacco, Katiuscia; Duca, Sergio; Cocito, Dario; D'Agata, Federico; Geminiani, Giuliano C.; Canavero, Sergio

    2009-01-01

    Background The spontaneous component of neuropathic pain (NP) has not been explored sufficiently with neuroimaging techniques, given the difficulty to coax out the brain components that sustain background ongoing pain. Here, we address for the first time the correlates of this component in an fMRI study of a group of eight patients suffering from diabetic neuropathic pain and eight healthy control subjects. Specifically, we studied the functional connectivity that is associated with spontaneous neuropathic pain with spatial independent component analysis (sICA). Principal Findings Functional connectivity analyses revealed a cortical network consisting of two anti-correlated patterns: one includes the left fusiform gyrus, the left lingual gyrus, the left inferior temporal gyrus, the right inferior occipital gyrus, the dorsal anterior cingulate cortex bilaterally, the pre and postcentral gyrus bilaterally, in which its activity is correlated negatively with pain and positively with the controls; the other includes the left precuneus, dorsolateral prefrontal, frontopolar cortex (both bilaterally), right superior frontal gyrus, left inferior frontal gyrus, thalami, both insulae, inferior parietal lobuli, right mammillary body, and a small area in the left brainstem, in which its activity is correlated positively with pain and negatively with the controls. Furthermore, a power spectra analyses revealed group differences in the frequency bands wherein the sICA signal was decomposed: patients' spectra are shifted towards higher frequencies. Conclusion In conclusion, we have characterized here for the first time a functional network of brain areas that mark the spontaneous component of NP. Pain is the result of aberrant default mode functional connectivity. PMID:19229326

  20. Fentanyl for neuropathic pain in adults.

    PubMed

    Derry, Sheena; Stannard, Cathy; Cole, Peter; Wiffen, Philip J; Knaggs, Roger; Aldington, Dominic; Moore, R Andrew

    2016-10-11

    Opioid drugs, including fentanyl, are commonly used to treat neuropathic pain, and are considered effective by some professionals. Most reviews have examined all opioids together. This review sought evidence specifically for fentanyl, at any dose, and by any route of administration. Other opioids are considered in separate reviews. To assess the analgesic efficacy of fentanyl for chronic neuropathic pain in adults, and the adverse events associated with its use in clinical trials. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase from inception to June 2016, together with the reference lists of retrieved articles, and two online study registries. We included randomised, double-blind studies of two weeks' duration or longer, comparing fentanyl (in any dose, administered by any route, and in any formulation) with placebo or another active treatment in chronic neuropathic pain. Two review authors independently searched for studies, extracted efficacy and adverse event data, and examined issues of study quality and potential bias. We did not carry out any pooled analyses. We assessed the quality of the evidence using GRADE. Only one study met our inclusion criteria. Participants were men and women (mean age 67 years), with postherpetic neuralgia, complex regional pain syndrome, or chronic postoperative pain. They were experiencing inadequate relief from non-opioid analgesics, and had not previously taken opioids for their neuropathic pain. The study used an enriched enrolment randomised withdrawal design. It was adequately blinded, but we judged it at unclear risk of bias for other criteria.Transdermal fentanyl (one-day fentanyl patch) was titrated over 10 to 29 days to establish the maximum tolerated and effective dose (12.5 to 50 µg/h). Participants who achieved a prespecified good level of pain relief with a stable dose of fentanyl, without excessive use of rescue medication or intolerable adverse events ('responders

  1. Treatment of Neuropathic Pain with Venlafaxine: A Systematic Review.

    PubMed

    Aiyer, Rohit; Barkin, Robert L; Bhatia, Anurag

    2016-11-11

    OBJECTIVE : To investigate the efficacy of venlafaxine for neuropathic pain and review literature to determine if the medication provides adequate neuropathic pain relief. METHODS : Literature was reviewed on MEDLINE using various key words. These key words include: "venlafaxine and pain," "venlafaxine ER and pain," "venlafaxine XR and pain," "venlafaxine and neuropathic pain," "venlafaxine and neuropathy," "SSRI and neuropathic pain," "SSRI and neuropathy," "SNRI and neuropathic pain," "SNRI and neuropathy," "serotonin reuptake inhibitor and neuropathic pain," "serotonin reuptake inhibitor and neuropathy," "serotonin norepinephrine reuptake inhibitor and neuropathic pain" and "serotonin norepinephrine reuptake inhibitor and neuropathy." Using this guideline, 13 articles were reviewed. RESULTS : A total of 13 studies reviewed, which are organized by date and diagnosis. It is evident that in the majority of studies, when compared with a placebo, there was a clinical significant reduction in neuropathic pain relief when using venlafaxine. Additionally, one study showed even more significant pain relief when using higher doses of venlafaxine (at least 150 mg). However, when compared with alternative neuropathic medications, venlafaxine for the most part did not perform any better in terms of efficacy. CONCLUSION : In conclusion, venlafaxine is a safe and well-tolerated analgesic drug for the symptomatic treatment of neuropathic pain, and there is limited evidence that high-dose venlafaxine (150 mg/day) can be even more beneficial. While the present evidence is quite encouraging regarding venlafaxine's use for neuropathic pain, further research is needed to continue to expand on these findings, particularly when in consideration with other possible pharmacological agents. © 2016 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Neuropathic changes in equine laminitis pain.

    PubMed

    Jones, Emma; Viñuela-Fernandez, Ignacio; Eager, Rachel A; Delaney, Ada; Anderson, Heather; Patel, Anisha; Robertson, Darren C; Allchorne, Andrew; Sirinathsinghji, Eva C; Milne, Elspeth M; MacIntyre, Neil; Shaw, Darren J; Waran, Natalie K; Mayhew, Joe; Fleetwood-Walker, Susan M

    2007-12-05

    Laminitis is a common debilitating disease in horses that involves painful disruption of the lamellar dermo-epidermal junction within the hoof. This condition is often refractory to conventional anti-inflammatory analgesia and results in unremitting pain, which in severe cases requires euthanasia. The mechanisms underlying pain in laminitis were investigated using quantification of behavioural pain indicators in conjunction with histological studies of peripheral nerves innervating the hoof. Laminitic horses displayed consistently altered or abnormal behaviours such as increased forelimb lifting and an increased proportion of time spent at the back of the box compared to normal horses. Electron micrographic analysis of the digital nerve of laminitic horses showed peripheral nerve morphology to be abnormal, as well as having reduced numbers of unmyelinated (43.2%) and myelinated fibers (34.6%) compared to normal horses. Sensory nerve cell bodies innervating the hoof, in cervical, C8 dorsal root ganglia (DRG), showed an upregulated expression of the neuronal injury marker, activating transcription factor-3 (ATF3) in both large NF-200-immunopositive neurons and small neurons that were either peripherin- or IB4-positive. A significantly increased expression of neuropeptide Y (NPY) was also observed in myelinated afferent neurons. These changes are similar to those reported in other neuropathic pain states and were not observed in the C4 DRG of laminitic horses, which is not associated with innervation of the forelimb. This study provides novel evidence for a neuropathic component to the chronic pain state associated with equine laminitis, indicating that anti-neuropathic analgesic treatment may well have a role in the management of this condition.

  3. Effect of Botulinum Toxin on Disabling Neuropathic Pain: A Case Presentation Suggesting a New Therapeutic Strategy.

    PubMed

    Buonocore, Michelangelo; Demartini, Laura; Mandrini, Silvia; Dall'Angelo, Anna; Dalla Toffola, Elena

    2017-02-01

    This case presentation describes a 47-year-old woman who developed complex regional pain syndrome type II with severe neuropathic pain following iatrogenic transection of the tibial nerve at the ankle. The pain and disability progressively worsened over time, markedly impaired ambulation, and were not relieved despite various analgesic treatments. After injection of botulinum toxin (abobotulinumtoxinA, BoNT-A) in the leg muscles the tendons of which pass through the tarsal tunnel (together with the tibial nerve), her pain decreased and her walking capacity improved. This case suggests a new therapeutic role for botulin toxin in treating peripheral neuropathic pain caused by movement-evoked ectopic potentials.

  4. Dose-related neuropathic and anti-neuropathic effects of simvastatin in vincristine-induced neuropathic pain in rats.

    PubMed

    Bhalla, Shrutya; Singh, Nirmal; Jaggi, Amteshwar Singh

    2015-06-01

    The present study explores the role of simvastatin in vincristine-induced neuropathic pain, which was induced by administering vincristine (100 µg/kg i.p.) for 10 days (two 5 day cycles with 2 days pause). Pain was assessed by determining mechanical hyperalgesia, mechanical dynamic allodynia, heat hyperalgesia and cold allodynia. Biochemically, myeloperoxidase (MPO) activity was measured along with serum cholesterol levels. Simvastatin (7.5, 15 and 30 mg/kg) was administered for 14 days after administration of vincristine. Simvastatin (7.5 and 15 mg/kg) reversed vincristine-induced neuropathic pain and attenuated vincristine-induced increase in MPO, without altering cholesterol levels. Simvastatin at higher dose (30 mg/kg) did not alter neuropathic pain despite decreasing MPO levels. Furthermore, administration of simvastatin (30 mg/kg i.p.) in vincristine treated rats as well as it's per se administration in normal rats reduced cholesterol levels. Per se administration of simvastatin in normal rats produced neuropathic pain. It is concluded that simvastatin attenuates neuropathic pain only at lower doses with no reduction in cholesterol levels and anti-inflammatory effects may possibly reverse neuropathic pain. However, despite reducing inflammation, simvastatin did not confer beneficial effects at higher doses at which there is reduction in cholesterol levels, suggesting the critical role of cholesterol in neuropathic pain induction.

  5. Beyond neuropathic pain: gabapentin use in cancer pain and perioperative pain.

    PubMed

    Yan, Peter Z; Butler, Paul M; Kurowski, Donna; Perloff, Michael D

    2014-07-01

    Gabapentin (GBP), originally an antiepileptic drug, is more commonly used in the treatment of neuropathic pain. In recent years, GBP has been used as an adjunct or primary therapy in non-neuropathic pain, most commonly for the treatment of perioperative and cancer pain. The aim of this study was to conduct a clinical evidence literature review of GBP's use in perioperative pain and cancer pain. Using PUBMED and OVID Medline databases, keyword searches for surgery and cancer in reference to GBP and pain were carried out. Nonblinded studies and case reports that did not present a unique finding were excluded. Studies that focused only on neuropathic pain were also excluded. An initial 142 references focusing on GBP's use in surgical pain and cancer pain were identified. Of these, 48 studies were quality of evidence at a level of II-2 or higher. Although efficacy varies, multiple well-designed clinical trials have demonstrated reduced pain and analgesic use with otolaryngology, orthopedic, mastectomy, and abdominal/pelvic surgical perioperative use of GBP, whereas there is limited or no efficacy for cardiothoracic surgery. Cancer pain studies have had greater design variability, often nonblinded, with pain benefit being mild to moderate, and more efficacious with partial neuropathic pain quality. Overall, GBP seems to have significant benefit in neuropathic and non-neuropathic pain associated with the perioperative period and cancer. Considering its favorable side effect profile, GBP represents a beneficial pain adjunctive therapy, beyond neuropathic symptoms.

  6. Neuropathic Pain and Spinal Cord Injury: Phenotypes and Pharmacological Management.

    PubMed

    Widerström-Noga, Eva

    2017-06-01

    Chronic neuropathic pain is a complicated condition after a spinal cord injury (SCI) that often has a lifelong and significant negative impact on life after the injury; therefore, improved pain management is considered a significant and unmet need. Neuropathic pain mechanisms are heterogeneous and the difficulty in determining their individual contribution to specific pain types may contribute to poor treatment outcomes in this population. Thus, identifying human neuropathic pain phenotypes based on pain symptoms, somatosensory changes, or cognitive and psychosocial factors that reflect specific spinal cord or brain mechanisms of neuropathic pain is an important goal. Once a pain phenotype can be reliably replicated, its relationship with biomarkers and clinical treatment outcomes can be analyzed, and thereby facilitate translational research and further the mechanistic understanding of individual differences in the pain experience and in clinical trial outcomes. The present article will discuss clinical aspects of SCI-related neuropathic pain, neuropathic pain phenotypes, pain mechanisms, potential biomarkers and pharmacological interventions, and progress regarding how defining neuropathic pain phenotypes may lead to more targeted treatments for these difficult pain conditions.

  7. Neuropathic Pain Features in Patients with Bone Metastases.

    PubMed

    Nakamura, N; Takahashi, O; Zenda, S; Kawamori, J; Ogita, M; Onozawa, M; Arahira, S; Toshima, M; Motegi, A; Hirano, Y; Hojo, H; Akimoto, T

    2016-03-01

    The results of previous randomised controlled trials suggest that radiation oncologists should consider the presence of neuropathic pain when they prescribe dose fractionations for painful bone metastases. Although validated screening tools for neuropathic pain features are currently available, the prevalence of such features among patients with painful bone metastases is still poorly understood. The purpose of this study was to estimate the prevalence of neuropathic pain features among patients who received palliative radiotherapy for painful bone metastases. We conducted a cohort survey of consecutive patients who received palliative radiotherapy for painful bone metastases at St Luke's International Hospital between 2013 and 2014. Patients were prospectively assessed before radiotherapy using the validated screening questionnaire to identify neuropathic pain components in Japanese patients. Pain with neuropathic features was prospectively defined using the total score of the seven-item questionnaire and a cut-off score ≥9. The pain response was assessed 2 months after the start of radiotherapy according to the criteria defined by the International Bone Metastases Consensus Working Party. Eighty-seven patients were assessed. Twenty-four per cent of patients (95% confidence interval: 16-35%) were diagnosed as having pain with neuropathic features. On multivariate analysis, no significant correlations were seen between neuropathic pain features and patient characteristics. Sixty-four patients (74%) were assessable 2 months after the start of radiotherapy. Overall response rates were 59% (95% confidence interval: 33-82%) in patients with neuropathic features and 55% (95% confidence interval: 40-70%) in those without such features. A considerable proportion of the patients were proven to have bone pain with neuropathic features. Further investigations are warranted to validate symptom assessment tools in cooperation with pain distribution and image findings, and to

  8. Neuropathic pain and reactive gliosis are reversed by dialdehydic compound in neuropathic pain rat models.

    PubMed

    Bianco, Maria Rosaria; Cirillo, Giovanni; Petrosino, Valentina; Marcello, Lorenza; Soleti, Antonio; Merizzi, Giulia; Cavaliere, Carlo; Papa, Michele

    2012-11-14

    The role of the purinergic system in the modulation of pain mechanisms suggests that it might be promising target for treating neuropathic pain. In this study we evaluated the effects of two different dialdehydic compounds: a modified stable adenosine (2-[1-(6-amminopurin-9-il)-2-osso-etossi]prop-2-enale, named MED1101), and oxidized ATP (Ox-ATP), in two different neuropathic pain rat models: the sciatic spared nerve injury (SNI) and paclitaxel evoked painful peripheral neuropathy (pPPN). Neuropathic animals were divided in groups as follows: (a) treated with intraperitoneal (i.p.) MED1101 or Ox-ATP for 21 days; (b) receiving vehicle (VEH) and (c) control (CTR) rats. The allodynic and hyperalgesic behavior was investigated by Von Frey filament test and thermal Plantar test, respectively. We evaluated by immunocytochemistry the astrocytic (GFAP) and microglial (Iba1) response on lumbar spinal cord sections. In either experimental models and using either substances, treated animals showed reduced allodynia and thermal hyperalgesia paralleled by a significant reduction of glial reaction in the spinal cord. These data prompt to hypothesize a potential role of dialdehydes as analgesic agent in chronic neuropathic pain and a possible role as anti-gliotic molecules. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  9. Fear of pain in children and adolescents with neuropathic pain and CRPS

    PubMed Central

    Simons, Laura E.

    2015-01-01

    A significant proportion of children and adolescents with chronic pain endorse elevated pain-related fear. Pain-related fear is associated with high levels of disability, depressive symptoms, and school impairment. Due to faulty nerve signaling, individuals with neuropathic pain and CRPS may be more prone to develop pain-related fear as they avoid use of and neglect the affected body area(s), resulting in exacerbated symptoms, muscle atrophy, maintenance of pain signaling, and ongoing pain-related disability. Not surprisingly, effective treatments for elevated pain-related fears involve exposure to previously avoided activities to down-regulate incorrect pain signaling. In the context of intensive interdisciplinary pain treatment of youth with neuropathic pain, decreasing pain-related fear is associated with improved physical and psychological functioning, while high initial pain-related fear is a risk factor for less treatment responsiveness. An innovative approach to targeting pain-related fear as well as evidence of a neural response to treatment involving decoupling of the amygdala with key fear circuits in youth with CRPS suggest breakthroughs in our ability to ameliorate these issues. PMID:26785161

  10. Somatosensory Profiles but Not Numbers of Somatosensory Abnormalities of Neuropathic Pain Patients Correspond with Neuropathic Pain Grading

    PubMed Central

    Konopka, Karl-Heinz; Harbers, Marten; Houghton, Andrea; Kortekaas, Rudie; van Vliet, Andre; Timmerman, Wia; den Boer, Johan A.; Struys, Michel M. R. F.; van Wijhe, Marten

    2012-01-01

    Due to the lack of a specific diagnostic tool for neuropathic pain, a grading system to categorize pain as ‘definite’, ‘probable’, ‘possible’ and ‘unlikely’ neuropathic was proposed. Somatosensory abnormalities are common in neuropathic pain and it has been suggested that a greater number of abnormalities would be present in patients with ‘probable’ and ‘definite’ grades. To test this hypothesis, we investigated the presence of somatosensory abnormalities by means of Quantitative Sensory Testing (QST) in patients with a clinical diagnosis of neuropathic pain and correlated the number of sensory abnormalities and sensory profiles to the different grades. Of patients who were clinically diagnosed with neuropathic pain, only 60% were graded as ‘definite’ or ‘probable’, while 40% were graded as ‘possible’ or ‘unlikely’ neuropathic pain. Apparently, there is a mismatch between a clinical neuropathic pain diagnosis and neuropathic pain grading. Contrary to the expectation, patients with ‘probable’ and ‘definite’ grades did not have a greater number of abnormalities. Instead, similar numbers of somatosensory abnormalities were identified for each grade. The profiles of sensory signs in ‘definite’ and ‘probable’ neuropathic pain were not significantly different, but different from the ‘unlikely’ grade. This latter difference could be attributed to differences in the prevalence of patients with a mixture of sensory gain and loss and with sensory loss only. The grading system allows a separation of neuropathic and non-neuropathic pain based on profiles but not on the total number of sensory abnormalities. Our findings indicate that patient selection based on grading of neuropathic pain may provide advantages in selecting homogenous groups for clinical research. PMID:22927981

  11. Prevalence of Neuropathic Pain in Patients with Traumatic Brachial Plexus Injury: A Multicenter Prospective Hospital-Based Study.

    PubMed

    Ciaramitaro, Palma; Padua, Luca; Devigili, Grazia; Rota, Eugenia; Tamburin, Stefano; Eleopra, Roberto; Cruccu, Giorgio; Truini, Andrea

    2017-03-03

    Prevalence and clinical characteristics of neuropathic pain due to traumatic brachial plexus injury. Observational epidemiological study. Hospital-based multicenter study. One hundred seven prospectively enrolled patients with brachial plexus injury. All the patients underwent clinical examination and neurophysiological testing for a definitive diagnosis of the brachial plexus lesion. The DN4 questionnaire was used to identify neuropathic pain, and the Neuropathic Pain Symptom Inventory (NPSI) to evaluate the different symptoms of neuropathic pain. The SF36 questionnaire and the Beck Depression Inventory (BDI) were used to assess quality of life and mood disturbances in patients with neuropathic pain. Of the 107 enrolled patients, 74 had pain (69%); neuropathic pain, as assessed by means of the DN4, was identified in 60 (56%) of these patients. According to the NPSI, the most frequent and severe pain type was the spontaneous burning pain. Clinical and neurophysiological findings showed that pain is unrelated to age but is associated with the severity of peripheral nerve damage. The SF36 questionnaire and BDI showed that neuropathic pain impairs quality of life and causes depression. Our study provides information on the prevalence, characteristics, and variables associated with neuropathic pain due to traumatic brachial plexus injuries that might provide a basis for improving the clinical management of this condition.

  12. Hematopoietic pannexin 1 function is critical for neuropathic pain

    PubMed Central

    Weaver, Janelle L.; Arandjelovic, Sanja; Brown, Gregory; K. Mendu, Suresh; S. Schappe, Michael; Buckley, Monica W.; Chiu, Yu-Hsin; Shu, Shaofang; Kim, Jin K.; Chung, Joyce; Krupa, Julia; Jevtovic-Todorovic, Vesna; Desai, Bimal N.; Ravichandran, Kodi S.; Bayliss, Douglas A.

    2017-01-01

    Neuropathic pain symptoms respond poorly to available therapeutics, with most treated patients reporting unrelieved pain and significant impairment in daily life. Here, we show that Pannexin 1 (Panx1) in hematopoietic cells is required for pain-like responses following nerve injury in mice, and a potential therapeutic target. Panx1 knockout mice (Panx1−/−) were protected from hypersensitivity in two sciatic nerve injury models. Bone marrow transplantation studies show that expression of functional Panx1 in hematopoietic cells is necessary for mechanical hypersensitivity following nerve injury. Reconstitution of irradiated Panx1 knockout mice with hematopoietic Panx1−/− cells engineered to re-express Panx1 was sufficient to recover hypersensitivity after nerve injury; this rescue required expression of a Panx1 variant that can be activated by G protein-coupled receptors (GPCRs). Finally, chemically distinct Panx1 inhibitors blocked development of nerve injury-induced hypersensitivity and partially relieved this hypersensitivity after it was established. These studies indicate that Panx1 expressed in immune cells is critical for pain-like effects following nerve injury in mice, perhaps via a GPCR-mediated activation mechanism, and suggest that inhibition of Panx1 may be useful in treating neuropathic pain. PMID:28195232

  13. Functional brain imaging: what has it brought to our understanding of neuropathic pain? A special focus on allodynic pain mechanisms.

    PubMed

    Peyron, Roland

    2016-02-01

    Brain responses to nociception are well identified. The same is not true for allodynic pain, a strong painful sensation in response to touch or innocuous cold stimuli that may be experienced by patients with neuropathic pain. Brain (or spinal cord) reorganization that may explain this paradoxical perception still remains largely unknown. Allodynic pain is associated with abnormally increased activity in SII and in the anterior insular cortex, contralateral and/or ipsilateral to allodynia. Because a bilateral increase in activity has been repeatedly reported in these areas in nociceptive conditions, the observed activation during allodynia can explain that a physiologically nonpainful stimulus could be perceived by the damaged nervous system as a painful one. Both secondary somatosensory and insular cortices receive input from the thalamus, which is a major relay of sensory and spinothalamic pathways, the involvement of which is known to be crucial for the development of neuropathic pain. Both thalamic function and structure have been reported to be abnormal or impaired in neuropathic pain conditions including in the basal state, possibly explaining the spontaneous component of neuropathic pain. A further indication as to how the brain can create neuropathic pain response in SII and insular cortices stems from examples of diseases, including single-case reports in whom a focal brain lesion leads to central pain disappearance. Additional studies are required to certify the contribution of these areas to the disease processes, to disentangle abnormalities respectively related to pain and to deafferentation, and, in the future, to guide targeting of stimulation studies.

  14. Methadone for neuropathic pain in adults.

    PubMed

    McNicol, Ewan D; Ferguson, McKenzie C; Schumann, Roman

    2017-05-17

    This review replaces an earlier review, "Methadone for chronic non-cancer pain in adults". This review serves to update the original and includes only studies of neuropathic pain. Methadone belongs to a class of analgesics known as opioids, that are considered the cornerstone of therapy for moderate-to-severe postsurgical pain and pain due to life-threatening illnesses; however, their use in neuropathic pain is controversial. Methadone has many characteristics that differentiate it from other opioids, which suggests that it may have a different efficacy and safety profile. To assess the analgesic efficacy and adverse events of methadone for chronic neuropathic pain in adults. We searched the following databases: CENTRAL (CRSO), MEDLINE (Ovid), and Embase (Ovid), and two clinical trial registries. We also searched the reference lists of retrieved articles. The date of the most recent search was 30 November 2016. We included randomised, double-blind studies of two weeks' duration or longer, comparing methadone (in any dose, administered by any route, and in any formulation) with placebo or another active treatment in chronic neuropathic pain. We used standard methodological procedures expected by Cochrane. Two review authors independently considered trials for inclusion in the review, assessed risk of bias, and extracted data. There were insufficient data to perform pooled analyses. We assessed the overall quality of the evidence for each outcome using GRADE and created a 'Summary of findings' table. We included three studies, involving 105 participants. All were cross-over studies, one involving 19 participants with diverse neuropathic pain syndromes, the other two involving 86 participants with postherpetic neuralgia. Study phases ranged from 20 days to approximately eight weeks. All administered methadone orally, in doses ranging from 10 mg to 80 mg daily. Comparators were primarily placebo, but one study also included morphine and tricyclic antidepressants

  15. Managing neuropathic pain in multiple sclerosis: Pharmacological interventions.

    PubMed

    Duffy, Samuel S; Lees, Justin G; Perera, Chamini J; Moalem-Taylor, Gila

    2017-09-06

    Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS). Of the plethora of motor and sensory disturbances experienced by sufferers, neuropathic pain is a highly prevalent and debilitating symptom, and at present remains extremely difficult to treat. Common forms of neuropathic pain seen in MS patients include central neuropathic pain, Lhermitte's phenomenon and trigeminal neuralgia, which are all speculated to arise from specific patterns of lesion formation. Efficacious pharmacological interventions for the treatment of neuropathic pain associated with MS are lacking, and have been largely informed by drug trials in peripheral neuropathies and spinal cord injury. Neuropathic pain in MS is inadequately relieved by conventional analgesics, and first-line therapies are generally comprised of anti-depressive and anti-convulsive drugs. A range of alternatives have been proposed and tested with variable success, including cannabinoids and certain opioid analgesics. Animals with experimental autoimmune encephalomyelitis (EAE), an autoimmune model of MS, also exhibit neuropathic pain symptoms. Studies aimed at understanding the mechanisms underlying EAE-induced neuropathic pain and investigating the efficacy of novel pharmacological interventions at the animal level offer an exciting area of future research, and may inform future therapeutic options for MS-associated neuropathic pain. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  16. Can treatment success with 5% lidocaine medicated plaster be predicted in cancer pain with neuropathic components or trigeminal neuropathic pain?

    PubMed

    Kern, Kai-Uwe; Nalamachu, Srinivas; Brasseur, Louis; Zakrzewska, Joanna M

    2013-01-01

    An expert group of 40 pain specialists from 16 countries performed a first assessment of the value of predictors for treatment success with 5% lidocaine-medicated plaster in the management of cancer pain with neuropathic components and trigeminal neuropathic pain. Results were based on the retrospective analysis of 68 case reports (sent in by participants in the 4 weeks prior to the conference) and the practical experience of the experts. Lidocaine plaster treatment was mostly successful for surgery or chemotherapy-related cancer pain with neuropathic components. A dose reduction of systemic pain treatment was observed in at least 50% of all cancer pain patients using the plaster as adjunct treatment; the presence of allodynia, hyperalgesia or pain quality provided a potential but not definitively clear indication of treatment success. In trigeminal neuropathic pain, continuous pain, severe allodynia, hyperalgesia, or postherpetic neuralgia or trauma as the cause of orofacial neuropathic pain were perceived as potential predictors of treatment success with lidocaine plaster. In conclusion, these findings provide a first assessment of the likelihood of treatment benefits with 5% lidocaine-medicated plaster in the management of cancer pain with neuropathic components and trigeminal neuropathic pain and support conducting large, well-designed multicenter studies.

  17. Can treatment success with 5% lidocaine medicated plaster be predicted in cancer pain with neuropathic components or trigeminal neuropathic pain?

    PubMed Central

    Kern, Kai-Uwe; Nalamachu, Srinivas; Brasseur, Louis; Zakrzewska, Joanna M

    2013-01-01

    An expert group of 40 pain specialists from 16 countries performed a first assessment of the value of predictors for treatment success with 5% lidocaine-medicated plaster in the management of cancer pain with neuropathic components and trigeminal neuropathic pain. Results were based on the retrospective analysis of 68 case reports (sent in by participants in the 4 weeks prior to the conference) and the practical experience of the experts. Lidocaine plaster treatment was mostly successful for surgery or chemotherapy-related cancer pain with neuropathic components. A dose reduction of systemic pain treatment was observed in at least 50% of all cancer pain patients using the plaster as adjunct treatment; the presence of allodynia, hyperalgesia or pain quality provided a potential but not definitively clear indication of treatment success. In trigeminal neuropathic pain, continuous pain, severe allodynia, hyperalgesia, or postherpetic neuralgia or trauma as the cause of orofacial neuropathic pain were perceived as potential predictors of treatment success with lidocaine plaster. In conclusion, these findings provide a first assessment of the likelihood of treatment benefits with 5% lidocaine-medicated plaster in the management of cancer pain with neuropathic components and trigeminal neuropathic pain and support conducting large, well-designed multicenter studies. PMID:23630431

  18. Pain in primary erythromelalgia--a neuropathic component?

    PubMed

    Orstavik, Kristin; Mørk, Cato; Kvernebo, Knut; Jørum, Ellen

    2004-08-01

    Erythromelalgia is a condition characterized by attacks of red, hot, painful extremities with relief of symptoms by cooling and aggravation by warmth. Although the main emphasis has been on pathophysiological mechanisms related to circulatory changes, recent reports have focused on an involvement of efferent small nerve fibers indicating a neuropathic component. Since the symptoms resemble those described in neuropathic pain, we wanted to investigate the possible affection of afferent nerve fibers. Twenty-five patients with primary erythromelalgia were examined by neurological testing, neurography and quantitative sensory testing. Thresholds for heat, cold, heat-pain and cold-pain detection were compared with those of a group of 29 healthy controls. The patients had significantly higher median heat (39.5 (36.1-40.8) and cold (29.3 (27.1-30.8)-detection thresholds at the dorsal aspects of their feet compared to the controls (37.0 (35.4-37.7) and 31.2 (30.3-31.5) respectively). These findings show an impaired small fiber function inside or close to the symptomatic area in this group of erythromelalgia patients. Seven patients had brush-evoked allodynia and fourteen had punctate hyperalgesia inside or close to the symptomatic areas in their feet. When comparing the individual results, there is a tendency to clustering of patients in two separate groups; reduced small fiber input/no hyperalgesia and normal thermal thresholds/hyperalgesia. Our results showing an affection of afferent small nerve fibers together with the nature of the symptoms, suggest that the pain experienced by erythromelalgia patients could have a neuropathic component.

  19. Treatments of traumatic neuropathic pain: a systematic review.

    PubMed

    Yao, Chenglun; Zhou, Xijie; Zhao, Bin; Sun, Chao; Poonit, Keshav; Yan, Hede

    2017-08-22

    Traumatic neuropathic pain caused by traumatic neuroma has long been bothering both doctors and patients, the mechanisms of traumatic neuropathic pain are widely discussed by researchers and the treatment is challenging. Clinical treatment of painful neuroma is unclear. Numerous treatment modalities have been introduced by experts in this field. However, there is still no single standard recognized treatment. Different forms of treatments have been tested in animals and humans, but pharmacotherapies (antidepressants, antiepileptics) remain the basis of traumatic neuropathic pain management. For intractable cases, nerve stump transpositions into a muscle, vein or bone are seen as traditional surgical procedures which provide a certain degree of efficacy. Novel surgical techniques have emerged in recent years, such as tube guided nerve capping, electrical stimulation and adipose autograft have substantially enriched the abundance of the treatment for traumatic neuropathic pain. Several treatments show advantages over the others in terms of pain relief and prevention of neuroma formation, making it difficult to pick out a single modality as the reference. An effective and standardized treatment for traumatic neuropathic pain would provide better choice for researchers and clinical workers. In this review, we summarized current knowledge on the treatment of traumatic neuropathic pain, and found a therapeutic strategy for this intractable pain. We tried to provide a useful guideline for choosing the right modality in management of traumatic neuropathic pain.

  20. [Chemokines and attraction of myeloid cells in peripheral neuropathic pains].

    PubMed

    Sapienza, Anaïs; Réaux-Le Goazigo, Annabelle; Rostène, William; Mélik-Parsadaniantz, Stéphane

    2014-01-01

    Chronic neuropathic pain has become a real social issue, due to the difficulty of its treatment and by the major impairment to quality of life that it causes in every day behavior. Understanding neurobiological basis and pathophysiological causes of diverse painful syndromes constantly evolves and reports the complexity of its mechanisms. Unfortunately this complexity makes it difficult to discover effective treatments against chronic pain syndromes, in particular as regards peripheral neuropathic pains. Recent studies reveal that, during chronic peripheral neuropathy, inflammatory mediators (in particular chemokines), besides their implications in the modulation of nociceptive messages and central neuroinflammatory mechanisms, play a critical role in the orchestration of the immune response induced by a peripheral nerve lesion. In this review, after a brief introduction about chemokines and their role in neuromodulation of the nociceptive message, we will attempt to define their functions and implications in the immune response associated to peripheral neuropathies. Thus, perfectly understanding the molecular and cellular communications between the nervous system and the immune system will be useful for the future development of novel and innovative therapeutic strategies against these highly disabling pathologies.

  1. Assessment of pain quality in chronic neuropathic and nociceptive pain clinical trials with the Neuropathic Pain Scale.

    PubMed

    Jensen, Mark P; Dworkin, Robert H; Gammaitoni, Arnold R; Olaleye, David O; Oleka, Napoleon; Galer, Bradley S

    2005-02-01

    Although a number of measures of pain qualities exist, little research has examined the potential for these measures to identify the unique effects of pain treatments on different pain qualities. We examined the utility of the Neuropathic Pain Scale (NPS) for assessing changes in pain qualities after open label lidocaine patch 5% in 3 samples of patients: patients with peripheral neuropathic pain, low back pain, and osteoarthritis. With one exception ("cold" pain in subjects with low back pain), each of the NPS items showed significant change after open label lidocaine patch. In addition, significantly larger changes were observed for the NPS items reflecting global pain intensity and pain unpleasantness and for items assessing sharp and deep pain than for items assessing cold, sensitive, and itchy pain. The pattern of changes in pain qualities did not differ across the 3 diagnostic groups, but it did differ from the patterns of changes in pain qualities associated with other analgesic treatments. The results support the potential utility of the NPS for assessing the patterns of changes in pain qualities that can be observed after pain treatment. Pain clinical trials that include measures of pain qualities, such as the NPS, might identify distinct patterns of treatment effects on those pain qualities. This research might be used to help clinicians target analgesics to match the specific qualities associated with a patient's pain and to better understand the mechanisms of analgesic effects in drug development programs.

  2. Neuropathic orofacial pain part 1--prevalence and pathophysiology.

    PubMed

    Vickers, E R; Cousins, M J

    2000-04-01

    Neuropathic pain is defined as "pain initiated or caused by a primary lesion or dysfunction in the nervous system". Neuropathic orofacial pain has previously been known as "atypical odontalgia" (AO) and "phantom tooth pain". The patient afflicted with neuropathic oral/orofacial pain may present to the dentist with a persistent, severe pain, yet there are no clearly identifiable clinical or radiographic abnormalities. Accordingly, multiple endodontic procedures may be instigated to remove the likely anatomical source of the pain, yet the pain persists. There have been few studies and limited patient numbers investigating the condition. Two retrospective studies revealed the incidence of persistent pain following endodontic treatment to be 3-6% and 5% of patients; one author with wide experience in assessing the condition estimated its prevalence at 125,000 individuals in the USA alone. In one study, 50% of neuropathic orofacial pain patients reported persistent pain specifically following endodontic treatment. Patients predisposed to the condition may include those suffering from recurrent cluster or migraine headaches. Neuropathic pain states include postherpetic neuralgia (shingles) and phantom limb/stump pain. The aberrant developmental neurobiology leading to this pain state is complex. Neuropathic pain serves no protective function, in contrast to physiological pain that warns of noxious stimuli likely to result in tissue damage. The relevant clinical features of neuropathic pain include: (i) precipitating factors such as trauma or disease (infection), and often a delay in onset after initial injury (days-months), (ii) typical complaints such as dysaesthesias (abnormal unpleasant sensations), pain that may include burning, and paroxysmal, lancinating or sharp qualities, and pain in an area of sensory deficit, (iii) on physical examination there may be hyperalgesia, allodynia and sympathetic hyperfunction, and (iv) the pathophysiology includes deafferentation

  3. Neuropathic Pain Treatment: Still a Challenge

    PubMed Central

    Nascimento, Osvaldo J.M.; Pessoa, Bruno L.; Orsini, Marco; Ribeiro, Pedro; Davidovich, Eduardo; Pupe, Camila; Filho, Pedro Moreira; Dornas, Ricardo Menezes; Masiero, Lucas; Bittencourt, Juliana; Bastos, Victor Hugo

    2016-01-01

    Neuropathic pain (NP) is the result of a series of conditions caused by diseases or lesions to the somatosensory system. Due to the better understanding of NP pathophysiology previously unexplored therapies have been used with encouraging results. In this group, acetyl-L-carnitine, alpha-lipoic-acid, cannabinoids, clonidine, EMA401, botulinum toxin type A and new voltage-gated sodium channel blockers, can be included. Besides, changing paradigms may occur with the advent of optogenetics and a better understanding of epigenetic regulation. We reviewed the published literature on the pharmacological treatment of NP. Despite the interesting results, randomized controlled trials are demanded the majority of the therapies previously mentioned. In spite of several studies for the relief of NP, pain control continues being a challenge. PMID:27441065

  4. Diabetic peripheral neuropathic pain: recognition and management.

    PubMed

    Cole, B Eliot

    2007-09-01

    The occurrence of diabetic peripheral neuropathy (DPN) is linked to poor glycemic control over time. While most people never develop diabetic peripheral neuropathic pain (DPNP) as a consequence of DPN, enough of them do that we must have effective options for the management of this disabling condition. Two years ago there were no formally approved medications for the treatment of DPNP, and now there are two medications with Food and Drug Administration approval for DPNP. One of these medications, duloxetine has been established to significantly improve pain and to address depression by its reuptake inhibition of norepinephrine and serotonin. This article examines the epidemiology of DPNP, its underlying pathogenesis, necessary evaluation methods, and treatment options available with a focus on the role of duloxetine.

  5. Neuropathic Pain Treatment: Still a Challenge.

    PubMed

    Nascimento, Osvaldo J M; Pessoa, Bruno L; Orsini, Marco; Ribeiro, Pedro; Davidovich, Eduardo; Pupe, Camila; Filho, Pedro Moreira; Dornas, Ricardo Menezes; Masiero, Lucas; Bittencourt, Juliana; Bastos, Victor Hugo

    2016-06-15

    Neuropathic pain (NP) is the result of a series of conditions caused by diseases or lesions to the somatosensory system. Due to the better understanding of NP pathophysiology previously unexplored therapies have been used with encouraging results. In this group, acetyl-L-carnitine, alpha-lipoic-acid, cannabinoids, clonidine, EMA401, botulinum toxin type A and new voltage-gated sodium channel blockers, can be included. Besides, changing paradigms may occur with the advent of optogenetics and a better understanding of epigenetic regulation. We reviewed the published literature on the pharmacological treatment of NP. Despite the interesting results, randomized controlled trials are demanded the majority of the therapies previously mentioned. In spite of several studies for the relief of NP, pain control continues being a challenge.

  6. Transient Receptor Potential Channels in neuropathic pain.

    PubMed

    Basso, Lilian; Altier, Christophe

    2016-10-27

    Neuropathic pain caused by disease or dysfunction of the nervous system is one of the most difficult pain conditions to treat. Symptoms include a hypersensitivity to mechanical and thermal stimuli, processed by specialized nociceptors that constitute the first line of defence of the somatosensory system. The detection of these stimuli depends on the TRP ion channel family, which activates upon damaging pressure, extreme temperature, or toxic endogenous and exogenous chemicals. This review will summarize the current knowledge of the contribution of TRP channels, particularly the thermosensitive TRP, including TRPV1, TRPA1 and TRPM8 channels that play a central role in the sensitization of nociceptive transduction. We will discuss the pharmacology of these receptors and their relative success in preclinical and clinical studies.

  7. Neuropathic pain treatment provides unexpected benefit.

    PubMed

    Keesling, Adam D; Wilson, Meg; Wilkins, Robert

    2017-06-01

    A 57-year-old African American woman was being treated at our clinic for neurogenic urinary incontinence (UI). The UI, which occurred day and night, began 2 years earlier following a laminectomy of vertebrae C3 to C6 with spinal fusion of C3 to C7 for cervical spinal stenosis. The UI persisted despite physical therapy and trials of oxybutynin and imipramine. Since the surgery, the patient had also been experiencing chronic (debilitating) neuropathic pain in both legs, and the sensation of incomplete bladder emptying. She denied bowel incontinence or saddle anesthesia. Her prescription medications included hydrocodone-acetaminophen 7.5/325 mg every 6 hours as needed for pain and lisinopril 20 mg/d for essential hypertension. The patient's body mass index was 23.3.

  8. High Prevalence of Chronic Pain With Neuropathic Characteristics After Open Reduction and Internal Fixation of Ankle Fractures.

    PubMed

    Rbia, Nadia; van der Vlies, Cornelis H; Cleffken, Berry I; Selles, Ruud W; Hovius, Steven E R; Nijhuis, Tim H J

    2017-09-01

    Unstable ankle fractures require treatment with open reduction and internal fixation (ORIF). Long-term functional outcome is satisfying in most patients; however, a number of patients have persistent complaints. Superficial nerve complications following ankle surgery may be the cause of chronic pain and disability. In this observational retrospective survey, a cohort of 527 women and men, who underwent ORIF in the period from January 2007 to January 2014, were invited to an online questionnaire. Pain symptoms were assessed using the McGill Pain Questionnaire (MPQ) and the Douleur Neuropathic en 4 Questions (DN4) Questionnaire. Descriptive statistics were used to present patient characteristics; a logistic regression model was used to analyze prognostic factors of neuropathic pain. A total of 271 patients completed the questionnaire. Mean follow-up period was 5.8 years (±1.9). Persistent neuropathic pain symptoms were present in 61 of all patients, and 51 of these patients reported an impaired quality of life caused by their symptoms. In univariate analysis, the following parameters were associated with neuropathic pain: age, hypertension, a thyroid disorder, lower back pain, fracture dislocations, and late complications such as nonunion, posttraumatic arthritis, or osteochondral injury. In multivariate analysis, an age between 40 and 60 years was found to be a significant predictor of neuropathic pain. Hypertension, dislocation, and late complications were significant predictors of persistent pain without neuropathic characteristics. The present study demonstrated a prevalence of persistent neuropathic pain symptoms after ORIF for ankle fractures in 23% of the respondents, which caused an impaired health-related quality of life. We identified 4 significant predictors of chronic and neuropathic pain after ORIF. This knowledge may aid the treating surgeon to identify patients who are at increased risk of persistent postoperative neuropathic pain and may affect the

  9. Neuropathic pain as part of chronic widespread pain: environmental and genetic influences.

    PubMed

    Momi, Sukhleen K; Fabiane, Stella Maris; Lachance, Genevieve; Livshits, Gregory; Williams, Frances M K

    2015-10-01

    Chronic widespread pain (CWP) has complex aetiology and forms part of the fibromyalgia syndrome. Recent evidence suggests a higher frequency of neuropathic pain features in those with CWP than previously thought. The aim of this study was to determine the prevalence of neuropathic pain features in individuals with CWP and to estimate the influence of genetic and environmental factors on neuropathic pain in CWP. Validated questionnaires (the London Fibromyalgia Screening Study questionnaire and PainDETECT questionnaire) were used to classify twins as having CWP and neuropathic pain, respectively. The prevalence of CWP was 14.7% (n = 4324), and of the 1357 twins invited to complete neuropathic pain screening, 15.9% of those having CWP demonstrated features of neuropathic pain. Neuropathic pain was found to be heritable (A = 37%; 95% confidence interval [CI]: 23%-50%) with unique environmental factors accounting for 63% (95% CI: 49%-79%) of the variance. Heritability of neuropathic pain and CWP were found to be correlated, 0.54 (95% CI: 0.42-0.65). Increasing age, raised body mass index, female gender, and smoking were all risk factors for neuropathic pain (P < 0.05), and CWP (P < 0.05). High socioeconomic status showed negative correlation with neuropathic pain (P = 0.003) and CWP (P = 0.001). Bivariate analysis of the 2 pain traits revealed that genetic predisposition to neuropathic pain is shared with that for CWP. This is the first study to provide formal heritability estimates for neuropathic pain in CWP. The findings suggest that at least some of the genetic factors underlying the development of neuropathic pain and CWP are the same.

  10. Prevalence of neuropathic pain in early multiple sclerosis.

    PubMed

    Heitmann, Henrik; Biberacher, Viola; Tiemann, Laura; Buck, Dorothea; Loleit, Verena; Selter, Rebecca C; Knier, Benjamin; Tölle, Thomas R; Mühlau, Mark; Berthele, Achim; Hemmer, Bernhard; Ploner, Markus

    2016-08-01

    Pain is considered a frequent symptom in multiple sclerosis. Neuropathic pain is the type of pain most closely related to the pathology of multiple sclerosis and its prevalence estimates vary largely. We prospectively assessed the prevalence of neuropathic pain in patients with early multiple sclerosis and investigated the association of neuropathic pain with other clinical parameters. A total of 377 outpatients with multiple sclerosis at an early disease stage were included in this prospective study. Mean disease duration was 4.2 years, mean Expanded Disability Status Scale (EDSS) score was 1.6, 96.8% of patients were classified as having relapsing-remitting multiple sclerosis. Neuropathic pain was assessed using the PainDETECT questionnaire (PDQ). Depression, fatigue and cognition were assessed using the Beck Depression Inventory (BDI), the Fatigue Scale for Motor and Cognitive Functions (FSMC) and the Paced Auditory Serial Addition Test. PDQ scores indicative of neuropathic pain were found in 4.2% of patients. Regression analysis revealed EDSS, BDI and FMSC scores as strongest predictors of PDQ scores. Neuropathic pain appears to be less frequent in early multiple sclerosis than expected and is significantly associated with disability, depression and fatigue. The assessment and therapy of pain in multiple sclerosis should thus take into account neuropsychiatric symptoms already at early disease stages. © The Author(s), 2015.

  11. A modified score to identify and discriminate neuropathic pain: a study on the German version of the neuropathic pain symptom inventory (NPSI)

    PubMed Central

    2011-01-01

    Background Neuropathic pain must be correctly diagnosed for optimal treatment. The questionnaire named Neuropathic Pain Symptom Inventory (NPSI) was developed in its original French version to evaluate the different symptoms of neuropathic pain. We hypothesized that the NPSI might also be used to differentiate neuropathic from non-neuropathic pain. Methods We translated the NPSI into German using a standard forward-backward translation and administered it in a case-control design to patients with neuropathic (n = 68) and non-neuropathic pain (headache and osteoarthritis, n = 169) to validate it and to analyze its discriminant properties, its sensitivity to change, and to detect neuropathic pain subgroups with distinct profiles. Results Using a sum score (the NPSI-G score), we found sensitivity to change (r between 0.37 and 0.5 for pain items of the graded chronic pain scale) and could distinguish between neuropathic and other pain on a group basis, but not for individual patients. Post hoc development of a discriminant score with optimized diagnostic properties to distinguish neuropathic pain from non-neuropathic pain resulted in an instrument with high sensitivity (91%) and acceptable specificity (70%). We detected six different pain profiles in the patient group with neuropathic pain; three profiles were found to be distinct. Conclusions The NPSI-G potentially combines the properties of a diagnostic tool and an instrument to identify subtypes of neuropathic pain. PMID:21861889

  12. Truncated TrkB.T1-mediated astrocyte dysfunction contributes to impaired motor function and neuropathic pain after spinal cord injury.

    PubMed

    Matyas, Jessica J; O'Driscoll, Cliona M; Yu, Laina; Coll-Miro, Marina; Daugherty, Sean; Renn, Cynthia L; Faden, Alan I; Dorsey, Susan G; Wu, Junfang

    2017-03-07

    Following spinal cord injury (SCI), astrocytes demonstrate long-lasting reactive changes, which are associated with the persistence of neuropathic pain and motor dysfunction. We previously demonstrated that up-regulation of trkB.T1, a truncated isoform of the Brain-derived Neurotrophic Factor (BDNF) receptor, contributes to gliosis after SCI, but little is known about the effects of TrkB.T1 on the function of astrocytes. As trkB.T1 is the sole isoform of trkB receptors expressed on astrocytes, we examined the function of trkB.T1-driven astrocytes in vitro and in vivo Immunohistochemistry showed that trkB.T1(+) cells were significantly up-regulated 7 days post-injury, with sustained elevation in white matter through 8 weeks. The latter increase was predominantly found in astrocytes. TrkB.T1 was also highly expressed by neurons and microglia/macrophages at 7 days post-injury and declined by 8 weeks. RNA sequencing of cultured astrocytes derived from trkB.T1(+/+) (WT) and trkB.T1(-/-) (KO) mice revealed down-regulation of migration and proliferation pathways in KO astrocytes. KO astrocytes also exhibited slower migration/proliferation in vitro in response to FBS or BDNF as compared to WT astrocytes. Reduced proliferation of astrocytes was also confirmed after SCI in astrocyte specific trkB.T1 KO mice; these animals also showed reduced hyperpathic responses, utilizing mechanical allodynia and pain-related measurements on the CatWalk, along with improved motor coordination. Together, our data indicate that trkB.T1 in astrocytes contributes to neuropathic pain and neurological dysfunction following SCI, suggesting that trkB.T1 may provide a novel therapeutic target for SCI.SIGNIFICANCE STATEMENTNeuropathic pain after spinal cord injury (SCI) may in part be caused by up-regulation of the BDNF receptor trkB.T1- the only isoform of trkB receptors that is expressed on astrocytes. Here, we showed that trkB.T1 is significantly increased in the injured mouse spinal cord, where

  13. [Neuropathic pain. How to open the blackbox].

    PubMed

    Maier, C; Baron, R; Sommer, C

    2015-10-01

    This article, without presuming to be comprehensive, gives a brief outline of the development of research on neuropathic pain in Germany. Current clinical research on this subject focusses on the validation of human models, patient phenotyping, mechanism-based classification and treatment as well as on molecular pathomechanisms. This clinical research is based to a large extent on the work of several internationally recognized basic researchers in the 1990s. In particular, findings from system physiology led to the analysis of clinical phenotypes and the underlying pathophysiology. In parallel, basic research achieved international top levels through the development of innovative methods. Close cooperation, building of consortia and European networking made major contributions to the success of this research.

  14. Diagnosis and medical treatment of neuropathic pain in leprosy 1

    PubMed Central

    Arco, Rogerio Del; Nardi, Susilene Maria Tonelli; Bassi, Thiago Gasperini; Paschoal, Vania Del Arco

    2016-01-01

    ABSTRACT Objective: to identify the difficulties in diagnosing and treating neuropathic pain caused by leprosy and to understand the main characteristics of this situation. Methods: 85 patients were treated in outpatient units with reference to leprosy and the accompanying pain. We used a questionnaire known as the Douleur Neuropathic 4 test and we conducted detailed neurological exams. As a result, 42 patients were excluded from the study for not having proved their pain. Results: Out of the 37 patients that experienced pain, 22 (59.5%) had neuropathic pain (or a mixture of this pain and their existing pain) and of these 90.8% considered this pain to be moderate or severe. 81.8% of the sample suffered with this pain for more than 6 months. Only 12 (54.5%) of the patients had been diagnosed with neuropathic pain and in almost half of these cases, this pain had not been diagnosed. With reference to medical treatment (n=12) for neuropathic pain, 5 (41.6%) responded that they became better. For the other 7 (58.4%) there were no changes in relation to the pain or in some cases the pain worsened in comparison to their previous state. Statistical analysis comparing improvements in relation to the pain amongst the patients that were treated (n=12) and those that were not, showed significant differences (value p=0.020). Conclusion: we noted difficulties in diagnosing neuropathic pain for leprosy in that almost half of the patients that were studied had not had their pain diagnosed. We attributed this to some factors such as the non-adoption of the appropriate protocols which led to inadequate diagnosis and treatment that overlooked the true picture. PMID:27508904

  15. Medial plantar nerve ligation as a novel model of neuropathic pain in mice: pharmacological and molecular characterization

    PubMed Central

    Sant’Anna, Morena B.; Kusuda, Ricardo; Bozzo, Tiago A.; Bassi, Gabriel S.; Alves-Filho, José C.; Cunha, Fernando Q.; Ferreira, Sergio H.; Souza, Guilherme R.; Cunha, Thiago M.

    2016-01-01

    Peripheral neuropathic pain is a consequence of an injury/disease of the peripheral nerves. The mechanisms involved in its pathophysiology are not entirely understood. To better understand the mechanisms involved in the development of peripheral nerve injury-induced neuropathic pain, more experimental models are required. Here, we developed a novel peripheral neuropathic pain model in mice by using a minimally invasive surgery and medial plantar nerve ligation (MPNL). After MPNL, mechanical allodynia was established, and mice quickly recovered from the surgery without any significant motor impairment. MPNL causes an increased expression of ATF-3 in the sensory neurons. At 14 days after surgery, gabapentin was capable of reversing the mechanical allodynia, whereas anti-inflammatory drugs and opioids were ineffective. MPNL-induced neuropathic pain was mediated by glial cells activation and the production of TNF-α and IL-6 in the spinal cord. These results indicate MPNL as a reasonable animal model for the study of peripheral neuropathic pain, presenting analgesic pharmacological predictivity to clinically used drugs. The results also showed molecular phenotypic changes similar to other peripheral neuropathic pain models, with the advantage of a lack of motor impairment. These features indicate that MPNL might be more appropriate for the study of neuropathic pain than classical models. PMID:27230787

  16. Neuropathic cancer pain: What we are dealing with? How to manage it?

    PubMed Central

    Esin, Ece; Yalcin, Suayib

    2014-01-01

    Cancer pain is a serious health problem, and imposes a great burden on the lives of patients and their families. Pain can be associated with delay in treatment, denial of treatment, or failure of treatment. If the pain is not treated properly it may impair the quality of life. Neuropathic cancer pain (NCP) is one of the most complex phenomena among cancer pain syndromes. NCP may result from direct damage to nerves due to acute diagnostic/therapeutic interventions. Chronic NCP is the result of treatment complications or malignancy itself. Although the reason for pain is different in NCP and noncancer neuropathic pain, the pathophysiologic mechanisms are similar. Data regarding neuropathic pain are primarily obtained from neuropathic pain studies. Evidence pertaining to NCP is limited. NCP due to chemotherapeutic toxicity is a major problem for physicians. In the past two decades, there have been efforts to standardize NCP treatment in order to provide better medical service. Opioids are the mainstay of cancer pain treatment; however, a new group of therapeutics called coanalgesic drugs has been introduced to pain treatment. These coanalgesics include gabapentinoids (gabapentin, pregabalin), antidepressants (tricyclic antidepressants, duloxetine, and venlafaxine), corticosteroids, bisphosphonates, N-methyl-D-aspartate antagonists, and cannabinoids. Pain can be encountered throughout every step of cancer treatment, and thus all practicing oncologists must be capable of assessing pain, know the possible underlying pathophysiology, and manage it appropriately. The purpose of this review is to discuss neuropathic pain and NCP in detail, the relevance of this topic, clinical features, possible pathology, and treatments of NCP. PMID:24790459

  17. Neuropathic Pain in Animal Models of Nervous System Autoimmune Diseases

    PubMed Central

    Tian, David H.; Perera, Chamini J.; Moalem-Taylor, Gila

    2013-01-01

    Neuropathic pain is a frequent chronic presentation in autoimmune diseases of the nervous system, such as multiple sclerosis (MS) and Guillain-Barre syndrome (GBS), causing significant individual disablement and suffering. Animal models of experimental autoimmune encephalomyelitis (EAE) and experimental autoimmune neuritis (EAN) mimic many aspects of MS and GBS, respectively, and are well suited to study the pathophysiology of these autoimmune diseases. However, while much attention has been devoted to curative options, research into neuropathic pain mechanisms and relief has been somewhat lacking. Recent studies have demonstrated a variety of sensory abnormalities in different EAE and EAN models, which enable investigations of behavioural changes, underlying mechanisms, and potential pharmacotherapies for neuropathic pain associated with these diseases. This review examines the symptoms, mechanisms, and clinical therapeutic options in these conditions and highlights the value of EAE and EAN animal models for the study of neuropathic pain in MS and GBS. PMID:23737643

  18. Peripheral nerve stimulation for the treatment of neuropathic craniofacial pain.

    PubMed

    Slavin, K V

    2007-01-01

    Treatment of neuropathic pain in the region of head and face presents a challenging problem for pain specialists. In particular, those patients who do not respond to conventional treatment modalities usually continue to suffer from pain due to lack of reliable medical and surgical approaches. Peripheral nerve stimulation (PNS) has been used for treatment of neuropathic pain for many decades, but only recently it has been systematically applied to the craniofacial region. Here we summarize published experience with PNS in treatment of craniofacial pain and discuss some technical details of the craniofacial PNS procedure.

  19. Human surrogate models of neuropathic pain: validity and limitations.

    PubMed

    Binder, Andreas

    2016-02-01

    Human surrogate models of neuropathic pain in healthy subjects are used to study symptoms, signs, and the hypothesized underlying mechanisms. Although different models are available, different spontaneous and evoked symptoms and signs are inducible; 2 key questions need to be answered: are human surrogate models conceptually valid, ie, do they share the sensory phenotype of neuropathic pain states, and are they sufficiently reliable to allow consistent translational research?

  20. Pregabalin in Neuropathic Pain: Evidences and Possible Mechanisms

    PubMed Central

    Verma, Vivek; Singh, Nirmal; Singh Jaggi, Amteshwar

    2014-01-01

    Pregabalin is an antagonist of voltage gated Ca2+ channels and specifically binds to alpha-2-delta subunit to produce antiepileptic and analgesic actions. It successfully alleviates the symptoms of various types of neuropathic pain and presents itself as a first line therapeutic agent with remarkable safety and efficacy. Preclinical studies in various animal models of neuropathic pain have shown its effectiveness in treating the symptoms like allodynia and hyperalgesia. Clinical studies in different age groups and in different types of neuropathic pain (peripheral diabetic neuropathy, fibromyalgia, post-herpetic neuralgia, cancer chemotherapy-induced neuropathic pain) have projected it as the most effective agent either as monotherapy or in combined regimens in terms of cost effectiveness, tolerability and overall improvement in neuropathic pain states. Preclinical studies employing pregabalin in different neuropathic pain models have explored various molecular targets and the signaling systems including Ca2+ channel-mediated neurotransmitter release, activation of excitatory amino acid transporters (EAATs), potassium channels and inhibition of pathways involving inflammatory mediators. The present review summarizes the important aspects of pregabalin as analgesic in preclinical and clinical studies as well as focuses on the possible mechanisms. PMID:24533015

  1. Methylcobalamin ameliorates neuropathic pain induced by vincristine in rats

    PubMed Central

    Xu, Jing; Wang, Wei; Zhong, Xiong-Xiong; Feng, Yi-Wei; Liu, Xian-Guo

    2016-01-01

    Background Vincristine, a widely used chemotherapeutic agent, often induces painful peripheral neuropathy and there are currently no effective drugs to prevent or treat this side effect. Previous studies have shown that methylcobalamin has potential analgesic effect in diabetic and chronic compression of dorsal root ganglion model; however, whether methylcobalamin has effect on vincristine-induced painful peripheral neuropathy is still unknown. Results We found that vincristine-induced mechanical allodynia and thermal hyperalgesia, accompanied by a significant loss of intraepidermal nerve fibers in the plantar hind paw skin and an increase in the incidence of atypical mitochondria in the sciatic nerve. Moreover, in the spinal dorsal horn, the activity of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and the protein expression of p-p65 as well as tumor necrosis factor α was increased, whereas the protein expression of IL-10 was decreased following vincristine treatment. Furthermore, intraperitoneal injection of methylcobalamin could dose dependently attenuate vincristine-induced mechanical allodynia and thermal hyperalgesia, which was associated with intraepidermal nerve fibers rescue, and atypical mitochondria prevalence decrease in the sciatic nerve. Moreover, methylcobalamin inhibited the activation of NADPH oxidase and the downstream NF-κB pathway. Production of tumor necrosis factor α was also decreased and production of IL-10 was increased in the spinal dorsal horn following methylcobalamin treatment. Intrathecal injection of Phorbol-12-Myristate-13-Acetate, a NADPH oxidase activator, could completely block the analgesic effect of methylcobalamin. Conclusions Methylcobalamin attenuated vincrinstine-induced neuropathic pain, which was accompanied by inhibition of intraepidermal nerve fibers loss and mitochondria impairment. Inhibiting the activation of NADPH oxidase and the downstream NF-κB pathway, resulting in the rebalancing of

  2. Increased Spinal Cord Na+-K+-2Cl− Cotransporter-1 (NKCC1) Activity Contributes to Impairment of Synaptic Inhibition in Paclitaxel-induced Neuropathic Pain*

    PubMed Central

    Chen, Shao-Rui; Zhu, Lihong; Chen, Hong; Wen, Lei; Laumet, Geoffroy; Pan, Hui-Lin

    2014-01-01

    Microtubule-stabilizing agents, such as paclitaxel (Taxol), are effective chemotherapy drugs for treating many cancers, and painful neuropathy is a major dose-limiting adverse effect. Cation-chloride cotransporters, such as Na+-K+-2Cl− cotransporter-1 (NKCC1) and K+-Cl− cotransporter-2 (KCC2), critically influence spinal synaptic inhibition by regulating intracellular chloride concentrations. Here we show that paclitaxel treatment in rats significantly reduced GABA-induced membrane hyperpolarization and caused a depolarizing shift in GABA reversal potential of dorsal horn neurons. However, paclitaxel had no significant effect on AMPA or NMDA receptor-mediated glutamatergic input from primary afferents to dorsal horn neurons. Paclitaxel treatment significantly increased protein levels, but not mRNA levels, of NKCC1 in spinal cords. Inhibition of NKCC1 with bumetanide reversed the paclitaxel effect on GABA-mediated hyperpolarization and GABA reversal potentials. Also, intrathecal bumetanide significantly attenuated hyperalgesia and allodynia induced by paclitaxel. Co-immunoprecipitation revealed that NKCC1 interacted with β-tubulin and β-actin in spinal cords. Remarkably, paclitaxel increased NKCC1 protein levels at the plasma membrane and reduced NKCC1 levels in the cytosol of spinal cords. In contrast, treatment with an actin-stabilizing agent had no significant effect on NKCC1 protein levels in the plasma membrane or cytosolic fractions of spinal cords. In addition, inhibition of the motor protein dynein blocked paclitaxel-induced subcellular redistribution of NKCC1, whereas inhibition of kinesin-5 mimicked the paclitaxel effect. Our findings suggest that increased NKCC1 activity contributes to diminished spinal synaptic inhibition and neuropathic pain caused by paclitaxel. Paclitaxel disrupts intracellular NKCC1 trafficking by interfering with microtubule dynamics and associated motor proteins. PMID:25253692

  3. Carbamazepine Withdrawal-induced Hyperalgesia in Chronic Neuropathic Pain.

    PubMed

    Ren, Zhenyu; Yang, Bing; Yang, Bin; Shi, Le; Sun, Qing-Li; Sun, A-Ping; Lu, Lin; Liu, Xiaoguang; Zhao, Rongsheng; Zhai, Suodi

    2015-11-01

    Combined pharmacological treatments are the most used approach for neuropathic pain. Carbamazepine, an antiepileptic agent, is generally used as a third-line treatment for neuropathic pain and can be considered an option only when patients have not responded to the first- and second-line medications. In the case presented herein, a patient with neuropathic pain was treated using a combined pharmacological regimen. The patient's pain deteriorated, despite increasing the doses of opioids, when carbamazepine was discontinued, potentially because carbamazepine withdrawal disrupted the balance that was achieved by the multifaceted pharmacological regimen, thus inducing hyperalgesia. Interestingly, when carbamazepine was prescribed again, the patient's pain was successfully managed. Animal research has reported that carbamazepine can potentiate the analgesic effectiveness of morphine in rodent models of neuropathic pain and postoperative pain. This clinical case demonstrates that carbamazepine may have a synergistic effect on the analgesic effectiveness of morphine and may inhibit or postpone opioid-induced hyperalgesia. We postulate that a probable mechanism of action of carbamazepine may involve -aminobutyric acid-ergic potentiation and the interruption of glutamatergic function via N-methyl-D-aspartate receptors. Further research is warranted to clarify the analgesic action of carbamazepine and its potential use for the prevention of opioid-induced hyperalgesia in chronic neuropathic pain patients.

  4. Antiepileptic drugs in the treatment of neuropathic pain.

    PubMed

    Eisenberg, Elon; River, Yaron; Shifrin, Ala; Krivoy, Norberto

    2007-01-01

    Antiepileptic drugs are an effective treatment for various forms of neuropathic pain of peripheral origin, although they rarely provide complete pain relief. Multiple multicentre randomised controlled trials have shown clear efficacy of gabapentin and pregabalin for postherpetic neuralgia and painful diabetic neuropathy. Theses drugs can be rapidly titrated and are well tolerated. Topiramate, lamotrigine, carbamazepine and oxcarbazepine are alternatives for the treatment of painful diabetic neuropathy, but should be titrated slowly. Carbamazepine remains the drug of choice for trigeminal neuralgia; however, oxcarbazepine and lamotrigine are potential alternatives. There is an apparent need for large-scale randomised controlled trials on the efficacy of antiepileptic drugs in neuropathic pain in general, and in cancer-related neuropathic pain and neuropathic pain of central origin in particular. Trials with long-term follow-up are required to establish the long-term efficacy of antiepileptic drugs in neuropathic pain. There is only limited scientific evidence to support the idea that drug combinations are likely to be more efficacious and safer than each drug alone; further studies are warranted in this area.

  5. Early postoperative neuropathic pain assessed by the DN4 score predicts an increased risk of persistent postsurgical neuropathic pain.

    PubMed

    Beloeil, Helene; Sion, Barthelemy; Rousseau, Chloe; Albaladejo, Pierre; Raux, Mathieu; Aubrun, Frederic; Martinez, Valeria

    2017-10-01

    Acute neuropathic pain can occur in the postoperative period but any link with persistent post-surgical neuropathic pain remains unclear. The objectives of this study were to prospectively describe the incidence of acute post-surgical neuropathic pain in a large population using the DN4 (clinician administered) questionnaire and to confirm the hypothetical link between acute and persistent neuropathic pain at 2 months after surgery in a large population using the DN2 (self administered) questionnaire. A multi-centre, prospective and observational trial. Two consecutive days in 27 hospitals in France. Six hundred and eight patients undergoing 13 different types of surgery. Fifteen patients were excluded as data were incomplete, and 229 (38.6%) and 260 (43.8%) were not contactable for assessment at 1 and 2 months after surgery, respectively. Pain was evaluated at least 2 h postoperatively on the same day (D0),on the second day (D2) and at 1 and 2 months after surgery (M1 and M2). Pain was assessed using a 10-point Numeric Rating Scale. If the Numeric Rating Scale score was greater than 0, neuropathic pain was assessed using a DN4 (clinician administered) questionnaire or using a DN2 (self-administered) questionnaire. Acute and persistent postsurgical neuropathic pain (PPSNP) were defined respectively by a DN4 score at least 4/10 on day 0 and/or day 2 and a DN2 score at least 3/7 at 2 months after surgery. Of the 593 patients included, 41.2% were in pain before surgery and 8.2% described neuropathic pain. Early after surgery, the majority of the 593 patients (72.2% on the day of surgery and 71.3% on day 2) experienced acute pain. It was neuropathic in nature in 5.6% of patients (95% CI, 3.6 to 8.3) on the day of surgery and 12.9% (95% CI, 9.7 to 16.7) on day 2. Two months after surgery, PPSNP was present in 33.3% of the 333 patients assessed. Multivariate analysis showed that a DN4 score at least 4/10 on the day of surgery or on day 2 was a significant risk factor

  6. Food-Derived Natural Compounds for Pain Relief in Neuropathic Pain

    PubMed Central

    Lim, Eun Yeong

    2016-01-01

    Neuropathic pain, defined as pain caused by a lesion or disease of the somatosensory nervous system, is characterized by dysesthesia, hyperalgesia, and allodynia. The number of patients with this type of pain has increased rapidly in recent years. Yet, available neuropathic pain medicines have undesired side effects, such as tolerance and physical dependence, and do not fully alleviate the pain. The mechanisms of neuropathic pain are still not fully understood. Injury causes inflammation and immune responses and changed expression and activity of receptors and ion channels in peripheral nerve terminals. Additionally, neuroinflammation is a known factor in the development and maintenance of neuropathic pain. During neuropathic pain development, the C-C motif chemokine receptor 2 (CCR2) acts as an important signaling mediator. Traditional plant treatments have been used throughout the world for treating diseases. We and others have identified food-derived compounds that alleviate neuropathic pain. Here, we review the natural compounds for neuropathic pain relief, their mechanisms of action, and the potential benefits of natural compounds with antagonistic effects on GPCRs, especially those containing CCR2, for neuropathic pain treatment. PMID:27891521

  7. Food-Derived Natural Compounds for Pain Relief in Neuropathic Pain.

    PubMed

    Lim, Eun Yeong; Kim, Yun Tai

    2016-01-01

    Neuropathic pain, defined as pain caused by a lesion or disease of the somatosensory nervous system, is characterized by dysesthesia, hyperalgesia, and allodynia. The number of patients with this type of pain has increased rapidly in recent years. Yet, available neuropathic pain medicines have undesired side effects, such as tolerance and physical dependence, and do not fully alleviate the pain. The mechanisms of neuropathic pain are still not fully understood. Injury causes inflammation and immune responses and changed expression and activity of receptors and ion channels in peripheral nerve terminals. Additionally, neuroinflammation is a known factor in the development and maintenance of neuropathic pain. During neuropathic pain development, the C-C motif chemokine receptor 2 (CCR2) acts as an important signaling mediator. Traditional plant treatments have been used throughout the world for treating diseases. We and others have identified food-derived compounds that alleviate neuropathic pain. Here, we review the natural compounds for neuropathic pain relief, their mechanisms of action, and the potential benefits of natural compounds with antagonistic effects on GPCRs, especially those containing CCR2, for neuropathic pain treatment.

  8. New developments in the pharmacotherapy of neuropathic chronic pelvic pain.

    PubMed

    Carey, Erin T; As-Sanie, Sawsan

    2016-12-01

    Advancements in further understanding the pathophysiology of chronic pelvic pain syndromes continue to direct therapy. The mechanisms of chronic pelvic pain are often multifactorial and therefore require a multidisciplinary approach. The final treatment plan is often an accumulation of organ-specific treatment and chronic pain medications directed to the CNS and PNS. This article is a review of commonly used medications for chronic pelvic neuropathic pain disorders as well as an introduction to recent innovative developments in pain medicine.

  9. New developments in the pharmacotherapy of neuropathic chronic pelvic pain

    PubMed Central

    Carey, Erin T; As-Sanie, Sawsan

    2016-01-01

    Advancements in further understanding the pathophysiology of chronic pelvic pain syndromes continue to direct therapy. The mechanisms of chronic pelvic pain are often multifactorial and therefore require a multidisciplinary approach. The final treatment plan is often an accumulation of organ-specific treatment and chronic pain medications directed to the CNS and PNS. This article is a review of commonly used medications for chronic pelvic neuropathic pain disorders as well as an introduction to recent innovative developments in pain medicine. PMID:28116131

  10. Factors Determining Outcome After Trigeminal Nerve Surgery for Neuropathic Pain.

    PubMed

    Zuniga, John R; Yates, David M

    2016-07-01

    Most patients who seek relief from trigeminal neuropathic pain by trigeminal microneurosurgery techniques do not show permanent pain relief after surgery. However, a small number of patients have permanent relief after surgery. The objective of this study was to determine factors that might be associated with the resolution, decrease, or recurrence of neuropathic pain after trigeminal nerve surgery in those patients who present with neuropathic pain before surgery. An ambispective study design was used to assess patients who underwent trigeminal nerve repair of the inferior alveolar and lingual nerve who had documented neuropathic pain before surgery from 2006 through 2014. The primary endpoint was the difference in pain intensity at 3, 6, and 12 months after surgery compared with presurgical intensity levels. Explanatory variables, including age at surgery, gender, site of nerve injury, etiology of nerve injury, classification of nerve injury, duration from injury to repair, health comorbidities, and type of repair performed, were evaluated as potential factors in the outcomes. Wilcoxon signed rank analysis was used to compare demographic and injury characteristics of patients who had pain relief, partial pain relief, and no pain relief after surgery. Two-way analysis of variance and logistic regression analysis were used to evaluate the association between neuropathic pain and the explanatory variables. Twenty-eight patients met the inclusion criteria. Three cohorts of patients were identified and analyzed. The no-recurrence cohort included 7 patients who had neuropathic pain before surgery that was resolved with surgery. The complete-recurrence (CR) cohort included 10 patients who had neuropathic pain before surgery and complete recurrence of pain intensity after surgery. The incomplete-recurrence (ICR) cohort included 11 patients who had neuropathic pain before surgery and partial recurrence of pain intensity after surgery. There was no statistical difference

  11. Transient receptor potential channel polymorphisms are associated with the somatosensory function in neuropathic pain patients.

    PubMed

    Binder, Andreas; May, Denisa; Baron, Ralf; Maier, Christoph; Tölle, Thomas R; Treede, Rolf-Detlef; Berthele, Achim; Faltraco, Frank; Flor, Herta; Gierthmühlen, Janne; Haenisch, Sierk; Huge, Volker; Magerl, Walter; Maihöfner, Christian; Richter, Helmut; Rolke, Roman; Scherens, Andrea; Uçeyler, Nurcan; Ufer, Mike; Wasner, Gunnar; Zhu, Jihong; Cascorbi, Ingolf

    2011-03-29

    Transient receptor potential channels are important mediators of thermal and mechanical stimuli and play an important role in neuropathic pain. The contribution of hereditary variants in the genes of transient receptor potential channels to neuropathic pain is unknown. We investigated the frequency of transient receptor potential ankyrin 1, transient receptor potential melastin 8 and transient receptor potential vanilloid 1 single nucleotide polymorphisms and their impact on somatosensory abnormalities in neuropathic pain patients. Within the German Research Network on Neuropathic Pain (Deutscher Forscbungsverbund Neuropathischer Schmerz) 371 neuropathic pain patients were phenotypically characterized using standardized quantitative sensory testing. Pyrosequencing was employed to determine a total of eleven single nucleotide polymorphisms in transient receptor potential channel genes of the neuropathic pain patients and a cohort of 253 German healthy volunteers. Associations of quantitative sensory testing parameters and single nucleotide polymorphisms between and within groups and subgroups, based on sensory phenotypes, were analyzed. Single nucleotide polymorphisms frequencies did not differ between both the cohorts. However, in neuropathic pain patients transient receptor potential ankyrin 1 710G>A (rs920829, E179K) was associated with the presence of paradoxical heat sensation (p = 0.03), and transient receptor potential vanilloid 1 1911A>G (rs8065080, I585V) with cold hypoalgesia (p = 0.0035). Two main subgroups characterized by preserved (1) and impaired (2) sensory function were identified. In subgroup 1 transient receptor potential vanilloid 1 1911A>G led to significantly less heat hyperalgesia, pinprick hyperalgesia and mechanical hypaesthesia (p = 0.006, p = 0.005 and p<0.001) and transient receptor potential vanilloid 1 1103C>G (rs222747, M315I) to cold hypaesthesia (p = 0.002), but there was absence of associations in subgroup 2. In

  12. Transient Receptor Potential Channel Polymorphisms Are Associated with the Somatosensory Function in Neuropathic Pain Patients

    PubMed Central

    Baron, Ralf; Maier, Christoph; Tölle, Thomas R.; Treede, Rolf-Detlef; Berthele, Achim; Faltraco, Frank; Flor, Herta; Gierthmühlen, Janne; Haenisch, Sierk; Huge, Volker; Magerl, Walter; Maihöfner, Christian; Richter, Helmut; Rolke, Roman; Scherens, Andrea; Üçeyler, Nurcan; Ufer, Mike; Wasner, Gunnar; Zhu, Jihong; Cascorbi, Ingolf

    2011-01-01

    Transient receptor potential channels are important mediators of thermal and mechanical stimuli and play an important role in neuropathic pain. The contribution of hereditary variants in the genes of transient receptor potential channels to neuropathic pain is unknown. We investigated the frequency of transient receptor potential ankyrin 1, transient receptor potential melastin 8 and transient receptor potential vanilloid 1 single nucleotide polymorphisms and their impact on somatosensory abnormalities in neuropathic pain patients. Within the German Research Network on Neuropathic Pain (Deutscher Forscbungsverbund Neuropathischer Schmerz) 371 neuropathic pain patients were phenotypically characterized using standardized quantitative sensory testing. Pyrosequencing was employed to determine a total of eleven single nucleotide polymorphisms in transient receptor potential channel genes of the neuropathic pain patients and a cohort of 253 German healthy volunteers. Associations of quantitative sensory testing parameters and single nucleotide polymorphisms between and within groups and subgroups, based on sensory phenotypes, were analyzed. Single nucleotide polymorphisms frequencies did not differ between both the cohorts. However, in neuropathic pain patients transient receptor potential ankyrin 1 710G>A (rs920829, E179K) was associated with the presence of paradoxical heat sensation (p = 0.03), and transient receptor potential vanilloid 1 1911A>G (rs8065080, I585V) with cold hypoalgesia (p = 0.0035). Two main subgroups characterized by preserved (1) and impaired (2) sensory function were identified. In subgroup 1 transient receptor potential vanilloid 1 1911A>G led to significantly less heat hyperalgesia, pinprick hyperalgesia and mechanical hypaesthesia (p = 0.006, p = 0.005 and p<0.001) and transient receptor potential vanilloid 1 1103C>G (rs222747, M315I) to cold hypaesthesia (p = 0.002), but there was absence of associations in subgroup 2. In

  13. Conclusions: chronic pain studies of lidocaine patch 5% using the Neuropathic Pain Scale.

    PubMed

    Argoff, Charles E

    2004-01-01

    Many chronic pain patients have multiple etiologies for their pain, and accurate characterization of pain qualities and pain relief is essential for managing their pain. The ability to utilize a validated tool for assessing pain qualities and for identifying unique analgesic therapy effects on different pain qualities may assist clinicians in devising an appropriate treatment regimen. The Neuropathic Pain Scale (NPS) is a novel pain metric for characterizing pain in 10 dimensions. The ability to differentiate among pain qualities for each patient may result in a more refined and effective choice of therapy. The three research articles in this Supplement demonstrate the utility of the NPS in chronic pain patients treated with the lidocaine patch 5%, a peripherally acting medication that is not associated with systemic accumulation of the active drug. Significant reduction in the intensity of commonly reported pain qualities in patients with neuropathic and non-neuropathic chronic pain due to low-back pain, osteoarthritis, post-herpetic neuralgia, and painful diabetic neuropathy were achieved. The NPS offers clinicians a reliable means to accurately identify pain qualities associated with each individual patient and to target and assess the efficacy of various therapeutic options on those pain components. Utilizing the NPS, the lidocaine patch 5% was effective in treating chronic pain of both neuropathic and non-neuropathic origins suggesting that a given treatment's effect on various pain qualities may be consistent across pain types.

  14. Botulinum Toxin for the Treatment of Neuropathic Pain.

    PubMed

    Park, JungHyun; Park, Hue Jung

    2017-08-24

    Botulinum toxin (BoNT) has been used as a treatment for excessive muscle stiffness, spasticity, and dystonia. BoNT for approximately 40 years, and has recently been used to treat various types of neuropathic pain. The mechanism by which BoNT acts on neuropathic pain involves inhibiting the release of inflammatory mediators and peripheral neurotransmitters from sensory nerves. Recent journals have demonstrated that BoNT is effective for neuropathic pain, such as postherpetic neuralgia, trigeminal neuralgia, and peripheral neuralgia. The purpose of this review is to summarize the experimental and clinical evidence of the mechanism by which BoNT acts on various types of neuropathic pain and describe why BoNT can be applied as treatment. The PubMed database was searched from 1988 to May 2017. Recent studies have demonstrated that BoNT injections are effective treatments for post-herpetic neuralgia, diabetic neuropathy, trigeminal neuralgia, and intractable neuropathic pain, such as poststroke pain and spinal cord injury.

  15. Fractalkine/CX3CR1 signaling during neuropathic pain

    PubMed Central

    Clark, Anna K.; Malcangio, Marzia

    2014-01-01

    Chronic pain represents a major problem in clinical medicine. Whilst the acute pain that is associated with tissue injury is a protective signal that serves to maintain homeostasis, chronic pain is a debilitating condition that persists long after the inciting stimulus subsides. Chronic neuropathic pain that develops following damage or disease of the nervous system is partially treated by current therapies, leaving scope for new therapies to improve treatment outcome. Peripheral nerve damage is associated with alterations to the sensory neuroaxis that promote maladaptive augmentation of nociceptive transmission. Thus, neuropathic pain patients exhibit exaggerated responses to noxious stimuli, as well as pain caused by stimuli which are normally non-painful. Increased nociceptive input from the periphery triggers physiological plasticity and long lasting transcriptional and post-translational changes in the CNS defined as central sensitization. Nerve injury induces gliosis which contributes to central sensitization and results in enhanced communication between neurons and microglial cells within the dorsal horn. Thus, identification of mechanisms regulating neuro-immune interactions that occur during neuropathic pain may provide future therapeutic targets. Specifically, chemokines and their receptors play a pivotal role in mediating neuro-immune communication which leads to increased nociception. In particular, the chemokine Fractalkine (FKN) and the CX3CR1 receptor have come to light as a key signaling pair during neuropathic pain states. PMID:24847207

  16. Brain morphological alternation in chronic pain patients with neuropathic characteristics

    PubMed Central

    Sugimine, Satomi; Kawamichi, Hiroaki; Obata, Hideaki; Saito, Shigeru

    2016-01-01

    Background Neuropathic characteristics are highly involved in the development of chronic pain both physically and psychologically. However, little is known about the relationship between neuropathic characteristics and brain morphological alteration. Objectives The aim of this study is to investigate the mechanisms of chronic pain development by examining the above-mentioned relationships by voxel-based morphometry in patients with chronic pain. Methods First, we assessed neuropathic characteristics using the painDETECT Questionnaire in 12 chronic pain patients. Second, to assess the gray matter volume changes by voxel-based morphometry, we conducted magnetic resonance imaging of the brain. We applied multiregression analysis of these two assessment methods. Results There were significant positive correlations between painDETECT Questionnaire scores and the gray matter volume in the bilateral anterior cingulate cortex and right posterior cingulate cortex. Conclusions Our findings suggest that neuropathic characteristics strongly affect the brain regions related to modulation of pain in patients with chronic pain and, therefore, contribute to the severity of chronic pain. PMID:27284013

  17. Neuropathic Pain Referrals to a Multidisciplinary Pediatric Cancer Pain Service

    PubMed Central

    Anghelescu, Doralina L.; Faughnan, Lane G.; Popenhagen, Mark P.; Oakes, Linda L.; Pei, Deqing; Burgoyne, Laura L.

    2012-01-01

    Objectives Neuropathic pain (NP) in children with cancer is not well characterized. We describe the prevalence of NP and the characteristics, duration of follow-up, and interventions provided for NP among patients referred to a pediatric oncology center’s pain management service. Methods Retrospective review of patient data from a 3.5-year period. Results Fifteen percent (66/439) of all referrals to our pain service were for NP (56/323 patients, 17%; 34 male, 22 female). The NP patient group had 1401 clinical visits (778 inpatient visits [55.5%] and 623 outpatient visits [44.5%]). Patients with NP had a significantly greater mean number of pain visits per consult (p=0.008) and significantly more days (median) of pain service follow-up (p <0.001) than did other patients. The most common cause of NP was cancer treatment rather than the underlying malignancy. Pharmacological management of NP was complex, often comprising 3 medications. Nonpharmacological approaches were used for 57.6% of NP referrals. Discussion NP is less frequently encountered than non-NP in children with cancer; nevertheless, it is more difficult to treat, requiring longer follow up, more clinical visits, complex pharmacological management, and the frequent addition of non-pharmacological interventions. PMID:24602431

  18. Introduction: chronic pain studies of the lidocaine patch 5% using the Neuropathic Pain Scale.

    PubMed

    Jensen, Mark P

    2004-01-01

    The manifestation of pain in any individual patient may result from a variety of underlying mechanisms that also may vary from one disease state to another. Global measures of pain intensity and relief are inadequate for characterizing specific pain qualities or identifying the unique effects of pain treatments on different pain qualities. The Neuropathic Pain Scale (NPS) is a recently developed measure designed to assess distinct pain qualities and may allow differentiation of therapeutic effects, even in cases where global pain response may be similar. Three studies are presented that provide preliminary evidence for the utility of the NPS for characterizing distinct pain qualities and changes in pain qualities in patients treated with the lidocaine patch 5% for a variety of neuropathic and non-neuropathic chronic pain conditions, including low-back pain, osteoarthritis, post-herpetic neuralgia, and painful diabetic neuropathy.

  19. Recent advances in pharmacological treatment of neuropathic pain.

    PubMed

    Finnerup, Nanna Brix; Sindrup, Søren Hein; Jensen, Troels Staehelin

    2010-07-14

    Recent studies investigating the pharmacological management of neuropathic pain support the efficacy of certain antidepressants, anticonvulsants, and opioids. Novel directions in drug applications include topical applications of patches with either lidocaine or capsaicin and intradermal injections of botulinum toxin. In cases of partial pain relief, drug combinations may be considered.

  20. Pregabalin in post traumatic neuropathic pain: Case studies

    PubMed Central

    Singh, Rakesh Kumar; Sinha, Vijay Prakash; Pal, U. S.; Yadav, Sharad C.; Singh, Maneesh K.

    2012-01-01

    Pregabalin is effective in the treatment of peripheral and central neuropathic pain. This study evaluated the effectiveness of pregablin in management of post traumatic peripheral nerve injury facial pain not responding to other medication like analgesics. Pregabalin was well tolerated. The most common adverse effects were dizziness and tiredness. PMID:23251069

  1. Cortical disinhibition in diabetic patients with neuropathic pain.

    PubMed

    Turgut, N; Altun, B U

    2009-12-01

    Motor cortex disinhibition has a role in the mechanism of neuropathic pain. The duration of the cortical silent period (CSP) is used as a measure of excitability in cortical inhibitory circuits. We investigated cortical disinhibition in diabetic patients with and without neuropathic pain. We studied diabetic patients with (n = 20) and without (n = 50) neuropathic pain, and control subjects (n = 30). Transcranial magnetic stimulation (TMS) was performed on the right hemisphere at rest, and surface electromyography was recorded from the left first dorsal interosseous muscle for evaluation of motor evoked potential (MEP) latency and amplitude. CSP was recorded from the left FDI, and TMS was then delivered while the subject was performing a voluntary contraction. We showed a low resting motor threshold, a short CSP duration, and a low CSP duration/MEP amplitude ratio in patients with neuropathic pain (P < 0.0001, P < 0.0001, P < 0.0001). Our findings demonstrate that diabetic patients with neuropathic pain have a cortical disinhibition.

  2. Fat Grafting for Neuropathic Pain After Severe Burns.

    PubMed

    Fredman, Rafi; Edkins, Renee E; Hultman, Charles Scott

    2016-06-01

    Chronic neuropathic pain after burn injury is a significant problem that affects up to 29% of burn patients. Neuropathic burn scar pain is a challenge for plastic and burn surgeons, who have limited solutions. Fat grafting, with its mechanical and regenerative qualities, can improve neuropathic pain from various traumatic and postsurgical etiologies, but its effectiveness in neuropathic burn scar pain has yet to be demonstrated. In this study, the possible role of lipotransfer in treating neuropathic burn scar pain is explored, focusing on safety, graft take, and short-term efficacy. We performed an institutional review board-approved, retrospective case review of 7 patients with chronic, refractory neuropathic pain, who underwent fat grafting to burn scars. These patients had failed conventional therapy, which included pharmacologic, medical, and laser treatment of the burn scars. Each patient had 2 sessions of fat grafting, spaced 2 months apart. The Patient-Reported Outcomes Measurement Information System (PROMIS) was used to assess pain perception, with patients answering the questionnaire before and after fat grafting, to assess subjective outcomes. Six of 7 patients had improvement in neuropathic pain after fat grafting, permitting reduction in their neuropharmacologic regimen. Tinel sign, present in all patients preoperatively, was absent on examination in all patients at follow-up. Three of the 5 patients who completed PROMIS questionnaires had PROMIS scores indicating improvement in pain by 1-year follow-up. One patient had similar preoperative and postoperative PROMIS scores, and 1 patient had an increase in pain at follow-up; however, he had suffered an additional burn to the same extremity. Analysis of pooled mean PROMIS scores reflects a statistically significant improvement in subjective outcomes by 1-year follow-up. Donor-site seroma in 1 patient was the only complication, with no cases of infection, wound breakdown, or graft loss. Adipose tissue can

  3. Histamine-induced itch converts into pain in neuropathic hyperalgesia.

    PubMed

    Baron, R; Schwarz, K; Kleinert, A; Schattschneider, J; Wasner, G

    2001-11-16

    Physiologically, itch and pain are transmitted in separate specific peripheral C-units and central afferent pathways. Some neuropathic pain patients with intact but sensitized (irritable) primary C-nociceptors have spontaneous pain, heat hyperalgesia, static and dynamic mechanical hyperalgesia. The question was whether cutaneous histamine application induces pain in these patients. For comparison histamine was applied into normal skin experimentally sensitized by capsaicin. Histamine application in the capsaicin-induced primary or secondary hyperalgesic skin did not change the intensity and quality of capsaicin pain. Itch was profoundly inhibited. Conversely, histamine application in neuropathic skin induced severe increase in spontaneous burning pain but no itch. In neuropathies irritable nociceptors may express histamine receptors or induce central sensitization to histaminergic stimuli so that itch converts into pain.

  4. Is there pain with neuropathic characteristics in patients with amyotrophic lateral sclerosis? A cross-sectional study.

    PubMed

    Moisset, Xavier; Cornut-Chauvinc, Catherine; Clavelou, Pierre; Pereira, Bruno; Dallel, Radhouane; Guy, Nathalie

    2016-05-01

    Amyotrophic lateral sclerosis is a progressive debilitating and lethal disorder, characterized by degeneration of motor neurons that warrant palliative care. Pain is frequent in patients with amyotrophic lateral sclerosis and significantly impacts on quality of life. To describe pain and assess the prevalence of pain with neuropathic characteristics in patients with amyotrophic lateral sclerosis. Cross-sectional survey from March 2009 to October 2013. Amyotrophic lateral sclerosis patients underwent multidisciplinary assessment and completed questionnaires measuring the severity and impact of pain and anxiety. The Douleur Neuropathique-4 questionnaire was used to look for pain with neuropathic characteristics. Of 96 clinical evaluations, 93 were usable for analysis (age at onset: 62 ± 12.5 years; disease duration: 34 ± 33 months). The overall pain prevalence was 66%, with 9% experiencing pain with neuropathic characteristics. Pain was most often located in the neck and shoulders (38% of pain patients). Neck and shoulder pain was associated with neck (p = 0.04) and proximal upper limb muscular weakness (p = 0.02), respectively. Pain was not associated with disease duration, respiratory or nutritional parameters, but with higher anxiety scores (p = 0.01). Patients with neuropathic characteristics pain did not differ significantly from patients with or without pain, except that they had higher minimal pain intensity score (p < 0.05). Neuropathic characteristics pain was frequently spontaneous (rarely evoked) and described as numbness, burning, electric shock, tingling, and pins-and-needle. Even if amyotrophic lateral sclerosis is a disease of the motor system, pain is frequent and can rarely have neuropathic characteristics. Pain must be always sought and appropriately treated to limit quality of life impairment. © The Author(s) 2015.

  5. Antidepressants and gabapentinoids in neuropathic pain: Mechanistic insights.

    PubMed

    Kremer, Mélanie; Salvat, Eric; Muller, André; Yalcin, Ipek; Barrot, Michel

    2016-12-03

    Neuropathic pain arises as a consequence of a lesion or disease affecting the somatosensory system. It is generally chronic and challenging to treat. The recommended pharmacotherapy for neuropathic pain includes the use of some antidepressants, such as tricyclic antidepressants (TCAs) (amitriptyline…) or serotonin and noradrenaline re-uptake inhibitors (duloxetine…), and/or anticonvulsants such as the gabapentinoids gabapentin or pregabalin. Antidepressant drugs are not acute analgesics but require a chronic treatment to relieve neuropathic pain, which suggests the recruitment of secondary downstream mechanisms as well as long-term molecular and neuronal plasticity. Noradrenaline is a major actor for the action of antidepressant drugs in a neuropathic pain context. Mechanistic hypotheses have implied the recruitment of noradrenergic descending pathways as well as the peripheral recruitment of noradrenaline from sympathetic fibers sprouting into dorsal root ganglia; and importance of both α2 and β2 adrenoceptors have been reported. These monoamine re-uptake inhibitors may also indirectly act as anti-proinflammatory cytokine drugs; and their therapeutic action requires the opioid system, particularly the mu (MOP) and/or delta (DOP) opioid receptors. Gabapentinoids, which target the voltage-dependent calcium channels α2δ-1 subunit, inhibit calcium currents, thus decreasing the excitatory transmitter release and spinal sensitization. Gabapentinoids also activate the descending noradrenergic pain inhibitory system coupled to spinal α2 adrenoceptors. Gabapentinoid treatment may also indirectly impact on neuroimmune actors, like proinflammatory cytokines. These drugs are effective against neuropathic pain both with acute administration at high dose and with repeated administration. This review focuses on mechanistic knowledge concerning chronic antidepressant treatment and gabapentinoid treatment in a neuropathic pain context. Copyright © 2016 IBRO. Published by

  6. Surgical animal models of neuropathic pain: Pros and Cons.

    PubMed

    Challa, Siva Reddy

    2015-03-01

    One of the biggest challenges for discovering more efficacious drugs for the control of neuropathic pain has been the diversity of chronic pain states in humans. It is now acceptable that different mechanisms contribute to normal physiologic pain, pain arising from tissue damage and pain arising from injury to the nervous system. To study pain transmission, spot novel pain targets and characterize the potential analgesic profile of new chemical entities, numerous experimental animal pain models have been developed that attempt to simulate the many human pain conditions. Among the neuropathic pain models, surgical models have paramount importance in the induction of pain states. Many surgical animal models exist, like the chronic constriction injury (CCI) to the sciatic nerve, partial sciatic nerve ligation (pSNL), spinal nerve ligation (SNL), spared nerve injury (SNI), brachial plexus avulsion (BPA), sciatic nerve transaction (SNT) and sciatic nerve trisection. Most of these models induce responses similar to those found in causalgia, a syndrome of sustained burning pain often seen in the distal extremity after partial peripheral nerve injury in humans. Researchers most commonly use these surgical models in both rats and mice during drug discovery to screen new chemical entities for efficacy in the area of neuropathic pain. However, there is scant literature that provides a comparative discussion of all these surgical models. Each surgical model has its own benefits and limitations. It is very difficult for a researcher to choose a suitable surgical animal model to suit their experimental set-up. Therefore, particular attention has been given in this review to comparatively provide the pros and cons of each model of surgically induced neuropathic pain.

  7. EFNS guidelines on neurostimulation therapy for neuropathic pain.

    PubMed

    Cruccu, G; Aziz, T Z; Garcia-Larrea, L; Hansson, P; Jensen, T S; Lefaucheur, J-P; Simpson, B A; Taylor, R S

    2007-09-01

    Pharmacological relief of neuropathic pain is often insufficient. Electrical neurostimulation is efficacious in chronic neuropathic pain and other neurological diseases. European Federation of Neurological Societies (EFNS) launched a Task Force to evaluate the evidence for these techniques and to produce relevant recommendations. We searched the literature from 1968 to 2006, looking for neurostimulation in neuropathic pain conditions, and classified the trials according to the EFNS scheme of evidence for therapeutic interventions. Spinal cord stimulation (SCS) is efficacious in failed back surgery syndrome (FBSS) and complex regional pain syndrome (CRPS) type I (level B recommendation). High-frequency transcutaneous electrical nerve stimulation (TENS) may be better than placebo (level C) although worse than electro-acupuncture (level B). One kind of repetitive transcranial magnetic stimulation (rTMS) has transient efficacy in central and peripheral neuropathic pains (level B). Motor cortex stimulation (MCS) is efficacious in central post-stroke and facial pain (level C). Deep brain stimulation (DBS) should only be performed in experienced centres. Evidence for implanted peripheral stimulations is inadequate. TENS and r-TMS are non-invasive and suitable as preliminary or add-on therapies. Further controlled trials are warranted for SCS in conditions other than failed back surgery syndrome and CRPS and for MCS and DBS in general. These chronically implanted techniques provide satisfactory pain relief in many patients, including those resistant to medication or other means.

  8. Low Dose Vaporized Cannabis Significantly Improves Neuropathic Pain

    PubMed Central

    Wilsey, Barth; Marcotte, Thomas D.; Deutsch, Reena; Gouaux, Ben; Sakai, Staci; Donaghe, Haylee

    2013-01-01

    We conducted a double-blind, placebo-controlled, crossover study evaluating the analgesic efficacy of vaporized cannabis in subjects, the majority of whom were experiencing neuropathic pain despite traditional treatment. Thirty-nine patients with central and peripheral neuropathic pain underwent a standardized procedure for inhaling either medium dose (3.53%), low dose (1.29%), or placebo cannabis with the primary outcome being VAS pain intensity. Psychoactive side-effects, and neuropsychological performance were also evaluated. Mixed effects regression models demonstrated an analgesic response to vaporized cannabis. There was no significant difference between the two active dose groups’ results (p>0.7). The number needed to treat (NNT) to achieve 30% pain reduction was 3.2 for placebo vs. low dose, 2.9 for placebo vs. medium dose, and 25 for medium vs. low dose. As these NNT are comparable to those of traditional neuropathic pain medications, cannabis has analgesic efficacy with the low dose being, for all intents and purposes, as effective a pain reliever as the medium dose. Psychoactive effects were minimal and well-tolerated, and neuropsychological effects were of limited duration and readily reversible within 1–2 hours. Vaporized cannabis, even at low doses, may present an effective option for patients with treatment-resistant neuropathic pain. PMID:23237736

  9. Distinct roles of matrix metalloproteases in the early- and late-phase development of neuropathic pain

    PubMed Central

    Kawasaki, Yasuhiko; Xu, Zhen-Zhong; Wang, Xiaoying; Park, Jong-Yeon; Zhuang, Zhi-Ye; Tan, Ping-Heng; Gao, Yong-Jing; Roy, Kristine; Corfas, Gabriel; Lo, Eng H.; Ji, Ru-Rong

    2008-01-01

    Treatment of neuropathic pain, triggered by multiple insults to the nervous system, is a clinical challenge because the underlying mechanisms of neuropathic pain development remain poorly understood 1-4. Most treatments do not differentiate between different phases of neuropathic pain pathophysiology and simply focus on blocking neurotransmission, producing transient pain relief. Here, we report that early and late phase neuropathic pain development after nerve injury require different matrix metalloproteinases (MMPs). After spinal nerve ligation, MMP-9 shows a rapid and transient upregulation in injured DRG primary sensory neurons consistent with an early phase of neuropathic pain, whereas MMP-2 shows a delayed response in DRG satellite cells and spinal astrocytes consistent with a late phase of neuropathic pain. Local inhibition of MMP-9 via an intrathecal route inhibits the early phase of neuropathic pain, whereas inhibition of MMP-2 suppresses late phase of neuropathic pain. Further, intrathecal administration of MMP-9 or MMP-2 is sufficient to produce neuropathic pain symptoms. Following nerve injury, MMP-9 induces neuropathic pain through interleukin-1β cleavage and microglia activation at early times, whereas MMP-2 maintains neuropathic pain through interleukin-1β cleavage and astrocyte activation at later times. Inhibition of MMP may provide a novel therapeutic approach for the treatment of neuropathic pain at different phases. PMID:18264108

  10. Analgesic effect of piracetam on peripheral neuropathic pain induced by chronic constriction injury of sciatic nerve in rats.

    PubMed

    Mehta, Ashish K; Bhati, Yogendra; Tripathi, Chakra D; Sharma, Krishna K

    2014-08-01

    Despite immense advances in the treatment strategies, management of neuropathic pain remains unsatisfactory. Piracetam is a prototype of nootropic drugs, used to improve cognitive impairment. The present study was designed to investigate the effect of piracetam on peripheral neuropathic pain in rats. Neuropathic pain was induced by the chronic constriction injury of the sciatic nerve. Following this, piracetam was intraperitoneally administered for 2 weeks in doses of 50, 100 and 200 mg/kg, and pain was assessed by employing the behavioural tests for thermal hyperalgesia (hot plate and tail flick tests) and cold allodynia (acetone test). After the induction of neuropathic pain, significant development of thermal hyperalgesia and cold allodynia was observed. The administration of piracetam (50 mg/kg) did not have any significant effect on all the behavioural tests. Further, piracetam (100 mg/kg) also had no effect on the hot plate and tail flick tests; however it significantly decreased the paw withdrawal duration in the acetone test. Piracetam in a dose of 200 mg/kg significantly modulated neuropathic pain as observed from the increased hot plate and tail flick latencies, and decreased paw withdrawal duration (in acetone test). Therefore, the present study suggests the potential use of piracetam in the treatment of neuropathic pain, which merits further clinical investigation.

  11. The Complement System in Neuropathic and Postoperative Pain

    PubMed Central

    Fritzinger, David C.; Benjamin, Daniel E.

    2017-01-01

    Certain types of pain are major unmet medical needs that affect more than 8 percent of the population. Neuropathic pain can be caused by many pathogenic processes including injury, autoimmune disease, neurological disease, endocrine dysfunction, infection, toxin exposure, and substance abuse and is frequently resistant to available pain therapies. The same can be said of postsurgical pain, which can arise from uncontrolled inflammation around the wound site. The complement system is part of the innate immune system and can both initiate and sustain acute and chronic inflammatory pain. Here we review the complement system and original investigations that identify potential drug targets within this system. Drugs that act to inhibit the complement system could fill major gaps in our current standard of care for neuropathic pain states. PMID:28154610

  12. Ganglioside GM3 synthase depletion reverses neuropathic pain and small fiber neuropathy in diet-induced diabetic mice

    PubMed Central

    Jayaraj, Nirupa D; Wilson, Heather M; Ren, Dongjun; Flood, Kelsey; Wang, Xiao-Qi; Shum, Andrew; Miller, Richard J; Paller, Amy S

    2016-01-01

    Background Small fiber neuropathy is a well-recognized complication of type 2 diabetes and has been shown to be responsible for both neuropathic pain and impaired wound healing. In previous studies, we have demonstrated that ganglioside GM3 depletion by knockdown of GM3 synthase fully reverses impaired wound healing in diabetic mice. However, the role of GM3 in neuropathic pain and small fiber neuropathy in diabetes is unknown. Purpose Determine whether GM3 depletion is able to reverse neuropathic pain and small fibers neuropathy and the mechanism of the reversal. Results We demonstrate that GM3 synthase knockout and the resultant GM3 depletion rescues the denervation in mouse footpad skin and fully reverses the neuropathic pain in diet-induced obese diabetic mice. In cultured dorsal root ganglia from diet-induced diabetic mice, GM3 depletion protects against increased intracellular calcium influx in vitro. Conclusions These studies establish ganglioside GM3 as a new candidate responsible for neuropathic pain and small fiber neuropathy in diabetes. Moreover, these observations indicate that systemic or topically applied interventions aimed at depleting GM3 may improve both the painful neuropathy and the wound healing impairment in diabetes by protecting against nerve end terminal degeneration, providing a disease-modifying approach to this common, currently intractable medical issue. PMID:27590073

  13. [Therapeutic advances in pharmaceutical treatment of neuropathic pain].

    PubMed

    Attal, N

    2011-12-01

    Neuropathic pain is difficult to treat. Recommended first-line treatments include tricyclic antidepressants and alpha2delta agonists pregabalin and gabapentin for multiple neuropathic conditions, the antidepressants duloxetine and venlafaxine in diabetic painful neuropathies and lidocaine patches for postherapetic neuralgia. Therapeutic prospects include focal therapy with sustained analgesic efficacy (capsaicin patches, botulinum toxin), treatments acting on new targets (i.e., cytokine inhibitors, metabotropic glutamate inhibitors, TRPV1 antagonists). The methodology of clinical trials also tends to take better into account the symptomatic profiles of patients, which should contribute to better prediction or responders to treatment.

  14. TDM-based imipramine treatment in neuropathic pain.

    PubMed

    Rasmussen, Peter V; Jensen, Troels S; Sindrup, Søren H; Bach, Flemming W

    2004-08-01

    Tricyclic antidepressants (TCA) are the best-documented treatment of neuropathic pain. TCAs have a pronounced interindividual pharmacokinetic variability and a narrow therapeutic index. The aim of this study was to characterize the plasma concentration-effect relationship of imipramine in neuropathic pain and to determine the usefulness of therapeutic drug monitoring (TDM) of TCA treatment in a population with noncancer chronic pain. To do this, 83 patients with chronic noncancer neuropathic pain were included. Information on previous use of TCA was collected, and patients were tested for the presence of hyperalgesia. Pain intensity and pain relief were recorded, and the Short Form McGill Pain Questionnaire and Major Depression Inventory were completed before and during a TDM-based imipramine treatment. Imipramine dose was increased in steps of 25 mg/d every second week, and blood samples were taken at every dose. Endpoints were best possible pain relief, unacceptable side effects, or insufficient pain relief despite plasma drug level > 500 nmol/L. Dose range used was 10-300 mg/d. The study showed that imipramine 75 mg/d caused a 36-fold interindividual variation in steady-state plasma drug concentrations. In 46 responders (global pain relief > 25%) the plasma drug concentration at which an individual maximal analgesic effect was obtained ranged from 50 to 1400 nmol/L, but for the majority it was below 400 nmol/L. The concentration-effect relationship was similar for patients with central versus peripheral neuropathic pain and independent of the presence of hyperalgesia. Previous treatment failure with non-TDM TCA treatment was not a predictor of poor response to TDM-based treatment. In conclusion, there is a pronounced interindividual variability in concentration-effect relationship for imipramine treatment in neuropathic pain, but the majority of patients obtain a maximal analgesic effect at drug levels below 400 nmol/L. The concentration-effect relationship is

  15. Neuropathic Pain in Patients with Burning Mouth Syndrome Evaluated Using painDETECT.

    PubMed

    Lopez-Jornet, Pia; Molino-Pagan, Diana; Parra-Perez, Paco; Valenzuela, Sara

    2017-01-04

    OBJECTIVE : This study set out to identify the neuropathic component of pain experienced by burning mouth syndrome (BMS) patients evaluated using painDETECT, a diagnostic tool that could easily be introduced into clinical practice. MATERIALS AND METHODS : This study included 64 patients (33 BMS and 31 suffering nociceptive pain). Each completed the painDETECT neuropathic pain questionnaire, the Hospital Anxiety and Depression Scale, and pain intensity was also measured using a visual analogue scale (VAS). RESULTS : Pain among BMS patients (evaluated by VAS) was 6.1 ± 1.9, and 4.3 ± 1.7 among nociceptive patients (P < 0.001). PainDETECT obtained total scores ≥ 19 in 21% of BMS patients, indicating the presence of neuropathic pain. When painDETECT pain descriptors were analyzed comparing the BMS group with nociceptive pain subjects, statistically significant differences were found for burning sensation (P < 0.010), prickling (P < 0.001), electric shock-like sensation (P = 0.046), thermal sensation (P < 0.001), and numbness (P = 0.002). Logistic regression analysis found that VAS scoring was the strongest determinant predicting neuropathic pain. CONCLUSION : The present study suggests that almost a third of BMS patients present neuropathic pain, which is strongly associated with the intensity of pain measured using VAS. These data could provide the basis for further research.

  16. Effect of antioxidant treatment on spinal GABA neurons in a neuropathic pain model in the mouse.

    PubMed

    Yowtak, June; Wang, Jigong; Kim, Hee Young; Lu, Ying; Chung, Kyungsoon; Chung, Jin Mo

    2013-11-01

    One feature of neuropathic pain is a reduced spinal gamma-aminobutyric acid (GABA)-ergic inhibitory function. However, the mechanisms behind this attenuation remain to be elucidated. This study investigated the involvement of reactive oxygen species in the spinal GABA neuron loss and reduced GABA neuron excitability in spinal nerve ligation (SNL) model of neuropathic pain in mice. The importance of spinal GABAergic inhibition in neuropathic pain was tested by examining the effects of intrathecally administered GABA receptor agonists and antagonists in SNL and naïve mice, respectively. The effects of SNL and antioxidant treatment on GABA neuron loss and functional changes were examined in transgenic GAD67-enhanced green fluorescent protein positive (EGFP+) mice. GABA receptor agonists transiently reversed mechanical hypersensitivity of the hind paw in SNL mice. On the other hand, GABA receptor antagonists made naïve mice mechanically hypersensitive. Stereological analysis showed that the numbers of enhanced green fluorescent protein positive (EGFP+) GABA neurons were significantly decreased in the lateral superficial laminae (I-II) on the ipsilateral L5 spinal cord after SNL. Repeated antioxidant treatments significantly reduced the pain behaviors and prevented the reduction in EGFP+ GABA neurons. The response rate of the tonic firing GABA neurons recorded from SNL mice increased with antioxidant treatment, whereas no change was seen in those recorded from naïve mice, which suggested that oxidative stress impaired some spinal GABA neuron activity in the neuropathic pain condition. Together the data suggest that neuropathic pain, at least partially, is attributed to oxidative stress, which induces both a GABA neuron loss and dysfunction of surviving GABA neurons. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  17. Low-dose vaporized cannabis significantly improves neuropathic pain.

    PubMed

    Wilsey, Barth; Marcotte, Thomas; Deutsch, Reena; Gouaux, Ben; Sakai, Staci; Donaghe, Haylee

    2013-02-01

    We conducted a double-blind, placebo-controlled, crossover study evaluating the analgesic efficacy of vaporized cannabis in subjects, the majority of whom were experiencing neuropathic pain despite traditional treatment. Thirty-nine patients with central and peripheral neuropathic pain underwent a standardized procedure for inhaling medium-dose (3.53%), low-dose (1.29%), or placebo cannabis with the primary outcome being visual analog scale pain intensity. Psychoactive side effects and neuropsychological performance were also evaluated. Mixed-effects regression models demonstrated an analgesic response to vaporized cannabis. There was no significant difference between the 2 active dose groups' results (P > .7). The number needed to treat (NNT) to achieve 30% pain reduction was 3.2 for placebo versus low-dose, 2.9 for placebo versus medium-dose, and 25 for medium- versus low-dose. As these NNTs are comparable to those of traditional neuropathic pain medications, cannabis has analgesic efficacy with the low dose being as effective a pain reliever as the medium dose. Psychoactive effects were minimal and well tolerated, and neuropsychological effects were of limited duration and readily reversible within 1 to 2 hours. Vaporized cannabis, even at low doses, may present an effective option for patients with treatment-resistant neuropathic pain. The analgesia obtained from a low dose of delta-9-tetrahydrocannabinol (1.29%) in patients, most of whom were experiencing neuropathic pain despite conventional treatments, is a clinically significant outcome. In general, the effect sizes on cognitive testing were consistent with this minimal dose. As a result, one might not anticipate a significant impact on daily functioning. Published by Elsevier Inc.

  18. P2X4R+ microglia drive neuropathic pain

    PubMed Central

    Beggs, Simon; Trang, Tuan; Salter, Michael W

    2016-01-01

    Neuropathic pain, the most debilitating of all clinical pain syndromes, may be a consequence of trauma, infection or pathology from diseases that affect peripheral nerves. Here we provide a framework for understanding the spinal mechanisms of neuropathic pain as distinct from those of acute pain or inflammatory pain. Recent work suggests that a specific microglia response phenotype characterized by de novo expression of the purinergic receptor P2X4 is critical for the pathogenesis of pain hypersensitivity caused by injury to peripheral nerves. Stimulating P2X4 receptors initiates a core pain signaling pathway mediated by release of brain-derived neurotrophic factor, which produces a disinhibitory increase in intracellular chloride in nociceptive (pain-transmitting) neurons in the spinal dorsal horn. The changes caused by signaling from P2X4R+ microglia to nociceptive transmission neurons may account for the main symptoms of neuropathic pain in humans, and they point to specific interventions to alleviate this debilitating condition. PMID:22837036

  19. Neuropathic pain in the orofacial region: The role of pain history. A retrospective study.

    PubMed

    Dieb, W; Moreau, N; Chemla, I; Descroix, V; Boucher, Y

    2017-06-01

    Orofacial neuropathic pain is often difficult to treat, mostly because of still unclear underlying mechanisms. The occurrence of such neuropathic pain varies depending on different factors, of which preexisting preoperative pain seems to be of high importance. The aim of this study was thus to test the hypothesis that prior history of pain could indeed be considered a risk factor for the development of orofacial neuropathic pain in the same region. The study was performed in the dental department of the Groupe Hospitalier Pitié-Salpêtrière (GHPS) in Paris, France. We investigated the presence of prior inflammatory pain before development of orofacial neuropathic pain in 56 patients. For each patient file, the following items were collected: age, gender; medical history; diagnosis; description of the pain (at time of consultation); presence or absence of prior dental treatment; date and type of dental treatment received. 41 patients (73%) of orofacial neuropathic pain patients had a history of pain compatible with an inflammatory condition; 4% (n=2) did not report any prior pain and 23% (n=13) could not remember. Among the patients with documented history of pain prior to neuropathy, 88% (n=36) received surgical treatment; 61%, (n=25) endodontic treatment and 22%, (n=9) restorative treatment. All eventually received endodontic treatment or tooth extraction. These dental treatments are compatible with the hypothesis of prior inflammatory pain in these patients. These results support the hypothesis that prior inflammatory pain could favor the development of orofacial neuropathic pain. Prevention and treatment of inflammatory trigeminal pain may therefore play a key role in preventing future neuropathic pain development. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  20. Cerebral stimulation for the affective component of neuropathic pain.

    PubMed

    Machado, Andre G; Baker, Kenneth B; Plow, Ela; Malone, Donald A

    2013-01-01

    To review the current state of cerebral stimulation for neuropathic pain and to propose that cerebral stimulation should aim also at the affective sphere of chronic pain rather than solely focusing on the primary sensory-discriminative sphere. The past and current goals of cerebral stimulation are reviewed as well as its limitations. A novel deep brain stimulation approach is proposed to evaluate this conceptual shift from somatosensory to affective sphere of pain targeting. Thalamic and other central pain syndromes are typically intractable to current treatment methods, including cerebral neuromodulation of somatosensory pathways, leading to long-term distress and disability. Our modern understanding of chronic pain pathophysiology is based largely on the neuromatrix theory, where cognitive, affective, and sensory-discriminative spheres contribute equally to the overall pain experience. During the last decade, the safety and feasibility of chronic stimulation of neural pathways related to mood and affect has been explored with promising results. Here, we propose a novel approach to modulate the affective sphere of chronic pain by targeting similar networks in patients with treatment-refractory central pain. Our primary goal is not to produce (or measure) analgesia, but rather to modulate the affective burden of chronic pain. Cerebral neuromodulation for neuropathic pain has had limited efficacy thus far. Shifting our aim to neural networks related to the affective sphere of pain may allow us to reduce pain conditioning and pain-related disability. Our ultimate goal is to promote rehabilitation from chronic pain-social and occupational. © 2012 International Neuromodulation Society.

  1. Duloxetine in the management of diabetic peripheral neuropathic pain

    PubMed Central

    Ormseth, Michelle J; Scholz, Beth A; Boomershine, Chad S

    2011-01-01

    Diabetic neuropathy affects up to 70% of diabetics, and diabetic peripheral neuropathic pain (DPNP) is the most common and debilitating of the diabetic neuropathies. DPNP significantly reduces quality of life and increases management costs in affected patients. Despite the impact of DPNP, management is poor with one-quarter of patients receiving no treatment and many treated with medications having little or no efficacy in managing DPNP. Duloxetine is one of two drugs approved by the United States Food and Drug Administration for DPNP management. Duloxetine is a serotonin and norepinephrine reuptake inhibitor (SNRI) proven safe, effective, and cost-saving in reducing DPNP symptoms at a dose of 60 mg/day. Duloxetine doses greater than 60 mg/day for DPNP management are not recommended since they are no more efficacious and associated with more side effects; addition of pregabalin or gabapentin for these patients may be beneficial. Side effects of duloxetine are generally mild and typical for the SNRI class including nausea, dizziness, somnolence, fatigue, sweating, dry mouth, constipation, and diarrhea. Given its other indications, duloxetine is a particularly good choice for DPNP treatment in patients with coexisting depression, anxiety, fibromyalgia, or chronic musculoskeletal pain. Duloxetine treatment had no clinically significant effect on glycemic control and did not increase the risk of cardiovascular events in diabetes patients. However, duloxetine use should be avoided in patients with hepatic disease or severe renal impairment. Given its safety, efficacy, and tolerability, duloxetine is an excellent choice for DPNP treatment in many patients. PMID:21845034

  2. Neuropathic pain assessment: update on laboratory diagnostic tools.

    PubMed

    Mainka, Tina; Maier, Christoph; Enax-Krumova, Elena K

    2015-10-01

    The purpose of this review was to provide an update on the diagnostic tools for neuropathic pain for clinical practice. The new definition of neuropathic pain by the International Association for the Study of Pain requires confirmation of a lesion or disease affecting the somatosensory system. In addition to traditional diagnostic procedures, for example, nerve conduction studies, skin biopsies depict morphological alteration and/or rarefication of the small intraepidermal nerve fibers and were recently used to identify small fiber abnormalities, for example, in patients with fibromyalgia or sarcoidosis. Quantitative sensory testing assesses the somatosensory function including both peripheral and central pathways. A recent consensus statement discussed its diagnostic value. Corneal confocal microscopy is a noninvasive method enabling in-vivo assessment of the small nerve fibers in the cornea and also seems to identify patients at risk for developing diabetic neuropathy at an early stage and to reflect the improvement of neuropathy after treatment. Further promising methods are the microneurography and nociceptive evoked potentials; however, they are technically challenging and their diagnostic value for clinical practice has yet to be confirmed. For diagnosing neuropathic pain, confirmation of a lesion or disease affecting the somatosensory system is needed. Better clinical phenotyping will hopefully enable individualized mechanism-based treatment of neuropathic pain.

  3. Evaluation of anticonvulsants for possible use in neuropathic pain.

    PubMed

    Waszkielewicz, A M; Gunia, A; Słoczyńska, K; Marona, H

    2011-01-01

    Neuropathic pain is a kind of pain related with functional abnormality of neurons. Despite large progress in pharmacotherapy, neuropathic pain is still considered an unmet need. Nowadays, there are few drugs registered for this condition, such as pregabalin, gabapentin, duloxetine, carbamazepine, and lidocaine. Among them, pregabalin, gabapentin and carbamazepine are well known antiepileptic drugs. Among the group of new antiepileptic drugs, which are addressed to 1% of human world population suffering from seizures, it turned out that 30% of the seizures resistant to pharmacotherapy has not enough market to justify the costs of drug development. Therefore, it is already a phenomenon that researchers turn their projects toward a larger market, related with possible similar mechanism. Anticonvulsant mechanism of action is in the first place among primary indications for drugs revealing potential analgesic activity. Therefore, many drug candidates for epilepsy, still in preclinical stage, are being evaluated for activity in neuropathic pain. This review is focusing on antiepileptic drugs, which are evaluated for their analgesic activity in major tests related with neuropathic pain. Relation between structure, mechanism of action and result in tests such as the Chung model (spinal nerve ligation SNL), the Bennett model (chronic constriction injury of sciatic nerve CCI) and other tests are considered. The first examples are carbamazepine, gabapentin, and lacosamide as drugs well established in epilepsy market as well as drug candidates such as valnoctamide, and other valproic acid derivatives, novel biphenyl pyrazole derivatives, etc. Moreover, clinical efficacy related with listed animal models has been discussed.

  4. Neuropathic pain in cancer patients treated with bortezomib.

    PubMed

    Expósito Vizcaíno, S; Casanova-Mollà, J; Escoda, L; Galán, S; Miró, J

    2016-07-27

    The neuropathic pain is the most habitual problem in the neuropathy induced by chemotherapy (NIQ) and the one that more interferes in the quality of life of the patients. His precocious detection turns out to be fundamental to reduce or to eliminate the problems that from this one stem. The aims of this study were: 1) determine the incident and NIQ's characteristics and neuropathic pain in patients with mieloma multiple (MM) treated with bortezomib, and 2) to evaluate the impact of the neuropathic pain in the activities of the daily life (AVD). All the patients diagnosed of MM candidates for treatment with bortezomib attended in the Hospital Joan XXIII during 2013, took part. The participants were interviewed individually and were reporting on the presence, the characteristics and the impact of the pain, as well as of the adverse effects of the bortezomib. There took part 22 persons, of which NIQ presented the half, being the degree 2 the predominant one. The most habitual location of the neuropathic pain was hands and feet; it was appearing in a spontaneous and progressive way deteriorating in rest and during the night, with predominance of positive symptoms. The impact of the pain was reflected in all the AVD. The principal limitation was the disability to enjoy the life. The peripheral neuropathy occupied the first place in order of subjective importance for the patient followed by the fatigue and the constipation. A proper assessment and early detection of neuropathic pain is critical to minimizing its impact on the quality of life of patients. Copyright © 2016 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  5. Amitriptyline effectively relieves neuropathic pain following treatment of breast cancer.

    PubMed

    Kalso, E; Tasmuth, T; Neuvonen, P J

    1996-02-01

    The effectiveness of amitriptyline in relieving neuropathic pain following treatment of breast cancer was studied in 15 patients in a randomised, double-blind placebo-controlled crossover study. The dose was escalated from 25 mg to 100 mg per day in 4 weeks. The placebo and amitriptyline phases were separated by a 2-week wash-out period. Visual analogue and verbal rating scales were used for the assessment of pain intensity and pain relief. Other measures included the number of daily activities disturbed by the pain, the Finnish McGill Pain Questionnaire, adverse effects, anxiety, depression, pressure threshold and grip strength. Amitriptyline significantly relieved neuropathic pain both in the arm and around the breast scar. Eight out of 15 patients had a more than 50% decrease in the pain intensity ('good responders') with a median dose of 50 mg of amitriptyline. The 7 patients who had a less than 50% effect had drug concentrations equaling those of the good responders. The 'poor responders' reported significantly more adverse effects with amitriptyline and placebo than the good responders. It is concluded that amitriptyline effectively reduced neuropathic pain following treatment of breast cancer. However, the adverse effects of amitriptyline put most of the patients off from using the drug regularly.

  6. Surgically-Induced Neuropathic Pain (SNPP): Understanding the Perioperative Process

    PubMed Central

    Borsook, David; Kussman, Barry D.; George, Edward; Becerra, Lino R.; Burke, Dennis W.

    2012-01-01

    Objective Nerve damage takes place during surgery. As a consequence, significant numbers (10–40%) of patients experience chronic neuropathic pain termed surgically induced neuropathic pain (SNPP). Background The initiating surgery and nerve damage set off a cascade of events that includes both pain and an inflammatory response, resulting in ‘peripheral’ and ‘central sensitization’, with the latter resulting from repeated barrages of neural activity from nociceptors. In affected patients these initial events produce chemical, structural and functional changes in the peripheral (PNS) and central nervous (CNS) systems. The maladaptive changes in damaged nerves lead to peripheral manifestations of the neuropathic state – allodynia, sensory loss, shooting pains etc., that can manifest long after the effects of the surgical injury have resolved. The CNS manifestations that occur are termed ‘centralization of pain’ and affect sensory, emotional and other (e.g., cognitive) systems as well as contributing to some of the manifestations of the chronic pain syndrome (e.g., depression). Conclusions Currently there are no objective measures of pain in the peri-operative period. As such intermittent pain or continuous may take place during and after surgery. New technologies including direct measures of specific brain function of nociception and new insights into preoperative evaluation of patients including genetic predisposition appear to provide initial opportunities for decreasing the burden of SNPP until treatments with high efficacy and low side effects that either prevent or treat pain are discovered. PMID:23059501

  7. Cerebral stimulation for the affective component of neuropathic pain

    PubMed Central

    Machado, Andre G.; Baker, Kenneth B.; Plow, Ela; Malone, Donald A.

    2012-01-01

    Objective To review the current state of cerebral stimulation for neuropathic pain and to propose that cerebral stimulation should aim at the affective sphere of chronic pain rather than solely focusing on the primary sensory-discriminative sphere. Methods The past and current goals of cerebral stimulation are reviewed as well as its limitations. A novel deep brain stimulation approach is proposed to evaluate this conceptual shift fromsomatosensory to affective sphere of pain targeting Approach Thalamic and other central pain syndromes aretypically intractable to current treatment methods, including cerebral neuromodulation of somatosensory pathways, leading to long-term distress and disability. Our modern understanding of chronic pain pathophysiology is based largely on the neuromatrix theory, where cognitive, affective and sensory-discriminative spheres contribute equally to the overall pain experience. During the last decade, the safety and feasibility of chronic stimulation of neural pathways related to mood and affect has been explored with promising results. Here, we propose a novel approach to modulate the affective sphere of chronic pain by targeting similar networks in patients with treatment-refractory central pain. Our primary goal is not to produce (or measure) analgesia, but rather to modulate the affective burden of chronic. Discussion Cerebral neuromodulation for neuropathic pain has had limited efficacy thus far. Shifting our aim to neural networks related to the affective sphere of pain may allow us to reduce pain conditioning and pain-related disability. Our ultimate goal is to promote rehabilitation from chronic pain - social and occupational. PMID:23094938

  8. Ionic channels and neuropathic pain: physiopathology and applications.

    PubMed

    Aurilio, Caterina; Pota, Vincenzo; Pace, Maria Caterina; Passavanti, Maria Beatrice; Barbarisi, Manlio

    2008-04-01

    Neuropathic pain is defined by the International Association for Pain research as a pain associated to a primary lesion or a dysfunction of the central or peripheral system. Over the past few years the causes of the neuropathic pain were not known and there were not good treatments for it, now we have a better knowledge of the physiopathological aspects and there is a wider diffusion of the research for target aimed therapies. The physiologic genesis of nervous messages occurs exclusively in skin sensorial endings or in nerve tissues as a consequence of an adequate sensorial stimulus and depends on the quick variations of the electric potential difference at the endings of ionic membranes. These variations of even 500 V a second are possible because of the presence of ionic channels. In neuropathic pain impulses can be originated even from ectopic sites. Ectopic discharges originated in a peripheral neuropathic system have an important role in the early stage of neuropathic pain development in two different ways. First they give an excess of spontaneous and evoked electric impulses to the central nervous system, causing a primitive neuropathic pain signal; then the ectopic activity develops and maintains the central sensitisation process. All this amplifies the afferent signals deriving from residual efferents that go on innerving cutaneous areas damaged and partly disnerved, causing tactile allodynie. Sodium channels are the greatest responsible for electrogenesis, that is the basis of the action potential generation and its propagation. Action potential begins after a depolarization such that it could cause a membrane transitory modification, turning prevalently permeable to Na+ more than to K+ as during a release phase. Neuropathy generates a local accumulation of sodium channels, with a consequent increase of density. This remodel seems to be the basis of neuro hyperexecitably. Calcium channels have also an important role in cell working. Intracellular calcium

  9. NOX4 is an early initiator of neuropathic pain.

    PubMed

    Geis, Christian; Geuss, Eva; Sommer, Claudia; Schmidt, Harald H H W; Kleinschnitz, Christoph

    2017-02-01

    Treatment of neuropathic pain remains challenging as the etiology is heterogeneous and pathomechanisms are incompletely understood. One possible mechanism is oxidative stress due to unphysiological reactive oxygen species (ROS) formation. The only know dedicated enzymatic source of ROS are NADPH oxidases of which the type 4 isoform (NOX4) has been suggested to be involved in the subacute and chronic phase of neuropathic pain. Here, we aim to translate this finding into a treatment strategy by examining the efficacy of the NOX1/4-specific inhibitor GKT136901 using the chronic constriction injury (CCI) mouse model of neuropathic pain. Unexpectedly, post-nerve lesion treatment using GKT136901 was ineffective to reduce pain-related behavior after CCI. We therefore re-investigated the role of NOX4 using an independent KO mouse model. Early after CCI we found an increase in pro-inflammatory cytokines, ROS formation and the oxidative stress marker nitrotyrosine in the lesioned nerve together with an upregulated Nox4 gene expression. In NOX4 KO mice, mechanical allodynia was markedly reduced from day 4 after nerve injury as were all ROS related and acute biomarkers. In addition, we observed a reduction in the CCI-induced upregulation of pro-inflammatory cytokines in the sciatic nerve and dorsal root ganglia along with NOX4-deficiency. Thus, we conclude that NOX4 is involved in the development of neuropathic pain states by producing oxidative stress and subsequent cytokine dysregulation at the lesion site. This appears at very early stages immediately after nerve injury explaining ineffectiveness of post-acute pharmacological NOX inhibition. We suggest that future target validation of NOX4 should now focus on defining the possible therapeutic window in human neuropathic pain. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Neutropenia occurring after starting gabapentin for neuropathic pain.

    PubMed

    Derbyshire, E; Martin, D

    2004-12-01

    We report a case of neutropenia occurring in a patient receiving gabapentin for neuropathic pain. Five weeks after treatment started, the patient was admitted to hospital with neutropenic sepsis. Gabapentin is widely used, and neutropenia is a rare adverse effect. This case highlights a serious and potential life-threatening complication.

  11. Neuropathic-like pain features and cross-sectional associations in rheumatoid arthritis.

    PubMed

    Koop, Sanne M W; ten Klooster, Peter M; Vonkeman, Harald E; Steunebrink, Laura M M; van de Laar, Mart A F J

    2015-09-03

    Increasing evidence indicates that features suggestive of neuropathic pain may also be present in patients with common rheumatic conditions. The objective of this study was to examine neuropathic-like pain symptoms and associated factors in patients with rheumatoid arthritis. We used the painDETECT screening tool to identify possible or likely neuropathic pain in 159 outpatients with rheumatoid arthritis. Patients additionally completed other self-reported measures, while clinical measures were assessed to calculate the 28-joint Disease Activity Score. Univariate analyses and multivariable logistic regression were used to identify factors associated with neuropathic pain features. According to the painDETECT, 27 patients (17.0 %) were classified as having likely neuropathic pain and 34 patients (21.4 %) as having possible neuropathic pain. Besides reporting more severe pain, patients with likely or possible neuropathic pain were more likely to meet the diagnostic criteria for fibromyalgia, to use analgesics, and to have more tender joints and a worse physical and mental health status as measured by the 36-item Short-Form health survey. In multivariable analysis, physical (P < 0.001) and mental health status (P = 0.006) remained significantly associated with neuropathic pain features, even after controlling for pain severity. These findings suggest that a sizeable proportion of patients with relatively well-controlled rheumatoid arthritis report symptoms suggestive of neuropathic pain. Neuropathic-like pain symptoms are independently associated with worse self-reported physical and mental health.

  12. [Personality and coping in neuropathic chronic pain: a predictable divorce].

    PubMed

    Soriano Pastor, José F; Monsalve Dolz, Vicente; Ibáñez Guerra, Elena; Gómez Carretero, Patricia

    2010-11-01

    We approach the problem about relationships between personality dimensions and the use of coping strategies in chronic pain patients. The most frequently used theoretical model in the area of stress and its relation to pain is the transactional model, taking into account that the incorporation of personality traits improves predictions via coping in the stress process. Following the Big Five model, the relationships between personality and coping strategies in patients with chronical neuropathic pain were established. The results showed slight relationships between the Big-Five dimensions and coping. A vulnerable personality profile in patients with chronic neuropathic pain was obtained, consisting of high neuroticism, low extraversion, openness to experience and responsibility, and moderate agreeableness.

  13. Neuromodulation of neuropathic pain syndrome induced by elapidae (cobra) envenomation.

    PubMed

    Stretanski, Michael F

    2009-01-01

    Objectives.  This study aims to demonstrate the utility of spinal cord stimulation in a neuropathic pain syndrome and overall decline in health and functional independence following elapid envenomation in a morbidly obese, insulin-dependent diabetic. Materials and Methods.  A two-lead, 16-electrode constant-current, independently controlled system is placed in the mid-cervical spine. Results.  Noted were a improvement in overall health status with better glycemic control and return to work status in response to adequate pain control. Conclusions.  The case serves as a model for other orphan pain cases with a seemingly esoteric etiology and adds to the existing body of literature that spinal cord stimulation and neuromodulation, in general, has a wide-ranging applicability peripheral neuropathic pain syndromes.

  14. How diagnostic tests help to disentangle the mechanisms underlying neuropathic pain symptoms in painful neuropathies.

    PubMed

    Truini, Andrea; Cruccu, Giorgio

    2016-02-01

    Neuropathic pain, ie, pain arising directly from a lesion or disease affecting the somatosensory afferent pathway, manifests with various symptoms, the commonest being ongoing burning pain, electrical shock-like sensations, and dynamic mechanical allodynia. Reliable insights into the mechanisms underlying neuropathic pain symptoms come from diagnostic tests documenting and quantifying somatosensory afferent pathway damage in patients with painful neuropathies. Neurophysiological investigation and skin biopsy studies suggest that ongoing burning pain primarily reflects spontaneous activity in nociceptive-fiber pathways. Electrical shock-like sensations presumably arise from high-frequency ectopic bursts generated in demyelinated, nonnociceptive, Aβ fibers. Although the mechanisms underlying dynamic mechanical allodynia remain debatable, normally innocuous stimuli might cause pain by activating spared and sensitized nociceptive afferents. Extending the mechanistic approach to neuropathic pain symptoms might advance targeted therapy for the individual patient and improve testing for new drugs.

  15. Neuropathic pain in people with cancer (part 2): pharmacological and non-pharmacological management.

    PubMed

    Taverner, Tarnia

    2015-08-01

    The aim of this paper is to provide an overview of the management of neuropathic pain associated with cancer and to provide helpful clinical advice for nurses working with patients who may have neuropathic pain. While cancer pain is a mixed-mechanism pain, this article will focus only on neuropathic pain management. The impact of neuropathic pain on patients' quality of life is great and while many patients recover from their cancer, a significant number continue to suffer from a neuropathic pain syndrome. Management of neuropathic pain is significantly different from management of nociceptive pain with respect to pharmacological and non-pharmacological strategies. Neuropathic pain is complex, and as such requires complex management using pharmacological as well as non-pharmacological approaches. Specific drugs for neuropathic pain may be effective for some patients, but not all; therefore, ongoing and comprehensive assessment and management are required. Furthermore, these patients may require trials of several drugs before they find one that works for them. It is important for nurses to understand neuropathic pain, its manifestation, impact on quality of life and management when nursing patients with neuropathic pain associated with cancer.

  16. Low doses of dextromethorphan have a beneficial effect in the treatment of neuropathic pain.

    PubMed

    Morel, Véronique; Pickering, Gisèle; Etienne, Monique; Dupuis, Amandine; Privat, Anne-Marie; Chalus, Maryse; Eschalier, Alain; Daulhac, Laurence

    2014-12-01

    N-methyl-D-aspartate receptor (NMDAR) antagonists may be given in persistent neuropathic pain, but adverse events especially with ketamine may limit their clinical use. Less central and cognitive adverse events are described with dextromethorphan and memantine. These molecules have been explored in many preclinical and clinical studies, but data are conflicting as regards neuropathic pain alleviation. Dextromethorphan and memantine have been administered to animals after spinal nerve ligation (SNL) to evaluate their antinociceptive/cognitive effects and associated molecular events, including the phosphorylation of several tyrosine (pTyr(1336), pTyr(1472)) residues in the NR2B NMDAR subunit. Spinal nerve ligation and sham animals received dextromethorphan (10 mg/kg, i.p.), memantine (20 mg/kg, i.p.) or saline (1 mL/kg, i.p.). These drugs were administered once symptoms of allodynia and hyperalgesia had developed. Tests were carried out before and after surgery. Tactile allodynia, mechanical hyperalgesia and spatial memory were, respectively, evaluated by von Frey, Randall & Selitto and Y-maze tests and molecular events by Western blot analysis. Spinal nerve-ligated animals displayed nociception and impaired spatial memory. Dextromethorphan, but not memantine, reversed neuropathic pain (NP) symptoms, restored spatial memory integrity and decreased the expression of pTyr(1336)NR2B. Following postoperative administration of dextromethorphan, this study has demonstrated for the first time a concordance between behaviour, cognitive function and molecular events via pTyr(1336)NR2B for neuropathic pain alleviation. Confirmation of these findings in patients would constitute a major step forward in the treatment of neuropathic pain and in the improvement of cognitive function and quality of life. © 2014 Société Française de Pharmacologie et de Thérapeutique.

  17. Topical capsaicin for chronic neuropathic pain in adults.

    PubMed

    Derry, Sheena; Lloyd, Rosalind; Moore, R Andrew; McQuay, Henry J

    2009-10-07

    Topical creams with capsaicin are used to treat pain from a wide range of chronic conditions including neuropathic pain. Following application to the skin capsaicin causes enhanced sensitivity to noxious stimuli, followed by a period with reduced sensitivity and, after repeated applications, persistent desensitisation. There is uncertainty about the efficacy and tolerability of capsaicin for treating painful chronic neuropathies. To review the evidence from controlled trials on the efficacy and tolerability of topically applied capsaicin in chronic neuropathic pain in adults. Cochrane CENTRAL, MEDLINE, EMBASE and Oxford Pain Relief Database, searched in May 2009. Randomised, double blind, placebo controlled studies of at least six weeks' duration, using topical capsaicin to treat neuropathic pain. Two review authors independently assessed trial quality and validity, and extracted data. Information was extracted on numbers of participants with pain relief (clinical improvement) after at least six weeks, and with local skin reactions, and used to calculate relative risk and numbers needed to treat to benefit (NNT) and harm (NNH). Details of definition of pain relief and specific adverse events were sought. Six studies (389 participants in total) compared regular application of low dose (0.075%) capsaicin cream with placebo cream; the NNT for any pain relief over six to eight weeks was 6.6 (4.1 to 17). Two studies (709 participants in total) compared a single application of high dose (8%) capsaicin patch with placebo patch; the NNT for >/= 30% pain relief over twelve weeks was 12 (6.4 to 70). Local skin reactions were more common with capsaicin, usually tolerable, and attenuated with time; the NNH for repeated low dose application was 2.5 (2.1 to 3.1). There were insufficient data to analyse either data set by condition or outcome definition. All studies satisfied minimum criteria for quality and validity, but maintenance of blinding remains a potential problem

  18. The incidence of neuropathic pain in bone metastases patients referred for palliative radiotherapy.

    PubMed

    Lechner, Breanne; Chow, Selina; Chow, Ronald; Zhang, Liying; Tsao, May; Danjoux, Cyril; Barnes, Elizabeth; DeAngelis, Carlo; Vuong, Sherlyn; Ganesh, Vithusha; Chow, Edward

    2016-03-01

    To estimate the prevalence of neuropathic pain in patients with symptomatic bone metastases referred for palliative radiotherapy. A prospective study of patients with symptomatic bone metastases was conducted. Patients referred for palliative radiotherapy completed the Self-Reported Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) questionnaire to assess for neuropathic pain. Patient demographics, medication use, and radiotherapy prescribed were collected. Statistical approaches to identify relationships between the presence of neuropathic and other patient factors were conducted. 62 patients completed the S-LANSS and 16 (25.8%) patients had a score suggesting neuropathic pain. Fifty-nine (95.2%) patients received radiotherapy with total of 81 sites treated, the most common sites were spine and pelvis. No statistically significant difference in fractionation was found between patients with and without neuropathic pain. Of the 16 patients with neuropathic pain, only 2 were receiving a neuropathic specific analgesic. No significant difference between demographic factors or radiation treatments between patients with and without neuropathic pain was found. There was no significant difference in worst pain score between these two groups. Pain with neuropathic features remains prevalent in a population of patients referred for palliative radiotherapy. More frequent prescription of pain medications targeting neuropathic pain may be warranted in this patient population. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  19. Neuropathic symptoms of the ocular surface: dryness, pain, and itch.

    PubMed

    Andersen, Hjalte H; Yosipovitch, Gil; Galor, Anat

    2017-10-01

    This review aims to describe the recent findings on epidemiology, pathophysiology, and management of neuropathic symptoms of the ocular surface, with a focus on potential similarities between sensations of dry eye, pain and itch. A narrative review of the literature was undertaken. Key references from research in dry eye, neuropathic symptoms of the ocular surface, ocular pain and itch, as well as general references on itch and pain neurobiology were included. Recent findings suggest aspects of dry eye, chronic ocular pain and itch symptomatology are driven by neuropathic pain mechanisms involving peripheral and central sensitization processes. Ocular dryness, pain, and itch are prevalent complaints with several of shared features. Multiple lines of evidence suggest that peripheral and central neuronal sensitization processes are involved in generating and maintaining ocular sensory symptoms. Research is warranted on the epidemiology of ocular sensations, molecular mechanisms involved in nociception and pruriception in the eye, electrophysiological alterations in animal models of eye conditions, and therapeutic modalities that can alleviate unpleasant ocular sensations.

  20. Current Status of Malignant Neuropathic Pain in Chinese Patients with Cancer: Report of a Hospital-based Investigation of Prevalence, Etiology, Assessment, and Treatment.

    PubMed

    Lu, Fan; Song, Li; Xie, Tian; Tian, Jie; Fan, Yuchao; Liu, Hui

    2017-01-01

    This study investigated the prevalence, etiology, assessment, treatment of pain in patients with cancer as well as their quality of life (QOL). Patients at the West China Hospital Cancer Center were invited to complete a questionnaire under the guidance of pain specialists. The questionnaire included general information, cancer pain status, its assessment, use of analgesics, and the effects of pain on QOL. In total, 1,050 patients were enrolled in the study. Of these, valid data were collected from 919 patients, among whom 454 (49.4%) suffered from pain, including 333 (36.2%) patients who had neuropathic pain symptoms. On average, the visual analog scale (VAS) score of patients with cancer pain was 3.30 ± 1.68. Significant differences in the VAS score and pain frequency between patients with nociceptive and neuropathic pain were observed (both P < 0.05). Dull pain ranked first (64, 52.9%) among the patients with nociceptive pain, whereas pins and needles pain (97, 64.7%) was the most common type of pain in patients with neuropathic pain. There was a significant difference in QOL between the nociceptive and neuropathic pain groups (P < 0.05). Only 183 of 454 patients with cancer pain used analgesics. Compared with the patients with pain not using any analgesics, those receiving analgesics had a significantly lower average pain relief rate (P = 0.027). Adjuvant analgesics were inadequately used (9.3%) in patients with neuropathic cancer pain. This study revealed the prevalence of neuropathic cancer pain in Chinese patients with cancer. Malignant neuropathic pain significantly impaired the patients' QOL. Insufficient assessment and inadequate analgesia still exist. These require more awareness and attention from both doctors and patients. © 2016 World Institute of Pain.

  1. Neuropathic pain in the community: more under-treated than refractory?

    PubMed

    Torrance, Nicola; Ferguson, Janice A; Afolabi, Ebenezer; Bennett, Michael I; Serpell, Michael G; Dunn, Kate M; Smith, Blair H

    2013-05-01

    Best current estimates of neuropathic pain prevalence come from studies using screening tools detecting pain with probable neuropathic features; the proportion experiencing significant, long-term neuropathic pain, and the proportion not responding to standard treatment are unknown. These "refractory" cases are the most clinically important to detect, being the most severe, requiring specialist treatment. The aim of this study was to estimate the proportion of neuropathic pain in the population that is "refractory," and to quantify associated clinical and demographic features. We posted self-administered questionnaires to 10,000 adult patients randomly selected from 10 general practitioner practices in 5 UK locations. The questionnaire contained chronic pain identification and severity questions, cause of pain, SF-12, EQ-5D, S-LANSS (Self-administered Leeds Assessment of Neuropathic Signs and Symptoms), PSEQ (Pain Self-Efficacy Questionnaire), use of neuropathic pain medications, and health care utilisation. These data were combined to determine the presence and characteristics of "refractory" neuropathic pain according to the defining features identified by a Delphi survey of international experts. Graded categories of chronic pain with and without neuropathic characteristics were generated, incorporating the refractory criteria. Completed questionnaires were returned by 4451 individuals (response rate 47%); 399 had "chronic pain with neuropathic characteristics" (S-LANSS positive, 8.9% of the study sample); 215 (53.9%) also reported a positive relevant history ("Possible neuropathic pain"); and 98 (4.5% of all Chronic Pain) also reported an "adequate" trial of at least one neuropathic pain drug ("Treated possible neuropathic pain"). The most refractory cases were associated with dramatically poorer physical and mental health, lower pain self-efficacy, higher pain intensity and pain-related disability, and greater health care service use. Copyright © 2013

  2. Management of Neuropathic Pain Associated with Spinal Cord Injury.

    PubMed

    Hagen, Ellen M; Rekand, Tiina

    2015-06-01

    Spinal cord injury (SCI) is an injury to the spinal cord that leads to varying degrees of motor and/or sensory deficits and paralysis. Chronic pain of both neuropathic and nociceptive type is common and contributes to reduced quality of life. The aim of the review is to provide current clinical understanding as well as discuss and evaluate efficacy of pharmacological interventions demonstrated in the clinical studies. The review was based on literature search in PubMed and Medline with words "neuropathic pain" and "spinal cord injury". The review included clinical studies and not experimental data nor case reports. A limited number of randomized and placebo-controlled studies concerning treatment options of neuropathic pain after SCI were identified. Amitriptyline, a tricyclic antidepressant and the antiepileptic drugs, gabapentin and pregabalin, are most studied with demonstrated efficacy, and considered to be the primary choice. Opioids have demonstrated conflicting results in the clinical studies. In addition, administration route used in the studies as well as reported side effects restrict everyday use of opioids as well as ketamine and lidocaine. Topical applications of capsaicin or lidocaine as well as intradermal injections of Botulinum toxin are new treatment modalities that are so far not studied on SCI population and need further studies. Non-pharmacological approaches may have additional effect on neuropathic pain. Management of pain should always be preceded by thorough clinical assessment of the type of pain. Patients need a follow-up to evaluate individual effect of applied measures. However, the applied management does not necessarily achieve satisfactory pain reduction. Further clinical studies are needed to evaluate the effect of both established and novel management options.

  3. Validation of the Greek Version of the DN4 Diagnostic Questionnaire for Neuropathic Pain.

    PubMed

    Sykioti, Panagiota; Zis, Panagiotis; Vadalouca, Athina; Siafaka, Ioanna; Argyra, Eriphili; Bouhassira, Didier; Stavropoulou, Evmorfia; Karandreas, Nikolaos

    2015-09-01

    The Douleur Neuropathique 4 questionnaire (DN4) was developed by the French Neuropathic Pain Group and is a simple and objective tool, primarily designed to screen for neuropathic pain. The aim of our study is to validate the DN4 in the Greek language. The study was set up as a prospective observational study. Two pain specialists independently examined patients and diagnosed them with neuropathic, nociceptive, or mixed pain, according to the International Association for the Study of Pain (IASP) definitions. A third and a fourth physician administered the DN4 questionnaire to the patients. Out of the 237 patients who met our inclusion criteria and had identical diagnoses regarding the type of pain, 123 were diagnosed with neuropathic, 59 with nociceptive, and 55 with mixed pain. Among patients with identical diagnoses of neuropathic or nociceptive pain, using a receiver operating characteristic (ROC) curve analysis, the area under the curve (AUC) was 0.92. A cutoff point of equal or greater than 4 resulted in a sensitivity of 93% and a specificity of 78%. Among patients suffering from pain with neuropathic element (neuropathic or mixed pain) or pain with no neuropathic element (nociceptive pain), using a ROC curve analysis, the AUC was 0.89. A cutoff point of equal or greater than 4 resulted in a sensitivity of 89% and a specificity of 78%. The Greek version of DN4 is a valid tool for discriminating between neuropathic and nociceptive pain conditions in daily practice. © 2014 World Institute of Pain.

  4. Chronic postsurgical pain and neuropathic symptoms after abdominal hysterectomy

    PubMed Central

    Beyaz, Serbülent Gökhan; Özocak, Hande; Ergönenç, Tolga; Palabıyık, Onur; Tuna, Ayça Taş; Kaya, Burak; Erkorkmaz, Ünal; Akdemir, Nermin

    2016-01-01

    Abstract Chronic postsurgical pain (CPSP) is an important clinic problem. It is assessed that prevalence of chronic pain extends to 30% but it is contended that there are various risk factors. We aimed to evaluate the prevalence of chronic pain after hysterectomy, risk factors of chronicity, neuropathic features of pain, and sensorial alterations at surgery area. Between years 2012 and 2015, 16 to 65 ages old patients that electively undergone total abdominal hysterectomy bilateral salpingo-oophorectomy and passed minimum 3 months after surgery were included to study. Visual analog scale (VAS) and Douleur Neuropathique 4-questionnaire (DN-4) surveys were used to evaluate pain symptoms, algometry device was used for evaluating abdominal pressure threshold and Von Frey Filament was used for sensorial alterations. Ninety-three of 165 eligible patients were included to study. As the groups were compared by demographic data, no difference was obtained (P > 0.05). There was no difference between groups regarding patient and surgery attributes (P > 0.05). Most frequently performed incision type was Pfannenstiel. Neuropathic symptoms were observed in 90 patients (96.8%). Sensorial alterations as hypoesthesia and hyperesthesia were detected around abdominal scar in 18 patients (19.4%) with pinprick test. Neuropathic symptoms should not be ignored in studies evaluating CPSP and a standard methodology should be designed for studies in this topic. PMID:27537570

  5. Spinal Interleukin-10 Therapy to Treat Peripheral Neuropathic Pain

    PubMed Central

    Milligan, Erin D.; Penzkover, Kathryn R.; Soderquist, Ryan G.; Mahoney, Melissa J.

    2012-01-01

    Introduction Current research indicates that chronic peripheral neuropathic pain includes a role for glia and the actions of proinflammatory factors. This review briefly discusses the glial and cytokine responses that occur following peripheral nerve damage in support of utilizing anti-inflammatory cytokine interleukin-10 therapy to suppress chronic peripheral neuropathic pain. Spinal Non-viral Interleukin-10 Gene Therapy IL-10 is one of the most powerful endogenous counter-regulators of pro-inflammatory cytokine function that acts in the nervous system. Subarachnoid (intrathecal) spinal injection of the gene encoding IL-10 delivered by non-viral vectors has several advantages over virally-mediated gene transfer methods and leads to profound pain relief in several animal models. Non-viral gene delivery Lastly, data are reviewed that non-viral DNA encapsulated by a biologically safe co-polymer, poly(lactic-co-glycolic) acid (PLGA), thought to protect DNA, leads to significantly improved therapeutic gene transfer in animal models, which additionally and significantly extends pain relief. Conclusions The impact of these early studies exploring anti-inflammatory genes emphasizes the exceptional therapeutic potential of new biocompatible intrathecal non-viral gene delivery approaches such as PLGA microparticles. Ultimately, ongoing expression of therapeutic genes are a viable option to treat chronic neuropathic pain in the clinic. PMID:22672183

  6. A Systematic Review of NMDA Receptor Antagonists for Treatment of Neuropathic Pain in Clinical Practice.

    PubMed

    Aiyer, Rohit; Mehta, Neel; Gungor, Semih; Gulati, Amitabh

    2017-09-01

    To investigate the efficacy of N-methyl-D-aspartate receptor (NMDA) receptor antagonists for neuropathic pain and review literature to determine if specific pharmacologic agents provide adequate neuropathic pain relief. Literature was reviewed on PubMed using a variety of key words for 8 NMDA receptor antagonists. These key words include: "Ketamine and Neuropathy", "Ketamine and Neuropathic Pain", "Methadone and Neuropathy", "Methadone and Neuropathic Pain", "Memantine and Neuropathic pain", "Memantine and Neuropathy", "Amantadine and Neuropathic Pain", "Amantadine and Neuropathy", "Dextromethorphan and Neuropathic Pain", "Dextromethorphan and Neuropathy", "Carbamazepine and Neuropathic Pain", "Carbamazepine and Neuropathy", "Valproic Acid and Neuropathy", "Valproic Acid and Neuropathic Pain", "Phenytoin and Neuropathy" and "Phenytoin and Neuropathic Pain". With the results, the papers were reviewed using the PRISMA (Preferred Reporting in Systematic and Meta-Analyses) guideline. A total of 58 randomized controlled trials were reviewed among 8 pharmacologic agents, which are organized by date and alphabetical order. Of the trials for ketamine, 15 showed some benefit for analgesia. Methadone had 3 beneficiary trials, while amantadine and memantine each only had 2 trials showing neuropathic analgesic properties. Dextromethorphan and Valproic Acid both had 4 randomized controlled trials that showed some neuropathic treatment benefit while carbamazepine had over 8 trials showing efficacy. Finally, phenytoin only had 1 trial that showed clinical response in treatment. It is evident there are a variety of NMDA receptor antagonist agents that should be considered for treatment of neuropathic pain. Nevertheless, continued and further investigation of the 8 pharmacologic agents is needed to continue to evaluate their efficacy for treatment of neuropathic pain.

  7. Gabapentin for chronic neuropathic pain and fibromyalgia in adults

    PubMed Central

    Moore, R Andrew; Wiffen, Philip J; Derry, Sheena; McQuay, Henry J

    2014-01-01

    Background This review updates parts of two earlier Cochrane reviews investigating effects of gabapentin in chronic neuropathic pain (pain due to nerve damage). Antiepileptic drugs are used to manage pain, predominantly for chronic neuropathic pain, especially when the pain is lancinating or burning. Objectives To evaluate the analgesic effectiveness and adverse effects of gabapentin for chronic neuropathic pain management. Search methods We identified randomised trials of gabapentin in acute, chronic or cancer pain from MEDLINE, EMBASE, and CENTRAL. We obtained clinical trial reports and synopses of published and unpublished studies from Internet sources. The date of the most recent search was January 2011. Selection criteria Randomised, double-blind studies reporting the analgesic and adverse effects of gabapentin in neuropathic pain with assessment of pain intensity and/or pain relief, using validated scales. Participants were adults aged 18 and over. Data collection and analysis Two review authors independently extracted data. We calculated numbers needed to treat to benefit (NNTs), concentrating on IMM-PACT (Initiative on Methods, Measurement and Pain Assessment in Clinical Trials) definitions of at least moderate and substantial benefit, and to harm (NNH) for adverse effects and withdrawal. Meta-analysis was undertaken using a fixed-effect model. Main results Twenty-nine studies (3571 participants), studied gabapentin at daily doses of 1200 mg or more in 12 chronic pain conditions; 78% of participants were in studies of postherpetic neuralgia, painful diabetic neuropathy or mixed neuropathic pain. Using the IMMPACT definition of at least moderate benefit, gabapentin was superior to placebo in 14 studies with 2831 participants, 43% improving with gabapentin and 26% with placebo; the NNT was 5.8 (4.8 to 7.2). Using the IMMPACT definition of substantial benefit, gabapentin was superior to placebo in 13 studies with 2627 participants, 31% improving with

  8. A review of the epidemiology of painful diabetic peripheral neuropathy, postherpetic neuralgia, and less commonly studied neuropathic pain conditions.

    PubMed

    Sadosky, Alesia; McDermott, Anne M; Brandenburg, Nancy A; Strauss, Marcie

    2008-01-01

    Although the burden of neuropathic pain is well-recognized, the descriptive epidemiology of specific neuropathic pain conditions has not been well-described. While painful diabetic peripheral neuropathy and postherpetic neuralgia have been widely evaluated, many other peripheral and central neuropathic pain syndromes have been less frequently studied. This review summarizes incidence and/or prevalence information about two relatively frequent neuropathic pain conditions-painful diabetic peripheral neuropathy and postherpetic neuralgia-and similarly summarizes the more limited epidemiologic information available for other peripheral and central neuropathic pain conditions. The data suggest that while our knowledge is still incomplete, the high frequency of several of these conditions in specific populations should be considered an important impetus for further studies designed to evaluate their contribution to the overall burden of neuropathic pain.

  9. Neuropathic pain in the community: More under-treated than refractory?

    PubMed Central

    Torrance, Nicola; Ferguson, Janice A.; Afolabi, Ebenezer; Bennett, Michael I.; Serpell, Michael G.; Dunn, Kate M.; Smith, Blair H.

    2013-01-01

    Best current estimates of neuropathic pain prevalence come from studies using screening tools detecting pain with probable neuropathic features; the proportion experiencing significant, long-term neuropathic pain, and the proportion not responding to standard treatment are unknown. These “refractory” cases are the most clinically important to detect, being the most severe, requiring specialist treatment. The aim of this study was to estimate the proportion of neuropathic pain in the population that is “refractory,” and to quantify associated clinical and demographic features. We posted self-administered questionnaires to 10,000 adult patients randomly selected from 10 general practitioner practices in 5 UK locations. The questionnaire contained chronic pain identification and severity questions, cause of pain, SF-12, EQ-5D, S-LANSS (Self-administered Leeds Assessment of Neuropathic Signs and Symptoms), PSEQ (Pain Self-Efficacy Questionnaire), use of neuropathic pain medications, and health care utilisation. These data were combined to determine the presence and characteristics of “refractory” neuropathic pain according to the defining features identified by a Delphi survey of international experts. Graded categories of chronic pain with and without neuropathic characteristics were generated, incorporating the refractory criteria. Completed questionnaires were returned by 4451 individuals (response rate 47%); 399 had “chronic pain with neuropathic characteristics” (S-LANSS positive, 8.9% of the study sample); 215 (53.9%) also reported a positive relevant history (“Possible neuropathic pain”); and 98 (4.5% of all Chronic Pain) also reported an “adequate” trial of at least one neuropathic pain drug (“Treated possible neuropathic pain”). The most refractory cases were associated with dramatically poorer physical and mental health, lower pain self-efficacy, higher pain intensity and pain-related disability, and greater health care service use

  10. Neuropathic pain management in chronic laminitis.

    PubMed

    Driessen, Bernd; Bauquier, Sébastien H; Zarucco, Laura

    2010-08-01

    Managing pain in horses afflicted by chronic laminitis is one of the greatest challenges in equine clinical practice because it is the dreadful suffering of the animals that most often forces the veterinarian to end the battle with this disease. The purpose of this review is to summarize our current understanding of the complex mechanisms involved in generating and amplifying pain in animals with laminitis and, based on this information, to propose a modified approach to pain therapy. Furthermore, a recently developed pain scoring technique is presented that may help better quantify pain and the monitoring of responses to analgesic treatment in horses with laminitis.

  11. Targeting angiotensin II type 2 receptor pathways to treat neuropathic pain and inflammatory pain.

    PubMed

    Smith, Maree T; Muralidharan, Arjun

    2015-01-01

    Neuropathic pain and chronic inflammatory pain are large unmet medical needs. Over the past two decades, numerous 'pain targets' have been identified for analgesic drug discovery. Despite promising results in rodent pain models, many compounds modulating such targets lacked efficacy in clinical trials. An exception is oral EMA401, a small-molecule angiotensin II type 2 receptor (AT2R) antagonist. Herein, angiotensin II/AT2R signaling-induced hyperexcitability and abnormal sprouting of cultured dorsal root ganglion neurons, together with radioligand binding, pharmacokinetics, analgesic efficacy and mode of action of small-molecule AT2R antagonists in rodent models of peripheral neuropathic and chronic inflammatory pain, are reviewed. The findings of a successful Phase IIa clinical trial of EMA401 in patients with neuropathic pain are presented in brief. The functional importance of angiotensin II/AT2R signaling has remained enigmatic for decades, and there are no clinically available medications that target the AT2R. However, on the basis of preclinical findings and recent clinical trial data showing that the peripherally restricted, small-molecule AT2R antagonist, EMA401, successfully alleviated neuropathic pain in a Phase II clinical trial, the AT2R is receiving considerable attention as a new therapeutic target with human validation for the relief of peripheral neuropathic and chronic inflammatory pain conditions.

  12. EZH2 regulates spinal neuroinflammation in rats with neuropathic pain.

    PubMed

    Yadav, Ruchi; Weng, Han-Rong

    2017-05-04

    Alteration in gene expression along the pain signaling pathway is a key mechanism contributing to the genesis of neuropathic pain. Accumulating studies have shown that epigenetic regulation plays a crucial role in nociceptive process in the spinal dorsal horn. In this present study, we investigated the role of enhancer of zeste homolog-2 (EZH2), a subunit of the polycomb repressive complex 2, in the spinal dorsal horn in the genesis of neuropathic pain in rats induced by partial sciatic nerve ligation. EZH2 is a histone methyltransferase, which catalyzes the methylation of histone H3 on K27 (H3K27), resulting in gene silencing. We found that levels of EZH2 and tri-methylated H3K27 (H3K27TM) in the spinal dorsal horn were increased in rats with neuropathic pain on day 3 and day 10 post nerve injuries. EZH2 was predominantly expressed in neurons in the spinal dorsal horn under normal conditions. The number of neurons with EZH2 expression was increased after nerve injury. More strikingly, nerve injury drastically increased the number of microglia with EZH2 expression by more than sevenfold. Intrathecal injection of the EZH2 inhibitor attenuated the development and maintenance of mechanical and thermal hyperalgesia in rats with nerve injury. Such analgesic effects were concurrently associated with the reduced levels of EZH2, H3K27TM, Iba1, GFAP, TNF-α, IL-1β, and MCP-1 in the spinal dorsal horn in rats with nerve injury. Our results highly suggest that targeting the EZH2 signaling pathway could be an effective approach for the management of neuropathic pain.

  13. Topical phenytoin for the treatment of neuropathic pain

    PubMed Central

    Kopsky, David J; Keppel Hesselink, Jan M

    2017-01-01

    We developed and tested a new putative analgesic cream, based on the anticonvulsant phenytoin in patients suffering from treatment refractory neuropathic pain. The use of commercial topical analgesics is not widespread due to the facts that capsaicin creams or patches can give rise to side effects, such as burning, and analgesic patches (e.g., lidocaine 5% patches) have complex handling, especially for geriatric patients. Only in a few countries, compounded creams based on tricyclic antidepressants or other (co-)analgesics are available. Such topical analgesic creams, however, are easy to administer and have a low propensity for inducing side effects. We, therefore, developed a new topical cream based on 5% and 10% phenytoin and described three successfully treated patients suffering from neuropathic pain. All patients were refractory to a number of other analgesics. In all patients, phenytoin cream was effective in reducing pain completely, without any side effects, and the tolerability was excellent. The onset of action of the phenytoin creams was within 30 minutes. Phenytoin cream might become a new treatment modality of the treatment of neuropathic pain. PMID:28280381

  14. Diagnosis and medical treatment of neuropathic pain in leprosy.

    PubMed

    Arco, Rogerio Del; Nardi, Susilene Maria Tonelli; Bassi, Thiago Gasperini; Paschoal, Vania Del Arco

    2016-08-08

    to identify the difficulties in diagnosing and treating neuropathic pain caused by leprosy and to understand the main characteristics of this situation. 85 patients were treated in outpatient units with reference to leprosy and the accompanying pain. We used a questionnaire known as the Douleur Neuropathic 4 test and we conducted detailed neurological exams. As a result, 42 patients were excluded from the study for not having proved their pain. Out of the 37 patients that experienced pain, 22 (59.5%) had neuropathic pain (or a mixture of this pain and their existing pain) and of these 90.8% considered this pain to be moderate or severe. 81.8% of the sample suffered with this pain for more than 6 months. Only 12 (54.5%) of the patients had been diagnosed with neuropathic pain and in almost half of these cases, this pain had not been diagnosed. With reference to medical treatment (n=12) for neuropathic pain, 5 (41.6%) responded that they became better. For the other 7 (58.4%) there were no changes in relation to the pain or in some cases the pain worsened in comparison to their previous state. Statistical analysis comparing improvements in relation to the pain amongst the patients that were treated (n=12) and those that were not, showed significant differences (value p=0.020). we noted difficulties in diagnosing neuropathic pain for leprosy in that almost half of the patients that were studied had not had their pain diagnosed. We attributed this to some factors such as the non-adoption of the appropriate protocols which led to inadequate diagnosis and treatment that overlooked the true picture. identificar as dificuldades em diagnosticar e tratar a dor neuropática causada pela hanseníase, bem como determinar as características principais dessa situação. examinaram-se 85 pacientes tratados no ambulatório de referência para hanseníase e referiam dor. Aplicou-se questionário, o teste Douleur Neuropathic 4, e criterioso exame neurológico pelo qual exclu

  15. Prevalence of neuropathic pain in knee or hip osteoarthritis: A systematic review and meta-analysis.

    PubMed

    French, Helen P; Smart, Keith M; Doyle, Frank

    2017-08-01

    Discordance between radiographic and pain severity in osteoarthritis (OA) has led researchers to investigate other pain mechanisms, including neuropathic pain. Accurate identification of any neuropathic pain in hip or knee OA is important for appropriate management, but neuropathic pain prevalence is unknown. We aimed to obtain an overall prevalence estimate by systematically reviewing and meta-analysing the prevalence of neuropathic pain in people with hip or knee OA. Observational studies which measured neuropathic pain in people aged 18 years and older with hip or knee OA were considered for inclusion. Electronic databases were searched up to February 2016. Two reviewers independently identified eligible studies and assessed methodological quality. Prevalence estimates and 95% confidence intervals were calculated using random effects meta-analytic techniques. Nine studies met the inclusion criteria. Study samples were from general population, hospital and community settings and all used self-report questionnaires to determine neuropathic pain. The overall prevalence estimate was 23% (95% CI: 10-39%), with considerable heterogeneity (I(2) = 97.9%, p < 0.001). This estimate was largely unchanged with subgroup analyses based on index joint, questionnaire type, setting and consideration of other potential causes of neuropathic pain. However, the estimate for two studies that excluded other potential causes of neuropathic pain was substantially higher (32%, 95% CI: 29-35%). Neuropathic pain prevalence in people with knee or hip OA is considerable at 23%, and may be higher after other potential causes of neuropathic pain are excluded. Concerns regarding the validity of neuropathic pain questionnaires, selection bias, methodological quality and study heterogeneity suggest caution with interpretation of these findings. Prevalence studies using standardised criteria for neuropathic pain are required. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Impact of Neuropathic Pain at the Population Level

    PubMed Central

    Vieira, Ana Shirley Maranhao; Baptista, Abrahao Fontes; Mendes, Livia; Silva, Kamilla Soares; Gois, Sharize Cristine de Araujo; Lima, Flavia Manoela de Almeida; Souza, Israel; Sa, Katia Nunes

    2014-01-01

    Background One of the chief complaints of individuals who frequent the Family Health Units is chronic pain which, in Salvador, affects over 40% of the population. However, little is known about the type of pain and its impact on quality of life (QoL) at population level. The aim of the study is to evaluate the impact of neuropathic pain on QoL in a community. Methods A descriptive cross-sectional study was conducted from March to October 2012, in a Family Health Unit, Salvador, Bahia, Brazil. The DN-4 (type of pain), body map (location), VAS (intensity) and SF-36 (QoL) instruments were applied. The Chi-square (univariate analysis) and logistic regression (multivariate) tests were used, with IC 95% and P < 0.05. Results In a sample of 191 individuals with chronic pain, predominantly women (86.4%), single (48.7%), nonwhite (93.2%), low educational (46.6%) and low economic (100%) level. The most affected locations of the body were knees, lumbar region and head. In 60.2% of interviewees, neuropathic pain, of high intensity (VAS = 7.09 ± 3.0) predominated, with duration of 8.53 ± 8.8 years and mean QoL was reduced in 47.13%. Conclusions Intense pain in the dorsal region and type of neuropathy are independent predictors for greater compromise of QoL. PMID:24578752

  17. Interventional management of neuropathic pain: NeuPSIG recommendations

    PubMed Central

    Dworkin, Robert H.; O’Connor, Alec B.; Kent, Joel; Mackey, Sean C.; Raja, Srinivasa N.; Stacey, Brett R.; Levy, Robert M.; Backonja, Miroslav; Baron, Ralf; Harke, Henning; Loeser, John D.; Treede, Rolf-Detlef; Turk, Dennis C.; Wells, Christopher D.

    2015-01-01

    Neuropathic pain (NP) is often refractory to pharmacologic and non-interventional treatment. On behalf of the International Association for the Study of Pain Neuropathic Pain Special Interest Group (NeuPSIG), the authors evaluated systematic reviews, clinical trials, and existing guidelines for the interventional management of NP. Evidence is summarized and presented for neural blockade, spinal cord stimulation (SCS), intrathecal medication, and neurosurgical interventions in patients with the following peripheral and central NP conditions: herpes zoster and postherpetic neuralgia (PHN); painful diabetic and other peripheral neuropathies; spinal cord injury NP; central post-stroke pain; radiculopathy and failed back surgery syndrome (FBSS); complex regional pain syndrome (CRPS); and trigeminal neuralgia and neuropathy. Due to the paucity of high-quality clinical trials, no strong recommendations can be made. Four weak recommendations based on the amount and consistency of evidence, including degree of efficacy and safety, are: (1) epidural injections for herpes zoster; (2) steroid injections for radiculopathy; (3) SCS for FBSS; and (4) SCS for CRPS type 1. Based on the available data, we recommend not to use sympathetic blocks for PHN nor RF lesions for radiculopathy. No other conclusive recommendations can be made due to the poor quality of available of data. Whenever possible, these interventions should either be part of randomized clinical trials or documented in pain registries. Priorities for future research include randomized clinical trials; long-term studies; and head-to-head comparisons among different interventional and non-interventional treatments. PMID:23748119

  18. Interventional management of neuropathic pain: NeuPSIG recommendations.

    PubMed

    Dworkin, Robert H; O'Connor, Alec B; Kent, Joel; Mackey, Sean C; Raja, Srinivasa N; Stacey, Brett R; Levy, Robert M; Backonja, Miroslav; Baron, Ralf; Harke, Henning; Loeser, John D; Treede, Rolf-Detlef; Turk, Dennis C; Wells, Christopher D

    2013-11-01

    Neuropathic pain (NP) is often refractory to pharmacologic and noninterventional treatment. On behalf of the International Association for the Study of Pain Neuropathic Pain Special Interest Group, the authors evaluated systematic reviews, clinical trials, and existing guidelines for the interventional management of NP. Evidence is summarized and presented for neural blockade, spinal cord stimulation (SCS), intrathecal medication, and neurosurgical interventions in patients with the following peripheral and central NP conditions: herpes zoster and postherpetic neuralgia (PHN); painful diabetic and other peripheral neuropathies; spinal cord injury NP; central poststroke pain; radiculopathy and failed back surgery syndrome (FBSS); complex regional pain syndrome (CRPS); and trigeminal neuralgia and neuropathy. Due to the paucity of high-quality clinical trials, no strong recommendations can be made. Four weak recommendations based on the amount and consistency of evidence, including degree of efficacy and safety, are: 1) epidural injections for herpes zoster; 2) steroid injections for radiculopathy; 3) SCS for FBSS; and 4) SCS for CRPS type 1. Based on the available data, we recommend not to use sympathetic blocks for PHN nor radiofrequency lesions for radiculopathy. No other conclusive recommendations can be made due to the poor quality of available data. Whenever possible, these interventions should either be part of randomized clinical trials or documented in pain registries. Priorities for future research include randomized clinical trials, long-term studies, and head-to-head comparisons among different interventional and noninterventional treatments.

  19. Neuropathic Pain Components in Patients with Lumbar Spinal Stenosis

    PubMed Central

    An, Howard S; Moon, Seong Hwan; Lee, Hwan Mo; Suh, Seung Woo; Chen, Ding; Jeon, Jin Ho

    2015-01-01

    Purpose To determine the prevalence and characteristics of neuropathic pain (NP) in patients with lumbar spinal stenosis (LSS) according to subgroup analysis of symptoms. Materials and Methods We prospectively enrolled subjects with LSS (n=86) who were scheduled to undergo spinal surgery. The patients were divided into two groups according to a chief complaint of radicular pain or neurogenic claudication. We measured patient's pain score using the visual analog scale (VAS), Oswestry Disability Index (ODI) and Leads Assessment of Neuropathic Symptoms and Signs (LANSS). According to LANSS value, the prevalence of NP component pain in patients with LSS was assessed. Statistical analysis was performed to find the relationship between LANSS scores and the other scores. Results From our sample of 86 patients, 31 (36.0%) had a NP component, with 24 (63.4%) in the radicular pain group having NP. However, only seven patients (15.6%) in the neurogenic claudication group had NP. The LANSS pain score was not significantly correlated with VAS scores for back pain, but did correlate with VAS scores for leg pain (R=0.73, p<0.001) and with ODI back pain scores (R=0.54, p<0.01). Conclusion One-third of the patients with LSS had a NP component. The presence of radicular pain correlated strongly with NP. The severity of leg pain and ODI score were also closely related to a NP component. This data may prove useful to understanding the pain characteristics of LSS and in better designing clinical trials for NP treatment in patients with LSS. PMID:26069129

  20. Emerging Relationships between Exercise, Sensory Nerves, and Neuropathic Pain

    PubMed Central

    Cooper, Michael A.; Kluding, Patricia M.; Wright, Douglas E.

    2016-01-01

    The utilization of physical activity as a therapeutic tool is rapidly growing in the medical community and the role exercise may offer in the alleviation of painful disease states is an emerging research area. The development of neuropathic pain is a complex mechanism, which clinicians and researchers are continually working to better understand. The limited therapies available for alleviation of these pain states are still focused on pain abatement and as opposed to treating underlying mechanisms. The continued research into exercise and pain may address these underlying mechanisms, but the mechanisms which exercise acts through are still poorly understood. The objective of this review is to provide an overview of how the peripheral nervous system responds to exercise, the relationship of inflammation and exercise, and experimental and clinical use of exercise to treat pain. Although pain is associated with many conditions, this review highlights pain associated with diabetes as well as experimental studies on nerve damages-associated pain. Because of the global effects of exercise across multiple organ systems, exercise intervention can address multiple problems across the entire nervous system through a single intervention. This is a double-edged sword however, as the global interactions of exercise also require in depth investigations to include and identify the many changes that can occur after physical activity. A continued investment into research is necessary to advance the adoption of physical activity as a beneficial remedy for neuropathic pain. The following highlights our current understanding of how exercise alters pain, the varied pain models used to explore exercise intervention, and the molecular pathways leading to the physiological and pathological changes following exercise intervention. PMID:27601974

  1. Emerging Relationships between Exercise, Sensory Nerves, and Neuropathic Pain.

    PubMed

    Cooper, Michael A; Kluding, Patricia M; Wright, Douglas E

    2016-01-01

    The utilization of physical activity as a therapeutic tool is rapidly growing in the medical community and the role exercise may offer in the alleviation of painful disease states is an emerging research area. The development of neuropathic pain is a complex mechanism, which clinicians and researchers are continually working to better understand. The limited therapies available for alleviation of these pain states are still focused on pain abatement and as opposed to treating underlying mechanisms. The continued research into exercise and pain may address these underlying mechanisms, but the mechanisms which exercise acts through are still poorly understood. The objective of this review is to provide an overview of how the peripheral nervous system responds to exercise, the relationship of inflammation and exercise, and experimental and clinical use of exercise to treat pain. Although pain is associated with many conditions, this review highlights pain associated with diabetes as well as experimental studies on nerve damages-associated pain. Because of the global effects of exercise across multiple organ systems, exercise intervention can address multiple problems across the entire nervous system through a single intervention. This is a double-edged sword however, as the global interactions of exercise also require in depth investigations to include and identify the many changes that can occur after physical activity. A continued investment into research is necessary to advance the adoption of physical activity as a beneficial remedy for neuropathic pain. The following highlights our current understanding of how exercise alters pain, the varied pain models used to explore exercise intervention, and the molecular pathways leading to the physiological and pathological changes following exercise intervention.

  2. Effect of Sildenafil on Neuropathic Pain and Hemodynamics in Rats

    PubMed Central

    Huang, Lan Ji; Choi, Jeong Il; Kim, Woong Mo; Lee, Hyung Gon; Kim, Yeo Ok

    2010-01-01

    Purpose The inhibition of phosphodiesterase 5 produces an antinociception through the increase of cyclic guanosine monophosphate (cGMP), and increasing cGMP levels enhance the release of γ-aminobutyric acid (GABA). Furthermore, this phosphodiesterase 5 plays a pivotal role in the regulation of the vasodilatation associated to cGMP. In this work, we examined the contribution of GABA receptors to the effect of sildenafil, a phosphodiesterase 5 inhibitor, in a neuropathic pain rat, and assessed the hemodynamic effect of sildenafil in normal rats. Materials and Methods Neuropathic pain was induced by ligation of L5/6 spinal nerves in Sprague-Dawley male rats. After observing the effect of intravenous sildenafil on neuropathic pain, GABAA receptor antagonist (bicuculline) and GABAB receptor antagonist (saclofen) were administered prior to delivery of sildenafil to determine the role of GABA receptors in the activity of sildenafil. For hemodynamic measurements, catheters were inserted into the tail artery. Mean arterial pressure (MAP) and heart rate (HR) were measured over 60 min following administration of sildenafil. Results Intravenous sildenafil dose-dependently increased the withdrawal threshold to the von Frey filament application in the ligated paw. Intravenous bicuculline and saclofen reversed the antinociception of sildenafil. Intravenous sildenafil increased the magnitude of MAP reduction at the maximal dosage, but it did not affect HR response. Conclusion These results suggest that sildenafil is active in causing neuropathic pain. Both GABAA and GABAB receptors are involved in the antinociceptive effect of sildenafil. Additionally, intravenous sildenafil reduces MAP without affecting HR. PMID:20046518

  3. Role of nucleus accumbens in neuropathic pain: linked multi-scale evidence in the rat transitioning to neuropathic pain.

    PubMed

    Chang, Pei-Ching; Pollema-Mays, Sarah Lynn; Centeno, Maria Virginia; Procissi, Daniel; Contini, Massimo; Baria, Alex Tomas; Martina, Marco; Apkarian, Apkar Vania

    2014-06-01

    Despite recent evidence implicating the nucleus accumbens (NAc) as causally involved in the transition to chronic pain in humans, underlying mechanisms of this involvement remain entirely unknown. Here we elucidate mechanisms of NAc reorganizational properties (longitudinally and cross-sectionally), in an animal model of neuropathic pain (spared nerve injury [SNI]). We observed interrelated changes: (1) In resting-state functional magnetic resonance imaging (fMRI), functional connectivity of the NAc to dorsal striatum and cortex was reduced 28days (but not 5days) after SNI; (2) Contralateral to SNI injury, gene expression of NAc dopamine 1A, 2, and κ-opioid receptors decreased 28days after SNI; (3) In SNI (but not sham), covariance of gene expression was upregulated at 5days and settled to a new state at 28days; and (4) NAc functional connectivity correlated with dopamine receptor gene expression and with tactile allodynia. Moreover, interruption of NAc activity (via lidocaine infusion) reversibly alleviated neuropathic pain in SNI animals. Together, these results demonstrate macroscopic (fMRI) and molecular reorganization of NAc and indicate that NAc neuronal activity is necessary for full expression of neuropathic pain-like behavior.

  4. Role of Nucleus Accumbens in Neuropathic Pain: Linked Multi-Scale Evidence in the Rat Transitioning to Neuropathic Pain

    PubMed Central

    Chang, Pei-Ching; Pollema-Mays, Sarah Lynn; Centeno, Maria Virginia; Procissi, Daniel; Contini, Massimos; Baria, Alex Tomas; Martina, Macro; Apkarian, Apkar Vania

    2015-01-01

    Despite recent evidence implicating the nucleus accumbens (NAc) as causally involved in the transition to chronic pain in humans, underlying mechanisms of this involvement remain entirely unknown. Here we elucidate mechanisms of NAc reorganizational properties (longitudinally and cross-sectionally), in an animal model of neuropathic pain (spared nerve injury, SNI). We observed inter-related changes: 1) In resting-state fMRI, functional connectivity of the NAc to dorsal striatum and cortex was reduced 28 days (but not 5 days) after SNI; 2) contralateral to SNI injury, gene expression of NAc dopamine 1A, 2, and κ-opioid receptors decreased 28 days after SNI; 3) In SNI (but not sham) covariance of gene expression was upregulated at 5 days and settled to a new state at 28 days; and 4) NAc functional connectivity correlated with dopamine receptor gene expression and with tactile allodynia. Moreover, interruption of NAc activity (via lidocaine infusion) reversibly alleviated neuropathic pain in SNI animals. Together, these results demonstrate macroscopic (fMRI) and molecular reorganization of NAc and indicate that NAc neuronal activity is necessary for full expression of neuropathic pain-like behavior. PMID:24607959

  5. A burden of illness study for neuropathic pain in Europe

    PubMed Central

    Liedgens, Hiltrud; Obradovic, Marko; De Courcy, Jonathan; Holbrook, Timothy; Jakubanis, Rafal

    2016-01-01

    Purpose Neuropathic pain (NP) is often severe and represents a major humanistic and economic burden. This study aimed at providing insight on this burden across France, Germany, Italy, Spain, and the UK, considering direct and indirect costs, productivity loss, and humanistic impact on patients and their families. Methods Physician questionnaires provided data on patients presenting with NP covering demographics, sick leave and retirement, number of consultations, drug treatments, and surgical procedures. Patients provided further demographic and disease-related data and completed the Work Productivity and Activity Impairment (WPAI), the EuroQol 5-Dimension (EQ-5D), and the Brief Pain Inventory (BPI) questionnaires. All health-related direct unitary costs were collected from relevant country-specific sources and adjusted to 2012 prices (€) where necessary. A subgroup analysis of costs based on diabetic peripheral neuropathy (n=894), fibromyalgia (n=300), and low back pain (n=963) was performed. Findings About 413 physicians completed a total of 3,956 patient records forms. Total annual direct health-care costs per patient ranged from €1,939 (Italy) to €3,131 (Spain). Annual professional caregiver costs ranged from €393 (France) to €1,242 (UK), but this only represented a small proportion of total care because much care is provided by family or friends. Sick leave costs ranged from €5,492 (UK) to €7,098 (France), with 10%–32% patients prevented from working at some point by NP. Total cost (including direct and indirect costs) of NP per patient was €10,313 in France (69% of the total cost), €14,446 in Germany (78%), €9,305 in Italy (69%), €10,597 in Spain (67%), and €9,685 in the UK (57%). Indirect costs (ie, sick leave) constituted the majority of costs in all five countries: €7,098 in France, €11,232 in Germany, €6,382 in Italy, €7,066 in Spain, and €5,492 in the UK. In the subgroup analysis, total annual direct costs per patient

  6. GABA and Central Neuropathic Pain following Spinal Cord Injury

    PubMed Central

    Gwak, Young S.; Hulsebosch, Claire E.

    2012-01-01

    Spinal cord injury induces maladaptive synaptic transmission in the somatosensory system that results in chronic central neuropathic pain. Recent literature suggests that glial-neuronal interactions are important modulators in synaptic transmission following spinal cord injury. Neuronal hyperexcitability is one of the predominant phenomenon caused by maladaptive synaptic transmission via altered glial-neuronal interactions after spinal cord injury. In the somatosensory system, spinal inhibitory neurons counter balance the enhanced synaptic transmission from peripheral input. For a decade, the literature suggests that hypofunction of GABAergic inhibitory tone is an important factor in the enhanced synaptic transmission that often results in neuronal hyperexcitability in dorsal horn neurons following spinal cord injury. Neurons and glial cells synergistically control intracellular chloride ion gradients via modulation of chloride transporters, extracellular glutamate and GABA concentrations via uptake mechanisms. Thus, the intracellular “GABA-glutamate-glutamine cycle” is maintained for normal physiological homeostasis. However, hyperexcitable neurons and glial activation after spinal cord injury disrupts the balance of chloride ions, glutamate and GABA distribution in the spinal dorsal horn and results in chronic neuropathic pain. In this review, we address spinal cord injury induced mechanisms in hypofunction of GABAergic tone that results in chronic central neuropathic pain. PMID:21216257

  7. Integrin signaling in inflammatory and neuropathic pain in the rat.

    PubMed

    Dina, Olayinka A; Parada, Carlos A; Yeh, Jenny; Chen, Xiaojie; McCarter, Gordon C; Levine, Jon D

    2004-02-01

    Many painful conditions are associated with alterations in the extracellular matrix (ECM) of affected tissues. While several integrins, the receptors for ECM proteins, are present on sensory neurons that mediate pain, the possible role of these cell adhesion molecules in inflammatory or neuropathic pain has not been explored. We found that the intradermal injection of peptide fragments of domains of laminin and fibronectin important for adhesive signaling selectively inhibited the hyperalgesia caused by prostaglandin E2 (PGE2) and epinephrine (EPI), respectively. The block of EPI hyperalgesia was mimicked by other peptides containing the RGD integrin-binding sequence. Monoclonal antibodies (mAbs) against the alpha1 or alpha3 integrin subunits, which participate in laminin binding, selectively blocked PGE2 hyperalgesia, while a mAb against the alpha5 subunit, which participates in fibronectin binding, blocked only EPI-induced hyperalgesia. A mAb against the beta1 integrin subunit, common to receptors for both laminin and fibronectin, inhibited hyperalgesia caused by both agents, as did the knockdown of beta1 integrin expression by intrathecal injection of antisense oligodeoxynucleotides. The laminin peptide, but not the fibronectin peptides, also reversibly abolished the longer lasting inflammatory hyperalgesia induced by carrageenan. Finally, the neuropathic hyperalgesia caused by systemic administration of the cancer chemotherapy agent taxol was reversibly inhibited by antisense knockdown of beta1 integrin. These results strongly implicate specific integrins in the maintenance of inflammatory and neuropathic hyperalgesia.

  8. Immune cell–derived opioids protect against neuropathic pain in mice

    PubMed Central

    Labuz, Dominika; Schmidt, Yvonne; Schreiter, Anja; Rittner, Heike L.; Mousa, Shaaban A.; Machelska, Halina

    2009-01-01

    The analgesic effects of leukocyte-derived opioids have been exclusively demonstrated for somatic inflammatory pain, for example, the pain associated with surgery and arthritis. Neuropathic pain results from injury to nerves, is often resistant to current treatments, and can seriously impair a patient’s quality of life. Although it has been recognized that neuronal damage can involve inflammation, it is generally assumed that immune cells act predominately as generators of neuropathic pain. However, in this study we have demonstrated that leukocytes containing opioids are essential regulators of pain in a mouse model of neuropathy. About 30%–40% of immune cells that accumulated at injured nerves expressed opioid peptides such as β-endorphin, Met-enkephalin, and dynorphin A. Selective stimulation of these cells by local application of corticotropin-releasing factor led to opioid peptide–mediated activation of opioid receptors in damaged nerves. This ultimately abolished tactile allodynia, a highly debilitating heightened response to normally innocuous mechanical stimuli, which is symptomatic of neuropathy. Our findings suggest that selective targeting of opioid-containing immune cells promotes endogenous pain control and offers novel opportunities for management of painful neuropathies. PMID:19139563

  9. Nerve injury and neuropathic pain — A question of age

    PubMed Central

    Fitzgerald, Maria; McKelvey, Rebecca

    2016-01-01

    The effects of peripheral nerve injury on somatosensory processing and pain are highly dependent upon the age at which the damage occurs. Adult nerve injury rapidly triggers neuropathic pain, but this is not so if the same nerve injury is performed in animals below postnatal day (P) 28, consistent with observations in paediatric patients. However, longitudinal studies show that pain hypersensitivity emerges later in life, when the animal reaches adolescence, an observation that could be of clinical importance. Here we discuss the evidence that the central consequences of nerve damage are critically determined by the status of neuroimmune regulation at different ages. In the first postnatal weeks, when spinal somatosensory circuits are undergoing synaptic reorganisation, the ‘default’ neuroimmune response is skewed in an anti-inflammatory direction, suppressing the excitation of dorsal horn neurons and preventing the onset of neuropathic pain. As animals grow up and the central nervous system matures, the neuroimmune profile shifts in a pro-inflammatory direction, unmasking a ‘latent’ pain response to an earlier nerve injury. The data predicts that nerve injury in infancy and childhood could go unnoticed at the time, but emerge as clinically ‘unexplained’ or ‘functional’ pain in adolescence. PMID:26220898

  10. Sustained-release pregabalin with methylcobalamin in neuropathic pain: an Indian real-life experience

    PubMed Central

    Dongre, Yasmin U; Swami, Onkar C

    2013-01-01

    Introduction Neuropathic pain is intense in nature and difficult to manage. Thus, the primary goal is maximum relief from pain. The aim of this study was to assess the efficacy and safety of a fixed-dose combination of sustained-release pregabalin and methylcobalamin in reducing neuropathic pain in Indian patients, in the real-life situation. Methods This was a multicenter, prospective, open-labeled, single-arm, observational, 14-day study. Patients received fixed dose combination of 75 or 150 mg sustained-release pregabalin combined with 1500 mcg immediate release methylcobalamin, depending on the clinical requirement. Data was collected for pain reduction and other positive and negative symptoms associated with neuropathy, including hyperesthesia, paresthesia, numbness/tingling, burning sensation, muscle weakness, sleep disturbances, and impairment of movement. Pain intensity was measured on a ten-point visual analog scale (VAS) (0 represented “no pain,” and 10 represented “worst pain ever”). The safety of the drug was also evaluated throughout the study duration. Data was analyzed using appropriate statistical methods. Results The overall reduction in mean VAS score over 14 days was 72.3%. The reduction in mean VAS score was significant as early as the first week. Both positive and negative symptoms of peripheral neuropathy were significantly improved in >50% patients within the 2 weeks. Giddiness (4.7%), followed by sedation (3.6%), dizziness (2.9%), drowsiness (2.3%), and nausea (2.3%) were the most commonly observed adverse effects. The overall efficacy and tolerability was rated as good to excellent by >95% of the investigators and patients. Conclusion Fixed dose combination of sustained-release pregabalin and methylcobalamin significantly reduced neuropathic pain, with significant improvement in both the positive and negative symptoms associated with neuropathy, in Indian patients and was well tolerated. PMID:23761981

  11. Gabapentin Treatment for Neuropathic Pain in a Child with Sciatic Nerve Injury

    PubMed Central

    Akkurt, Halil Ekrem; Gümüş, Haluk; Göksu, Hamit; Odabaşı, Ömer Faruk; Yılmaz, Halim

    2015-01-01

    There are a restricted number of studies about usage of gabapentin for neuropathic pain treatment of pediatric patients. We shared a 12-year-old male case with severe neuropathic pain that hindered the rehabilitation programme for the loss of muscle power and movement limitation. Neuropathic pain developed after peripheral sciatic damage due to firearm traumatisation did not respond to other medical treatments but healed nearly completely after gabapentin usage. PMID:26346828

  12. A pharmacological treatment algorithm for localized neuropathic pain.

    PubMed

    Allegri, Massimo; Baron, Ralf; Hans, Guy; Correa-Illanes, Gerardo; Mayoral Rojals, Victor; Mick, Gerard; Serpell, Michael

    2016-01-01

    Neuropathic pain is caused by a lesion or disease affecting the somatosensory system and is difficult to manage, often proving refractory to existing treatments. In more than half of cases, it is localized and affects a specific, clearly circumscribed area of the body (localized neuropathic pain, or LNP). A recently developed screening tool enables patients with probable neuropathic pain/LNP to be identified quickly and easily. In view of the conflicting current treatment recommendations, an advisory board of pain specialists met in June 2015 to develop a complementary treatment guidance algorithm, for use in the primary care setting and by non-pain specialists. The starting point of the algorithm is a diagnosis of LNP and there was consensus that first-line treatment should be a topical analgesic agent, because the benefit/risk ratios are far better than for systemic agents. Topical application offers site-specific delivery, a lower total systemic dose and avoidance of first-pass metabolism, reducing the risk of adverse events and drug/drug interactions. The 5% lidocaine medicated plaster has most evidence supporting its use in LNP, producing effective analgesia and reducing the associated area of allodynia, but other topical agents include capsaicin, clonidine and botulinum toxin type A. Treatment should be commenced with the topical agent of choice, and the patient re-assessed after an appropriate period. Where the response is good the topical agent is continued, with a re-evaluation after 3-6 months. A systemic agent (e.g. gabapentin, pregabalin, duloxetine, venlafaxine) is added if there is only a partial response, or substituted if there is no response, and the patient re-assessed after a month. If there is poor or no response to the systemic agent the patient should be switched to an alternative one and, if this also proves ineffective, referred to a pain specialist.

  13. Inhibition of YAP/TAZ Activity in Spinal Cord Suppresses Neuropathic Pain.

    PubMed

    Xu, Ni; Wu, Ming-Zheng; Deng, Xue-Ting; Ma, Ping-Chuan; Li, Ze-Hua; Liang, Lei; Xia, Meng-Fan; Cui, Dong; He, Duan-Duan; Zong, Yuan; Xie, Zhong; Song, Xue-Jun

    2016-09-28

    Neuropathic pain, often caused by nerve injury, is a major clinical challenge. Mechanisms that underlie neuropathic pain remain elusive and effective medications are limited. Numerous investigations of pain mechanisms have focused on alterations and phenotypic switches of the nociceptive transmitters and modulators, as well as on their receptors and downstream signaling pathways that have already exerted roles in the pain processes of mature nervous systems. We have demonstrated recently that nerve injury may elicit neuronal alterations that recapitulate events occurring during development. Signaling of the representative activated molecule Wnt thus becomes a trigger for the development of neuropathic pain and is a potential therapeutic target. We report that the transcriptional regulators YAP and TAZ, which orchestrate Wnt response via incorporation in the β-catenin destruction complex, are key in the pathogenesis of neuropathic pain and may serve as an "ON-OFF" switch for neuropathic pain status in rats. Peripheral nerve injury causes rapid-onset and long-lasting nuclear accumulation of YAP/TAZ/β-catenin in the spinal dorsal horn. Spinal inhibition or knock-down of either YAP or TAZ suppresses mechanical allodynia induced by nerve injury or the pain initiators lysophosphatidic acid and Wnt3a. Promoting the nuclear accumulation of YAP/TAZ leads to mechanical hypersensitivity in naive animals. Further, we discovered a new small molecule, dCTB, which targets YAP/TAZ/β-catenin and can greatly suppress neuropathic pain and the associated neurochemical alterations. Our study reveals that YAP and TAZ are core mechanisms underlying the pathogenesis of neuropathic pain and are targets in the screening for potent analgesics for the treatment of neuropathic pain. Mechanisms that underlie neuropathic pain remain elusive. We have demonstrated recently that nerve injury can activate Wnt signaling, which becomes a trigger for the development of neuropathic pain. We report

  14. Cannabinoid-opioid interactions during neuropathic pain and analgesia

    PubMed Central

    Bushlin, Ittai; Rozenfeld, Raphael; Devi, Lakshmi A

    2009-01-01

    Opiates and exogenous cannabinoids, both potent analgesics used for the treatment of patients with neuropathic pain, bind to and activate class A G-protein coupled receptors (GPCRs). Several lines of evidence have recently suggested that opioid and cannabinoid receptors can functionally interact in the central nervous system (CNS). These interactions may be direct, such as through receptor heteromerization, or indirect, such as through signaling cross-talk that includes agonist-mediated release and/or synthesis of endogenous ligands that can activate downstream receptors. Interactions between opioid and cannabinoid receptors may mediate many of the behavioral phenomena associated with use of these drugs, including the production of acute antinociception and the development of tolerance and cross-tolerance to the antinociceptive effects of opioid and cannabinoid-specific ligands. This review summarizes behavioral, anatomical, and molecular data characterizing these interactions during the development of neuropathic pain and during antinociceptive treatment with these drugs alone or in combination. These studies are critical for understanding how the receptor systems involved in pain relief are altered during acute or chronic pain, and for designing better antinociceptive drug therapies, such as the combined use of opioid and cannabinoid receptor agonists or selective activation of receptor heteromers, that directly target the altered neurophysiology of patients experiencing pain. PMID:19857996

  15. Rediscovery of Nefopam for the Treatment of Neuropathic Pain

    PubMed Central

    Kim, Kyung Hoon

    2014-01-01

    Nefopam (NFP) is a non-opioid, non-steroidal, centrally acting analgesic drug that is derivative of the non-sedative benzoxazocine, developed and known in 1960s as fenazocine. Although the mechanisms of analgesic action of NFP are not well understood, they are similar to those of triple neurotransmitter (serotonin, norepinephrine, and dopamine) reuptake inhibitors and anticonvulsants. It has been used mainly as an analgesic drug for nociceptive pain, as well as a treatment for the prevention of postoperative shivering and hiccups. Based on NFP's mechanisms of analgesic action, it is more suitable for the treatment of neuropathic pain. Intravenous administration of NFP should be given in single doses of 20 mg slowly over 15-20 min or with continuous infusion of 60-120 mg/d to minimize adverse effects, such as nausea, cold sweating, dizziness, tachycardia, or drowsiness. The usual dose of oral administration is three to six times per day totaling 90-180 mg. The ceiling effect of its analgesia is uncertain depending on the mechanism of pain relief. In conclusion, the recently discovered dual analgesic mechanisms of action, namely, a) descending pain modulation by triple neurotransmitter reuptake inhibition similar to antidepressants, and b) inhibition of long-term potentiation mediated by NMDA from the inhibition of calcium influx like gabapentinoid anticonvulsants or blockade of voltage-sensitive sodium channels like carbamazepine, enable NFP to be used as a therapeutic agent to treat neuropathic pain. PMID:24748937

  16. Prevalence and associations of neuropathic pain in a cohort of multi-ethnic Asian low back pain patients.

    PubMed

    Kew, Yueting; Tan, Cheng-Yin; Ng, Chong-Jing; Thang, Sue-Sien; Tan, Leong-Hooi; Khoo, Yvonne Khaii; Lim, Jun-Ni; Ng, Jia-Hui; Chan, Chris Yin-Wei; Kwan, Mun-Keong; Goh, Khean-Jin

    2017-04-01

    The prevalence of neuropathic low back pain differs in different ethnic populations. The aims of the study are to determine its frequency and associations in a multi-ethnic cohort of Asian low back pain patients. This was a cross-sectional study of low back patients seen at the University of Malaya Medical Centre, Kuala Lumpur, Malaysia. Neuropathic low back pain patients were identified using the painDETECT questionnaire and compared with non-neuropathic (unclear or nociceptive) low back pain patients, in terms of socio-demographic and clinical factors, pain severity (numerical pain rating scale, NPRS), disability (Roland Morris Disability Questionnaire, RMDQ), as well as anxiety and depression (Hospital Anxiety and Depression Scale, HADS). Of 210 patients, 26 (12.4%) have neuropathic low back pain. Neuropathic pain is associated with non-Chinese ethnicity, higher body mass index and pain radiation below the knee. Patients with neuropathic pain have significantly higher NPRS and RMDQ scores, and there are more subjects with anxiety on HADS. However, there are no differences between the groups in age, gender, pain duration or underlying diagnosis of low back pain. The prevalence of neuropathic low back pain in a multi-ethnic Malaysian cohort is lower than previously reported in other populations with possible differences between ethnic groups. It is associated with greater pain severity, disability and anxiety.

  17. Amitriptyline and phenytoin prevents memory deficit in sciatic nerve ligation model of neuropathic pain.

    PubMed

    Abdulmajeed, Wahab Imam; Ibrahim, Ridwan Babatunde; Ishola, Azeez Olakunle; Balogun, Wasiu Gbolahan; Cobham, Ansa Emmanuel; Amin, Abdulbasit

    2016-03-01

    Phenytoin and amitriptyline are often reported to attenuate pain in chronic conditions. Information on their ability to ameliorate cognitive impairment associated with neuropathic pain remains unclear due to mixed results from studies. This study investigated the effects of phenytoin and amitriptyline on memory deficit associated with neuropathic pain. Twenty-eight adult male Wistar rats were randomly divided into four groups: A, B, C, and D (n=7). Groups A, B, C, and D served as sham control, sciatic nerve ligated untreated, sciatic nerve ligated receiving amitriptyline (5 mg/kg), and sciatic nerve ligated receiving phenytoin (10 mg/kg) respectively. Treatments lasted for 14 days, after which both 'Y' maze and novel object recognition test (NOR) were performed. On the last day of treatment, the animals were anesthetized and their brain excised, and the prefrontal cortices and sciatic nerve were processed histologically using hematoxylin and eosin. There was memory impairment in the sciatic nerve ligated untreated group which was statistically significant (p<0.05) when compared to the phenytoin-treated, amitriptyline-treated, and sham control groups using the 'Y' maze and NOR tests. Histological quantification showed that the prefrontal cortices of the ligated animals showed increased neural population in comparison to normal control. These increases were significantly marked in the untreated ligated group. Sciatic nerve of untreated ligated group showed high demyelination and axonal degeneration which was ameliorated in the treated animals. The administration of amitriptyline and phenytoin can ameliorate neuronal injury, demyelination, and memory impairment associated with neuropathic pain in Wistar rats.

  18. Patient-reported neuropathic pain in adolescent and young adult cancer patients.

    PubMed

    Acquazzino, Melissa A; Igler, Eva C; Dasgupta, Mahua; Simpson, Pippa; Browning, Meghen B; Brandow, Amanda M

    2017-03-01

    Neuropathic pain, a known complication of cancer and its treatments, negatively impacts quality of life. There are limited data using screening tools to aid in the diagnosis of neuropathic pain in cancer patients. Our primary objective was to determine the proportion of adolescent and young adult cancer patients reporting neuropathic pain on a patient-completed, neuropathic pain screening tool. This prospective, cohort study enrolled patients 14-39 years of age who were receiving therapy for primary cancer diagnosis, cancer relapse, or had recently completed treatment. The painDETECT, a patient-completed, neuropathic pain screening tool used down to age 14, was administered a maximum of three times in on-therapy patients and once in off-therapy patients. Provider documentation of neuropathic pain at the corresponding visit was abstracted from the medical record. Seventy-eight patients participated. Median (interquartile range) age at study enrollment was 18.1 (16-19.4) years and 47% were female. Cancer diagnoses included 41% leukemia, 26% solid tumor, 23% lymphoma, and 10% central nervous system tumor. The proportion of patients reporting neuropathic pain was 26% (95% confidence interval [CI] 16-40%) in on-therapy patients and 11% (95% CI 3-27%) in off-therapy patients. In patients reporting neuropathic pain, only 26% had a clinical diagnosis of neuropathic pain documented in the medical record at the corresponding visit. Neuropathic pain occurs in one in four adolescents and young adults receiving cancer therapy. Use of screening tools may increase the detection of neuropathic pain in adolescents and young adults receiving cancer therapy and could ultimately improve pain treatment. © 2016 Wiley Periodicals, Inc.

  19. Enhanced serotonin and mesolimbic dopamine transmissions in a rat model of neuropathic pain.

    PubMed

    Sagheddu, Claudia; Aroni, Sonia; De Felice, Marta; Lecca, Salvatore; Luchicchi, Antonio; Melis, Miriam; Muntoni, Anna Lisa; Romano, Rosaria; Palazzo, Enza; Guida, Francesca; Maione, Sabatino; Pistis, Marco

    2015-10-01

    In humans, affective consequences of neuropathic pain, ranging from depression to anxiety and anhedonia, severely impair quality of life and are a major disease burden, often requiring specific medications. Depressive- and anxiety-like behaviors have also been observed in animal models of peripheral nerve injury. Dysfunctions in central nervous system monoamine transmission have been hypothesized to underlie depressive and anxiety disorders in neuropathic pain. To assess whether these neurons display early changes in their activity that in the long-term might lead to chronicization, maladaptive plasticity and affective consequences, we carried out in vivo extracellular single unit recordings from serotonin neurons in the dorsal raphe nucleus (DRN) and from dopamine neurons in ventral tegmental area (VTA) in the spared nerve injury (SNI) model of neuropathic pain in rats. Extracellular dopamine levels and the expression of dopamine D1, D2 receptors and tyrosine hydroxylase (TH) were measured in the nucleus accumbens. We report that, two weeks following peripheral nerve injury, discharge rate of serotonin DRN neurons and burst firing of VTA dopamine cells are enhanced, when compared with sham-operated animals. We also observed higher extracellular dopamine levels and reduced expression of D2, but not D1, receptors and TH in the nucleus accumbens. Our study confirms that peripheral neuropathy induces changes in the serotonin and dopamine systems that might be the early result of chronic maladaptation to persistent pain. The allostatic activation of these neural systems, which mirrors that already described as a consequence of stress, might lead to depression and anxiety previously observed in neuropathic animals but also an attempt to cope positively with the negative experience.

  20. Neuropathic pain-induced depressive-like behavior and hippocampal neurogenesis and plasticity are dependent on TNFR1 signaling.

    PubMed

    Dellarole, Anna; Morton, Paul; Brambilla, Roberta; Walters, Winston; Summers, Spencer; Bernardes, Danielle; Grilli, Mariagrazia; Bethea, John R

    2014-10-01

    Patients suffering from neuropathic pain have a higher incidence of mood disorders such as depression. Increased expression of tumor necrosis factor (TNF) has been reported in neuropathic pain and depressive-like conditions and most of the pro-inflammatory effects of TNF are mediated by the TNF receptor 1 (TNFR1). Here we sought to investigate: (1) the occurrence of depressive-like behavior in chronic neuropathic pain and the associated forms of hippocampal plasticity, and (2) the involvement of TNFR1-mediated TNF signaling as a possible regulator of such events. Neuropathic pain was induced by chronic constriction injury of the sciatic nerve in wild-type and TNFR1(-/-) mice. Anhedonia, weight loss and physical state were measured as symptoms of depression. Hippocampal neurogenesis, neuroplasticity, myelin remodeling and TNF/TNFRs expression were analyzed by immunohistochemical analysis and western blot assay. We found that neuropathic pain resulted in the development of depressive symptoms in a time dependent manner and was associated with profound hippocampal alterations such as impaired neurogenesis, reduced expression of neuroplasticity markers and myelin proteins. The onset of depressive-like behavior also coincided with increased hippocampal levels of TNF, and decreased expression of TNF receptor 2 (TNFR2), which were all fully restored after mice spontaneously recovered from pain. Notably, TNFR1(-/-) mice did not develop depressive-like symptoms after injury, nor were there changes in hippocampal neurogenesis and plasticity. Our data show that neuropathic pain induces a cluster of depressive-like symptoms and profound hippocampal plasticity that are dependent on TNF signaling through TNFR1.

  1. ATP Receptors Gate Microglia Signaling in Neuropathic Pain

    PubMed Central

    Trang, Tuan; Beggs, Simon; Salter, Michael W.

    2013-01-01

    Microglia were described by Pio del Rio-Hortega (1932) as being the ‘third element’ distinct from neurons and astrocytes. Decades after this observation, the function and even the very existence of microglia as a distinct cell type was a topic of intense debate and conjecture. However, considerable advances have been made towards understanding the neurobiology of microglia resulting in a radical shift in our view of them as being passive bystanders that have solely immune and supportive roles, to being active principal players that contribute to central nervous system pathologies caused by disease or following injury. Converging lines of evidence implicate microglia as being essential in the pathogenesis of neuropathic pain, a debilitating chronic pain condition that can occur after peripheral nerve damage caused by disease, infection, or physical injury. A key molecule that modulates microglial activity is ATP, an endogenous ligand of the P2-purinoceptor family consisting of P2X ionotropic and P2Y metabotropic receptors. Microglia express several P2 receptor subtypes, and of these the P2X4, P2X7, and P2Y12 receptor subtypes have been implicated in neuropathic pain. The P2X4 receptor has emerged as the core microglia-neuron signaling pathway: activation of this receptor causes release of brain-derived neurotrophic factor (BDNF) which causes disinhibition of pain-transmission neurons in spinal lamina I. The present review highlights recent advances in understanding the signaling and regulation of P2 receptors expressed in microglia and the implications for microglia-neuron interactions for the management of neuropathic pain. PMID:22116040

  2. Differential pain modulation properties in central neuropathic pain after spinal cord injury.

    PubMed

    Gruener, Hila; Zeilig, Gabi; Laufer, Yocheved; Blumen, Nava; Defrin, Ruth

    2016-07-01

    It seems that central neuropathic pain (CNP) is associated with altered abilities to modulate pain; whereas dysfunction in descending pain inhibition is associated with the extent of chronic pain distribution, enhanced pain excitation is associated with the intensity of chronic pain. We investigated the hypothesis that CNP is associated with decreased descending pain inhibition along with increased neuronal excitability and that both traits are associated with spinothalamic tract (STT) damage. Chronic spinal cord injury subjects with CNP (n = 27) and without CNP (n = 23) and healthy controls (n = 20) underwent the measurement of pain adaptation, conditioned pain modulation (CPM), tonic suprathreshold pain (TSP), and spatial summation of pain above injury level. Central neuropathic pain subjects also underwent at and below-lesion STT evaluation and completed the questionnaires. Central neuropathic pain subjects showed decreased CPM and increased enhancement of TSP compared with controls. Among CNP subjects, the dysfunction of CPM and pain adaptation correlated positively with the number of painful body regions. The magnitude of TSP and spatial summation of pain correlated positively with CNP intensity. STT scores correlated with CNP intensity and with TSP, so that the more affected the STT below injury level, the greater the CNP and TSP magnitude. It seems that CNP is associated with altered abilities to modulate pain, whereas dysfunction in descending pain inhibition is associated with the extent of chronic pain distribution and enhanced pain excitation is associated with the intensity of chronic pain. Thus, top-down processes may determine the spread of CNP, whereas bottom-up processes may determine CNP intensity. It also seems that the mechanisms of CNP may involve STT-induced hyperexcitability. Future, longitudinal studies may investigate the timeline of this scenario.

  3. Case Report: Neuropathic pain in a patient with congenital insensitivity to pain.

    PubMed

    Wheeler, Daniel W; Lee, Michael C H; Harrison, E Katherine; Menon, David K; Woods, C Geoffrey

    2014-01-01

    We report a unique case of a woman with Channelopathy-associated Insensitivity to Pain (CIP) Syndrome, who developed features of neuropathic pain after sustaining pelvic fractures and an epidural hematoma that impinged on the right fifth lumbar (L5) nerve root. Her pelvic injuries were sustained during painless labor, which culminated in a Cesarean section. She had been diagnosed with CIP as child, which was later confirmed when she was found to have null mutations of the SCN9A gene that encodes the voltage-gated sodium channel Nav1.7. She now complains of troubling continuous buzzing in both legs and a vice-like squeezing in the pelvis on walking. Quantitative sensory testing showed that sensory thresholds to mechanical stimulation of the dorsum of both feet had increased more than 10-fold on both sides compared with tests performed before her pregnancy. These findings fulfill the diagnostic criteria for neuropathic pain. Notably, she mostly only experiences the negative symptoms (such as numbness and tingling, but also electric shocks), and she has not reported sharp or burning sensations, although the value of verbal descriptors is somewhat limited in a person who has never felt pain before. However, her case strongly suggests that at least some of the symptoms of neuropathic pain can persist despite the absence of the Nav1.7 channel. Pain is a subjective experience and this case sheds light on the transmission of neuropathic pain in humans that cannot be learned from knockout mice.

  4. Transcutaneous electrical nerve stimulation (TENS) for neuropathic pain in adults.

    PubMed

    Gibson, William; Wand, Benedict M; O'Connell, Neil E

    2017-09-14

    Neuropathic pain, which is due to nerve disease or damage, represents a significant burden on people and society. It can be particularly unpleasant and achieving adequate symptom control can be difficult. Non-pharmacological methods of treatment are often employed by people with neuropathic pain and may include transcutaneous electrical nerve stimulation (TENS). This review supersedes one Cochrane Review 'Transcutaneous electrical nerve stimulation (TENS) for chronic pain' (Nnoaham 2014) and one withdrawn protocol 'Transcutaneous electrical nerve stimulation (TENS) for neuropathic pain in adults' (Claydon 2014). This review replaces the original protocol for neuropathic pain that was withdrawn. To determine the analgesic effectiveness of TENS versus placebo (sham) TENS, TENS versus usual care, TENS versus no treatment and TENS in addition to usual care versus usual care alone in the management of neuropathic pain in adults. We searched CENTRAL, MEDLINE, Embase, PsycINFO, AMED, CINAHL, Web of Science, PEDro, LILACS (up to September 2016) and various clinical trials registries. We also searched bibliographies of included studies for further relevant studies. We included randomised controlled trials where TENS was evaluated in the treatment of central or peripheral neuropathic pain. We included studies if they investigated the following: TENS versus placebo (sham) TENS, TENS versus usual care, TENS versus no treatment and TENS in addition to usual care versus usual care alone in the management of neuropathic pain in adults. Two review authors independently screened all database search results and identified papers requiring full-text assessment. Subsequently, two review authors independently applied inclusion/exclusion criteria to these studies. The same review authors then independently extracted data, assessed for risk of bias using the Cochrane standard tool and rated the quality of evidence using GRADE. We included 15 studies with 724 participants. We found a

  5. Botulinum Toxin for Neuropathic Pain: A Review of the Literature

    PubMed Central

    Oh, Hyun-Mi; Chung, Myung Eun

    2015-01-01

    Botulinum neurotoxin (BoNT), derived from Clostridium botulinum, has been used therapeutically for focal dystonia, spasticity, and chronic migraine. Its spectrum as a potential treatment for neuropathic pain has grown. Recent opinions on the mechanism behind the antinociceptive effects of BoNT suggest that it inhibits the release of peripheral neurotransmitters and inflammatory mediators from sensory nerves. There is some evidence showing the axonal transport of BoNT, but it remains controversial. The aim of this review is to summarize the experimental and clinical evidence of the antinociceptive effects, mechanisms, and therapeutic applications of BoNT for neuropathic pain conditions, including postherpetic neuralgia, complex regional pain syndrome, and trigeminal neuralgia. The PubMed and OvidSP databases were searched from 1966 to May 2015. We assessed levels of evidence according to the American Academy of Neurology guidelines. Recent studies have suggested that BoNT injection is an effective treatment for postherpetic neuralgia and is likely efficient for trigeminal neuralgia and post-traumatic neuralgia. BoNT could also be effective as a treatment for diabetic neuropathy. It has not been proven to be an effective treatment for occipital neuralgia or complex regional pain syndrome. PMID:26287242

  6. Changing general medical practices in the management of neuropathic pain

    PubMed

    Poucher, Mathieu; Cherrier, Claude; Poucher, Anne-Christelle; Di Patrizio, Paolo

    2016-10-19

    Objective: The objective of this study was to determine current practices in the Lorraine region in the treatment of neuropathic pain and to assess the challenges faced by general practitioners (GPs). Methods: We conducted a qualitative study by the focus group technique, by constituting a balanced panel of GPs to meet diversification requirements. The number of focus groups was defined to obtain data saturation. The lead author of this study acted as an observer, while a facilitator was responsible for moderating the debate. Analysis of transcripts was performed in two ways: firstly, several readings of the transcripts to highlight the main ideas emerging from these discussions, and secondly, integration of verbatim transcripts in NVivo 10 software to allow complementary computer analysis. Results: The GPs interviewed reported that they prescribed Clonazepam (Rivotril®), Carbamazepine (Tegretol®) and Amitriptyline (Laroxyl®) less often than ten years ago, and Gabapentin (Neurontin®), Pregabalin (Lyrica®), Venlafaxin (Effexor®) and Duloxetine (Cymbalta®) more often than ten years ago. They reported many difficulties in the daily management of these patients, especially concerning the psychological or psychiatric components associated with this pain, comorbidities, iatrogenic effects, the inefficacy of the available molecules, the difficulties of access to a specialist (including pain centres), acceptance of treatment by patients, limiting requirements (restrictive marketing authorisations, withdrawal of certain products…). Conclusion: The treatment of neuropathic pain raises a number of difficulties for GPs, but changes in prescribing habits reflect a constant adaptation of clinical practices.

  7. Chronic Orofacial Pain: Burning Mouth Syndrome and Other Neuropathic Disorders

    PubMed Central

    Tait, Raymond C; Ferguson, McKenzie; Herndon, Christopher M

    2017-01-01

    Chronic orofacial pain is a symptom associated with a wide range of neuropathic, neurovascular, idiopathic, and myofascial conditions that affect a significant proportion of the population. While the collective impact of the subset of the orofacial pain disorders involving neurogenic and idiopathic mechanisms is substantial, some of these are relatively uncommon. Hence, patients with these disorders can be vulnerable to misdiagnosis, sometimes for years, increasing the symptom burden and delaying effective treatment. This manuscript first reviews the decision tree to be followed in diagnosing any neuropathic pain condition, as well as the levels of evidence needed to make a diagnosis with each of several levels of confidence: definite, probable, or possible. It then examines the clinical literature related to the idiopathic and neurogenic conditions that can occasion chronic orofacial pain, including burning mouth syndrome, trigeminal neuralgia, glossopharyngeal neuralgia, post-herpetic neuralgia, and atypical odontalgia. Temporomandibular disorders also are examined as are other headache conditions, even though they are not neurologic conditions, because they are common and can mimic symptoms of the latter disorders. For each of these conditions, the paper reviews literature regarding incidence and prevalence, physiologic and other contributing factors, diagnostic signs and symptoms, and empirical evidence regarding treatments. Finally, in order to improve the quality and accuracy of clinical diagnosis, as well as the efficiency with which effective treatment is initiated and delivered, criteria are offered that can be instrumental in making a differential diagnosis. PMID:28638895

  8. Capsaicinoids in the treatment of neuropathic pain: a review

    PubMed Central

    Pappagallo, Marco

    2014-01-01

    The treatment of neuropathic pain is difficult. Oral pharmaceuticals have significant side effects, and treatment efficacy tends to be modest. The use of topical analgesics reduces the potential for systemic side effects and allows direct application of medications to the area of pain. The natural spicy substance, capsaicin, has historically been known for its topical use. Capsaicin, once applied to the skin, causes a brief initial sensitization followed by a prolonged desensitization of the local pain nerves. This occurs through stimulation of the transient receptor potential vanilloid-1 (TRPV1) expressing pain nerve fibers. While low-dose capsaicin has not resulted in good efficacy, the larger dose 8% topical capsaicin has had some of the best data currently available in the treatment of post-herpetic neuralgia (PHN) and other neuropathic conditions. This paper discusses the data currently existing for capsaicin 8% in the treatment of PHN. It further reviews data for the low-dose capsaicin products and the current status in the development of other capsaicinoids, e.g. resiniferotoxin, and high-concentration liquid capsaicin. PMID:24409200

  9. Statins alleviate experimental nerve injury-induced neuropathic pain.

    PubMed

    Shi, Xiang Qun; Lim, Tony K Y; Lee, Seunghwan; Zhao, Yuan Qing; Zhang, Ji

    2011-05-01

    The statins are a well-established class of drugs that lower plasma cholesterol levels by inhibiting HMG-CoA (3-hydroxy-3-methyl-glutaryl-coenzyme A) reductase. They are widely used for the treatment of hypercholesterolemia and for the prevention of coronary heart disease. Recent studies suggest that statins have anti-inflammatory effects beyond their lipid-lowering properties. We sought to investigate whether statins could affect neuropathic pain by mediating nerve injury-associated inflammatory responses. The effects of hydrophilic rosuvastatin and lipophilic simvastatin were examined in the mouse partial sciatic nerve ligation model. Systemic daily administration of either statin from days 0 to 14 completely prevented the development of mechanical allodynia and thermal hyperalgesia. When administered from days 8 to 14 after injury, both statins dose-dependently reduced established hypersensitivity. After treatment, the effects of the statins were washed out within 2 to 7 days, depending on dose. Effects of both statins in alleviating mechanical allodynia were further confirmed in a different injury-associated neuropathic pain model, mental nerve chronic constriction, in rats. Both statins were able to abolish interleukin-1β expression in sciatic nerve triggered by nerve ligation. Additionally, quantitative analysis with Iba-1 and glial fibrillary acid protein immunoreactivity demonstrated that rosuvastatin and simvastatin significantly reduced the spinal microglial and astrocyte activation produced by sciatic nerve injury. The increase of interleukin-1β mRNA in the ipsilateral side of spinal cords was also reduced by the treatment of either statin. We identified a potential new application of statins in the treatment of neuropathic pain. The pain-alleviating effects of statins are likely attributable to their immunomodulatory effects.

  10. Neuropathic Pain in Elderly Patients with Chronic Low Back Painand Effects of Pregabalin: A Preliminary Study

    PubMed Central

    Ito, Kenyu; Hida, Tetsuro; Ito, Sadayuki; Harada, Atsushi

    2015-01-01

    Study Design Preliminary study. Purpose To assess the association of neuropathic pain with chronic low back pain (LBP) and the effect of pregabalin on neuropathic pain in the elderly. Overview of Literature Of those with chronic LBP, 37% were predominantly presenting with neuropathic pain in young adults. Pregabalin is effective for pain in patients with diabetic neuropathy and peripheral neuralgia. No study has reported on the effects of pregabalin for chronic LBP in elderly patients yet. Methods Pregabalin was administered to 32 patients (age, ≥65 years) with chronic LBP for 4 weeks. Pain and activities of daily living were assessed using the Neuropathic Pain Screening Questionnaire (NePSQ), the pain DETECT questionnaire, visual analog scale, the Japanese Orthopedic Association score, the short form of the McGill Pain Questionnaire and the Roland Morris Disability Questionnaire. Modic change and spinal canal stenosis were investigated using magnetic resonance imaging. Results Altogether, 43.3% of patients had neuropathic pain according to the NePSQ and 15.6% patients had pain according to the pain DETECT. The efficacy rate of pregabalin was 73.3%. A significant effect was observed in patients with neuropathic pain after 4 weeks of administration. Conclusions Neuropathic pain was slightly less frequently associated with chronic LBP in the elderly. Pregabalin was effective in reducing pain in patients with chronic LBP accompanied with neuropathic pain. Lumbar spinal stenosis and lower limb symptoms were observed in patients with neuropathic pain. We recommend the use of pregabalin for patients after evaluating a screening score, clinical symptoms and magnetic resonance imaging studies. PMID:25901238

  11. Activation of Corticostriatal Circuitry Relieves Chronic Neuropathic Pain

    PubMed Central

    Lee, Michelle; Manders, Toby R.; Eberle, Sarah E.; Su, Chen; D'amour, James; Yang, Runtao; Lin, Hau Yueh; Deisseroth, Karl; Froemke, Robert C.

    2015-01-01

    Neural circuits that determine the perception and modulation of pain remain poorly understood. The prefrontal cortex (PFC) provides top-down control of sensory and affective processes. While animal and human imaging studies have shown that the PFC is involved in pain regulation, its exact role in pain states remains incompletely understood. A key output target for the PFC is the nucleus accumbens (NAc), an important component of the reward circuitry. Interestingly, recent human imaging studies suggest that the projection from the PFC to the NAc is altered in chronic pain. The function of this corticostriatal projection in pain states, however, is not known. Here we show that optogenetic activation of the PFC produces strong antinociceptive effects in a rat model (spared nerve injury model) of persistent neuropathic pain. PFC activation also reduces the affective symptoms of pain. Furthermore, we show that this pain-relieving function of the PFC is likely mediated by projections to the NAc. Thus, our results support a novel role for corticostriatal circuitry in pain regulation. PMID:25834050

  12. The prevalence of neuropathic pain: clinical evaluation compared with screening tools in a community population.

    PubMed

    Yawn, Barbara P; Wollan, Peter C; Weingarten, Toby N; Watson, James C; Hooten, W Michael; Melton, L Joseph

    2009-04-01

    Neuropathic pain is reported to be common based on studies from specialty centers and survey studies. However, few prevalence estimates have been completed in a community population using clinical evaluation. To develop an estimate of the prevalence of neuropathic pain in community-dwelling adults. Data from a mailed survey (N = 3,575 community respondents), telephone interview (N = 907), and a clinical examination (N = 205) were linked to estimate the population prevalence of neuropathic pain. Using the clinical examination as the "gold" standard, estimates from several screening tools were developed and adjusted to the Olmsted County, MN adult population. The estimated community prevalence of neuropathic pain from the clinical examination (gold standard) was 9.8%. Most other estimates were lower, including a 3.0% population prevalence using the Berger criteria and 8.8% using the Leeds Assessment of Neuropathic Symptoms and Signs. Only the prevalence rate based on self-report of nerve pain was higher (12.4%). Overlap among the groups each tool identified as having "neuropathic predominant pain" was only modest and the groups had significantly different rates of depressive symptoms, anxiety, limited functional ability, and use of complementary and alternative medicine. The estimated rates and personal characteristics of community residents with "neuropathic pain" vary widely depending on the tools used to identify neuropathic pain. None of the screening tools compared well with clinical evaluation. The differences in the groups identified by alternative screening methods become of major importance when reporting neuropathic pain epidemiology, studying therapies for neuropathic pain, or attempting to translate neuropathic pain research into clinical practice.

  13. Thalamic activity and biochemical changes in individuals with neuropathic pain following spinal cord injury

    PubMed Central

    Gustin, S.M.; Wrigley, P.J.; Youssef, A.M.; McIndoe, L.; Wilcox, S.L.; Rae, C.D.; Edden, R; Siddall, P.J.; Henderson, L.A.

    2015-01-01

    There is increasing evidence relating thalamic changes to the generation and/or maintenance of neuropathic pain. We have recently reported that neuropathic orofacial pain is associated with altered thalamic anatomy, biochemistry and activity, which may result in disturbed thalamocortical oscillatory circuits. Despite this evidence, it is possible that these thalamic changes are not responsible for the presence of pain per se, but result as a consequence of the injury. To clarify this subject, we compared brain activity and biochemistry in 12 people with below-level neuropathic pain after complete thoracic spinal cord injury to 11 people with similar injuries and no neuropathic pain and 21 age and gender matched healthy controls. Quantitative arterial spinal labelling was used to measure thalamic activity and magnetic resonance spectroscopy was used to determine changes in neuronal variability quantifying N-acetylaspartate and alterations in inhibitory function quantifying gamma amino butyric acid. This study revealed that the presence of neuropathic pain is associated with significant changes in thalamic biochemistry and neuronal activity. More specifically, the presence of neuropathic pain following spinal cord injury is associated with significant reductions in thalamic N-acetylaspartate, gamma amino butyric acid content and blood flow in the region of the thalamic reticular nucleus. Spinal cord injury on its own did not account for these changes. These findings support the hypothesis that neuropathic pain is associated with altered thalamic structure and function, which may disturb central processing and play a key role in the experience of neuropathic pain. PMID:24530612

  14. KLF15 regulates dopamine D2 receptor and participates in mouse models of neuropathic pain.

    PubMed

    Zhou, Junfei; Wang, Fang; Xu, Chang; Zhou, Zipeng; Zhang, Wei

    2017-10-14

    Neuropathic pain is caused by damage to the nervous system, resulting in aberrant pain. The mechanism underlying neuropathic pain remains largely unknown. Krüppel-like factor 15 (KLF15) is a member of the Krüppel-like factor family of transcriptional factors. Here in this study, we aimed to investigate the potential role of the transcriptional factor KLF15 in neuropathic pain. The mRNA and protein levels of Klf15 were significantly increased in the neurons of mouse undergoing neuropathic pain induced by sciatic nerve chronic constrictive injury (CCI) or unilateral spared nerve injury (SNI). In neurons, the upregulation of Klf15 was triggered by the inflammatory factor tumor necrosis factor alpha (TNF-α). As a transcriptional factor, KLF15 promoted the expression of dopamine D2 receptor (Drd2), which is a receptor essentially involved in neuropathic pain. KLF15 bound to the promoter of Drd2 directly and promoted the promoter activity of Drd2. Finally, we showed that knockout of Klf15 repressed the sensitivity in neuropathic pain induced by CCI or SNI. In conclusion, KLF15 is induced in neuropathic pain via a TNF-α-dependent manner and contributes to neuropathic pain partially through promoting the expression of dopamine D2 receptor. Copyright © 2017. Published by Elsevier Inc.

  15. Brain-evoked potentials as a tool for diagnosing neuropathic pain.

    PubMed

    Pazzaglia, Costanza; Valeriani, Massimiliano

    2009-05-01

    Neuropathic pain is a complex subject, not completely understood yet, and it is quite common in clinical practice, even outside of a neurological context. Neuropathic pain, often being a chronic process, alters and profoundly affects the quality of life. Therefore, the management of neuropathic pain involves a multidimensional approach, as physicians have to take care not only of the objective aspects of the problem, but also of the subjective experiences of pain. This explains why the attainment of a diagnosis becomes so important, as it allows clinicians to treat the patients with the best therapeutic approach. Several studies report the use of brain-evoked potentials for studying patients suffering from neuropathic pain. In particular, laser- and contact heat-evoked potentials have proved useful for the diagnosis of clinical conditions characterized by neuropathic pain. However, although these tools are reliable and safe instruments to assess function of the nociceptive system, their use is still largely confined to research purposes.

  16. Neuropathic pruritus.

    PubMed

    Misery, Laurent; Brenaut, Emilie; Le Garrec, Raphaële; Abasq, Claire; Genestet, Steeve; Marcorelles, Pascale; Zagnoli, Fabien

    2014-07-01

    Pruritus, also known as itch, is a very common, unpleasant sensation that elicits an urge to scratch. Its origin is not always in the skin, and neuropathic itch that is caused by neuronal or glial damage is common, but poorly understood by both dermatologists and neurologists. Although pruritus has not been considered as serious a symptom as pain, it is difficult to treat and--if chronic--can severely impair quality of life. Neuropathic itch is often associated with other clinical symptoms, most commonly neuropathic pain, and hypersensitization to stimuli is present in both pruritus and pain of neuropathic origin. The shared aetiology can aid in finding suitable treatment for itch in some cases, but more detailed knowledge of the mechanisms of itch, along with standardized, well-controlled trials, is needed. Pruritus research is an emerging but currently very active field, and our understanding of this sensation is rapidly increasing. Here, we review new discoveries regarding the role of the nervous system and the contribution of different pathways in pruritus, discuss the different aetiologies of neuropathic itch, and outline currently available and potential strategies for managing neuropathic pruritus.

  17. Enhancing m currents: a way out for neuropathic pain?

    PubMed

    Rivera-Arconada, Ivan; Roza, Carolina; Lopez-Garcia, Jose A

    2009-01-01

    Almost three decades ago, the M current was identified and characterized in frog sympathetic neurons (Brown and Adams, 1980). The years following this discovery have seen a huge progress in the understanding of the function and the pharmacology of this current as well as on the structure of the underlying ion channels. Therapies for a number of syndromes involving abnormal levels of excitability in neurons are benefiting from research on M currents. At present, the potential of M current openers as analgesics for neuropathic pain is under discussion. Here we offer a critical view of existing data on the involvement of M currents in pain processing. We believe that enhancement of M currents at the site of injury may become a powerful strategy to alleviate pain in some peripheral neuropathies.

  18. TREM2/DAP12 Signal Elicits Proinflammatory Response in Microglia and Exacerbates Neuropathic Pain.

    PubMed

    Kobayashi, Masaaki; Konishi, Hiroyuki; Sayo, Akira; Takai, Toshiyuki; Kiyama, Hiroshi

    2016-10-26

    Neuropathic pain afflicts millions of people, and the development of an effective treatment for this intractable pain is an urgent issue. Recent evidence has implicated microglia in neuropathic pain. The present study showed that the DNAX-activating protein of 12 kDa (DAP12) and its associated "triggering receptor expressed on myeloid cells 2" (TREM2) were predominantly expressed by microglia in the dorsal horn after spinal nerve injury, revealing a role for TREM2/DAP12 signaling in neuropathic pain. Nerve injury-induced proinflammatory cytokine expression in microglia and pain behaviors were significantly suppressed in Dap12-deficient mice. Furthermore, intrathecal administration of TREM2 agonistic antibody induced proinflammatory cytokine expression, as well as neuropathic pain, in mice without nerve injury. The agonistic antibody induced proinflammatory responses and neuropathic pain was not observed in Dap12-deficient mice. Together, these results suggest that TREM2/DAP12-mediated signals in microglia exacerbate nerve injury-induced neuropathic pain by inducing proinflammatory cytokine secretion from microglia. Suppression of DAP12-mediated signals could be a therapeutic target for neuropathic pain. Recent studies have revealed that activated microglia in the spinal dorsal horn exacerbate neuropathic pain, which has suggested that suppression of microglial activity should be considered as a therapeutic target. However, only a few molecules have been identified as regulators of microglial activity. In this study, we focused on a receptor complex of TREM2 and DAP12, both of which are expressed by microglia and have been implicated in the pathogenesis of Alzheimer's disease, and demonstrated that TREM2/DAP12 signaling promoted proinflammatory responses in microglia and exacerbates neuropathic pain. The present results revealed the functional significance of TREM2/DAP12 signaling in microglial activation after neuronal injury, and could help in the development of

  19. The impact of neuropathic pain and other comorbidities on the quality of life in patients with diabetes.

    PubMed

    Dermanovic Dobrota, Vesna; Hrabac, Pero; Skegro, Dinko; Smiljanic, Ranko; Dobrota, Savko; Prkacin, Ingrid; Brkljacic, Neva; Peros, Kristijan; Tomic, Martina; Lukinovic-Skudar, Vesna; Basic Kes, Vanja

    2014-12-03

    Diabetic polyneuropathy (DPN) is one of the most common complications of diabetes and can exist with or without neuropathic pain. We were interested in how neuropathic pain impairs the quality of life in diabetic patients and what is the role of comorbidities in this condition. The study included 80 patients with painful DPN (group "P") and 80 patients with DPN, but without neuropathic pain (group "D"). Visual analogue scale (VAS) and Leeds assessment of neuropathic symptoms and signs (LANSS) pain scale were used for assessment of neuropathic pain, SF-36 standardized questionnaire for assessment of the quality of life and BDI questionnaire for assessment of depression. Subjects in group P had statistically significantly lower values compared to group D in all 8 dimensions and both summary values of the SF-36 scale. We ascribe the extremely low results of all parameters of SF-36 scale in group P to painful diabetic polyneuropathy with its complications. The patients in group D showed higher average values in all dimension compared to group P, but also somewhat higher quality of life compared to general population of Croatia in 4 of 8 dimensions, namely vitality (VT), social functioning (SF), role-emotional (RE) and mental health (MH), which was unexpected result. Clinically, the most pronounced differences between two groups were noted in sleeping disorders and problems regarding micturition and defecation , which were significantly more expressed in group P. The similar situation was with walking distance and color-doppler sonography of carotid arteries, which were significantly worse in group P. Consequently, subjects in group P were more medicated than the patients in group D, particularly with tramadol, antiepileptics and antidepressants. Painful DPN is a major factor that influences various aspects of quality of life in diabetic patients. Additionally, this study gives an overview of diabetic population in the Republic of Croatia, information that could prove

  20. Combined approaches for the relief of spinal cord injury-induced neuropathic pain.

    PubMed

    Gwak, Young S; Kim, Hee Young; Lee, Bong Hyo; Yang, Chae Ha

    2016-04-01

    The adequate treatment of spinal cord injury (SCI)-induced neuropathic pain still remains an unresolved problem. The current medications predominantly used in the SCI-induced neuropathic pain therapy are morphine, anticonvulsants, antidepressants, and antiepileptics, which suggests that psychiatric aspects might be important factors in the treatment of neuropathic pain. It is well documented that the modulation of the sensory events is not a unique way for achieving pain relief. In addition, pain patients still express dissatisfaction and complain of unwanted effects of the medications, suggesting that alternative approaches for the treatment of neuropathic pain are essential. In psychiatry, pain relief represents relaxation and a feeling of comfort and satisfaction, which suggests that cognitive and emotional motivations are important factors in the treatment of neuropathic pain. The comorbidity of chronic pain and psychiatric disorders, which is well recognized, suggests that the effective therapeutic relief for neuropathic pain induced by SCI can be achieved in conjunction with the management of the sensory and psychiatric aspects of patient. In this review, we address the feasibility of a combined acupuncture and pharmacotherapy treatment for the relief of neuropathic pain behavior following SCI. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Chronic pain in Gaucher disease: skeletal or neuropathic origin?

    PubMed

    Devigili, Grazia; De Filippo, Michele; Ciana, Giovanni; Dardis, Andrea; Lettieri, Christian; Rinaldo, Sara; Macor, Daniela; Moro, Alessandro; Eleopra, Roberto; Bembi, Bruno

    2017-08-31

    Pain is one of the most disabling symptoms of Gaucher disease. It is referred by the majority of Gaucher patients and often persists despite long-term enzyme replacement treatment. It has been mainly considered as nociceptive pain secondary to skeletal involvement but it is described even in the absence of bone disease without a clear explanation. In the last years an increasing number of reports have described the presence of neurological manifestation in Gaucher type 1 patients, including subclinical large fibre neuropathy. In our Gaucher clinic we have observed the recurrence of painful symptoms in a group of type 1 Gaucher patients even after a long-term enzyme replacement therapy. A cross-sectional study was designed to investigate the pathophysiology of pain in a cohort of 25 Gaucher patients (13 females, 12 males). Twenty-two patients received enzyme replacement therapy for a period of time ranging from 10 to >20 years, while three were new diagnosis. Pain was classified as bone or neurologic related on the basis of anamnestic data, clinical and electrophysilogical examinations. Intensity and quality of pain were recorded by Douleur Neuropathique en 4 questionnaire and Neuropathic Pain Symptom Inventory. Neuroalgological evaluation, quantitative sensory testing, nerve conduction studies and evaluation of epidermal nerve fibres density were performed. Comorbidities for peripheral neuropathy were excluded. Thirteen patients complained of pain suggestive of neuropathic origin with proximal patchy distribution, six manifested severe pain paroxysmal, nine pinprick hypoesthesia and 17 thermal hypoesthesia. At quantitative sensory testing, all of them showed high cold thresholds with errata sensation (burning instead of cold), paradoxical heat sensation and mechanic hypoesthesia; three patients showed pressure pain hyperalgesia. Epidermal denervation was present in 19 patients, 12 of them with non-length dependent pattern. These results confirm the role of

  2. Cannabinoids as pharmacotherapies for neuropathic pain: from the bench to the bedside.

    PubMed

    Rahn, Elizabeth J; Hohmann, Andrea G

    2009-10-01

    Neuropathic pain is a debilitating form of chronic pain resulting from nerve injury, disease states, or toxic insults. Neuropathic pain is often refractory to conventional pharmacotherapies, necessitating validation of novel analgesics. Cannabinoids, drugs that share the same target as Delta(9)-tetrahydrocannabinol (Delta(9)-THC), the psychoactive ingredient in cannabis, have the potential to address this unmet need. Here, we review studies evaluating cannabinoids for neuropathic pain management in the clinical and preclinical literature. Neuropathic pain associated with nerve injury, diabetes, chemotherapeutic treatment, human immunodeficiency virus, multiple sclerosis, and herpes zoster infection is considered. In animals, cannabinoids attenuate neuropathic nociception produced by traumatic nerve injury, disease, and toxic insults. Effects of mixed cannabinoid CB(1)/CB(2) agonists, CB(2) selective agonists, and modulators of the endocannabinoid system (i.e., inhibitors of transport or degradation) are compared. Effects of genetic disruption of cannabinoid receptors or enzymes controlling endocannabinoid degradation on neuropathic nociception are described. Specific forms of allodynia and hyperalgesia modulated by cannabinoids are also considered. In humans, effects of smoked marijuana, synthetic Delta(9)-THC analogs (e.g., Marinol, Cesamet) and medicinal cannabis preparations containing both Delta(9)-THC and cannabidiol (e.g., Sativex, Cannador) in neuropathic pain states are reviewed. Clinical studies largely affirm that neuropathic pain patients derive benefits from cannabinoid treatment. Subjective (i.e., rating scales) and objective (i.e., stimulus-evoked) measures of pain and quality of life are considered. Finally, limitations of cannabinoid pharmacotherapies are discussed together with directions for future research.

  3. Outcome predictors for treatment success with 5% lidocaine medicated plaster in low back pain with neuropathic components and neuropathic pain after surgical and nonsurgical trauma

    PubMed Central

    Nicolaou, Andrew; Nicholson, Bruce; Hans, Guy; Brasseur, Louis

    2011-01-01

    Five percent lidocaine medicated plaster has been proven efficacious for the symptomatic relief of neuropathic pain in diverse pain conditions which might be attributed to a common localized symptomatology in these indications, possibly with common predictors of treatment success. To discuss potential symptoms and other factors predicting response to treatment with lidocaine plaster for the indications of low back pain with neuropathic components and neuropathic pain after surgical and nonsurgical trauma, 44 pain specialists from 17 countries attended a two-day conference meeting in December 2009. Discussions were based on the retrospective analysis of case reports (sent in by participants in the four weeks prior to the meeting) and the practical experience of the participants. The results indicate some predictors for success with 5% lidocaine medicated plaster for the two indications. Localized pain, hyperalgesia and/or allodynia, and other positive sensory symptoms, such as dysesthesia, were considered positive predictors, whereas widespread pain and negative sensory symptoms were regarded as negative predictors. Paresthesia, diagnosis, and site of pain were considered to be of no predictive value. Common symptomatology with other neurologic pathologies suggests that treatment of localized neuropathic pain symptoms with the plaster can be considered across different neuropathic pain indications. PMID:21386952

  4. Referred sensations and neuropathic pain following spinal cord injury

    PubMed Central

    Soler, M.D.; Kumru, H.; Vidal, J.; Pelayo, R.; Tormos, J.M.; Fregni, F.; Navarro, X.; Pascual-Leone, A.

    2013-01-01

    It has been proposed that painful and non-painful referred sensations (RSs) are associated with reorganization of sensory pathways in patients with complete spinal cord injury (SCI). In order to investigate the referred sensation (RS) phenomenon and its correlation with neuropathic pain (NP) 48 patients with complete SCI, 24 with chronic NP and 24 without pain or paraesthesias were studied using clinical examination and neurophysiological tests. Patients reporting RSs were re-examined at 2 and 10 weeks after the first examination. We defined the presence of RS as sensations perceived below the injury level in response to touch and pinprick stimuli in various body points above the injury level. The examination was carried out by one researcher applying the stimuli to the patient under two visual conditions (open and closed eyes), and then asking the patient to make tactile self-stimulation. Seven patients with SCI and NP (29%) reported RS below the injury level. RS were well located and consistently evoked at repeated examinations. Touch and pinprick stimulation elicited similar RS that were non-painful in six patients and painful in one. Visual feedback did not change RS perception and characteristics. None of the patients in the SCI group without NP presented RS. In conclusion, our results indicate that RS is relatively frequent in patients with complete SCI and NP. The common occurrence of RS in patients with NP and the location of the sensations in the same area as NP suggest that pain and RS share common pathophysiological mechanisms. PMID:20471171

  5. Differential drug effects on spontaneous and evoked pain behavior in a model of trigeminal neuropathic pain

    PubMed Central

    Deseure, K; Hans, GH

    2017-01-01

    Purpose Baclofen and morphine have shown efficacy against mechanical allodynia after infraorbital nerve chronic constriction injury (IoN-CCI). No drug effects have yet been reported on spontaneous trigeminal neuropathic pain. It has been proposed that the directed face grooming behavior that also develops following IoN-CCI offers a measure of spontaneous trigeminal neuropathic pain. Subjects and methods We examined the effects of a continuous 1-week infusion of 30 mg/day carbamazepine (the first-line drug treatment for trigeminal neuralgia), 1.06 mg/day baclofen, 4.18 mg/day clomipramine, and 5 mg/day morphine on spontaneous and mechanically evoked pain behavior (ie, directed face grooming and von Frey testing) in IoN-CCI rats. Results Isolated face grooming was significantly reduced in rats receiving carbamazepine and baclofen but not in clomipramine- or morphine-treated rats. All drugs showed significant antiallodynic effects; carbamazepine showed the strongest effects, whereas clomipramine had only minor efficacy. Conclusion The tested drugs have differential effects in the IoN-CCI model, and different neuropathological mechanisms may underlie the different somatosensory symptoms in this model. A mechanism-based approach may be needed to treat (trigeminal) neuropathic pain. The present data support IoN-CCI as a model of trigeminal neuralgia in which isolated face grooming is used as a measure of spontaneous neuropathic pain. PMID:28184169

  6. The effects of music therapy on pain in patients with neuropathic pain.

    PubMed

    Korhan, Esra Akın; Uyar, Meltem; Eyigör, Can; Hakverdioğlu Yönt, Gülendam; Çelik, Serkan; Khorshıd, Leyla

    2014-03-01

    The aim of this study was to investigate the effect of relaxing music on pain intensity in patients with neuropathic pain. A quasi-experimental study, repeated measures design was used. Thirty patients, aged 18-70 years, with neuropathic pain and hospitalized in an Algology clinic were identified as a convenience sample. Participants received 60 minutes of music therapy. Classical Turkish music was played to patients using a media player (MP3) and headphones. Participants had pain scores taken immediately before the intervention and at the 30th and 60th minutes of the intervention. Data were collected over a 6-month period in 2012. The patients' mean pain intensity scores were reduced by music, and that decrease was progressive over the 30th and 60th minutes of the intervention, indicating a cumulative dose effect. The results of this study implied that the inclusion of music therapy in the routine care of patients with neuropathic pain could provide nurses with an effective practice for reducing patients' pain intensity. Copyright © 2014 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

  7. Cellular prion protein protects from inflammatory and neuropathic pain.

    PubMed

    Gadotti, Vinicius M; Zamponi, Gerald W

    2011-08-16

    Cellular prion protein (PrPC) inhibits N-Methyl-D-Aspartate (NMDA) receptors. Since NMDA receptors play an important role in the transmission of pain signals in the dorsal horn of spinal cord, we thus wanted to determine if PrPC null mice show a reduced threshold for various pain behaviours.We compared nociceptive thresholds between wild type and PrPC null mice in models of inflammatory and neuropathic pain, in the presence and the absence of a NMDA receptor antagonist. 2-3 months old male PrPC null mice exhibited an MK-801 sensitive decrease in the paw withdrawal threshold in response both mechanical and thermal stimuli. PrPC null mice also exhibited significantly longer licking/biting time during both the first and second phases of formalin-induced inflammation of the paw, which was again prevented by treatment of the mice with MK-801, and responded more strongly to glutamate injection into the paw. Compared to wild type animals, PrPC null mice also exhibited a significantly greater nociceptive response (licking/biting) after intrathecal injection of NMDA. Sciatic nerve ligation resulted in MK-801 sensitive neuropathic pain in wild-type mice, but did not further augment the basal increase in pain behaviour observed in the null mice, suggesting that mice lacking PrPC may already be in a state of tonic central sensitization. Altogether, our data indicate that PrPC exerts a critical role in modulating nociceptive transmission at the spinal cord level, and fit with the concept of NMDA receptor hyperfunction in the absence of PrPC.

  8. Quercetin alleviates thermal and cold hyperalgesia in a rat neuropathic pain model by inhibiting Toll-like receptor signaling.

    PubMed

    Ji, Chunmei; Xu, Yongsheng; Han, Fang; Sun, Dehai; Zhang, Hanli; Li, Xiumei; Yao, Xiaoyin; Wang, Hong

    2017-10-01

    Neuropathic pain is caused by lesion or disease of the nervous system, which results in abnormal spontaneous and evoked pain. It's common in clinical practice and greatly impairs the life quality of patients, but the effective treatment is still lacking. In this study, we aimed to explore the effect of quercetin (QUE) on neuropathic pain and the underlying mechanisms. Spinal nerve ligation (SNL) was performed in Sprague Dawley rats to establish the neuropathic pain model. Single or continuous oral administration of QUE after the operation or continuous administration before the operation was applied to evaluate the effects of QUE on SNL-induced thermal and cold hyperalgesia. Dorsal root ganglions from these rats were harvested to analyze the expression levels of some inflammatory mediators. Primary cultured astrocytes and HEK293 cells were used to further explore the downstream signaling pathways of QUE. Both single and continuous oral administration of QUE dose-dependently alleviated SNL-induced thermal and cold hyperalgesia. Pre-administration also attenuated neuropathic pain symptoms. Meanwhile, SNL-induced increase in protein or mRNA levels of some inflammatory mediators could be down-regulated by QUE treatment. Furthermore, QUE reduced the phosphorylation of TAK1, IKK and JNK2 in cultured astrocytes. Moreover, luciferase assay in HEK293 cells showed that QUE dose-dependently inhibited NF-κB activity only via TAK1. QUE exerts anti-inflammatory effects and alleviates neuropathic pain through the inhibition of Toll-like receptor signaling pathway. It could shed some light on the potential applications of QUE in chronic pain therapy. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  9. Effects of intraperitoneal thymoquinone on chronic neuropathic pain in rats.

    PubMed

    Amin, Bahareh; Taheri, Mohammad Mehdi Heravi; Hosseinzadeh, Hossein

    2014-10-01

    In this study, we evaluated the protective effects of thymoquinone, the major constituent of Nigella sativa seeds on the neuropathic pain of rats with chronic constrictive injury of the sciatic nerve. Rats received repeated administration of thymoquinone (1.25, 2.5, and 5 mg/kg, i. p.) once a day for 14 days, beginning immediately after the nerve injury. Mechanical allodynia, cold allodynia, and thermal hyperalgesia were assessed with the von Frey filament, acetone drop, or radiant heat stimulus, respectively. Recent evidence points towards a role of oxidative stress, spinal glia activation, and cell death in the pathogenesis of neuropathic pain. Ionized calcium-binding adapter molecule 1 (a marker of microglia), glial fibrillary acidic protein (a marker of astroglia), Bcl2-associated X protein (a proapoptotic protein), and B-cell lymphoma protein 2 (an antiapoptotic protein) were measured using Western blot on days 3, 7, and 14 post chronic constrictive injury. The changes in the protein levels of malondialdehyde and glutathione, biomarkers of oxidative stress, were assessed by spectrophotometric assay on day 14 post chronic constrictive injury. Repeated treatment with thymoquinone (2.5 and 5 mg/kg) significantly alleviated behavioral signs of neuropathic pain. In the lumbar spinal cord of neuropathic rats, ionized calcium-binding adapter molecule 1 and Bcl2-associated X protein increased on day 3 post chronic constrictive injury, whereas B-cell lymphoma protein 2 did not significantly change. After repeated thymoquinone administration, the elevated Bcl2-associated X protein and ionized calcium-binding adapter molecule reduced on day 3, while the level of B-cell lymphoma protein 2 was even stimulated. Ionized calcium-binding adapter molecule and Bcl2-associated X protein/B-cell lymphoma protein 2 ratio declined by days 7 and 14; consequently, there were no significant differences among groups. No or little change was observed in the glial fibrillary acidic

  10. Metabolite Concentrations in the Anterior Cingulate Cortex Predict High Neuropathic Pain Impact After Spinal Cord Injury

    DTIC Science & Technology

    2013-02-01

    in diabetes neuropathy [45] in which ACC NAA concentrations were no different in subjects with neuropathic pain compared with pain-free control...brain regions in patients with diabetes and painful neuropathy . Diabetes Care. 2008; 31:980–1. [PubMed: 18299445] 46. Spielberger, CD.; Garsuch, RC... diabetes [45] and after SCI [34]. Basic research suggests that glial activation is an important mechanism underlying neuropathic pain after SCI [22,23

  11. Self-Reported Neuropathic Pain Characteristics of Women With Provoked Vulvar Pain: A Preliminary Investigation.

    PubMed

    Dargie, Emma; Gilron, Ian; Pukall, Caroline F

    2017-04-01

    Provoked vestibulodynia (PVD) is a common chronic genital pain condition affecting approximately 12% of premenopausal women. Although parallels have been drawn between PVD and neuropathic pain (NP), no studies have examined self-reported NP characteristics in PVD. To explore pain symptoms that resemble NP reported by those with PVD and compare responses with those with an established NP condition. Women with provoked vulvar pain (PVP; n = 65) completed online questionnaires designed to assess characteristics of NP. Responses were compared with those of women with postherpetic neuralgia (PHN; n = 30). In addition to a range of descriptive questions, participants completed the McGill Pain Questionnaire, the Self-Complete Leeds Assessment of Neuropathic Signs and Symptoms (S-LANSS), the Neuropathic Pain Symptom Inventory (NPSI), and the Pain Quality Assessment Scale (PQAS). PVP exhibits some neuropathic characteristics, typically evoked pain (as opposed to the more constant pain of PHN) indicative of allodynia and hyperalgesia. Specifically, women with PVP scored, on average, higher than the NP cutoff on the S-LANSS, and there were no significant differences between women with PVP and those with PHN on some NPSI subscales. However, women with PHN reported more NP symptoms on the PQAS, S-LANSS, and other NPSI subscales. Validated NP questionnaires could be of particular use for health care professionals who need a more efficient way to assess symptoms of patients with PVP and should be included in future studies investigating the mechanisms and treatment of this pain. This study takes a unique approach to the examination of PVP by using multiple validated NP measures to compare pain characteristics with those of a group of participants with PHN, an established NP condition. However, it is limited by self-reported data not confirmed with clinical examination, small size of the PHN group, and the severity of the pain experienced in the PVP group. Women with PVP report

  12. Selective small molecule angiotensin II type 2 receptor antagonists for neuropathic pain: preclinical and clinical studies.

    PubMed

    Smith, Maree T; Anand, Praveen; Rice, Andrew S C

    2016-02-01

    Neuropathic pain affects up to 10% of the general population, but drug treatments recommended for the treatment of neuropathic pain are associated with modest efficacy and/or produce dose-limiting side effects. Hence, neuropathic pain is an unmet medical need. In the past 2 decades, research on the pathobiology of neuropathic pain has revealed many novel pain targets for use in analgesic drug discovery programs. However, these efforts have been largely unsuccessful as molecules that showed promising pain relief in rodent models of neuropathic pain generally failed to produce analgesia in early phase clinical trials in patients with neuropathic pain. One notable exception is the angiotensin II type 2 (AT2) receptor that has clinical validity on the basis of a successful double-blind, randomized, placebo-controlled, clinical trial of EMA401, a highly selective, orally active, peripherally restricted AT2 receptor antagonist in patients with postherpetic neuralgia. In this study, we review research to date on target validation, efficacy, and mode of action of small molecule AT2 receptor antagonists in rodent models of peripheral neuropathic pain and in cultured human sensory neurons, the preclinical pharmacokinetics of these compounds, and the outcome of the above clinical trial.

  13. A New Rat Model of Cisplatin-induced Neuropathic Pain

    PubMed Central

    Lin, Hai; Heo, Bong Ha

    2015-01-01

    Background Chemotherapy-induced peripheral neuropathy is a major side effect of anti-cancer drugs, and our knowledge of its mechanisms is lacking. Several models for chemotherapy-induced neuropathy have been introduced. However, the outcomes of these models differ significantly among laboratories. Our object was to create a model of chemotherapy-induced neuropathy in rats with cancer. Methods Female Sprague-Dawley rats were used. Mammary rat metastasis tumor (MRMT-1) cells were implanted subcutaneously in rats. Chemotherapy-induced peripheral neuropathy was induced by injection of cisplatin once a day for four days. The responses to mechanical and thermal stimuli were examined using von Frey filaments, acetone, and radiant heat. Results Cisplatin (2 mg/kg/day) produced mechanical allodynia, while it did not induce cold allodynia or thermal hyperalgesia. This dose of cisplatin could work successfully against cancer. Body weight loss was not observed in cisplatin-treated rats, nor were other abnormal behaviors noted in the same rats. Conclusions Repeated injection of intraperitoneal cisplatin induced peripheral neuropathic pain in rats. Thus, this type of rat model has broad applicability in studies related to searching for the mechanism of cisplatin-induced mechanical allodynia and agents for the treatment of neuropathic pain. PMID:26495078

  14. Neuropathic pain in the general population: a systematic review of epidemiological studies.

    PubMed

    van Hecke, O; Austin, Sophie K; Khan, Rafi A; Smith, B H; Torrance, N

    2014-04-01

    Most patients with neuropathic pain symptoms present and are managed in primary care, with only a minority being referred for specialist clinical assessment and diagnoses. Previous reviews have focused mainly on specific neuropathic pain conditions based in specialist settings. This is the first systematic review of epidemiological studies of neuropathic pain in the general population. Electronic databases were searched from January 1966 to December 2012, and studies were included where the main focus was on neuropathic pain prevalence and/or incidence, either as part of a specific neuropathic pain-related condition or as a global entity in the general population. We excluded studies in which data were extracted from pain or other specialist clinics or focusing on specific population subgroups. Twenty-one articles were identified and underwent quality assessment and data extraction. Included studies differed in 3 main ways: method of data retrieval, case ascertainment tool used, and presentation of prevalence/incidence rates. This heterogeneity precluded any meta-analysis. We categorised comparable incidence and prevalence rates into 2 main subgroups: (1) chronic pain with neuropathic characteristics (range 3-17%), and (2) neuropathic pain associated with a specific condition, including postherpetic neuralgia (3.9-42.0/100,000 person-years [PY]), trigeminal neuralgia (12.6-28.9/100,000 PY), painful diabetic peripheral neuropathy (15.3-72.3/100,000 PY), glossopharyngeal neuralgia (0.2-0.4/100,000 PY). These differences highlight the importance of a standardised approach for identifying neuropathic pain in future epidemiological studies. A best estimate of population prevalence of pain with neuropathic characteristics is likely to lie between 6.9% and 10%. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  15. Cervico-thoracic or lumbar sympathectomy for neuropathic pain and complex regional pain syndrome.

    PubMed

    Straube, Sebastian; Derry, Sheena; Moore, R Andrew; McQuay, Henry J

    2010-07-07

    This review is an update on 'Sympathectomy for neuropathic pain' originally published in Issue 2, 2003. The concept that many neuropathic pain syndromes (traditionally this definition would include complex regional pain syndromes (CRPS)) are "sympathetically maintained pains" has historically led to treatments that interrupt the sympathetic nervous system. Chemical sympathectomies use alcohol or phenol injections to destroy ganglia of the sympathetic chain, while surgical ablation is performed by open removal or electrocoagulation of the sympathetic chain, or minimally invasive procedures using thermal or laser interruption. To review the evidence from randomised, double blind, controlled trials on the efficacy and safety of chemical and surgical sympathectomy for neuropathic pain. Sympathectomy could be compared with placebo (sham) or other active treatment. We searched MEDLINE, EMBASE and The Cochrane Library to May 2010. We screened references in the retrieved articles and literature reviews, and contacted experts in the field of neuropathic pain. Randomised, double blind, placebo or active controlled studies assessing the effects of sympathectomy for neuropathic pain and CRPS. Two review authors independently assessed trial quality and validity, and extracted data. No pooled analysis of data was possible. Only one study satisfied our inclusion criteria, comparing percutaneous radiofrequency thermal lumbar sympathectomy with lumbar sympathetic neurolysis using phenol in 20 participants with CRPS. There was no comparison of sympathectomy versus sham or placebo. No dichotomous pain outcomes were reported. Average baseline scores of 8-9/10 on several pain scales fell to about 4/10 initially (1 day) and remained at 3-5/10 over four months. There were no significant differences between groups, except for "unpleasant sensation", which was higher with radiofrequency ablation. One participant in the phenol group experienced postsympathectomy neuralgia, while two in the

  16. The prevalence of neuropathic pain: Clinical evaluation compared with screening tools in a community population

    PubMed Central

    Yawn, Barbara P.; Wollan, Peter C.; Weingarten, Toby N.; Watson, James C.; Hooten, W. Michael; Melton, L. Joseph

    2010-01-01

    Background Neuropathic pain is reported to be common based on studies from specialty centers and survey studies. However, few prevalence estimates have been completed in a community population using clinical evaluation. Objective To develop an estimate of the prevalence of neuropathic pain in community dwelling adults. Methods Data from a mailed survey (n=3575 community respondents), telephone interview (n=905), and a clinical examination (n=205) were linked to estimate the population prevalence of neuropathic pain. Using the clinical examination as the “gold” standard, estimates from several screening tools were developed and adjusted to the Olmsted County, Minnesota adult population. Results The estimated community prevalence of neuropathic pain from the clinical examination (gold standard) was 9.8%. Most other estimates were lower, including a 3.0% population prevalence using the Berger criteria and 8.8% using the S-LANSS. Only the prevalence rate based on self-report of nerve pain was higher (12.4%). Overlap among the groups each tool identified as having “neuropathic predominant pain” was only modest and the groups had significantly different rates of depressive symptoms, anxiety, limited functional ability and use of complementary and alternative medicine (CAM). Conclusions The estimated rates and personal characteristics of community residents with “neuropathic pain” varies widely depending on the tools used to identify neuropathic pain. None of the screening tools compared well to clinical evaluation. The differences in the groups identified by alternative screening methods become of major importance when reporting neuropathic pain epidemiology, studying therapies for neuropathic pain or attempting to translate neuropathic pain research into clinical practice. PMID:20849570

  17. Inhibition of mechanical allodynia in neuropathic pain by TLR5-mediated A-fiber blockade

    PubMed Central

    Xu, Zhen-Zhong; Kim, Yong Ho; Bang, Sangsu; Zhang, Yi; Berta, Temugin; Wang, Fan; Oh, Seog Bae; Ji, Ru-Rong

    2016-01-01

    SUMMARY Mechanical allodynia, induced by normally innocuous low-threshold mechanical stimulation, represents a cardinal feature of neuropathic pain. Blockade or ablation of high-threshold small-diameter unmyelinated C-fibers has limited effects on mechanical allodynia1–4. While large myelinated A-fibers, in particular Aβ-fibers, have previously been implicated in mechanical allodynia5–7, an A-fiber-selective pharmacological blocker is still lacking. Here we report a new method for targeted silencing of A-fibers in neuropathic pain. We found that Toll-like receptor 5 (TLR5) is co-expressed with neurofilament-200 in large-diameter A-fiber neurons in the dorsal root ganglion (DRG). Activation of TLR5 with its ligand flagellin results in neuronal entry of the membrane impermeable lidocaine derivative QX-314, leading to TLR5-dependent blockade of sodium currents predominantly in A-fiber neurons of mouse DRGs. Intraplantar co-application of flagellin and QX-314 (flagellin/QX-314) dose-dependently suppressed mechanical allodynia following chemotherapy, nerve injury, and diabetic neuropathy, but this blockade is abrogated in Tlr5-deficient mice. In vivo electrophysiology demonstrated that flagellin/QX-314 co-application selectively suppressed Aβ-fiber conduction in naive and chemotherapy-treated mice. TLR5-mediated Aβ blockade but not capsaicin-mediated C-fiber blockade also reduced chemotherapy-induced ongoing pain without impairing motor function. Finally, flagellin/QX-314 co-application suppressed sodium currents in large-diameter human DRG neurons. Thus, our findings provide a new tool for targeted silencing of Aβ-fibers and neuropathic pain treatment. PMID:26479925

  18. The characteristics of chronic pain after non-traumatic, non-compressive myelopathy: Focus on neuropathic pain.

    PubMed

    Eom, Young In; Kim, Min; Joo, In Soo

    2017-05-01

    The aim of this study was to assess the characteristics of neuropathic pain after non-traumatic, non-compressive (NTNC) myelopathy and find potential predictors for neuropathic pain. We analyzed 54 patients with NTNC myelopathy. The Short Form McGill Pain Questionnaire (SF-MPQ) and the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) were used to assess pain. Health-related QOL was evaluated by the Short Form 36-item (SF-36) health survey. Out of 48 patients with pain, 16 (33.3%) patients experienced neuropathic pain. Mean age was significantly lower in patients with neuropathic pain than in patients with non-neuropathic pain (39.1 ± 12.5 vs. 49.8 ± 9.3, P = 0.002). There were no statistically significant differences in the other variables including sex, etiology of myelopathy, pain and QOL scores between the two groups. A binary logistic regression revealed that onset age under 40, and non-idiopathic etiology were independent predictors of the occurrence of neuropathic pain. Both SF-MPQ and LANSS scores were significantly correlated with SF-36 scores, adjusted by age, sex, presence of diabetes mellitus, and current EDSS scores (r = -0.624, P < 0.0001 for SF-MPQ; r = -0.357, P = 0.017 for LANSS). Neuropathic pain must be one of serious complications in patients with NTNC myelopathy and also affects their quality of life. Onset age and etiology of myelopathy are important factors in the development of neuropathic pain in NTNC myelopathy.

  19. Efficacy of Venlafaxine in Neuropathic Pain: A Narrative Review of Optimized Treatment.

    PubMed

    Trouvin, Anne-Priscille; Perrot, Serge; Lloret-Linares, Célia

    2017-06-01

    The prevalence of neuropathic pain is high in the general population, and high priority is given to the management of this pain condition. The treatment of neuropathic pain remains challenging, despite the publication of national and international recommendations. The purpose of this narrative review of venlafaxine (VLX) is to provide a better knowledge of the pharmacology of this drug and a clearer view of its efficacy and tolerability in neuropathic pain. Two independent reviewers searched PubMed with the following search terms: serotonin and noradrenalin reuptake inhibitors OR VLX hydrochloride AND pain. The reviewers included all clinical studies that investigated VLX in neuropathic pain conditions and excluded animal studies, studies on fibromyalgia, studies that focused on the prevention of neuropathic pain, case reports, and studies that did not clearly describe neuropathic pain in the included patients. We describe the 13 studies that we analyzed. Eleven were randomized clinical trials, and the comparator was placebo in 8 studies. Nine studies reported that VLX was effective against neuropathic pain. However, among the trials, only one against placebo included a large number of patients with >200 participants and one against prégabaline and carbamazepine had >200 patients. Most of the adverse events reported in the selected studies were consistent with known adverse events of VLX, and most were mild to moderate. However, most studies were of very short duration. Most of the clinical studies found that VLX was effective and well tolerated. However, given the limited number of study and the limitations of all these studies, further large clinical trials are needed. Currently, considering the limited therapeutic options for treating neuropathic pain and the highly variable nature of responses to all drugs, VLX has a place as a treatment option for neuropathic pain. Copyright © 2017 Elsevier HS Journals, Inc. All rights reserved.

  20. CXCL13 drives spinal astrocyte activation and neuropathic pain via CXCR5

    PubMed Central

    Jiang, Bao-Chun; Cao, De-Li; Zhang, Xin; Zhang, Zhi-Jun; He, Li-Na; Li, Chun-Hua; Zhang, Wen-Wen; Wu, Xiao-Bo; Berta, Temugin; Ji, Ru-Rong; Gao, Yong-Jing

    2016-01-01

    Recent studies have implicated chemokines in microglial activation and pathogenesis of neuropathic pain. C-X-C motif chemokine 13 (CXCL13) is a B lymphocyte chemoattractant that activates CXCR5. Using the spinal nerve ligation (SNL) model of neuropathic pain, we found that CXCL13 was persistently upregulated in spinal cord neurons after SNL, resulting in spinal astrocyte activation via CXCR5 in mice. shRNA-mediated inhibition of CXCL13 in the spinal cord persistently attenuated SNL-induced neuropathic pain. Interestingly, CXCL13 expression was suppressed by miR-186-5p, a microRNA that colocalized with CXCL13 and was downregulated after SNL. Spinal overexpression of miR-186-5p decreased CXCL13 expression, alleviating neuropathic pain. Furthermore, SNL induced CXCR5 expression in spinal astrocytes, and neuropathic pain was abrogated in Cxcr5–/– mice. CXCR5 expression induced by SNL was required for the SNL-induced activation of spinal astrocytes and microglia. Intrathecal injection of CXCL13 was sufficient to induce pain hypersensitivity and astrocyte activation via CXCR5 and ERK. Finally, intrathecal injection of CXCL13-activated astrocytes induced mechanical allodynia in naive mice. Collectively, our findings reveal a neuronal/astrocytic interaction in the spinal cord by which neuronally produced CXCL13 activates astrocytes via CXCR5 to facilitate neuropathic pain. Thus, miR-186-5p and CXCL13/CXCR5-mediated astrocyte signaling may be suitable therapeutic targets for neuropathic pain. PMID:26752644

  1. CXCL13 drives spinal astrocyte activation and neuropathic pain via CXCR5.

    PubMed

    Jiang, Bao-Chun; Cao, De-Li; Zhang, Xin; Zhang, Zhi-Jun; He, Li-Na; Li, Chun-Hua; Zhang, Wen-Wen; Wu, Xiao-Bo; Berta, Temugin; Ji, Ru-Rong; Gao, Yong-Jing

    2016-02-01

    Recent studies have implicated chemokines in microglial activation and pathogenesis of neuropathic pain. C-X-C motif chemokine 13 (CXCL13) is a B lymphocyte chemoattractant that activates CXCR5. Using the spinal nerve ligation (SNL) model of neuropathic pain, we found that CXCL13 was persistently upregulated in spinal cord neurons after SNL, resulting in spinal astrocyte activation via CXCR5 in mice. shRNA-mediated inhibition of CXCL13 in the spinal cord persistently attenuated SNL-induced neuropathic pain. Interestingly, CXCL13 expression was suppressed by miR-186-5p, a microRNA that colocalized with CXCL13 and was downregulated after SNL. Spinal overexpression of miR-186-5p decreased CXCL13 expression, alleviating neuropathic pain. Furthermore, SNL induced CXCR5 expression in spinal astrocytes, and neuropathic pain was abrogated in Cxcr5-/- mice. CXCR5 expression induced by SNL was required for the SNL-induced activation of spinal astrocytes and microglia. Intrathecal injection of CXCL13 was sufficient to induce pain hypersensitivity and astrocyte activation via CXCR5 and ERK. Finally, intrathecal injection of CXCL13-activated astrocytes induced mechanical allodynia in naive mice. Collectively, our findings reveal a neuronal/astrocytic interaction in the spinal cord by which neuronally produced CXCL13 activates astrocytes via CXCR5 to facilitate neuropathic pain. Thus, miR-186-5p and CXCL13/CXCR5-mediated astrocyte signaling may be suitable therapeutic targets for neuropathic pain.

  2. Botulinum toxin for neuropathic pain and spasticity: an overview.

    PubMed

    Brown, E Alexandra; Schütz, Sonja G; Simpson, David M

    2014-03-01

    In recent years, a large body of data has surfaced reporting the therapeutic benefit of botulinum toxin injection in multiple conditions. The aim of this review is: to summarize the highest quality literature pertaining to clinical application of botulinum toxin in neuropathic pain conditions including postherpetic neuralgia, trigeminal neuralgia, diabetic polyneuropathy, post-traumatic neuralgia, carpal tunnel syndrome, complex regional pain syndrome, phantom limb and stump pain, and occipital neuralgia; to provide an overview of the clinical trials using botulinum toxin in adult spasticity; and to assign levels of evidence according to the American Academy of Neurology guidelines. In summary, there is level A evidence for established efficacy in postherpetic neuralgia and adult spasticity; level B evidence for probable efficacy in trigeminal neuralgia and post-traumatic neuralgia; level B evidence for probable lack of efficacy in carpal tunnel syndrome; level C evidence for possible efficacy in diabetic polyneuropathy; and level U (insufficient) evidence in complex regional pain syndrome, phantom limb and stump pain, and occipital neuralgia.

  3. [Guidelines for the clinical management of neuropathic pain (II)].

    PubMed

    Aguilera-Muñoz, J; Arizaga-Cuesta, E; Carpio-Rodas, A; Crump, J; Díaz-Heredia, F; Fernández, C F; Griego, J M; Guerrero, D; Hincapié, M; León, M X; Moyano, J; Navarro-Chávez, M; Rangel-Galvis, C E; Rodríguez, R; Salazar-Bolaños, E; Sarmiento, A; Terán Saá-Jaramillo, D; Tettamanti, D; Valencia, D; Vargas-Gómez, J J

    Up to 5% of the population suffers from neuropathic pain (NP). A bibliographical search in several databases revealed that, to date, there are no protocols to guide physicians who are not specialists in pain that enable them to treat NP and thus improve patients' quality of life. The aim of this study is to provide Spanish-speaking physicians who are not specialists in pain with a set of guidelines for the treatment of NP. A bibliographical search was performed in order to base the results and conclusions on the evidence-based medicine methodology. First, we review the most effective clinical and paraclinical methods for diagnosing NP, and the LANSS pain scale is reported as the most appropriate method of clinically evaluating NP. The anatomical paths and the physiology of pain are then described and we review the molecular variables involved. Finally, we point out the current therapeutic options and propose an algorithm for the treatment of NP. There is no specific set of guidelines for the treatment of NP. At the present time, the keystone of NP treatment consists in the use of antidepressant and anticonvulsive drugs. There is a need for further clinical trials to prove the effectiveness of using combined medication.

  4. Neuropathic Pain Components in Patients with Cancer: Prevalence, Treatment, and Interference with Daily Activities.

    PubMed

    Oosterling, Anne; te Boveldt, Nienke; Verhagen, Constans; van der Graaf, Winette T; Van Ham, Maaike; Van der Drift, Miep; Vissers, Kris; Engels, Yvonne

    2016-04-01

    Pain and neuropathic symptoms impact quality of life of patients with cancer. To obtain more insight in the prevalence, severity, and treatment of neuropathic symptoms in patients with cancer and their interference with daily activities, we conducted a cross-sectional study at the outpatient clinic of a Dutch university hospital. A cross-sectional study among outpatients with cancer. To identify pain, its intensity, quality, and interference with daily activities, the Brief Pain Inventory (BPI) was used. Neuropathic symptoms were identified with the Douleur Neuropathique (DN4) interview and pain characteristics with the McGill Pain Questionnaire (MPQ). Pain medication and adjuvant analgesics were also collected with a prestructured questionnaire. Descriptives, chi-squared tests, t-tests, and a logistic regression analysis were conducted. 892 patients completed the questionnaires. Twenty-three percent (n = 204) reported moderate to severe pain, and 19% (n = 170) scored positive on neuropathic symptoms (DN4 ≥ 3). Particularly in patients with a rating on a numeric rating scale (NRS) < 5, existence of neuropathic symptoms significantly increased interference with daily activities. Of patients with neuropathic symptoms, 8% received adjuvant pain treatment. Receiving curative treatment, using a systemic drug with neurotoxicity, having had an operation, and having had a lymph node dissection independently contributed to having neuropathic symptoms. This study shows that over 40% of the patients with moderate to severe pain also have neuropathic symptoms, causing increased interference with daily activities. Most of these patients do not receive adjuvant analgesics. There is a need to improve management of neuropathic symptoms in patients with cancer. © 2015 World Institute of Pain.

  5. Neuropathic pain in dogs and cats: if only they could tell us if they hurt.

    PubMed

    Mathews, Karol A

    2008-11-01

    Neuropathic pain is difficult to diagnose in veterinary patients because they are unable to verbalize their pain. By assuming that neuropathic pain may exist based on the history of events that each patient has experienced, a focused client history and neurologic examination may identify a lesion resulting in persistent or spontaneous pain. Once neuropathic pain is diagnosed, a trial analgesic or acupuncture session(s) should be prescribed with instructions for owners to observe behavior. Dosing of the analgesic can be titrated to the patient's needs while avoiding adverse effects. When a particular analgesic may be ineffectual, an alternate class should be tried. As research into the neurobiologic mechanisms of neuropathic pain continues, specific therapies for its management should eventually appear in the human clinical setting and subsequently be investigated for veterinary clinical use.

  6. Neuropathic pain: an updated grading system for research and clinical practice.

    PubMed

    Finnerup, Nanna B; Haroutounian, Simon; Kamerman, Peter; Baron, Ralf; Bennett, David L H; Bouhassira, Didier; Cruccu, Giorgio; Freeman, Roy; Hansson, Per; Nurmikko, Turo; Raja, Srinivasa N; Rice, Andrew S C; Serra, Jordi; Smith, Blair H; Treede, Rolf-Detlef; Jensen, Troels S

    2016-08-01

    The redefinition of neuropathic pain as "pain arising as a direct consequence of a lesion or disease affecting the somatosensory system," which was suggested by the International Association for the Study of Pain (IASP) Special Interest Group on Neuropathic Pain (NeuPSIG) in 2008, has been widely accepted. In contrast, the proposed grading system of possible, probable, and definite neuropathic pain from 2008 has been used to a lesser extent. Here, we report a citation analysis of the original NeuPSIG grading paper of 2008, followed by an analysis of its use by an expert panel and recommendations for an improved grading system. As of February, 2015, 608 eligible articles in Scopus cited the paper, 414 of which cited the neuropathic pain definition. Of 220 clinical studies citing the paper, 56 had used the grading system. The percentage using the grading system increased from 5% in 2009 to 30% in 2014. Obstacles to a wider use of the grading system were identified, including (1) questions about the relative significance of confirmatory tests, (2) the role of screening tools, and (3) uncertainties about what is considered a neuroanatomically plausible pain distribution. Here, we present a revised grading system with an adjusted order, better reflecting clinical practice, improvements in the specifications, and a word of caution that even the "definite" level of neuropathic pain does not always indicate causality. In addition, we add a table illustrating the area of pain and sensory abnormalities in common neuropathic pain conditions and propose areas for further research.

  7. Palmitoylethanolamide, a naturally occurring disease-modifying agent in neuropathic pain.

    PubMed

    Skaper, Stephen D; Facci, Laura; Fusco, Mariella; Della Valle, Maria Federica; Zusso, Morena; Costa, Barbara; Giusti, Pietro

    2014-04-01

    Persistent pain affects nearly half of all people seeking medical care in the US alone, and accounts for at least $80 billion worth of lost productivity each year. Among all types of chronic pain, neuropathic pain stands out: this is pain resulting from damage or disease of the somatosensory nervous system, and remains largely untreatable. With few available treatment options, neuropathic pain represents an area of significant and growing unmet medical need. Current treatment of peripheral neuropathic pain involves several drug classes, including opioids, gabapentinoids, antidepressants, antiepileptic drugs, local anesthetics and capsaicin. Even so, less than half of patients achieve partial relief. This review discusses a novel approach to neuropathic pain management, based on knowledge of: the role of glia and mast cells in pain and neuroinflammation; the body's innate mechanisms to maintain cellular homeostasis when faced with external stressors provoking, for example, inflammation. The discovery that palmitoylethanolamide, a member of the N-acylethanolamine family which is produced from the lipid bilayer on-demand, is capable of exerting anti-allodynic and anti-hyperalgesic effects by down-modulating both microglial and mast cell activity has led to the application of this fatty acid amide in several clinical studies of neuropathic pain, with beneficial outcome and no indication of adverse effects at pharmacological doses. Collectively, the findings presented here propose that palmitoylethanolamide merits further consideration as a disease-modifying agent for controlling inflammatory responses and related chronic and neuropathic pain.

  8. Cervico-thoracic or lumbar sympathectomy for neuropathic pain and complex regional pain syndrome

    PubMed Central

    Straube, Sebastian; Derry, Sheena; Moore, R Andrew; McQuay, Henry J

    2014-01-01

    Background This review is an update on ‘Sympathectomy for neuropathic pain’ originally published in Issue 2, 2003. The concept that many neuropathic pain syndromes (traditionally this definition would include complex regional pain syndromes (CRPS)) are “sympathetically maintained pains” has historically led to treatments that interrupt the sympathetic nervous system. Chemical sympathectomies use alcohol or phenol injections to destroy ganglia of the sympathetic chain, while surgical ablation is performed by open removal or electrocoagulation of the sympathetic chain, or minimally invasive procedures using thermal or laser interruption. Objectives To review the evidence from randomised, double blind, controlled trials on the efficacy and safety of chemical and surgical sympathectomy for neuropathic pain. Sympathectomy could be compared with placebo (sham) or other active treatment. Search methods We searched MEDLINE, EMBASE and The Cochrane Library to May 2010. We screened references in the retrieved articles and literature reviews, and contacted experts in the field of neuropathic pain. Selection criteria Randomised, double blind, placebo or active controlled studies assessing the effects of sympathectomy for neuropathic pain and CRPS. Data collection and analysis Two review authors independently assessed trial quality and validity, and extracted data. No pooled analysis of data was possible. Main results Only one study satisfied our inclusion criteria, comparing percutaneous radiofrequency thermal lumbar sympathectomy with lumbar sympathetic neurolysis using phenol in 20 participants with CRPS. There was no comparison of sympathectomy versus sham or placebo. No dichotomous pain outcomes were reported. Average baseline scores of 8-9/10 on several pain scales fell to about 4/10 initially (1 day) and remained at 3-5/10 over four months. There were no significant differences between groups, except for “unpleasant sensation”, which was higher with

  9. The clinical characteristics of neuropathic pain in patients with total brachial plexus avulsion: A 30-case study.

    PubMed

    Zhou, Yingjie; Liu, Peixi; Rui, Jing; Zhao, Xin; Lao, Jie

    2016-08-01

    Neuropathic pain in patients with total brachial plexus avulsion has always been a sophisticated problem in clinical practice. For further researches on objective diagnosis, alleviation or even cure of neuropathic pain, we need to conclude the basic clinical features including pain intensity, distribution, type and possible risk factors. Thirty cases of patients with total brachial plexus avulsion were included and their baseline information was collected. Pain was evaluated by Present Pain Index using a visual analog scale; Douleur Neuropathique 4 was used for screening neuropathic pain. For more detailed pain description, the Neuropathic Pain Symptoms Inventory questionnaire and a picture showing the exact pain district were both fulfilled by all the eligible participants. The relationship between neuropathic pain and basic information, injury conditions, accompanied conditions and quality of life was tested. All the participants were male in both groups. The neuropathic pain group contained 22 patients (73.33%) with the mean age of 30.18±9.47; while 29.00±7.95 in the other group. Patients with neuropathic pain presented variously in pain degree, location, type and time phase, according to the results of the Neuropathic Pain Symptoms Inventory questionnaire. Nevertheless, most pain distributed on the region of hand. Among several related factors, alcohol abuse may be possible risk factors of neuropathic pain (p=0.03). Quality of life was significantly affected by pain (p<0.01). Neuropathic pain in patients with total brachial avulsion was characterized with heterogeneity in pain distribution, intensity, type and also time phase. Bad life habits might be risk factors associated with neuropathic pain. Neuropathic pain might affect quality of life of the patients with total brachial plexus avulsion remarkably. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Cervico-thoracic or lumbar sympathectomy for neuropathic pain and complex regional pain syndrome.

    PubMed

    Straube, Sebastian; Derry, Sheena; Moore, R Andrew; Cole, Peter

    2013-09-02

    This review is an update of a review first published in Issue 2, 2003, which was substantially updated in Issue 7, 2010. The concept that many neuropathic pain syndromes (traditionally this definition would include complex regional pain syndromes (CRPS)) are "sympathetically maintained pains" has historically led to treatments that interrupt the sympathetic nervous system. Chemical sympathectomies use alcohol or phenol injections to destroy ganglia of the sympathetic chain, while surgical ablation is performed by open removal or electrocoagulation of the sympathetic chain or by minimally invasive procedures using thermal or laser interruption. To review the evidence from randomised, double blind, controlled trials on the efficacy and safety of chemical and surgical sympathectomy for neuropathic pain, including complex regional pain syndrome. Sympathectomy may be compared with placebo (sham) or other active treatment, provided both participants and outcome assessors are blind to treatment group allocation. On 2 July 2013, we searched CENTRAL, MEDLINE, EMBASE, and the Oxford Pain Relief Database. We reviewed the bibliographies of all randomised trials identified and of review articles and also searched two clinical trial databases, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform, to identify additional published or unpublished data. We screened references in the retrieved articles and literature reviews and contacted experts in the field of neuropathic pain. Randomised, double blind, placebo or active controlled studies assessing the effects of sympathectomy for neuropathic pain and CRPS. Two review authors independently assessed trial quality and validity, and extracted data. No pooled analysis of data was possible. Only one study satisfied our inclusion criteria, comparing percutaneous radiofrequency thermal lumbar sympathectomy with lumbar sympathetic neurolysis using phenol in 20 participants with CRPS. There was no comparison of

  11. MicroRNA-93 alleviates neuropathic pain through targeting signal transducer and activator of transcription 3.

    PubMed

    Yan, Xue-Tao; Ji, Li-Juan; Wang, Zhiyu; Wu, Xingjun; Wang, Quan; Sun, Shujie; Lu, Jing-Min; Zhang, Yang

    2017-05-01

    Emerging evidence suggests that microRNAs (miRNAs) play a critical role in the pathogenesis of neuropathic pain. However, the exact role of miRNAs in regulating neuropathic pain remains largely unknown. In this study, we aimed to investigate the potential role of miR-93 in a rat model of neuropathic pain induced by chronic constriction sciatic nerve injury (CCI). We found a significant decrease of miR-93 in the spinal cord of CCI rats compared with sham rats. Overexpression of miR-93 significantly alleviated neuropathic pain development and reduced inflammatory cytokine expression, including interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and IL-6 in CCI rats. By bioinformatic analysis and dual-luciferase reporter assay, we found that miR-93 directly targeted the 3'-untranslated region (UTR) of signal transducer and activator of transcription 3 (STAT3), an important regulator of inflammation. Overexpression of miR-93 markedly suppressed the expression of STAT3 in vitro and in vivo. Furthermore, overexpression of STAT3 significantly reversed the miR-93 overexpression-induced suppressive effects on neuropathic pain development and neuroinflammation. Taken together, our study suggests that miR-93 inhibits neuropathic pain development of CCI rats possibly through inhibiting STAT3-mediated neuroinflammation. Our findings indicate that miR-93 may serve as a novel therapeutic target for neuropathic pain intervention. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. MiR-150 alleviates neuropathic pain via inhibiting toll-like receptor 5.

    PubMed

    Ji, Li-Juan; Shi, Jing; Lu, Jing-Min; Huang, Qiang-Min

    2017-07-07

    MicroRNAs (miRNAs) are reported as vital participators in the pathophysiological course of neuropathic pain. However, the underlying mechanisms of the functional roles of miRNAs in neuropathic pain are largely unknown. This study was designed to explore the potential role of miR-150 in regulating the process of neuropathic pain in a rat model established by chronic sciatic nerve injury (CCI). Overexpression of miR-150 greatly alleviated neuropathic pain development and reduced inflammatory cytokine expression, including COX-2, interleukin IL-6, and tumor necrosis factor (TNF)-α in CCI rats. By bioinformatic analysis, 3'-untranslated region (UTR) of Toll-like receptor (TLR5) was predicted to be a target of miR-150. TLR5 commonly serves as an important regulator of inflammation. Overexpression of miR-150 significantly suppressed the expression of TLR5 in vitro and in vivo. Furthermore, upregulation of TLR5 decreased the miR-150 expression and downregulation of TLR5 increased miR-150, respectively. Overexpression of TLR5 significantly reversed the miR-150-induced suppressive effects on neuropathic pain. In conclusion, our current study indicates that miR-150 may inhibit neuropathic pain development of CCI rats through inhibiting TLR5-mediated neuroinflammation. Our findings suggest that miR-150 may provide a novel therapeutic target for neuropathic pain treatment. © 2017 Wiley Periodicals, Inc.

  13. Multimodal approaches to the management of neuropathic pain: the role of topical analgesia.

    PubMed

    de Leon-Casasola, Oscar A

    2007-03-01

    Because of their localized activity and low systemic absorption, topical analgesics have a favorable safety profile and a low risk for drug-drug interactions. There is a growing body of evidence on the efficacy and safety of these agents in a variety of pain disorders, including the most prevalent neuropathic pain conditions. The molecular basis for the usage of peripheral analgesics in neuropathic pain and the available clinical trial evidence for a wide variety of topical agents are reviewed.

  14. Economic burden of back and neck pain: effect of a neuropathic component.

    PubMed

    Kleinman, Nathan; Patel, Aarti A; Benson, Carmela; Macario, Alex; Kim, Myoung; Biondi, David M

    2014-08-01

    This was a retrospective database analysis (2001-2009) of employees' medical, prescription drug, and absence costs and days from sick leave, short- and long-term disability, and workers' compensation. Employees with an ICD-9 diagnostic code for back or neck pain and an ICD-9 for a back- or neck-related neuropathic condition (eg, myelopathy, compression of the spinal cord, neuritis, radiculitis) or radiculopathy were considered to have nociceptive back or neck pain with a neuropathic component. Employees with an ICD-9 for back pain or neck pain and no ICD-9 for a back- or neck-related neuropathic condition or radiculopathy were defined to have nociceptive back or neck pain. Patients with nociceptive back or neck pain with a neuropathic component were classified as having or not having prior nociceptive pain. Annual costs (medical and prescription drug costs and absence costs) and days from sick leave, short- and long-term disability, and workers' compensation were evaluated. Mean annual total costs were highest ($8512) for nociceptive pain with a neuropathic component with prior nociceptive pain (n=9162 employees), $7126 for nociceptive pain with a neuropathic component with no prior nociceptive pain (n=5172), $5574 for nociceptive pain only (n=35,347), and $3017 for control employees with no back or neck pain diagnosis (n=226,683). Medical, short-term disability, and prescription drugs yielded the highest incremental costs compared to controls. Mean total absence days/year were 8.26, 7.86, 5.70, and 3.44, respectively. The economic burden of back pain or neck pain is increased when associated with a neuropathic component.

  15. Topical capsaicin (high concentration) for chronic neuropathic pain in adults.

    PubMed

    Derry, Sheena; Rice, Andrew Sc; Cole, Peter; Tan, Toni; Moore, R Andrew

    2017-01-13

    This review is an update of 'Topical capsaicin (high concentration) for chronic neuropathic pain in adults' last updated in Issue 2, 2013. Topical creams with capsaicin are used to treat peripheral neuropathic pain. Following application to the skin, capsaicin causes enhanced sensitivity, followed by a period with reduced sensitivity and, after repeated applications, persistent desensitisation. High-concentration (8%) capsaicin patches were developed to increase the amount of capsaicin delivered; rapid delivery was thought to improve tolerability because cutaneous nociceptors are 'defunctionalised' quickly. The single application avoids noncompliance. Only the 8% patch formulation of capsaicin is available, with a capsaicin concentration about 100 times greater than conventional creams. High-concentration topical capsaicin is given as a single patch application to the affected part. It must be applied under highly controlled conditions, often following local anaesthetic, due to the initial intense burning sensation it causes. The benefits are expected to last for about 12 weeks, when another application might be made. To review the evidence from controlled trials on the efficacy and tolerability of topically applied, high-concentration (8%) capsaicin in chronic neuropathic pain in adults. For this update, we searched CENTRAL, MEDLINE, Embase, two clinical trials registries, and a pharmaceutical company's website to 10 June 2016. Randomised, double-blind, placebo-controlled studies of at least 6 weeks' duration, using high-concentration (5% or more) topical capsaicin to treat neuropathic pain. Two review authors independently searched for studies, extracted efficacy and adverse event data, and examined issues of study quality and potential bias. Where pooled analysis was possible, we used dichotomous data to calculate risk ratio and numbers needed to treat for one additional event, using standard methods.Efficacy outcomes reflecting long-duration pain relief after a

  16. Histone deacetylase inhibitors relieve morphine resistance in neuropathic pain after peripheral nerve injury.

    PubMed

    Uchida, Hitoshi; Matsushita, Yosuke; Araki, Kohei; Mukae, Takehiro; Ueda, Hiroshi

    2015-08-01

    Neuropathic pain is often insensitive to morphine. Our previous study has demonstrated that neuron-restrictive silencer factor represses mu opioid receptor (MOP) gene expression in the dorsal root ganglion (DRG) via histone hypoacetylation-mediated mechanisms after peripheral nerve injury, thereby causing loss of peripheral morphine analgesia. Here, we showed that histone deacetylase (HDAC) inhibitors, such as trichostatin A and valproic acid, restored peripheral and systemic morphine analgesia in neuropathic pain. Also, these agents blocked nerve injury-induced MOP down-regulation in the DRG. These results suggest that HDAC inhibitors could serve as adjuvant analgesics to morphine for the management of neuropathic pain.

  17. Angiotensin II type 2-receptor: new clinically validated target in the treatment of neuropathic pain.

    PubMed

    Rice, A S C; Smith, M T

    2015-02-01

    Neuropathic pain is a large unmet medical need. The angiotensin II type 2 (AT2 ) receptor is a target with promising data in rodent models of peripheral neuropathic pain. The AT2 receptor has attracted attention on the basis of human data from a proof-of-concept clinical trial showing that oral EMA401, a highly selective, peripherally restricted, small molecule AT2 receptor antagonist, at 100 mg twice-daily for 4 weeks, alleviated postherpetic neuralgia, an often intractable type of peripheral neuropathic pain. © 2014 American Society for Clinical Pharmacology and Therapeutics.

  18. Presynaptic GABAergic inhibition regulated by BDNF contributes to neuropathic pain induction

    PubMed Central

    Chen, Jeremy Tsung-chieh; Guo, Da; Campanelli, Dario; Frattini, Flavia; Mayer, Florian; Zhou, Luming; Kuner, Rohini; Heppenstall, Paul A.; Knipper, Marlies; Hu, Jing

    2014-01-01

    The gate control theory proposes the importance of both pre- and post-synaptic inhibition in processing pain signal in the spinal cord. However, although postsynaptic disinhibition caused by brain-derived neurotrophic factor (BDNF) has been proved as a crucial mechanism underlying neuropathic pain, the function of presynaptic inhibition in acute and neuropathic pain remains elusive. Here we show that a transient shift in the reversal potential (EGABA) together with a decline in the conductance of presynaptic GABAA receptor result in a reduction of presynaptic inhibition after nerve injury. BDNF mimics, whereas blockade of BDNF signalling reverses, the alteration in GABAA receptor function and the neuropathic pain syndrome. Finally, genetic disruption of presynaptic inhibition leads to spontaneous development of behavioural hypersensitivity, which cannot be further sensitized by nerve lesions or BDNF. Our results reveal a novel effect of BDNF on presynaptic GABAergic inhibition after nerve injury and may represent new strategy for treating neuropathic pain. PMID:25354791

  19. Neuropathic Pain and Psychological Morbidity in Patients with Treated Leprosy: A Cross-Sectional Prevalence Study in Mumbai

    PubMed Central

    Lasry-Levy, Estrella; Hietaharju, Aki; Pai, Vivek; Ganapati, Ramaswamy; Rice, Andrew S. C.; Haanpää, Maija; Lockwood, Diana N. J.

    2011-01-01

    Background Neuropathic pain has been little studied in leprosy. We assessed the prevalence and clinical characteristics of neuropathic pain and the validity of the Douleur Neuropathique 4 questionnaire as a screening tool for neuropathic pain in patients with treated leprosy. The association of neuropathic pain with psychological morbidity was also evaluated. Methodology/Principal Findings Adult patients who had completed multi-drug therapy for leprosy were recruited from several Bombay Leprosy Project clinics. Clinical neurological examination, assessment of leprosy affected skin and nerves and pain evaluation were performed for all patients. Patients completed the Douleur Neuropathique 4 and the 12-item General Health Questionnaire to identify neuropathic pain and psychological morbidity. Conclusions/Significance One hundred and one patients were recruited, and 22 (21.8%) had neuropathic pain. The main sensory symptoms were numbness (86.4%), tingling (68.2%), hypoesthesia to touch (81.2%) and pinprick (72.7%). Neuropathic pain was associated with nerve enlargement and tenderness, painful skin lesions and with psychological morbidity. The Douleur Neuropathique 4 had a sensitivity of 100% and specificity of 92% in diagnosing neuropathic pain. The Douleur Neuropathique 4 is a simple tool for the screening of neuropathic pain in leprosy patients. Psychological morbidity was detected in 15% of the patients and 41% of the patients with neuropathic pain had psychological morbidity. PMID:21408111

  20. Neuropathic pain modifies antioxidant activity in rat spinal cord.

    PubMed

    Guedes, Renata P; Bosco, Lidiane Dal; Teixeira, Camila M; Araújo, Alex S R; Llesuy, Susana; Belló-Klein, Adriane; Ribeiro, Maria Flávia M; Partata, Wania A

    2006-05-01

    Oxidative stress is an important pathophysiological mechanism of many neurological diseases. Reactive oxygen and nitrogen species have been cited as molecules involved in the nociceptive process. In this study, rats were submitted to sciatic nerve transection (SNT) for induction of neuropathic pain, and enzyme activities of SOD and catalase as well as lipid peroxidation (LPO) were measured in the lumbosacral spinal cord. The results show that LPO was not changed after SNT. SOD activity was reduced 7 days after SNT, while the change in catalase activity occurred on the third and seventh days in both sham and SNT animals. Hyperalgesia in SNT group was detected at the same points in time. These results suggest that SNT was not a strong enough stimulus to deplete all antioxidant content in the spinal cord, since increase in LPO was not detected. However, the role of oxidative stress in nociception can not be excluded.

  1. Pain-related psychological distress, self-rated health and significance of neuropathic pain in Danish soldiers injured in Afghanistan.

    PubMed

    Duffy, J R; Warburg, F E; Koelle, S-F T; Werner, M U; Nielsen, P R

    2015-11-01

    Pain and mental health concerns are prevalent among veterans. While the majority of research has focused on chronic pain as an entity, there has been little work directed towards investigating the role of neuropathic pain in relation to psychological comorbidity. As such, we hypothesised that participants with signs of neuropathic pain would report higher levels of psychological distress and diminished self-rated health compared to those without a neuropathic component. A retrospective review of standardised questionnaires (PainDETECT Questionnaire, Post-traumatic Stress Disorder Checklist-Civilian, the Hospital Anxiety and Depression Scale, and EuroQOL Visual Analogue Scale) administered to injured soldiers. The participants were classified into three groups according to the PainDETECT questionnaire: non-neuropathic pain, possible neuropathic pain and definite neuropathic pain. Fifty-three participants were included. The Post-traumatic Stress Disorder Checklist-Civilian score was in median (interquartile range) 26 (22-31), the Hospital Anxiety and Depression Scale score was 4 (2-6.5) and 2 (1-5) for anxiety and depression respectively. Evidence of neuropathic pain correlated positively with the Post-traumatic Stress Disorder Checklist-Civilian score (rho = 0.469, P < 0.001) and Hospital Anxiety and Depression Scale subscale for anxiety score (rho = 0.357, P = 0.009), and inversely with the EuroQOL Visual Analogue Scale score (rho = -0.361, P = 0.008). In multivariate regression analyses, the associations remained when adjusting for socio-demographics and clinical characteristics. The results from the present study suggest that neuropathic pain is related to increased psychological distress and deterioration in self-rated health in injured soldiers. © 2015 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  2. Metabolic brain activity suggestive of persistent pain in a rat model of neuropathic pain.

    PubMed

    Thompson, Scott J; Millecamps, Magali; Aliaga, Antonio; Seminowicz, David A; Low, Lucie A; Bedell, Barry J; Stone, Laura S; Schweinhardt, Petra; Bushnell, M Catherine

    2014-05-01

    Persistent pain is a central characteristic of neuropathic pain conditions in humans. Knowing whether rodent models of neuropathic pain produce persistent pain is therefore crucial to their translational applicability. We investigated the spared nerve injury (SNI) model of neuropathic pain and the formalin pain model in rats using positron emission tomography (PET) with the metabolic tracer [18F]fluorodeoxyglucose (FDG) to determine if there is ongoing brain activity suggestive of persistent pain. For the formalin model, under brief anesthesia we injected one hindpaw with 5% formalin and the FDG tracer into a tail vein. We then allowed the animals to awaken and observed pain behavior for 30min during the FDG uptake period. The rat was then anesthetized and placed in the scanner for static image acquisition, which took place between minutes 45 and 75 post-tracer injection. A single reference rat brain magnetic resonance image (MRI) was used to align the PET images with the Paxinos and Watson rat brain atlas. Increased glucose metabolism was observed in the somatosensory region associated with the injection site (S1 hindlimb contralateral), S1 jaw/upper lip and cingulate cortex. Decreases were observed in the prelimbic cortex and hippocampus. Second, SNI rats were scanned 3weeks post-surgery using the same scanning paradigm, and region-of-interest analyses revealed increased metabolic activity in the contralateral S1 hindlimb. Finally, a second cohort of SNI rats was scanned while anesthetized during the tracer uptake period, and the S1 hindlimb increase was not observed. Increased brain activity in the somatosensory cortex of SNI rats resembled the activity produced with the injection of formalin, suggesting that the SNI model may produce persistent pain. The lack of increased activity in S1 hindlimb with general anesthetic demonstrates that this effect can be blocked, as well as highlights the importance of investigating brain activity in awake and behaving rodents.

  3. Metabolic brain activity suggestive of persistent pain in a rat model of neuropathic pain

    PubMed Central

    Thompson, Scott J; Millecamps, Magali; Aliaga, Antonio; Seminowicz, David A; Low, Lucie A; Bedell, Barry J; Stone, Laura S; Schweinhardt, Petra; Bushnell, M Catherine

    2014-01-01

    Persistent pain is a central characteristic of neuropathic pain conditions in humans. Knowing whether rodent models of neuropathic pain produce persistent pain is therefore crucial to their translational applicability. We investigated the Spared Nerve Injury (SNI) model of neuropathic pain and the formalin pain model in rats using Positron Emission Tomography (PET) with the metabolic tracer [18F]fluorodeoxyglucose (FDG) to determine if there is ongoing brain activity suggestive of persistent pain. For the formalin model, under brief anesthesia we injected one hindpaw with 5% formalin and the FDG tracer into a tail vein. We then allowed the animals to awaken and observed pain behavior for 30 min during the FDG uptake period. The rat was then anesthetized and placed in the scanner for static image acquisition, which took place between minutes 45 and 75 post-tracer injection. A single reference rat brain magnetic resonance image (MRI) was used to align the PET images with the Paxinos and Watson rat brain atlas. Increased glucose metabolism was observed in the somatosensory region associated with the injection site (S1 hindlimb contralateral), S1 jaw/upper lip and cingulate cortex. Decreases were observed in the prelimbic cortex and hippocampus. Second, SNI rats were scanned 3 weeks post-surgery using the same scanning paradigm, and region-of-interest analyses revealed increased metabolic activity in the contralateral S1 hindlimb. Finally, a second cohort of SNI rats were scanned while anesthetized during the tracer uptake period, and the S1 hindlimb increase was not observed. Increased brain activity in the somatosensory cortex of SNI rats resembled the activity produced with the injection of formalin, suggesting that the SNI model may produce persistent pain. The lack of increased activity in S1 hindlimb with general anesthetic demonstrates that this effect can be blocked, as well as highlights the importance of investigating brain activity in awake and behaving

  4. Gelsemine alleviates both neuropathic pain and sleep disturbance in partial sciatic nerve ligation mice

    PubMed Central

    Wu, Yu-er; Li, Ya-dong; Luo, Yan-jia; Wang, Tian-xiao; Wang, Hui-jing; Chen, Shuo-nan; Qu, Wei-min; Huang, Zhi-li

    2015-01-01

    Aim: Gelsemine, an alkaloid from the Chinese herb Gelsemium elegans (Gardn & Champ) Benth., is effective in mitigating chronic pain in rats. In the present study we investigated whether the alkaloid improved sleep disturbance, the most common comorbid symptoms of chronic pain, in a mouse model of neuropathic pain. Methods: Mice were subjected to partial sciatic nerve ligation (PSNL). After the mice were injected with gelsemine or pregabalin (the positive control) intraperitoneally, mechanical allodynia and thermal hyperalgesia were assessed, and electroencephalogram (EEG)/electromyogram (EMG) recording was performed. Motor performance of the mice was assessed using rota-rod test. c-Fos expression in the brain was analyzed with immunohistochemical staining. Results: In PSNL mice, gelsemine (2 and 4 mg/kg) increased the mechanical threshold for 4 h and prolonged the thermal latencies for 3 h. Furthermore, gelsemine (4 mg/kg, administered at 6:30 AM) increased non-rapid eye movement (non-REM, NREM) sleep, decreased wakefulness, but did not affect REM sleep during the first 3 h in PSNL mice. Sleep architecture analysis showed that gelsemine decreased the mean duration of wakefulness and increased the total number of episodes of NREM sleep during the first 3 h after the dosing. Gelsemine (4 mg/kg) did not impair motor coordination in PSNL mice. Immunohistochemical study showed that PSNL increased c-Fos expression in the neurons of the anterior cingulate cortex, and gelsemine (4 mg/kg) decreased c-Fos expression by 58%. Gelsemine (4 mg/kg, administered at either 6:30 AM or 8:30 PM) did not produce hypnotic effect in normal mice. Pregabalin produced similar antinociceptive and hypnotic effects, but impaired motor coordination in PSNL mice. Conclusion: Gelsemine is an effective agent for treatment of both neuropathic pain and sleep disturbance in PSNL mice; anterior cingulate cortex might play a role in the hypnotic effects of gelsemine. PMID:26388157

  5. Gelsemine alleviates both neuropathic pain and sleep disturbance in partial sciatic nerve ligation mice.

    PubMed

    Wu, Yu-er; Li, Ya-dong; Luo, Yan-jia; Wang, Tian-xiao; Wang, Hui-jing; Chen, Shuo-nan; Qu, Wei-min; Huang, Zhi-li

    2015-11-01

    Gelsemine, an alkaloid from the Chinese herb Gelsemium elegans (Gardn & Champ) Benth., is effective in mitigating chronic pain in rats. In the present study we investigated whether the alkaloid improved sleep disturbance, the most common comorbid symptoms of chronic pain, in a mouse model of neuropathic pain. Mice were subjected to partial sciatic nerve ligation (PSNL). After the mice were injected with gelsemine or pregabalin (the positive control) intraperitoneally, mechanical allodynia and thermal hyperalgesia were assessed, and electroencephalogram (EEG)/electromyogram (EMG) recording was performed. Motor performance of the mice was assessed using rota-rod test. c-Fos expression in the brain was analyzed with immunohistochemical staining. In PSNL mice, gelsemine (2 and 4 mg/kg) increased the mechanical threshold for 4 h and prolonged the thermal latencies for 3 h. Furthermore, gelsemine (4 mg/kg, administered at 6:30 AM) increased non-rapid eye movement (non-REM, NREM) sleep, decreased wakefulness, but did not affect REM sleep during the first 3 h in PSNL mice. Sleep architecture analysis showed that gelsemine decreased the mean duration of wakefulness and increased the total number of episodes of NREM sleep during the first 3 h after the dosing. Gelsemine (4 mg/kg) did not impair motor coordination in PSNL mice. Immunohistochemical study showed that PSNL increased c-Fos expression in the neurons of the anterior cingulate cortex, and gelsemine (4 mg/kg) decreased c-Fos expression by 58%. Gelsemine (4 mg/kg, administered at either 6:30 AM or 8:30 PM) did not produce hypnotic effect in normal mice. Pregabalin produced similar antinociceptive and hypnotic effects, but impaired motor coordination in PSNL mice. Gelsemine is an effective agent for treatment of both neuropathic pain and sleep disturbance in PSNL mice; anterior cingulate cortex might play a role in the hypnotic effects of gelsemine.

  6. The importance of TRPV1-sensitisation factors for the development of neuropathic pain.

    PubMed

    Malek, Natalia; Pajak, Agnieszka; Kolosowska, Natalia; Kucharczyk, Mateusz; Starowicz, Katarzyna

    2015-03-01

    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.

  7. Thalamic activity and biochemical changes in individuals with neuropathic pain after spinal cord injury.

    PubMed

    Gustin, S M; Wrigley, P J; Youssef, A M; McIndoe, L; Wilcox, S L; Rae, C D; Edden, R A E; Siddall, P J; Henderson, L A

    2014-05-01

    There is increasing evidence relating thalamic changes to the generation and/or maintenance of neuropathic pain. We have recently reported that neuropathic orofacial pain is associated with altered thalamic anatomy, biochemistry, and activity, which may result in disturbed thalamocortical oscillatory circuits. Despite this evidence, it is possible that these thalamic changes are not responsible for the presence of pain per se, but result as a consequence of the injury. To clarify this subject, we compared brain activity and biochemistry in 12 people with below-level neuropathic pain after complete thoracic spinal cord injury with 11 people with similar injuries and no neuropathic pain and 21 age- and gender-matched healthy control subjects. Quantitative arterial spinal labelling was used to measure thalamic activity, and magnetic resonance spectroscopy was used to determine changes in neuronal variability quantifying N-acetylaspartate and alterations in inhibitory function quantifying gamma amino butyric acid. This study revealed that the presence of neuropathic pain is associated with significant changes in thalamic biochemistry and neuronal activity. More specifically, the presence of neuropathic pain after spinal cord injury is associated with significant reductions in thalamic N-acetylaspartate, gamma amino butyric acid content, and blood flow in the region of the thalamic reticular nucleus. Spinal cord injury on its own did not account for these changes. These findings support the hypothesis that neuropathic pain is associated with altered thalamic structure and function, which may disturb central processing and play a key role in the experience of neuropathic pain. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  8. [Analysis of TRPV1 gene polymorphisms in Spanish patients with neuropathic pain].

    PubMed

    Armero, Pilar; Muriel, Clemente; López, Mónica; Santos, Juan; González-Sarmiento, Rogelio

    2012-06-02

    The vanilloid receptor TRPV1 is a molecular integrator of painful stimuli. Several recent studies suggest that TRPV1 may play a role in development and maintenance of chronic pain. In an attempt to determine if genotypic variations in TRPV1 gene could be involved in the susceptibility to suffer neuropathic pain we have studied genetic variants of human TRPV1 gene. We have studied the distribution of Met315Ile and Ile585Val TRPV1 polymorphisms in a total of 440 Caucasian subjects: 232 patients with neuropathic pain and 208 healthy subjects matched by age and sex. The polymorphisms were analyzed with polymerase chain reaction (PCR) using TaqMan probes specific for each allele. Our results show that the distribution of Met315Ile and Ile585Val genotypes and alleles is similar in patients with neuropathic pain and in healthy subjects. However, the Met315Met genotype is more frequent in females diagnosed as suffering neuropathic pain. No differences were observed when we segregate the patients according to visual analogue scale values. The observation of differences in the distribution of Met315Ile TRPV1 genotypes only in females diagnosed of neuropathic pain suggests that this polymorphism, together with other physiological factors such as sex, may influence individual susceptibility to neuropathic pain. Copyright © 2011 Elsevier España, S.L. All rights reserved.

  9. Topical analgesics for neuropathic pain: preclinical exploration, clinical validation, future development.

    PubMed

    Sawynok, J

    2014-04-01

    Topical analgesics applied locally to skin or to specialized compartments modify pain by actions on sensory nerve endings and/or adjacent cellular elements. With this approach, there are low systemic drug levels, good tolerability and few drug interactions, and combination with oral formulations is feasible. The goal of this review is to provide an overview of the potential for topical analgesics to contribute to improved management of neuropathic pain. Mechanistic and preclinical studies indicate much potential for development of novel topical analgesics for neuropathic pain. In humans, two topical analgesics are approved for use in post-herpetic neuralgia (lidocaine 5% medicated plaster, capsaicin 8% patch), and there is evidence for efficacy in other neuropathic pain conditions. Comparative trials indicate similar efficacy between topical and oral analgesics. Not all individuals respond to topical analgesics, and there is interest in determining factors (patient factors, sensory characteristics) which might predict responsiveness to topical analgesics. There is a growing number of controlled trials and case reports of investigational agents (vasodilators, glutamate receptor antagonists, α2-adrenoreceptor agonists, antidepressants, centrally acting drugs), including combinations of several agents, indicating these produce pain relief in neuropathic pain. There is interest in compounding topical analgesics for neuropathic pain, but several challenges remain for this approach. Topical analgesics have the potential to be a valuable additional approach for the management of neuropathic pain.

  10. Mechanisms of Electroacupuncture-Induced Analgesia on Neuropathic Pain in Animal Model

    PubMed Central

    Kim, Woojin; Kim, Sun Kwang; Min, Byung-Il

    2013-01-01

    Neuropathic pain remains as one of the most difficult clinical pain syndromes to treat. Electroacupuncture (EA), involving endogenous opioids and neurotransmitters in the central nervous system (CNS), is reported to be clinically efficacious in various fields of pain. Although multiple experimental articles were conducted to assess the effect of EA-induced analgesia, no review has been published to assess the efficacy and clarify the mechanism of EA on neuropathic pain. To this aim, this study was firstly designed to evaluate the EA-induced analgesic effect on neuropathic pain and secondly to guide and help future efforts to advance the neuropathic pain treatment. For this purpose, articles referring to the analgesic effect of acupuncture on neuropathic pain and particularly the work performed in our own laboratory were analyzed. Based on the articles reviewed, the role of spinal opioidergic, adrenergic, serotonergic, cholinergic, and GABAergic receptors in the mechanism of EA-induced analgesia was studied. The results of this research demonstrate that μ and δ opioid receptors, α 2-adrenoreceptors, 5-HT1A and 5-HT3 serotonergic receptors, M1 muscarinic receptors, and GABAA and GABAB GABAergic receptors are involved in the mechanisms of EA-induced analgesia on neuropathic pain. PMID:23983779

  11. Neuropathic ocular pain due to dry eye is associated with multiple comorbid chronic pain syndromes

    PubMed Central

    Galor, Anat; Covington, Derek; Levitt, Alexandra E.; McManus, Katherine T.; Seiden, Benjamin; Felix, Elizabeth R.; Kalangara, Jerry; Feuer, William; Patin, Dennis J.; Martin, Eden R.; Sarantopoulos, Konstantinos D.; Levitt, Roy C.

    2015-01-01

    Recent data demonstrate that dry eye (DE) susceptibility and other chronic pain syndromes (CPS) such as chronic widespread pain, irritable bowel syndrome and pelvic pain, may share common heritable factors. Previously, we showed that DE patients describing more severe symptoms tended to report features of neuropathic ocular pain (NOP). We hypothesize that patients with a greater number of CPS would have a different DE phenotype compared to those with fewer CPS. We recruited a cohort of 154 DE patients from the Miami Veterans Affairs Hospital and defined high and low CPS groups by cluster analysis. In addition to worse non-ocular pain complaints and higher PTSD and depression scores (P<0.01), we found that the high CPS group reported more severe neuropathic-type DE symptoms compared to the low CPS group, including worse ocular pain assessed via 3 different pain scales (P<0.05), with similar objective corneal DE signs. This is the first study to demonstrate DE patients who manifest a greater number of comorbid CPS report more severe DE symptoms and features of NOP. These findings provide further evidence that NOP may represent a central pain disorder, and that shared mechanistic factors may underlie vulnerability to some forms of DE and other comorbid CPS. PMID:26606863

  12. EFNS guidelines on neuropathic pain assessment: revised 2009.

    PubMed

    Cruccu, G; Sommer, C; Anand, P; Attal, N; Baron, R; Garcia-Larrea, L; Haanpaa, M; Jensen, T S; Serra, J; Treede, R-D

    2010-08-01

    We have revised the previous EFNS guidelines on neuropathic pain (NP) assessment, which aimed to provide recommendations for the diagnostic process, screening tools and questionnaires, quantitative sensory testing (QST), microneurography, pain-related reflexes and evoked potentials, functional neuroimaging and skin biopsy. We have checked and rated the literature published in the period 2004-2009, according to the EFNS method of classification for diagnostic procedures. Most of the previous recommendations were reinforced by the new studies. The main revisions relate to: (i) the new definition of NP and a diagnostic grading system; (ii) several new validated clinical screening tools that identify NP components, and questionnaires which assess the different types of NP; (iii) recent high-quality studies on laser-evoked potentials (LEPs) and skin biopsy. History and bedside examination are still fundamental to a correct diagnosis, whilst screening tools and questionnaires are useful in indicating probable NP; QST is also useful for indicating the latter, and to assess provoked pains and treatment response. Amongst laboratory tests, LEPs are the best tool for assessing Adelta pathway dysfunction, and skin biopsy for assessing neuropathies with distal loss of unmyelinated nerve fibres.

  13. Topical ambroxol for the treatment of neuropathic pain. An initial clinical observation.

    PubMed

    Kern, K-U; Weiser, T

    2015-12-01

    Neuropathic pain is difficult to treat, and the available options are often inadequate. The expectorant ambroxol also acts as a strong local anaesthetic and blocks sodium channels about 40 times more potently than lidocaine. It preferentially inhibits the channel subtype Nav 1.8, which is expressed especially in nociceptive C-fibres. In view of the low toxicity of ambroxol, it seemed reasonable to try using it for the treatment of neuropathic pain that failed to respond to other standard options. The medical records of seven patients with severe neuropathic pain and pain reduction following topical ambroxol treatment are reported retrospectively. As standard therapies had not proved sufficient, a topical ambroxol 20% cream was repeatedly applied by the patients in the area of neuropathic pain. The reasons for neuropathic pain were postherpetic neuralgia (2 ×), mononeuropathy multiplex, phantom pain, deafferentation pain, postoperative neuralgia and foot neuropathy of unknown origin. The individual mean pain intensity reported was between 4 and 6/10 (NRS), maximum pain at 6-10/10 (NRS). The pain reduction achieved individually following ambroxol cream was 2-8 points (NRS) within 5-30 min and lasted for 3-8 h. Pain attacks were reduced in all five patients presenting with this problem. Four patients with no improvement after lidocaine 5% and one patient with no response to capsaicin 8% nevertheless experienced a pain reduction with topical ambroxol. No patient reported any side effects or skin changes during a treatment that has since been continued for up to 4 years. Ambroxol acts as a strong local anaesthetic and preferentially inhibits the nociceptively relevant sodium channel subtype Nav 1.8. For the first time, we report below on a relevant pain relief following topical ambroxol 20% cream in patients with neuropathic pain. In view of the positive side effect profile, the clinical benefit in patients with pain should be investigated further.

  14. Metabolite concentrations in the anterior cingulate cortex predict high neuropathic pain impact after spinal cord injury

    PubMed Central

    Widerström-Noga, Eva; Pattany, Pradip M.; Cruz-Almeida, Yenisel; Felix, Elizabeth R.; Perez, Salome; Cardenas, Diana D.; Martinez-Arizala, Alberto

    2013-01-01

    Persistent pain is a common reason for reduced quality of life after a spinal cord injury (SCI). Biomarkers of neuropathic pain may facilitate translational research and the understanding of underlying mechanisms. Research suggests that pain and affective distress are anatomically and functionally integrated in the anterior cingulate cortex and can modulate sensory and affective aspects of pain. We hypothesized that severe neuropathic pain with a significant psychosocial impact would be associated with metabolite concentrations (obtained by magnetic resonance spectroscopy) in the anterior cingulate cortex, indicating neuronal and/or glial dysfunction. Participants with SCI and severe, high-impact neuropathic pain (SCI-HPI; n = 16), SCI and moderate, low-impact neuropathic pain (SCI-LPI; n = 24), SCI without neuropathic pain (SCI-noNP; n = 14), and able-bodied, pain-free control subjects (A-B; n = 22) underwent a 3-T magnetic resonance imaging brain scan. Analyses revealed that the SCI-HPI group had significantly higher levels of myoinositol (Ins) (P < .000), creatine (P = .007), and choline (P = .014), and significantly lower levels of N-acetyl aspartate/Ins (P = .024) and glutamate-glutamine (Glx)/Ins (P = .003) ratios than the SCI-LPI group. The lower Glx/Ins ratio significantly discriminated between SCI-HPI and the A-B (P = .006) and SCI-noNP (P = .026) groups, displayed excellent test-retest reliability, and was significantly related to greater pain severity, interference, and affective distress. This suggests that the combination of lower glutamatergic metabolism and proliferation of glia and glial activation are underlying mechanisms contributing to the maintenance of severe neuropathic pain with significant psychosocial impact in chronic SCI. These findings indicate that the Glx/Ins ratio may be a useful biomarker for severe SCI-related neuropathic pain with significant psychosocial impact. PMID:23141478

  15. Therapeutic potential for leukocyte elastase in chronic pain states harboring a neuropathic component.

    PubMed

    Bali, Kiran Kumar; Kuner, Rohini

    2017-09-13

    Neuropathic pain is an integral component of several chronic pain conditions and poses a major health problem worldwide. Despite emerging understanding of mechanisms behind neuropathic pain, the available treatment options are still limited in efficacy or associated with side effects, therefore making it necessary to find viable alternatives. In a genetic screen, we recently identified SerpinA3N, a serine protease inhibitor secreted in response to nerve damage by the dorsal root ganglion neurons and we showed that SerpinA3N acts against induction of neuropathic pain by inhibiting the T-cell- and neutrophil-derived protease, leucocyte elastase (LE). In the current study, via detailed in vivo pharmacology combined with analyses of evoked- and spontaneous pain-related behaviors in mice, we report that on systemic delivery, a single dose of 3 independent LE inhibitors can block established nociceptive hypersensitivity in early and late phases in the spared nerve injury model of traumatic neuropathic pain in mice. We further report the strong efficacy of systemic LE inhibitors in reversing ongoing pain in 2 other clinically relevant mouse models-painful diabetic neuropathy and cancer pain. Detailed immunohistochemical analyses on the peripheral tissue samples revealed that both T-Lymphocytes and neutrophils are the sources of LE on peripheral nerve injury, whereas neutrophils are the primary source of LE in diabetic neuropathic conditions. In summary, our results provide compelling evidence for a strong therapeutic potential of generic LE inhibitors for the treatment of neuropathic pain and other chronic pain conditions harboring a neuropathic pain component.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission

  16. Metabolite concentrations in the anterior cingulate cortex predict high neuropathic pain impact after spinal cord injury.

    PubMed

    Widerström-Noga, Eva; Pattany, Pradip M; Cruz-Almeida, Yenisel; Felix, Elizabeth R; Perez, Salome; Cardenas, Diana D; Martinez-Arizala, Alberto

    2013-02-01

    Persistent pain is a common reason for reduced quality of life after a spinal cord injury (SCI). Biomarkers of neuropathic pain may facilitate translational research and the understanding of underlying mechanisms. Research suggests that pain and affective distress are anatomically and functionally integrated in the anterior cingulate cortex and can modulate sensory and affective aspects of pain. We hypothesized that severe neuropathic pain with a significant psychosocial impact would be associated with metabolite concentrations (obtained by magnetic resonance spectroscopy) in the anterior cingulate cortex, indicating neuronal and/or glial dysfunction. Participants with SCI and severe, high-impact neuropathic pain (SCI-HPI; n=16), SCI and moderate, low-impact neuropathic pain (SCI-LPI; n=24), SCI without neuropathic pain (SCI-noNP; n=14), and able-bodied, pain-free control subjects (A-B; n=22) underwent a 3-T magnetic resonance imaging brain scan. Analyses revealed that the SCI-HPI group had significantly higher levels of myoinositol (Ins) (P<.000), creatine (P=.007), and choline (P=.014), and significantly lower levels of N-acetyl aspartate/Ins (P=.024) and glutamate-glutamine (Glx)/Ins (P=.003) ratios than the SCI-LPI group. The lower Glx/Ins ratio significantly discriminated between SCI-HPI and the A-B (P=.006) and SCI-noNP (P=.026) groups, displayed excellent test-retest reliability, and was significantly related to greater pain severity, interference, and affective distress. This suggests that the combination of lower glutamatergic metabolism and proliferation of glia and glial activation are underlying mechanisms contributing to the maintenance of severe neuropathic pain with significant psychosocial impact in chronic SCI. These findings indicate that the Glx/Ins ratio may be a useful biomarker for severe SCI-related neuropathic pain with significant psychosocial impact.

  17. Tramadol and Propentofylline Coadministration Exerted Synergistic Effects on Rat Spinal Nerve Ligation-Induced Neuropathic Pain

    PubMed Central

    Wang, Huan; Wang, Wei; Zhang, Hui; Liu, Rui; Xu, Li-Xian; Mei, Xiao-Peng

    2013-01-01

    Neuropathic pain is an intractable clinical problem. Drug treatments such as tramadol have been reported to effectively decrease neuropathic pain by inhibiting the activity of nociceptive neurons. It has also been reported that modulating glial activation could also prevent or reverse neuropathic pain via the administration of a glial modulator or inhibitor, such as propentofylline. Thus far, there has been no clinical strategy incorporating both neuronal and glial participation for treating neuropathic pain. Therefore, the present research study was designed to assess whether coadministration of tramadol and propentofylline, as neuronal and glial activation inhibitors, respectively, would exert a synergistic effect on the reduction of rat spinal nerve ligation (SNL)-induced neuropathic pain. Rats underwent SNL surgery to induce neuropathic pain. Pain behavioral tests were conducted to ascertain the effect of drugs on SNL-induced mechanical allodynia with von-Frey hairs. Proinflammatory factor interleukin-1β (IL-1β) expression was also detected by Real-time RT-PCR. Intrathecal tramadol and propentofylline administered alone relieved SNL-induced mechanical allodynia in a dose-dependent manner. Tramadol and propentofylline coadministration exerted a more potent effect in a synergistic and dose dependent manner than the intrathecal administration of either drug alone. Real-time RT-PCR demonstrated IL-1β up-expression in the ipsilateral spinal dorsal horn after the lesion, which was significantly decreased by tramadol and propentofylline coadministration. Inhibiting proinflammatory factor IL-1β contributed to the synergistic effects of tramadol and propentofylline coadministration on rat peripheral nerve injury-induced neuropathic pain. Thus, our study provided a rationale for utilizing a novel strategy for treating neuropathic pain by blocking the proinflammatory factor related pathways in the central nervous system. PMID:24009718

  18. Recommendations for the pharmacological management of neuropathic pain: an overview and literature update.

    PubMed

    Dworkin, Robert H; O'Connor, Alec B; Audette, Joseph; Baron, Ralf; Gourlay, Geoffrey K; Haanpää, Maija L; Kent, Joel L; Krane, Elliot J; Lebel, Alyssa A; Levy, Robert M; Mackey, Sean C; Mayer, John; Miaskowski, Christine; Raja, Srinivasa N; Rice, Andrew S C; Schmader, Kenneth E; Stacey, Brett; Stanos, Steven; Treede, Rolf-Detlef; Turk, Dennis C; Walco, Gary A; Wells, Christopher D

    2010-03-01

    The Neuropathic Pain Special Interest Group of the International Association for the Study of Pain recently sponsored the development of evidence-based guidelines for the pharmacological treatment of neuropathic pain. Tricyclic antidepressants, dual reuptake inhibitors of serotonin and norepinephrine, calcium channel alpha(2)-delta ligands (ie, gabapentin and pregabalin), and topical lidocaine were recommended as first-line treatment options on the basis of the results of randomized clinical trials. Opioid analgesics and tramadol were recommended as second-line treatments that can be considered for first-line use in certain clinical circumstances. Results of several recent clinical trials have become available since the development of these guidelines. These studies have examined botulinum toxin, high-concentration capsaicin patch, lacosamide, selective serotonin reuptake inhibitors, and combination therapies in various neuropathic pain conditions. The increasing number of negative clinical trials of pharmacological treatments for neuropathic pain and ambiguities in the interpretation of these negative trials must also be considered in developing treatment guidelines. The objectives of the current article are to review the Neuropathic Pain Special Interest Group guidelines for the pharmacological management of neuropathic pain and to provide a brief overview of these recent studies.

  19. Possible modulation of PPAR-γ cascade against depression caused by neuropathic pain in rats.

    PubMed

    Garg, Shanky; Deshmukh, Vishwajit Ravindra; Prasoon, Pranav

    2017-09-09

    Sciatic nerve ligation causes neuropathic pain with chronic constriction injury (CCI). However, there is no published report on the effect of pioglitazone as an antidepressant in the treatment of depression induced by neuropathic pain with CCI in rats. The aim of this study was to evaluate the effect of pioglitazone as an antidepressant by targeting oxidative stress by the peripheral neuropathic pain model using the CCI of the sciatic nerve. Behavioral studies were carried out to measure thermal hyperalgesia and cold allodynia as markers of neuropathic pain and force swim test for depression. These were followed by estimation of biochemical parameters which include lipid peroxidation (LPO), reduced glutathione, catalase, nitrite and superoxide dismutase (SOD) in the rat brains as a measure of oxidative stress. We administered two intraperitoneal doses of pioglitazone (4.5 and 9.0 mg/kg, i.p.) to the treated group for 28 consecutive days from the day of injury and behavioral as well as biochemical evaluations were performed. The results suggested that the administration of pioglitazone significantly countered the neuropathic pain induced depression as interpreted through elevated pain threshold of tactile allodynia and thermal hyperalgesia followed by decreased immobility time in the 9.0 mg/kg dose group. It may be concluded that the oxidative stress plays a critical role in the pathogenesis of neuropathic pain and depression as evidenced by the behavioral studies and the changes in the levels of lipid peroxidase, nitrite, catalase, and glutathione and SOD.

  20. Neuropathic pain may be common in chronic lower limb tendinopathy: a prospective cohort study.

    PubMed

    Wheeler, Patrick C

    2017-02-01

    To identify the prevalence of neuropathic pain, through the use of the painDETECT questionnaire, in a cohort of patients with chronic lower limb tendinopathy conditions. Patients with chronic lower limb tendinopathy conditions treated within a Sport and Exercise Medicine hospital clinic were identified from clinical records. At the time of the clinical consultation, pain and painDETECT scores were recorded. In total, 282 suitable patients with chronic lower limb tendinopathy conditions were identified who had completed a painDETECT questionnaire. There was a median age of 51.9 years, 35% of patients were male and a median duration of symptoms of 24.0 months. There was a median score of 7.0/10 for self-reported 'average' pain and 8.0/10 for self-reported 'worst' pain. There was a median painDETECT score of 14.0, 28% of respondents scored 19 or higher with painDETECT (neuropathic component to pain may be likely), 29% scored 13-18 (equivocal result) and 43% of respondents scored 12 or less (neuropathic pain component was unlikely). This study suggests that neuropathic pain as identified by the painDETECT questionnaire may be common in patients with chronic lower limb tendinopathy conditions. It is unclear if patients with tendinopathy who have neuropathic pain may have poorer outcomes from initial treatments, contributing to the high proportion seen in secondary care. These are results from a single hospital clinic, and comparison with a control group is currently lacking. However, on the results to date, neuropathic pain should be considered in management strategies in patients with chronic tendinopathy.

  1. [Topical ambroxol for the treatment of neuropathic pain: A first clinical observation. German version].

    PubMed

    Kern, K-U; Weiser, T

    2015-12-01

    Neuropathic pain is difficult to treat and available options are frequently not sufficient. The expectorant ambroxol also works as a strong local anesthetic and blocks sodium channels about 40 times more potently than lidocaine. Ambroxol preferentially inhibits the channel subtype Nav 1.8, which is expressed particularly in nociceptive C fibers. Due to the low toxicity, topical ambroxol seemed to represent a reasonable therapeutic attempt for treatment of neuropathic pain resistant to other standard options. Medical records of 7 patients with severe neuropathic pain, in whom many attempts at treatment with approved substances were not sufficient or possible, are reported retrospectively. Patients were then treated with topical ambroxol 20% cream applied in the area of neuropathic pain. Causes of neuropathic pain were postherpetic neuralgia (2-×), mononeuropathy multiplex, phantom pain, deafferentation pain, postoperative neuralgia and an unclear allodynia of the foot. Mean pain intensity was reported as 4-6/10 on a numeric rating scale (NRS) and maximum pain intensity as 6-10/10. Pain reduction following ambroxol cream was 2-8 points (NRS) within 15-30 min and lasted 3-8 h. Pain attacks were reduced in all 5 patients presenting this problem. Topical ambroxol achieved pain reduction in 4 patients with no improvement after lidocaine 5% and 1 patient with no response to capsaicin 8%. No adverse events or skin changes have been observed, and the longest treatment duration is currently 4 years. Ambroxol acts as a strong local anesthetic and preferentially inhibits the nociceptive-relevant sodium channel subtype Nav 1.8. For the first time, we report relevant pain reduction following topical Ambroxol 20% cream in patients with neuropathic pain. Regarding the advantageous profile with rare side effects, the clinical benefit for pain patients should be further investigated.

  2. Neuropathic pain may be common in chronic lower limb tendinopathy: a prospective cohort study

    PubMed Central

    Wheeler, Patrick C

    2016-01-01

    Background: To identify the prevalence of neuropathic pain, through the use of the painDETECT questionnaire, in a cohort of patients with chronic lower limb tendinopathy conditions. Methods: Patients with chronic lower limb tendinopathy conditions treated within a Sport and Exercise Medicine hospital clinic were identified from clinical records. At the time of the clinical consultation, pain and painDETECT scores were recorded. Results: In total, 282 suitable patients with chronic lower limb tendinopathy conditions were identified who had completed a painDETECT questionnaire. There was a median age of 51.9 years, 35% of patients were male and a median duration of symptoms of 24.0 months. There was a median score of 7.0/10 for self-reported ‘average’ pain and 8.0/10 for self-reported ‘worst’ pain. There was a median painDETECT score of 14.0, 28% of respondents scored 19 or higher with painDETECT (neuropathic component to pain may be likely), 29% scored 13–18 (equivocal result) and 43% of respondents scored 12 or less (neuropathic pain component was unlikely). Conclusions: This study suggests that neuropathic pain as identified by the painDETECT questionnaire may be common in patients with chronic lower limb tendinopathy conditions. It is unclear if patients with tendinopathy who have neuropathic pain may have poorer outcomes from initial treatments, contributing to the high proportion seen in secondary care. These are results from a single hospital clinic, and comparison with a control group is currently lacking. However, on the results to date, neuropathic pain should be considered in management strategies in patients with chronic tendinopathy. PMID:28386400

  3. Analysis of long-standing nociceptive and neuropathic pain in patients with post-polio syndrome.

    PubMed

    Werhagen, Lars; Borg, Kristian

    2010-06-01

    The purpose of this study was to analyze pain, both nociceptive and neuropathic, in patients with post-polio syndrome (PPS) and relate the pain to age at the initial polio infection, age at examination, to gender and disability. The study was conducted in a university hospital department. Patients with PPS were interviewed at their regular visits about pain, its character, intensity and localization. A clinical examination, including a thorough neurological examination, was performed. Data included age at time of polio infection, age at time of examination and gender. Pain intensity was measured with the VAS-scale and walking capability by the WISCI-scale. One hundred sixty-three (88 women, 75 men) patients were included in the study. Pain was present in 109 (67%). Pain was more frequently reported by women (82%) than by men (49%). 96 patients experienced nociceptive pain, 10 patients both neuropathic and nociceptive pain and three experienced pure neuropathic pain. Half of the patients with pain experienced pain in more than one body region. When neuropathic pain was present, another additional neurological disorder was diagnosed. Pain was more often found in younger patients (around 70%) than in older patients (around 50%). In summary pain is common in patients with PPS and most patients experienced nociceptive pain. Women have pain more often than men. Older patients experience pain more seldom than younger patients. Age at time of primary polio infection is important for the development of pain. When neuropathic pain is present, it is important to proceed with neurological examination to find an adequate diagnosis.

  4. High Prevalence of Neuropathic Pain Features in Patients with Knee Osteoarthritis: A Cross-Sectional Study.

    PubMed

    Oteo-Álvaro, Ángel; Ruiz-Ibán, Miguel A; Miguens, Xoan; Stern, Andrés; Villoria, Jesús; Sánchez-Magro, Isabel

    2015-09-01

    The present epidemiological research evaluated the prevalence of neuropathic pain characteristics in patients with painful knee osteoarthritis (OA) and the plausibility that such neuropathic features were specific of OA. Outpatients with chronic pain associated with knee OA who attended orthopedic surgery or rehabilitation clinics were systematically screened for neuropathic pain with the Douleur Neuropathique in 4 questions (DN4) questionnaire. Data from medical files and those obtained during a single structured clinical interview were correlated with the DN4 scores. Information on potential confounders of neuropathic-like qualities of knee pain was collected to evaluate as much as possible only the symptoms attributable to OA. Of 2,776 patients recruited, 2,167 patients provided valid data from 2,992 knees. The DN4 was scored positively (≥ 4) in 1,125 patients (51.9%) and 1,459 knees (48.8%). When patients with potential confounders were excluded, the respective prevalences were 33.3% and 29.4%. Patients who scored positively in the DN4 had more severe pain, greater structural damage, and more potential confounders of neuropathic pain. Three potential confounders conveyed much of the variability explained by regression analyses. However, latent class analyses revealed that the concourse of other factors is required to explain the neuropathic pain qualities. A relevant proportion of patients with chronic pain associated with knee OA featured neuropathic pain qualities that were not explained by other conditions. The present research has provided reasonable epidemiological grounds to attempt their definite diagnosis and classification. © 2014 World Institute of Pain.

  5. Quality of life and functional capacity are adversely affected in osteoarthritis patients with neuropathic pain.

    PubMed

    Aşkın, Ayhan; Özkan, Ayten; Tosun, Aliye; Demirdal, Ümit Seçil; İsnaç, Fethi

    2017-03-01

    The aim of this study was to examine the neuropathic pain component of knee osteoarthritis (OA) patients and to investigate the relationship between neuropathic pain, disease stage, functional state, depression, anxiety, and quality of life. This study included 60 patients with knee OA. All demographic data and radiological results were recorded. Visual Analog Scale (VAS), Timed Up and Go Test, Chair Stand Test, Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC), PainDETECT questionnaire, DN4 questionnaire, Short form-36 questionnaire, and Hospital Anxiety Depression Scale were performed for each patient. Neuropathic pain was detected in 66.7% of patients based on the PainDETECT scale and in 46.7% of patients based on DN4 scale. VAS-resting, OA grade, WOMAC scores, and SF-scores showed a significant difference in patients that detected neuropathic pain with PainDETECT (p<0.05). Based on the DN4 scale, patients with neuropathic pain had significantly higher WOMAC scores and significantly lower SF-36 scores (p<0.05). The PainDETECT questionnaire scores showed positive correlations with Timed Up-and-go Test, VAS-resting, WOMAC scores, Hospital Anxiety Depression Scale scores, and a negative correlation with all SF-36 scores (p<0.05). DN4 questionnaire scores showed a negative correlation with SF-36 scores and positive correlation with WOMAC scores (p<0.05). To conclude, it should be kept in mind that patients with knee OA who describe intense pain may have a neuropathic component involved in the clinical condition. Quality of life and functional capacity are adversely affected in patients with knee OA who have neuropathic pain. This should be taken into account while planning the treatment of these patients. Copyright © 2017. Published by Elsevier Taiwan.

  6. The influence of thiamin on the efficacy of pregabalin in rats with spinal nerve ligation (SNL)-induced neuropathic pain.

    PubMed

    Liu, Lin; Ma, Song-He; Xia, Ling-Jie

    2016-08-01

    The thiamin is often used in the treatment of neuropathy, and pregabalin is often used to treat neuropathic pain. Our study examined the influence of thiamin on the efficacy of pregabalin in a rat model of spinal nerve ligation (SNL)-induced neuropathic pain. Sprague-Dawley male rats were randomly divided into six groups. The neuropathic pain-relieving properties were measured by plantar test, cold plate test, and hot plate test after administration of pregabalin (i.v) and/or thiamin (i.p) in SNL rats 14 days after operation. In the therapy period, pregabalin, or thiamin alone all produced antinociceptive effects in rats with neuropathic pain. And combination treatment of thiamin and pregabalin resulted in an enhanced pain relief compared to the administration of pregabalin or thiamin alone. Combination of thiamin and pregabalin produces an additive antinociceptive effect in neuropathic pain rats, this drug combination may offer a beneficial treatment option for neuropathic pain.

  7. Antinociceptive effect of Brazilian armed spider venom toxin Tx3-3 in animal models of neuropathic pain.

    PubMed

    Dalmolin, Gerusa Duarte; Silva, Cássia Regina; Rigo, Flávia Karine; Gomes, Guilherme Monteiro; Cordeiro, Marta do Nascimento; Richardson, Michael; Silva, Marco Aurélio Romano; Prado, Marco Antonio Máximo; Gomez, Marcus Vinicius; Ferreira, Juliano

    2011-10-01

    Venoms peptides have produced exceptional sources for drug development to treat pain. In this study we examined the antinociceptive and side effects of Tx3-3, a peptide toxin isolated from Phoneutria nigriventer venom, which inhibits high-voltage-dependent calcium channels (VDCC), preferentially P/Q and R-type VDCC. We tested the effects of Tx3-3 in animal models of nociceptive (tail-flick test), neuropathic (partial sciatic nerve ligation and streptozotocin-induced diabetic neuropathy), and inflammatory (intraplantar complete Freund's adjuvant) pain. In the tail-flick test, both intrathecal (i.t.) and intracerebroventricular (i.c.v.) injection of Tx3-3 in mice caused a short-lasting effect (ED(50) and 95% confidence intervals of 8.8 [4.1-18.8] and 3.7 [1.6-8.4] pmol/site for i.t. and i.c.v. injection, respectively), without impairing motor functions, at least at doses 10-30 times higher than the effective dose. By comparison, ω-conotoxin MVIIC, a P/Q and N-type VDCC blocker derived from Conus magus venom, caused significant motor impairment at doses close to efficacious dose in tail flick test. Tx3-3 showed a long-lasting antinociceptive effect in neuropathic pain models. Intrathecal injection of Tx3-3 (30 pmol/site) decreased both mechanical allodynia produced by sciatic nerve injury in mice and streptozotocin-induced allodynia in mice and rats. On the other hand, i.t. injection of Tx3-3 did not alter inflammatory pain. Taken together, our data show that Tx3-3 shows prevalent antinociceptive effects in the neuropathic pain models and does not cause adverse motor effects at antinociceptive efficacious doses, suggesting that this peptide toxin holds promise as a novel therapeutic agent for the control of neuropathic pain. The Brazilian armed spider Tx3-3, a new P/Q and R-type calcium channel blocker, effectively alleviates allodynia in animal neuropathic pain models. Copyright © 2011 International Association for the Study of Pain. Published by Elsevier B.V. All

  8. [Case of acute exacerbation of neuropathic cancer pain rapidly relieved by simultaneous oral intake of immediate release oxycodone and pregabalin].

    PubMed

    Baba, Mika; Gomwo, Ikuo

    2012-10-01

    Cancer pain consists of continuous pain lasting almost all day and transient exacerbation of pain called breakthrough pain. Breakthrough pain is classified as somatic pain and visceral pain, neuropathic pain according to the character of pain. Although the immediate release opioid is used as the first treatment of choice to breakthrough pain, the effect is not enough when it shows the character of neuropathic pain. Pregabalin has become the first medicine for the treatment of neuropathic pain, and it sometimes reveals prompt analgesic effect based on its pharmacological profile. It has also been reported that pregabalin used with oxycodine reveals analgesic effect with smaller dosage than pregabalin alone. We experienced a young patient with lung cancer suffering from sudden exacerbation of symptomatic sciatica, whose pain was markedly reduced within 30 minutes by taking immediate release oxycodone 5 mg and pregabalin 75 mg simultaneously. Conclusions : Pregabalin with immediate release oxycodone simultaneously may be able to improve acute exacerbation of neuropathic cancer pain rapidly.

  9. Peripheral sensory neuron injury contributes to neuropathic pain in experimental autoimmune encephalomyelitis

    PubMed Central

    Wang, I-Ching; Chung, Chen-Yen; Liao, Fang; Chen, Chih-Cheng; Lee, Cheng-Han

    2017-01-01

    Multiple sclerosis (MS)-induced neuropathic pain deteriorates quality of life in patients but is often refractory to treatment. In experimental autoimmune encephalomyelitis (EAE), a rodent model of MS, animals develop neuropathy and inflammation-induced tissue acidosis, which suggests the involvement of acid-sensing ion channels (ASICs). Also, peripheral neuropathy is reported in MS patients. However, the involvement of the peripheral nervous system (PNS) in MS neuropathic pain remains elusive. This study investigated the contribution of ASICs and peripheral neuropathy in MS-induced neuropathic pain. Elicited pain levels were as high in Asic1a−/−, Asic2−/− and Asic3−/− mice as wild-type mice even though only Asic1a−/− mice showed reduced EAE disease severity, which indicates that pain in EAE was independent of disease severity. We thus adopted an EAE model without pertussis toxin (EAEnp) to restrain activated immunity in the periphery and evaluate the PNS contribution to pain. Both EAE and EAEnp mice showed similar pain behaviors and peripheral neuropathy in nerve fibers and DRG neurons. Moreover, pregabalin significantly reduced neuropathic pain in both EAE and EAEnp mice. Our findings highlight the essential role of the PNS in neuropathic pain in EAE and pave the way for future development of analgesics without side effects in the CNS. PMID:28181561

  10. Brain anatomy changes associated with persistent neuropathic pain following spinal cord injury.

    PubMed

    Gustin, S M; Wrigley, P J; Siddall, P J; Henderson, L A

    2010-06-01

    Persistent neuropathic pain commonly occurs following spinal cord injury (SCI). It remains one of the most challenging management problems in this condition. In order to develop more effective treatments, a better understanding of the neural changes associated with neuropathic SCI pain is required. The aim of this investigation was to use diffusion tensor imaging (DTI) to determine if persistent neuropathic pain following SCI is associated with changes in regional brain anatomy and connectivity. In 23 subjects with complete thoracic SCI, 12 with below-level neuropathic pain and 11 without pain, and 45 healthy control subjects, a series of whole-brain DTI scans were performed. The mean diffusivity (MD) of each voxel was calculated and values compared between groups. This analysis revealed that neuropathic pain following SCI is associated with significant differences in regional brain anatomy. These anatomical changes were located in pain-related regions as well as regions of the classic reward circuitry, that is, the nucleus accumbens and orbitofrontal, dorsolateral prefrontal, and posterior parietal cortices. The right posterior parietal cortex projected to most regions that displayed an anatomical change. Analysis of the fiber tracts connecting areas of MD differences revealed no significance differences in MD values between the SCI pain, SCI no pain, and control groups.

  11. miR-155 modulates the progression of neuropathic pain through targeting SGK3

    PubMed Central

    Liu, Shaoxing; Zhu, Bo; Sun, Yan; Xie, Xianfeng

    2015-01-01

    This study aimed to illustrate the potential effects of miR-155 in neuropathic pain and its potential mechanism. Spragure-Dawley (SD) rats were used for neuropathic pain model of bilateral chronic constriction injury (bCCI) construction. Effects of miR-155 expression on pain threshold of mechanical stimuli (MWT), paw withdrawal threshold latency (PMTL) and cold threshold were analyzed. Target for miR-155 was analyzed using bioinformatics methods. Moreover, effects of miR-155 target gene expression on pain thresholds were also assessed. Compared with the controls and sham group, miR-155 was overexpressed in neuropathic pain rats (P<0.05), but miR-155 slicing could significantly decreased the pain thresholds (P<0.05). Serum and glucocorticoid regulated protein kinase 3 (SGK3) was predicted as the target gene for miR-155, and miR-155 expression was negatively correlated to SGK3 expression. Furthermore, SGK3 overexpression could significantly decreased the pain thresholds which was the same as miR-155 (P<0.05). Moreover, miR-155 slicing and SGK3 overexpression could significantly decrease the painthreshold. The data presented in this study suggested that miR-155 slicing could excellently alleviate neuropathic pain in rats through targeting SGK3 expression. miR-155 may be a potential therapeutic target for neuropathic pain treatment. PMID:26823753

  12. Modulation of neuropathic-pain-related behaviour by the spinal endocannabinoid/endovanilloid system

    PubMed Central

    Starowicz, Katarzyna; Przewlocka, Barbara

    2012-01-01

    Neuropathic pain refers to chronic pain that results from injury to the nervous system. The mechanisms involved in neuropathic pain are complex and involve both peripheral and central phenomena. Although numerous pharmacological agents are available for the treatment of neuropathic pain, definitive drug therapy has remained elusive. Recent drug discovery efforts have identified an original neurobiological approach to the pathophysiology of neuropathic pain. The development of innovative pharmacological strategies has led to the identification of new promising pharmacological targets, including glutamate antagonists, microglia inhibitors and, interestingly, endogenous ligands of cannabinoids and the transient receptor potential vanilloid type 1 (TRPV1). Endocannabinoids (ECs), endovanilloids and the enzymes that regulate their metabolism represent promising pharmacological targets for the development of a successful pain treatment. This review is an update of the relationship between cannabinoid receptors (CB1) and TRPV1 channels and their possible implications for neuropathic pain. The data are focused on endogenous spinal mechanisms of pain control by anandamide, and the current and emerging pharmacotherapeutic approaches that benefit from the pharmacological modulation of spinal EC and/or endovanilloid systems under chronic pain conditions will be discussed. PMID:23108547

  13. Neuropathic pain in breast cancer survivors: using the ID pain as a screening tool.

    PubMed

    Reyes-Gibby, Cielito; Morrow, Phuong Khanh; Bennett, Michael I; Jensen, Mark P; Shete, Sanjay

    2010-05-01

    Neuropathic pain (NP) is a debilitating symptom experienced by a number of patients with cancer. We evaluated the validity of ID Pain as a screening tool for NP in breast cancer survivors using the Self-Report Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) and a reported diagnosis of NP as criterion measures. Two hundred forty breast cancer survivors with a mean age of 58 years (standard deviation=16) participated in this survey. Forty-five percent of the sample reported having pain in the past week. Of those reporting pain, 33% reported that they had been diagnosed by their health care provider with NP, 39% had a positive ID Pain (> or = 2) score, and 19% had a positive S-LANSS score. The most commonly endorsed ID Pain item was "hot/burning" (n=48) followed by feeling "numb" (n=47) and "pins and needles" (n=45). Total ID Pain score was significantly associated with a clinical diagnosis of NP (r=0.41; P<0.001) and the S-LANSS total score (r=0.54; P<0.001). Receiver operating curve analysis demonstrated that ID Pain has a predictive validity of 0.72 and 0.70 for diagnosis of NP as made by clinicians and the S-LANSS, respectively. We also found that an ID Pain score greater than or equal to 2 corresponded with the likelihood of NP in this sample, consistent with the original ID Pain development study. This study provides evidence for ID Pain as a valid screening measure for NP in breast cancer survivors.

  14. N-acetyl-cysteine attenuates neuropathic pain by suppressing matrix metalloproteinases.

    PubMed

    Li, Jiajie; Xu, Lujie; Deng, Xueting; Jiang, Chunyi; Pan, Cailong; Chen, Lu; Han, Yuan; Dai, Wenling; Hu, Liang; Zhang, Guangqin; Cheng, Zhixiang; Liu, Wentao

    2016-08-01

    The treatment of neuropathic pain remains a clinical challenge because of its unclear mechanisms and broad clinical morbidity. Matrix metalloproteinase (MMP)-9 and MMP-2 have previously been described as key components in neuropathic pain because of their facilitation of inflammatory cytokine maturation and induction of neural inflammation. Therefore, the inhibition of MMPs may represent a novel therapeutic approach to the treatment of neuropathic pain. In this study, we report that N-acetyl-cysteine (NAC), which is a broadly used respiratory drug, significantly attenuates neuropathic pain through a unique mechanism of MMP inhibition. Both the in vitro (0.1 mM) and in vivo application of NAC significantly suppressed the activity of MMP-9/2. Orally administered NAC (50, 100, and 200 mg/kg) not only postponed the occurrence but also inhibited the maintenance of chronic constrictive injury (CCI)-induced neuropathic pain in rats. The administration of NAC blocked the maturation of interleukin-1β, which is a critical substrate of MMPs, and markedly suppressed the neuronal activation induced by CCI, including inhibiting the phosphorylation of protein kinase Cγ, NMDAR1, and mitogen-activated protein kinases. Finally, NAC significantly inhibited CCI-induced microglia activation but elicited no notable effects on astrocytes. These results demonstrate an effective and safe approach that has been used clinically to alleviate neuropathic pain through the powerful inhibition of the activation of MMPs.

  15. Role of Drp1, a key mitochondrial fission protein, in neuropathic pain.

    PubMed

    Ferrari, Luiz F; Chum, Adrienne; Bogen, Oliver; Reichling, David B; Levine, Jon D

    2011-08-03

    While oxidative stress has been implicated in small-fiber painful peripheral neuropathies, antioxidants are only partially effective to treat patients. We have tested the hypothesis that Drp1 (dynamin-related protein 1), a GTPase that catalyzes the process of mitochondrial fission, which is a mechanism central for the effect and production of reactive oxygen species (ROS), plays a central role in these neuropathic pain syndromes. Intrathecal administration of oligodeoxynucleotide antisense against Drp1 produced a decrease in its expression in peripheral nerve and markedly attenuated neuropathic mechanical hyperalgesia caused by HIV/AIDS antiretroviral [ddC (2',3'-dideoxycytidine)] and anticancer (oxaliplatin) chemotherapy in male Sprague Dawley rats. To confirm the role of Drp1 in these models of neuropathic pain, as well as to demonstrate its contribution at the site of sensory transduction, we injected a highly selective Drp1 inhibitor, mdivi-1, at the site of nociceptive testing on the dorsum of the rat's hindpaw. mdivi-1 attenuated both forms of neuropathic pain. To evaluate the role of Drp1 in hyperalgesia induced by ROS, we demonstrated that intradermal hydrogen peroxide produced dose-dependent hyperalgesia that was inhibited by mdivi-1. Finally, mechanical hyperalgesia induced by diverse pronociceptive mediators involved in inflammatory and neuropathic pain-tumor necrosis factor α, glial-derived neurotrophic factor, and nitric oxide-was also inhibited by mdivi-1. These studies provide support for a substantial role of mitochondrial fission in preclinical models of inflammatory and neuropathic pain.

  16. Nerve Regenerative Effects of GABA-B Ligands in a Model of Neuropathic Pain

    PubMed Central

    Cavalli, Erica; Pajardi, Giorgio

    2014-01-01

    Neuropathic pain arises as a direct consequence of a lesion or disease affecting the peripheral somatosensory system. It may be associated with allodynia and increased pain sensitivity. Few studies correlated neuropathic pain with nerve morphology and myelin proteins expression. Our aim was to test if neuropathic pain is related to nerve degeneration, speculating whether the modulation of peripheral GABA-B receptors may promote nerve regeneration and decrease neuropathic pain. We used the partial sciatic ligation- (PSL-) induced neuropathic model. The biochemical, morphological, and behavioural outcomes of sciatic nerve were analysed following GABA-B ligands treatments. Simultaneous 7-days coadministration of baclofen (10 mg/kg) and CGP56433 (3 mg/kg) alters tactile hypersensitivity. Concomitantly, specific changes of peripheral nerve morphology, nerve structure, and myelin proteins (P0 and PMP22) expression were observed. Nerve macrophage recruitment decreased and step coordination was improved. The PSL-induced changes in nociception correlate with altered nerve morphology and myelin protein expression. Peripheral synergic effects, via GABA-B receptor activation, promote nerve regeneration and likely ameliorate neuropathic pain. PMID:25165701

  17. Can chronic neuropathic pain following thoracic surgery be predicted during the postoperative period?

    PubMed

    Searle, Robert D; Simpson, Matthew P; Simpson, Karen H; Milton, Richard; Bennett, Michael I

    2009-12-01

    Chronic pain following thoracic surgery is common and associated with neuropathic symptoms, however, the proportion of patients with neuropathic pain in the immediate postoperative period is unknown. We aimed to determine the proportion of patients who have neuropathic symptoms and signs immediately after, and at three months following thoracic surgery. The study was designed as a prospective observational cohort study. We identified patients with pain of predominantly neuropathic origin using the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) score in the immediate postoperative period and the self-report LANSS (S-LANSS) version three months after surgery. One hundred patients undergoing video assisted thoracic surgery (VATS) or thoracotomy completed LANSS scores preoperatively and in the immediate postoperative period. Eighty-seven percent completed three months S-LANSS follow-up scores. Eight percent of patients had positive LANSS scores in the immediate postoperative period; 22% of patients had positive S-LANSS scores three months following surgery. There was a significant association between positive scores in the acute and chronic periods (relative risk (RR) 3.5, [95% confidence interval (CI) 1.7-7.2]). Identifying pain of predominantly neuropathic origin in the postoperative period with a simple pain score can help identify those at risk of developing chronic pain with these features following thoracic surgery.

  18. Antihyperalgesic effects of clomipramine and tramadol in a model of posttraumatic trigeminal neuropathic pain in mice.

    PubMed

    Alvarez, Pedro; Brun, Aurore; Labertrandie, Anaïs; Lopez, José; Correa, Alejandro; Constandil, Luís; Hernández, Alejandro; Pelissier, Teresa

    2011-01-01

    To develop a behavioral model in mice that is capable of mimicking some distinctive symptoms of human posttraumatic trigeminal neuropathic pain such as spontaneous pain, cold allodynia, and chemical÷inflammatory hyperalgesia, and to use this model to investigate the antinociceptive effects of clomipramine and tramadol, two drugs used for the treatment of neuropathic pain. A partial tight ligature of the right infraorbital nerve by an intraoral access or a sham procedure was performed. Fourteen days later, mice were subcutaneously injected with saline or drugs and the spontaneous nociceptive behavior, as well as the responses to topical acetone and to formalin or capsaicin injected into the ipsilateral vibrissal pad, were assessed. Data were analyzed by ANOVA. Neuropathic mice exhibited an increased spontaneous rubbing÷scratching of the ipsilateral vibrissal pad, together with enhanced responses to cooling (acetone) and the chemical irritants (formalin, capsaicin). Clomipramine and tramadol produced an antihyperalgesic effect on most of these nociceptive responses, but tramadol was ineffective on capsaicin-induced hyperalgesia. Nociceptive responses in this neuropathic pain model in mice exhibited a pattern consistent with the pain described by posttraumatic trigeminal neuropathic patients. The selective antihyperalgesic effect obtained with two commonly used drugs for treating neuropathic pain confirms the validity of this preclinical model.

  19. Blocking the GABA transporter GAT-1 ameliorates spinal GABAergic disinhibition and neuropathic pain induced by paclitaxel

    PubMed Central

    Yadav, Ruchi; Yan, Xisheng; Maixner, Dylan W.; Gao, Mei; Weng, Han-Rong

    2015-01-01

    Paclitaxel is a chemotherapeutic agent widely used for treating carcinomas. Patients receiving paclitaxel often develop neuropathic pain and have a reduced quality of life which hinders the use of this life-saving drug. In this study, we determined the role of GABA transporters in the genesis of paclitaxel-induced neuropathic pain using behavioral tests, electrophysiology, and biochemical techniques. We found that tonic GABA receptor activities in the spinal dorsal horn were reduced in rats with neuropathic pain induced by paclitaxel. In normal controls, tonic GABA receptor activities were mainly controlled by the GABA transporter GAT-1 but not GAT-3. In the spinal dorsal horn, GAT-1 was expressed at presynaptic terminals and astrocytes while GAT-3 was only expressed in astrocytes. In rats with paclitaxel-induced neuropathic pain, the protein expression of GAT-1 was increased while GAT-3 was decreased. This was concurrently associated with an increase of global GABA uptake. The paclitaxel-induced attenuation of GABAergic tonic inhibition was ameliorated by blocking GAT-1 but not GAT-3 transporters. Paclitaxel-induced neuropathic pain was significantly attenuated by the intrathecal injection of a GAT-1 inhibitor. These findings suggest that targeting GAT-1 transporters for reversing disinhibition in the spinal dorsal horn may be a useful approach for treating paclitaxel-induced neuropathic pain. PMID:25827582

  20. Gender differences in a mouse model of chemotherapy-induced neuropathic pain.

    PubMed

    Naji-Esfahani, H; Vaseghi, G; Safaeian, L; Pilehvarian, A-A; Abed, A; Rafieian-Kopaei, M

    2016-02-01

    Chemotherapy-induced neuropathic pain is one of the major problems for cancer patients. Although paclitaxel and cisplatin are widely used in women, most laboratory studies of chemotherapy-induced neuropathic pain have been conducted on male animals. The current study examined the gender differences in chemotherapy-induced neuropathic pain in mice. Neuropathic pain was induced by intraperitoneal injection of paclitaxel (2 mg/kg) for five consecutive days and cisplatin (1 mg/kg) for seven consecutive days. Cold allodynia was evaluated by measuring the paw withdrawal frequency and duration of paw licking in mice; however, mechanical allodynia was assessed by von Frey filaments. Neuropathic pain began to manifest after a few days (P < 0.001). Cold allodynia was more robust in female mice (P < 0.001) treated with paclitaxel, while no differences were observed between the two genders in the manifestation of paclitaxel-induced mechanical allodynia. Interestingly, no gender differences were observed in cisplatin-induced cold and mechanical allodynia tests. In conclusion, gender differences play a major role in neuropathic pain induced by paclitaxel. The differences between male and female animals should be considered in future studies and the findings should be generalized to humans with caution.

  1. Deep brain stimulation of the dorsal anterior cingulate cortex for the treatment of chronic neuropathic pain.

    PubMed

    Russo, Jennifer F; Sheth, Sameer A

    2015-06-01

    Chronic neuropathic pain is estimated to affect 3%-4.5% of the worldwide population. It is associated with significant loss of productive time, withdrawal from the workforce, development of mood disorders such as depression and anxiety, and disruption of family and social life. Current medical therapeutics often fail to adequately treat chronic neuropathic pain. Deep brain stimulation (DBS) targeting subcortical structures such as the periaqueductal gray, the ventral posterior lateral and medial thalamic nuclei, and the internal capsule has been investigated for the relief of refractory neuropathic pain over the past 3 decades. Recent work has identified the dorsal anterior cingulate cortex (dACC) as a new potential neuromodulation target given its central role in cognitive and affective processing. In this review, the authors briefly discuss the history of DBS for chronic neuropathic pain in the United States and present evidence supporting dACC DBS for this indication. They review existent literature on dACC DBS and summarize important findings from imaging and neurophysiological studies supporting a central role for the dACC in the processing of chronic neuropathic pain. The available neurophysiological and empirical clinical evidence suggests that dACC DBS is a viable therapeutic option for the treatment of chronic neuropathic pain and warrants further investigation.

  2. New investigational drugs for the treatment of neuropathic pain.

    PubMed

    Sałat, Kinga; Kowalczyk, Paula; Gryzło, Beata; Jakubowska, Anna; Kulig, Katarzyna

    2014-08-01

    Neuropathic pain (NP) is a chronic condition that arises from a lesion or dysfunction of the somatosensory nervous system. However, there are several new targets and novel technologies in the pipeline to address this unmet medical need. In this review, the authors briefly discuss a direction of the development of agents that could be potentially used in NP treatment. Special attention is paid to 1.7-selective voltage-gated sodium channels, N-type voltage-gated calcium channels, angiotensin II (Ang II) AT₂ receptors and nerve growth factor (NGF) as promising targets for new drugs. Furthermore, the article also presents and discusses, in detail, the results of Phase II clinical studies with the AT₂ receptor antagonist - EMA401 in NP (the results of Phase II clinical trials of other described compounds are not available, yet). There is a real hope that new drugs for NP may be available soon. This hope is based on advancing methods of genomics, developing new targets and more efficient drug screening. Some forms of direct influence on voltage-gated ion channels have a place in the treatment of NP, while the development of entirely novel Ang II AT₂ receptor antagonists or NGF inhibitors may be available for many chronic pain sufferers in the foreseeable future.

  3. Altered rate-dependent depression of the spinal H-reflex as an indicator of spinal disinhibition in models of neuropathic pain.

    PubMed

    Lee-Kubli, Corinne A G; Calcutt, Nigel A

    2014-02-01

    The unpredictable efficacy of current therapies for neuropathic pain may reflect diverse etiological mechanisms operating between, and within, diseases. As descriptions of pain rarely establish specific mechanisms, a tool that can identify underlying causes of neuropathic pain would be useful in developing patient-specific treatments. Rate-dependent depression (RDD), a measure of the change in amplitude of the Hoffman reflex over consecutive stimulations, is attenuated in diabetic rats that also exhibit impaired spinal γ-aminobutyric acid (GABA)A receptor function, reduced spinal potassium chloride co-transporter (KCC2) expression, and indices of painful neuropathy. To investigate whether loss of RDD is a reliable indicator of the contribution of spinal GABAergic dysfunction to neuropathic pain, we assessed RDD, tactile allodynia, and formalin-evoked hyperalgesia in 3 models: rats treated acutely with brain-derived neurotrophic factor (BDNF), diabetic rats treated with the BDNF-sequestering molecule tyrosine receptor kinase B/Fc (TrkB/Fc), and rats with paclitaxel-induced neuropathy. Delivery of BDNF to the spinal cord of normal rats produced RDD deficits and features of painful neuropathy associated with disrupted GABAA receptor-mediated inhibitory function and reduced dorsal spinal KCC2 expression. Treating diabetic rats with TrkB/Fc restored RDD and alleviated indices of painful neuropathy. In paclitaxel-treated rats, RDD was not impaired and behavioral indices of neuropathic pain were not associated with spinal GABAergic dysfunction or reduced dorsal spinal KCC2 expression. Our data reveal BDNF as part of the mechanism underlying spinal cord disinhibition caused by altered GABAA receptor function in diabetic rats and suggest that RDD deficits may be a useful indicator of neuropathic pain states associated with spinal disinhibition, thereby revealing specific therapeutic targets. Copyright © 2013 International Association for the Study of Pain. Published by

  4. HIV Distal Neuropathic Pain Is Associated with Smaller Ventral Posterior Cingulate Cortex.

    PubMed

    Keltner, John R; Connolly, Colm G; Vaida, Florin; Jenkinson, Mark; Fennema-Notestine, Christine; Archibald, Sarah; Akkari, Cherine; Schlein, Alexandra; Lee, Jisu; Wang, Dongzhe; Kim, Sung; Li, Han; Rennels, Austin; Miller, David J; Kesidis, George; Franklin, Donald R; Sanders, Chelsea; Corkran, Stephanie; Grant, Igor; Brown, Gregory G; Atkinson, J Hampton; Ellis, Ronald J

    2017-03-01

    . Despite modern antiretroviral therapy, HIV-associated neuropathy is one of the most prevalent, disabling and treatment-resistant complications of HIV disease. The presence and intensity of distal neuropathic pain is not fully explained by the degree of peripheral nerve damage. A better understanding of brain structure in HIV distal neuropathic pain may help explain why some patients with HIV neuropathy report pain while the majority does not. Previously, we reported that more intense distal neuropathic pain was associated with smaller total cerebral cortical gray matter volumes. The objective of this study was to determine which parts of the cortex are smaller. . HIV positive individuals with and without distal neuropathic pain enrolled in the multisite (N = 233) CNS HIV Antiretroviral Treatment Effects (CHARTER) study underwent structural brain magnetic resonance imaging. Voxel-based morphometry was used to investigate regional brain volumes in these structural brain images. . Left ventral posterior cingulate cortex was smaller for HIV positive individuals with versus without distal neuropathic pain (peak P  = 0.017; peak t = 5.15; MNI coordinates x = -6, y = -54, z = 20). Regional brain volumes within cortical gray matter structures typically associated with pain processing were also smaller for HIV positive individuals having higher intensity ratings of distal neuropathic pain. . The posterior cingulate is thought to be involved in inhibiting the perception of painful stimuli. Mechanistically a smaller posterior cingulate cortex structure may be related to reduced anti-nociception contributing to increased distal neuropathic pain.

  5. Neuropathic Pain Is Constitutively Suppressed in Early Life by Anti-Inflammatory Neuroimmune Regulation

    PubMed Central

    McKelvey, Rebecca; Berta, Temugin; Old, Elizabeth; Ji, Ru-Rong

    2015-01-01

    Peripheral nerve injury can trigger neuropathic pain in adults but not in infants; indeed, for unknown reasons, neuropathic pain is rare before adolescence. We show here that the absence of neuropathic pain response in infant male rats and mice following nerve injury is due to an active, constitutive immune suppression of dorsal horn pain activity. In contrast to adult nerve injury, which triggers a proinflammatory immune response in the spinal dorsal horn, infant nerve injury triggers an anti-inflammatory immune response, characterized by significant increases in IL-4 and IL-10. This immediate anti-inflammatory response can also be evoked by direct C-fiber nerve stimulation in infant, but not adult, mice. Blockade of the anti-inflammatory activity with intrathecal anti-IL10 unmasks neuropathic pain behavior in infant nerve injured mice, showing that pain hypersensitivity in young mice is actively suppressed by a dominant anti-inflammatory neuroimmune response. As infant nerve injured mice reach adolescence (postnatal day 25–30), the dorsal horn immune profile switches from an anti-inflammatory to a proinflammatory response characterized by significant increases in TNF and BDNF, and this is accompanied by a late onset neuropathic pain behavior and increased dorsal horn cell sensitivity to cutaneous mechanical and cold stimuli. These findings show that neuropathic pain following early life nerve injury is not absent but suppressed by neuroimmune activity and that “latent” pain can still emerge at adolescence, when the neuroimmune profile changes. The data may explain why neuropathic pain is rare in young children and also why it can emerge, for no observable reason, in adolescent patients. PMID:25589741

  6. The prevalence of neuropathic pain is high following treatment for breast cancer: a systematic review.

    PubMed

    Ilhan, Emre; Chee, Edwin; Hush, Julia; Moloney, Niamh

    2017-07-03

    Pain is common, but often poorly managed following breast cancer treatment. Screening questionnaires and the Neuropathic Pain Special Interest Group (NeuPSIG) criteria are two clinical approaches used to determine whether pain has neuropathic components, which may enable better pain management. The aims of this review were (1) to synthesise data from the literature on neuropathic pain prevalence in women following breast cancer treatment; (2) to investigate whether the prevalence of neuropathic pain differed between studies using screening questionnaires and the NeuPSIG criteria. We searched for studies that administered a validated neuropathic pain screening questionnaire and/or the NeuPSIG criteria to women treated for early-stage (I-III) breast cancer. Thirteen studies using screening questionnaires (N=3,792), and 3 studies using components of the NeuPSIG criteria (N=621) were included. Meta-analyses were conducted for questionnaire data but not NeuPSIG criteria data due to inadequate homogeneity. Among all participants treated for early-stage breast cancer, pooled prevalence estimates (95% confidence interval) ranged between 14.2% (8.3 to 21.4) to 27.2% (24.7 to 88.4) for studies using screening questionnaires; studies using NeuPSIG criteria reported prevalence rates from 24.1% to 31.3%. Among those who reported pain following treatment, the pooled prevalence estimate (95% confidence interval) of neuropathic pain from screening questionnaires ranged from 32.6% (24.2 to 41.6) to 58.2% (24.7 to 88.4); studies using NeuPSIG criteria reported prevalence rates from 29.5% to 57.1%. These prevalence estimates are higher than those reported for other types of cancer, and emphasise the need to assess the contribution of neuropathic pain following breast cancer treatment.

  7. Neuropathic pain is constitutively suppressed in early life by anti-inflammatory neuroimmune regulation.

    PubMed

    McKelvey, Rebecca; Berta, Temugin; Old, Elizabeth; Ji, Ru-Rong; Fitzgerald, Maria

    2015-01-14

    Peripheral nerve injury can trigger neuropathic pain in adults but not in infants; indeed, for unknown reasons, neuropathic pain is rare before adolescence. We show here that the absence of neuropathic pain response in infant male rats and mice following nerve injury is due to an active, constitutive immune suppression of dorsal horn pain activity. In contrast to adult nerve injury, which triggers a proinflammatory immune response in the spinal dorsal horn, infant nerve injury triggers an anti-inflammatory immune response, characterized by significant increases in IL-4 and IL-10. This immediate anti-inflammatory response can also be evoked by direct C-fiber nerve stimulation in infant, but not adult, mice. Blockade of the anti-inflammatory activity with intrathecal anti-IL10 unmasks neuropathic pain behavior in infant nerve injured mice, showing that pain hypersensitivity in young mice is actively suppressed by a dominant anti-inflammatory neuroimmune response. As infant nerve injured mice reach adolescence (postnatal day 25-30), the dorsal horn immune profile switches from an anti-inflammatory to a proinflammatory response characterized by significant increases in TNF and BDNF, and this is accompanied by a late onset neuropathic pain behavior and increased dorsal horn cell sensitivity to cutaneous mechanical and cold stimuli. These findings show that neuropathic pain following early life nerve injury is not absent but suppressed by neuroimmune activity and that "latent" pain can still emerge at adolescence, when the neuroimmune profile changes. The data may explain why neuropathic pain is rare in young children and also why it can emerge, for no observable reason, in adolescent patients.

  8. Prevalence of Neuropathic Pain in Radiotherapy Oncology Units

    SciTech Connect

    Manas, Ana; Monroy, Jose Luis; Ramos, Avelino Alia; Cano, Carmen; Lopez-Gomez, Vanessa; Masramon, Xavier; Perez, Maria

    2011-10-01

    Purpose: Neuropathic pain (NP) in cancer patients severely impacts quality of life. Radiotherapy (RT) may cause NP, and at the same time, cancer patients visit RT units for pain relief. NP prevalence at these sites and current analgesic treatment should be assessed to improve management. Methods and Materials: This epidemiological, prospective, multicenter study was undertaken to assess NP prevalence, according to Douleur Neuropathique 4 questions questtionaire (DN4) test results, and analgesic management in cancer pain patients visiting RT oncologic units. Secondary analyses assessed NP etiology and pain intensity (using the Brief Pain Inventory-Short Form) and impact (using the Hospital Anxiety and Depression Scale (HADS), Medical Outcomes Study [MOS] for Sleep, and the Health Survey Short Form-12). Results: A total of 1,098 patients with any kind of pain were registered. NP prevalence was 31.1% (95% confidence interval, 28.4%--33.9%); 291 NP patients (mean age, 62.2 {+-}12.5 years and 57.7% men) were eligible for study; 49% of patients were overweight. The most frequent tumors were those of breast and lung, and stage IIIB was the most common cancer stage. The tumors caused 75% of NP cases. Anxiety, sleepiness, and depression were common. At 8 weeks, pain intensity and interference with daily activities decreased significantly for 50.8% of responders. Depression and anxiety (p < 0.0001) scores on the Physical Component Summary and Mental Component Summary measures (p < 0.0001) and all MOS-Sleep subscales, except for snoring, improved significantly. The percentage of satisfied patients increased from 13.8% to 87.4% (p < 0.0001) with the current analgesic treatment, which meant a 1.2- and 6-fold increase (p < 0.0001) in narcotic analgesics and anticonvulsants, respectively, compared to previous treatment. Conclusions: NP is highly prevalent at RT oncology units, with sleepiness, anxiety, and depression as frequent comorbidities. There is a need to improve

  9. A prospective study of neuropathic pain induced by thoracotomy: incidence, clinical description, and diagnosis.

    PubMed

    Guastella, Virginie; Mick, Gérard; Soriano, Christophe; Vallet, Laurent; Escande, Georges; Dubray, Claude; Eschalier, Alain

    2011-01-01

    This study evaluated prospectively the incidence of neuropathic pain after thoracotomy, described its clinical characteristics, and delineated landmarks for its diagnosis in daily practice. We evaluated clinically painful symptoms and sensory deficits in 54 patients after lateral/posterolateral thoracotomy for broncho-pulmonary carcinoma with standardized surgical and analgesic procedures. At 2months, 49 patients suffered from non malignant thoracic pain, and at 6months 38 patients (loss to follow-up for 7) reported persisting pain. In 35 patients, painful symptoms and sensory deficits could be evaluated using a standardized clinical bedside procedure. According to the grading system proposed by Treede et al. [41], neuropathic pain was considered probable in 21 patients, while use of the DN4 questionnaire concluded that neuropathic pain was probable in 17 patients. The two diagnostic procedures provided similar conclusions in 16 patients. Morphine consumption during the early post-operative period (mean 111.3±30.8mg/day) and pain intensity (VAS: mean 5.71±2.1) were significantly higher in patients suffering from neuropathic pain than in other patients with pain (mean 80±21.4mg/day; VAS: mean 3.9±2.4). The clinical picture in most patients with neuropathic pain included electric shocks and severe multimodal hypoesthesia in the sensory area of 5th/6th intercostal nerves. Thus, our results indicate a minimal incidence of chronic post-thoracotomy pain at 70% and that of neuropathic pain at 29%, this latter being clinically suggested by a combination of certain symptoms and reinforced by the DN4 questionnaire when sensory deficit at scar is present.

  10. Exploring acute-to-chronic neuropathic pain in rats after contusion spinal cord injury.

    PubMed

    Gaudet, Andrew D; Ayala, Monica T; Schleicher, Wolfgang E; Smith, Elana J; Bateman, Emily M; Maier, Steven F; Watkins, Linda R

    2017-09-01

    Spinal cord injury (SCI) causes chronic pain in 65% of individuals. Unfortunately, current pain management is inadequate for many SCI patients. Rodent models could help identify how SCI pain develops, explore new treatment strategies, and reveal whether acute post-SCI morphine worsens chronic pain. However, few studies explore or compare SCI-elicited neuropathic pain in rats. Here, we sought to determine how different clinically relevant contusion SCIs in male and female rats affect neuropathic pain, and whether acute morphine worsens later chronic SCI pain. First, female rats received sham surgery, or 150kDyn or 200kDyn midline T9 contusion SCI. These rats displayed modest mechanical allodynia and long-lasting thermal hyperalgesia. Next, a 150kDyn (1s dwell) midline contusion SCI was performed in male and female rats. Interestingly, males, but not females showed SCI-elicited mechanical allodynia; rats of both sexes had thermal hyperalgesia. In this model, acute morphine treatment had no significant effect on chronic neuropathic pain symptoms. Unilateral SCIs can also elicit neuropathic pain that could be exacerbated by morphine, so male rats received unilateral T13 contusion SCI (100kDyn). These rats exhibited significant, transient mechanical allodynia, but not thermal hyperalgesia. Acute morphine did not exacerbate chronic pain. Our data show that specific rat contusion SCI models cause neuropathic pain. Further, chronic neuropathic pain elicited by these contusion SCIs was not amplified by our course of early post-trauma morphine. Using clinically relevant rat models of SCI could help identify novel pain management strategies. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Modulating the Delicate Glial-Neuronal Interactions in Neuropathic Pain: Promises and Potential Caveats

    PubMed Central

    Tiwari, Vinod; Guan, Yun; Raja, Srinivasa N.

    2014-01-01

    During neuropathic pain, glial cells (mainly astrocytes and microglia) become activated and initiate a series of signaling cascades that modulate pain processing at both spinal and supraspinal levels. It has been generally accepted that glial cell activation contributes to neuropathic pain because glia release proinflammatory cytokines, chemokines, and factors such as calcitonin gene-related peptide, substance P, and glutamate, which are known to facilitate pain signaling. However, recent research has shown that activation of glia also leads to some beneficial outcomes. Glia release anti-inflammatory factors that protect against neurotoxicity and restore normal pain. Accordingly, use of glial inhibitors might compromise the protective functions of glia in addition to suppressing their detrimental effects. With a better understanding of how different conditions affect glial cell activation, we may be able to promote the protective function of glia and pave the way for future development of novel, safe, and effective treatments of neuropathic pain. PMID:24820245

  12. Forebrain GABAergic neuron precursors integrate into adult spinal cord and reduce injury-induced neuropathic pain

    PubMed Central

    Bráz, JM; Sharif-Naeini, R; Vogt, D; Kriegstein, A; Alvarez-Buylla, A; Rubenstein, JL; Basbaum, AI

    2012-01-01

    Neuropathic pain is a chronic debilitating disease characterized by mechanical allodynia and spontaneous pain. Because symptoms are often unresponsive to conventional methods of pain treatment, new therapeutic approaches are essential. Here, we describe a strategy that not only ameliorates symptoms of neuropathic pain, but is also potentially disease modifying. We show that transplantation of immature telencephalic GABAergic interneurons from the mouse medial ganglionic eminence (MGE) into the adult mouse spinal cord completely reverses the mechanical hypersensitivity produced by peripheral nerve injury. Underlying this improvement is a remarkable integration of the MGE transplants into the host spinal cord circuitry, in which the transplanted cells make functional connections with both primary afferent and spinal cord neurons. By contrast, MGE transplants were not effective against inflammatory pain. Our findings suggest that MGE-derived GABAergic interneurons overcome the spinal cord hyperexcitability that is a hallmark of nerve-injury induced neuropathic pain. PMID:22632725

  13. Peroxisome proliferator-activated receptor agonists modulate neuropathic pain: a link to chemokines?

    PubMed Central

    Freitag, Caroline M.; Miller, Richard J.

    2014-01-01

    Chronic pain presents a widespread and intractable medical problem. While numerous pharmaceuticals are used to treat chronic pain, drugs that are safe for extended use and highly effective at treating the most severe pain do not yet exist. Chronic pain resulting from nervous system injury (neuropathic pain) is common in conditions ranging from multiple sclerosis to HIV-1 infection to type II diabetes. Inflammation caused by neuropathy is believed to contribute to the generation and maintenance of neuropathic pain. Chemokines are key inflammatory mediators, several of which (MCP-1, RANTES, MIP-1α, fractalkine, SDF-1 among others) have been linked to chronic, neuropathic pain in both human conditions and animal models. The important roles chemokines play in inflammation and pain make them an attractive therapeutic target. Peroxisome proliferator-activated receptors (PPARs) are a family of nuclear receptors known for their roles in metabolism. Recent research has revealed that PPARs also play a role in inflammatory gene repression. PPAR agonists have wide-ranging effects including inhibition of chemokine expression and pain behavior reduction in animal models. Experimental evidence suggests a connection between the pain ameliorating effects of PPAR agonists and suppression of inflammatory gene expression, including chemokines. In early clinical research, one PPARα agonist, palmitoylethanolamide (PEA), shows promise in relieving chronic pain. If this link can be better established, PPAR agonists may represent a new drug therapy for neuropathic pain. PMID:25191225

  14. Silicon-Containing GABA Derivatives, Silagaba Compounds, as Orally Effective Agents for Treating Neuropathic Pain without Central-Nervous-System-Related Side Effects

    PubMed Central

    2014-01-01

    Neuropathic pain is a chronic condition resulting from neuronal damage. Pregabalin, the (S)-isomer of 3-isobutyl-γ-aminobutyric acid (GABA), is widely used to treat neuropathic pain, despite the occurrence of central nervous system (CNS)-related side effects such as dizziness and somnolence. Here we describe the pharmacology of novel GABA derivatives containing silicon–carbon bonds, silagaba compounds. Silagaba131, 132, and 161 showed pregabalin-like analgesic activities in animal models of neuropathic pain, but in contrast to pregabalin they did not impair neuromuscular coordination in rotarod tests. Pharmacokinetic studies showed that brain exposure to silagaba compounds was lower than that to pregabalin. Surprisingly, despite their potent analgesic action in vivo, silagaba compounds showed only weak binding to α2-δ protein. These compounds may be useful to study mechanisms of neuropathic pain. Our results also indicate that silagaba132 and 161 are candidates for orally effective treatment of neuropathic pain without CNS-related side effects. PMID:24738473

  15. The effectiveness of cannabinoids in the management of chronic nonmalignant neuropathic pain: a systematic review.

    PubMed

    Boychuk, Darrell G; Goddard, Greg; Mauro, Giovanni; Orellana, Maria F

    2015-01-01

    To carry out a systematic review to assess the effectiveness of cannabis extracts and cannabinoids in the management of chronic nonmalignant neuropathic pain. Electronic database searches were performed using Medline, PubMed, Embase, all evidence-based medicine reviews, and Web of Science, through communication with the Canadian Consortium for the Investigation of Cannabinoids (CCIC), and by searching printed indices from 1950. Terms used were marijuana, marihuana, cannabis, cannabinoids, nabilone, delta- 9-tetrahydrocannabinol, cannabidiol, ajulemic acid, dronabinol, pain, chronic, disease, and neuropathic. Randomized placebo-controlled trials (RCTs) involving cannabis and cannabinoids for the treatment of chronic nonmalignant pain were selected. Outcomes considered were reduction in pain intensity and adverse events. Of the 24 studies that examined chronic neuropathic pain, 11 studies were excluded. The 13 included studies were rated using the Jadad Scale to measure bias in pain research. Evaluation of these studies suggested that cannabinoids may provide effective analgesia in chronic neuropathic pain conditions that are refractory to other treatments. Cannabis-based medicinal extracts used in different populations of chronic nonmalignant neuropathic pain patients may provide effective analgesia in conditions that are refractory to other treatments. Further high-quality studies are needed to assess the impact of the duration of the treatment as well as the best form of drug delivery.

  16. The selective sigma-1 receptor antagonist E-52862 attenuates neuropathic pain of different aetiology in rats.

    PubMed

    Gris, Georgia; Portillo-Salido, Enrique; Aubel, Bertrand; Darbaky, Yassine; Deseure, Kristof; Vela, José Miguel; Merlos, Manuel; Zamanillo, Daniel

    2016-04-18

    E-52862 is a selective σ1R antagonist currently undergoing phase II clinical trials for neuropathic pain and represents a potential first-in-class analgesic. Here, we investigated the effect of single and repeated administration of E-52862 on different pain-related behaviours in several neuropathic pain models in rats: mechanical allodynia in cephalic (trigeminal) neuropathic pain following chronic constriction injury of the infraorbital nerve (IoN), mechanical hyperalgesia in streptozotocin (STZ)-induced diabetic polyneuropathy, and cold allodynia in oxaliplatin (OX)-induced polyneuropathy. Mechanical hypersensitivity induced after IoN surgery or STZ administration was reduced by acute treatment with E-52862 and morphine, but not by pregabalin. In the OX model, single administration of E-52862 reversed the hypersensitivity to cold stimuli similarly to 100 mg/kg of gabapentin. Interestingly, repeated E-52862 administration twice daily over 7 days did not induce pharmacodynamic tolerance but an increased antinociceptive effect in all three models. Additionally, as shown in the STZ and OX models, repeated daily treatment with E-52862 attenuated baseline pain behaviours, which supports a sustained modifying effect on underlying pain-generating mechanisms. These preclinical findings support a role for σ1R in neuropathic pain and extend the potential for the use of selective σ1R antagonists (e.g., E-52862) to the chronic treatment of cephalic and extra-cephalic neuropathic pain.

  17. The selective sigma-1 receptor antagonist E-52862 attenuates neuropathic pain of different aetiology in rats

    PubMed Central

    Gris, Georgia; Portillo-Salido, Enrique; Aubel, Bertrand; Darbaky, Yassine; Deseure, Kristof; Vela, José Miguel; Merlos, Manuel; Zamanillo, Daniel

    2016-01-01

    E-52862 is a selective σ1R antagonist currently undergoing phase II clinical trials for neuropathic pain and represents a potential first-in-class analgesic. Here, we investigated the effect of single and repeated administration of E-52862 on different pain-related behaviours in several neuropathic pain models in rats: mechanical allodynia in cephalic (trigeminal) neuropathic pain following chronic constriction injury of the infraorbital nerve (IoN), mechanical hyperalgesia in streptozotocin (STZ)-induced diabetic polyneuropathy, and cold allodynia in oxaliplatin (OX)-induced polyneuropathy. Mechanical hypersensitivity induced after IoN surgery or STZ administration was reduced by acute treatment with E-52862 and morphine, but not by pregabalin. In the OX model, single administration of E-52862 reversed the hypersensitivity to cold stimuli similarly to 100 mg/kg of gabapentin. Interestingly, repeated E-52862 administration twice daily over 7 days did not induce pharmacodynamic tolerance but an increased antinociceptive effect in all three models. Additionally, as shown in the STZ and OX models, repeated daily treatment with E-52862 attenuated baseline pain behaviours, which supports a sustained modifying effect on underlying pain-generating mechanisms. These preclinical findings support a role for σ1R in neuropathic pain and extend the potential for the use of selective σ1R antagonists (e.g., E-52862) to the chronic treatment of cephalic and extra-cephalic neuropathic pain. PMID:27087602

  18. An Intensive Locomotor Training Paradigm Improves Neuropathic Pain following Spinal Cord Compression Injury in Rats.

    PubMed

    Dugan, Elizabeth A; Sagen, Jacqueline

    2015-05-01

    Spinal cord injury (SCI) is often associated with both locomotor deficits and sensory dysfunction, including debilitating neuropathic pain. Unfortunately, current conventional pharmacological, physiological, or psychological treatments provide only marginal relief for more than two-thirds of patients, highlighting the need for improved treatment options. Locomotor training is often prescribed as an adjunct therapy for peripheral neuropathic pain but is rarely used to treat central neuropathic pain. The goal of this study was to evaluate the potential anti-nociceptive benefits of intensive locomotor training (ILT) on neuropathic pain consequent to traumatic SCI. Using a rodent SCI model for central neuropathic pain, ILT was initiated either 5 d after injury prior to development of neuropathic pain symptoms (the "prevention" group) or delayed until pain symptoms fully developed (∼3 weeks post-injury, the "reversal" group). The training protocol consisted of 5 d/week of a ramping protocol that started with 11 m/min for 5 min and increased in speed (+1 m/min/week) and time (1-4 minutes/week) to a maximum of two 20-min sessions/d at 15 m/min by the fourth week of training. ILT prevented and reversed the development of heat hyperalgesia and cold allodynia, as well as reversed developed tactile allodynia, suggesting analgesic benefits not seen with moderate levels of locomotor training. Further, the analgesic benefits of ILT persisted for several weeks once training had been stopped. The unique ability of an ILT protocol to produce robust and sustained anti-nociceptive effects, as assessed by three distinct outcome measures for below-level SCI neuropathic pain, suggests that this adjunct therapeutic approach has great promise in a comprehensive treatment strategy for SCI pain.

  19. Longitudinal FDG microPET imaging of neuropathic pain: does cerebellar activity correlate with neuropathic pain development in a rat model?

    PubMed

    Kim, Jinhyung; Shin, Jaewoo; Oh, Jin-Hwan; Jung, Hyun Ho; Kim, Young-Bo; Cho, Zang-Hee; Chang, Jin Woo

    2015-06-01

    We used [F-18] FDG microPET imaging as part of a longitudinal study to investigate changes in the brain. Glucose metabolism during the development of neuropathic pain after tibial and sural nerve transection (TST) model rats. MicroPET images were obtained 1 week before operation and then weekly for 8 weeks post-operation. The behavioral test was performed immediately after the every FDG administration. After TST modeling, neuropathic pain rats showed increased mechanical sensitivity of the injured hind paw. The withdrawal response to mechanical pain stimulation by von Frey filaments was observed within the first week (3.8 ± 0.73), and it rapidly increased in the third week (7.13 ± 0.82). This response reached a peak in the fourth week after surgery (9.0 ± 0.53), which persisted until the eighth week. In microPET scan imaging, cerebellum, which initially started from the ansiform lobule, was activated gradually to all part from the third week in all image acquisitions through the eighth week. The longitudinal microPET scan study of brains from neuropathic pain rat models showed sequential cerebellar activity that was in accordance with results from behavioral test responses, thus supporting a role for the cerebellum in the development of neuropathic pain.

  20. Sciatic nerve cuffing in mice: a model of sustained neuropathic pain.

    PubMed

    Benbouzid, Malika; Pallage, Viviane; Rajalu, Mathieu; Waltisperger, Elisabeth; Doridot, Stéphane; Poisbeau, Pierrick; Freund-Mercier, Marie José; Barrot, Michel

    2008-07-01

    Because of its severity, chronicity, resistance to usual therapy and its consequences on quality of life, neuropathic pain represents a real clinical challenge. Fundamental research on this pathology uses metabolic, pharmacological or traumatic models in rodents that reproduce the characteristic human pain symptoms. In 1996, Mosconi and Kruger morphologically described a model of peripheral neuropathy in which a cuff of polyethylene tubing was placed around the sciatic nerve in rats. In the present study, we evaluated the behavioral consequences of this neuropathic pain model in C57Bl/6J mice which is the main genetic background used for studies in transgenic mice. A short cuff of polyethylene tubing was unilaterally placed around the main branch of the sciatic nerve. It induced an ipsilateral heat thermal hyperalgesia lasting around 3 weeks, and a sustained ipsilateral mechanical allodynia lasting at least 2 months. We showed that this neuropathic pain model is insensitive to ketoprofen, a non-steroidal anti-inflammatory drug. Morphine treatment acutely suppressed the mechanical allodynia, but tolerance to this effect rapidly developed. The analysis of video recordings revealed that most aspects of spontaneous behavior remained unaffected on the long term, excepted for a decrease in the time spent at social interaction for the neuropathic mice. Using the elevated plus-maze and the marble-burying test, we also showed that neuropathic mice develop an anxiety phenotype. Our data indicate that sciatic nerve cuffing in mice is a pertinent model for the study of nociceptive and emotional consequences of sustained neuropathic pain.

  1. Recent Developments Regarding Voltage-Gated Sodium Channel Blockers for the Treatment of Inherited and Acquired Neuropathic Pain Syndromes

    PubMed Central

    Theile, Jonathan W.; Cummins, Theodore R.

    2011-01-01

    Chronic and neuropathic pain constitute significant health problems affecting millions of individuals each year. Pain sensations typically originate in sensory neurons of the peripheral nervous system which relay information to the central nervous system (CNS). Pathological pain sensations can arise as result of changes in excitability of these peripheral sensory neurons. Voltage-gated sodium channels are key determinants regulating action potential generation and propagation; thus, changes in sodium channel function can have profound effects on neuronal excitability and pain signaling. At present, most of the clinically available sodium channel blockers used to treat pain are non-selective across sodium channel isoforms and can contribute to cardio-toxicity, motor impairments, and CNS side effects. Numerous strides have been made over the last decade in an effort to develop more selective and efficacious sodium channel blockers to treat pain. The purpose of this review is to highlight some of the more recent developments put forth by research universities and pharmaceutical companies alike in the pursuit of developing more targeted sodium channel therapies for the treatment of a variety of neuropathic pain conditions. PMID:22007172

  2. The effect of progesterone on expression and development of neuropathic pain in a rat model of peripheral neuropathy.

    PubMed

    Verdi, Javad; Jafari-Sabet, Majid; Mokhtari, Rasool; Mesdaghinia, Azam; Banafshe, Hamid Reza

    2013-01-15

    Neuropathic pain results from lesions or diseases affecting the somatosensory system. The management of patients with chronic neuropathic pain remains a challenge. Several studies support the crucial role of neuroactive steroids in the modulation of pain. The present study was designed to investigate the effect of systemic administration of progesterone on expression and development of hyperalgesia and allodynia scores in chronic constriction injury model of neuropathic pain in rat. Progesterone at doses of 5, 10 and 15 mg/kg and its vehicle were injected intraperitoneally on days 1-13 after the surgery to study the effect of progesterone on development of neuropathic pain and only on 14th day post-surgery in order to assess its effect on expression of neuropathic pain.The chronic administration of progesterone significantly reduced the behavioral scores of cold- and mechano-allodynia and heat hyperalgesia but single dose of progesterone did not have any effect on behavioral scores of neuropathic pain. Our data indicate that the early chronic administration of progesterone prevents the development of neuropathic pain but its acute injection does not change the expression of neuropathic pain. These results suggest that progesterone could be considered as a new approach for management of neuropathic pain. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Cholinergic Neurotransmission in the Posterior Insular Cortex Is Altered in Preclinical Models of Neuropathic Pain: Key Role of Muscarinic M2 Receptors in Donepezil-Induced Antinociception

    PubMed Central

    Ferrier, Jérémy; Bayet-Robert, Mathilde; Dalmann, Romain; El Guerrab, Abderrahim; Aissouni, Youssef; Graveron-Demilly, Danielle; Chalus, Maryse; Pinguet, Jérémy; Eschalier, Alain; Richard, Damien; Daulhac, Laurence; Balayssac, David

    2015-01-01

    Neuropathic pain is one of the most debilitating pain conditions, yet no therapeutic strategy has been really effective for its treatment. Hence, a better understanding of its pathophysiological mechanisms is necessary to identify new pharmacological targets. Here, we report important metabolic variations in brain areas involved in pain processing in a rat model of oxaliplatin-induced neuropathy using HRMAS 1H-NMR spectroscopy. An increased concentration of choline has been evidenced in the posterior insular cortex (pIC) of neuropathic animal, which was significantly correlated with animals' pain thresholds. The screening of 34 genes mRNA involved in the pIC cholinergic system showed an increased expression of the high-affinity choline transporter and especially the muscarinic M2 receptors, which was confirmed by Western blot analysis in oxaliplatin-treated rats and the spared nerve injury model (SNI). Furthermore, pharmacological activation of M2 receptors in the pIC using oxotremorine completely reversed oxaliplatin-induced mechanical allodynia. Consistently, systemic treatment with donepezil, a centrally active acetylcholinesterase inhibitor, prevented and reversed oxaliplatin-induced cold and mechanical allodynia as well as social interaction impairment. Intracerebral microdialysis revealed a lower level of acetylcholine in the pIC of oxaliplatin-treated rats, which was significantly increased by donepezil. Finally, the analgesic effect of donepezil was markedly reduced by a microinjection of the M2 antagonist, methoctramine, within the pIC, in both oxaliplatin-treated rats and spared nerve injury rats. These findings highlight the crucial role of cortical cholinergic neurotransmission as a critical mechanism of neuropathic pain, and suggest that targeting insular M2 receptors using central cholinomimetics could be used for neuropathic pain treatment. SIGNIFICANCE STATEMENT Our study describes a decrease in cholinergic neurotransmission in the posterior insular

  4. Pattern of neuropathic pain induced by topical capsaicin application in healthy subjects.

    PubMed

    Lötsch, Jörn; Dimova, Violeta; Hermens, Hanneke; Zimmermann, Michael; Geisslinger, Gerd; Oertel, Bruno G; Ultsch, Alfred

    2015-03-01

    Human experimental pain models are widely used to study drug effects under controlled conditions, but they require further optimization to better reflect clinical pain conditions. To this end, we measured experimentally induced pain in 110 (46 men) healthy volunteers. The quantitative sensory testing (QST) battery (German Research Network on Neuropathic Pain) was applied on untreated ("control") and topical capsaicin-hypersensitized ("test") skin. Z-transformed QST-parameter values obtained at the test site were compared with corresponding values published from 1236 patients with neuropathic pain using Bayesian statistics. Subjects were clustered for the resemblance of their QST pattern to neuropathic pain. Although QST parameter values from the untreated site agreed with reference values, several QST parameters acquired at the test site treated with topical capsaicin deviated from normal. These deviations resembled in 0 to 7 parameters of the QST pattern observed in patients with neuropathic pain. Higher degrees (50%-60%) of resemblance to neuropathic QST pattern were obtained in 18% of the subjects. Inclusion in the respective clusters was predictable at a cross-validated accuracy of 86.9% by a classification and regression tree comprising 3 QST parameters (mechanical pain sensitivity, wind-up ratio, and z-transformed thermal sensory limen) from the control sites. Thus, we found that topical capsaicin partly induced the desired clinical pattern of neuropathic pain in a preselectable subgroup of healthy subjects to a degree that fuels expectations that experimental pain models can be optimized toward mimicking clinical pain. The subjects, therefore, qualify for enrollment in analgesic drug studies that use highly selected cohorts to enhance predictivity for clinical analgesia.

  5. Leptin is essential for microglial activation and neuropathic pain after preganglionic cervical root avulsion.

    PubMed

    Chang, Kai-Ting; Lin, Yi-Lo; Lin, Chi-Te; Hong, Chen-Jei; Tsai, May-Jywan; Huang, Wen-Cheng; Shih, Yang-Hsin; Lee, Yi-Yen; Cheng, Henrich; Huang, Ming-Chao

    2017-10-15

    Preganglionic cervical root avulsion (PCRA) affects both the peripheral and central nervous systems and is often associated with neuropathic pain. Unlike peripheral nerve injuries (PNI), central lesions caused by disruption of cervical roots from the spinal cord following PCRA contribute to the generation of neuropathic pain. Leptin is involved in the development of neuropathic pain after PNI by affecting neurons. However, whether leptin is involved in microglial activation leading to neuropathic pain after PCRA is unknown. Preganglionic avulsion of the left 6(th)-8(th) cervical roots was performed in C57B/6J mice and leptin-deficient mice. A leptin antagonist or leptin was administered to C57B/6J mice and leptin-deficient mice after injury, respectively. The expression pattern of spinal and supraspinal microglia was examined by immunofluorescent staining. Von Frey filaments were used to test pain sensitivity. Leptin is essential for the development of neuropathic pain after PCRA. Allodynia was absent in the leptin-deficient mice and the mice administered the leptin antagonist. We also found that leptin deficiency or the administration of its antagonist inhibited the development of microgliosis in the dorsal horn and brainstem. Furthermore, increase in the expression of CD86 and iNOS, and Wallerian degeneration were noted in the spinal cord. The administration of exogenous leptin to leptin-deficient mice reversed these effects. We concluded that leptin is involved in the proliferation and activation of microglia, which in turn enhances the development of neuropathic pain. Blocking the effects of leptin might be a target for the treatment of neuropathic pain after PCRA. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Synergistic Interaction Between Dexmedetomidine and Ulinastatin Against Vincristine-Induced Neuropathic Pain in Rats.

    PubMed

    Nie, Bilin; Zhang, Subo; Huang, Zhuxi; Huang, Jingxiu; Chen, Xiaodi; Zheng, Yaochao; Bai, Xiaohui; Zeng, Weian; Ouyang, Handong

    2017-07-08

    Antimicrotubulin chemotherapeutic agents such as vincristine (VCR), often induce peripheral neuropathic pain. It is usually permanent and seriously harmful to cancer patients' quality of life and can result in the hampering of clinical treatments. Currently, there is no definitive therapy, and many of the drugs approved for the treatment of other neuropathic pain have shown little or no analgesic effect. It is therefore vital to find new and novel therapeutic strategies for patients suffering from chemotherapeutic agent-induced neuropathic pain to improve patients' quality of life. This study shows that intrathecal injections of dexmedetomidine (DEX), or intraperitoneally administered ulinastatin (UTI) significantly reduces Sprague Dawley rats' mechanical allodynia induced by VCR via upregulation of interleukin-10 expression and activating the α2-adrenergic receptor in dorsal root ganglion (DRG). Moreover, when combined there is a synergistic interaction between DEX and UTI, which acts against VCR-induced neuropathic pain. This synergistic interaction between DEX and UTI may be partly attributed to a common analgesic pathway in which the upregulation of interleukin -10 plays an important role via activating α2-adrenergic receptor in rat dorsal root ganglion. The combined use of DEX and UTI does not affect the rat's blood pressure, heart rate, sedation, motor score, spatial learning, or memory function. All of these show that the combined use of DEX and UTI is an effective method in relieving VCR-induced neuropathic pain in rats. This article documents the synergistic interaction between 2 widely used drugs, DEX and UTI, against VCR-induced neuropathic pain. The results provide a potential target and novel drug administrated method for the clinical treatment of chemotherapy-induced peripheral neuropathic pain. Copyright © 2017 American Pain Society. Published by Elsevier Inc. All rights reserved.

  7. Tempol Ameliorates and Prevents Mechanical Hyperalgesia in a Rat Model of Chemotherapy-Induced Neuropathic Pain

    PubMed Central

    Kim, Hee Kee; Hwang, Seon-Hee; Abdi, Salahadin

    2017-01-01

    Chemotherapy-induced neuropathic pain is difficult to treat and prevent. Tempol decreases cellular superoxide radical levels and oxidative stress. The aims of our study were to investigate the analgesic and preventive effects of tempol on paclitaxel-induced neuropathic pain in rats and to identify the associated mechanisms of action. Neuropathic pain was induced with intraperitoneally injected paclitaxel on four alternate days in male Sprague–Dawley rats. Tempol was administered systemically as a single injection and a continuous infusion before or after the injection of paclitaxel. The mechanical threshold for allodynia, protein levels, and free radical levels were measured using von Frey filaments, Western blotting, and live cell imaging, respectively. After the rats developed neuropathic pain behavior, a single intraperitoneal injection and continuous infusion of tempol ameliorated paclitaxel-induced mechanical allodynia. Systemic infusion of tempol in the early phase of the development of pain behavior prevented the development of paclitaxel-induced pain behavior. Paclitaxel increased the levels of phosphorylated protein kinase C, phosphorylated nuclear factor κB, phosphodiesterase 4D (PDE4D), IL-1β, and monocyte chemoattractant protein-1 in the lumbar dorsal root ganglia; however, tempol decreased these levels. Paclitaxel also increased superoxide levels in a culture of primary dorsal root ganglion cells and tempol decreased these levels. In conclusion, tempol alleviates and prevents chemotherapy-induced neuropathic pain in rats by reducing the levels of inflammatory cytokines and free radicals in dorsal root ganglia. PMID:28138318

  8. The Molecular and Pharmacological Mechanisms of HIV-Related Neuropathic Pain

    PubMed Central

    Hao, Shuanglin

    2013-01-01

    Infection of the nervous system with the human immunodeficiency virus (HIV-1) can lead to cognitive, motor and sensory disorders. HIV-related sensory neuropathy (HIV-SN) mainly contains the HIV infection-related distal sensory polyneuropathy (DSP) and antiretroviral toxic neuropathies (ATN). The main pathological features that characterize DSP and ATN include retrograde (“dying back”) axonal degeneration of long axons in distal regions of legs or arms, loss of unmyelinated fibers, and variable degree of macrophage infiltration in peripheral nerves and dorsal root ganglia (DRG). One of the most common complaints of HIV-DSP is pain. Unfortunately, many conventional agents utilized as pharmacologic therapy for neuropathic pain are not effective for providing satisfactory analgesia in painful HIV-related distal sensory polyneuropathy, because the molecular mechanisms of the painful HIV-SDP are not clear in detail. The HIV envelope glycoprotein, gp120, appears to contribute to this painful neuropathy. Recently, preclinical studies have shown that glia activation in the spinal cord and DRG has become an attractive target for attenuating chronic pain. Cytokines/chemokines have been implicated in a variety of painful neurological diseases and in animal models of HIV-related neuropathic pain. Mitochondria injured by ATN and/or gp120 may be also involved in the development of HIV-neuropathic pain. This review discusses the neurochemical and pharmacological mechanisms of HIV-related neuropathic pain based on the recent advance in the preclinical studies, providing insights into novel pharmacological targets for future therapy. PMID:24403874

  9. Pain-related evoked potentials after intraepidermal electrical stimulation to Aδ and C fibers in patients with neuropathic pain.

    PubMed

    Omori, Shigeki; Isose, Sagiri; Misawa, Sonoko; Watanabe, Keisuke; Sekiguchi, Yukari; Shibuya, Kazumoto; Beppu, Minako; Amino, Hiroshi; Kuwabara, Satoshi

    2017-03-18

    Neuropathic pain can result from neuronal hyperexcitability and complex interactions of the nociceptive pathways. Intraepidermal electrical stimulation (IES) is a novel technique that can selectively activate Aδ and C fibers. To investigate patterns of changes in Aδ- and C-mediated brain responses in patients with neuropathic pain using IES, we recorded pain-related evoked potential (PREP) after IES of Aδ and C fibers in 20 patients with neuropathic pain and 15 age-matched healthy volunteers. We evaluated PREP latencies, amplitudes, and amplitude ratios of PREPs after C/Aδ-fiber stimulation. PREP amplitudes after Aδ-fiber stimulation tended to be smaller in the patient group, whereas there were no significant differences in amplitudes after C-fiber stimulation between the patient and normal control groups. PREP amplitude ratios after C/Aδ-fiber stimulation were significantly greater in the patient group than in the control group, and the higher ratio tended to be associated with a greater visual analog scale score. Patients with neuropathic pain had a tendency towards decreased Aδ amplitudes and significantly increased C/Aδ PREP amplitude ratios and this ratio appeared to be associated with the intensity of pain. Our findings suggest that decreased inhibition of the Aδ to C nociceptive systems is associated with generation of neuropathic pain.

  10. 5% Lidocaine-medicated plaster for the treatment of chronic peripheral neuropathic pain: complex regional pain syndrome and other neuropathic conditions

    PubMed Central

    Calderón, Enrique; Calderón-Seoane, María Eloísa; García-Hernández, Rafael; Torres, Luis Miguel

    2016-01-01

    Objectives Chronic neuropathic pain and chronic complex regional pain syndrome (CRPS), in particular, are debilitating and difficult-to-treat conditions that have a strong impact on patient’s quality of life. The aim of this study was to evaluate the effectiveness of 5% lidocaine-medicated plaster as add-on therapy in patients with chronic peripheral neuropathic pain conditions, including CRPS. Patients and methods This was a single-center, prospective, observational study set in a specialized pain unit of a tertiary hospital in Spain. A total of 56 patients with long-standing peripheral neuropathic pain, ten of them with CRPS, received 5% lidocaine-medicated plaster as add-on analgesic therapy for 6 months. Results After 6 months of treatment, a ≥50% reduction in pain intensity was attained by 75% of patients, as measured by numeric rating scale (NRS) for pain. The average NRS score was reduced by 61% (4.7 points), from a baseline mean score of 7.8 to an end point mean score of 3.1. Marked improvements were also observed in the CRPS group: six out of ten patients achieved a ≥50% reduction in NRS score, and the average NRS score for patients with CRPS was reduced by 51% (4.0 points), from a baseline mean score of 7.9 to an end point mean score of 3.9. The improvements in pain intensity were partially translated into a decrease in disability index and in anxiety levels. Conclusion 5% Lidocaine-medicated plaster may be useful as add-on therapy for a number of peripheral neuropathic pain conditions, including CRPS. PMID:27785090

  11. 5% Lidocaine-medicated plaster for the treatment of chronic peripheral neuropathic pain: complex regional pain syndrome and other neuropathic conditions.

    PubMed

    Calderón, Enrique; Calderón-Seoane, María Eloísa; García-Hernández, Rafael; Torres, Luis Miguel

    2016-01-01

    Chronic neuropathic pain and chronic complex regional pain syndrome (CRPS), in particular, are debilitating and difficult-to-treat conditions that have a strong impact on patient's quality of life. The aim of this study was to evaluate the effectiveness of 5% lidocaine-medicated plaster as add-on therapy in patients with chronic peripheral neuropathic pain conditions, including CRPS. This was a single-center, prospective, observational study set in a specialized pain unit of a tertiary hospital in Spain. A total of 56 patients with long-standing peripheral neuropathic pain, ten of them with CRPS, received 5% lidocaine-medicated plaster as add-on analgesic therapy for 6 months. After 6 months of treatment, a ≥50% reduction in pain intensity was attained by 75% of patients, as measured by numeric rating scale (NRS) for pain. The average NRS score was reduced by 61% (4.7 points), from a baseline mean score of 7.8 to an end point mean score of 3.1. Marked improvements were also observed in the CRPS group: six out of ten patients achieved a ≥50% reduction in NRS score, and the average NRS score for patients with CRPS was reduced by 51% (4.0 points), from a baseline mean score of 7.9 to an end point mean score of 3.9. The improvements in pain intensity were partially translated into a decrease in disability index and in anxiety levels. 5% Lidocaine-medicated plaster may be useful as add-on therapy for a number of peripheral neuropathic pain conditions, including CRPS.

  12. Neuropathic pain: an updated grading system for research and clinical practice

    PubMed Central

    Finnerup, Nanna B.; Haroutounian, Simon; Kamerman, Peter; Baron, Ralf; Bennett, David L.H.; Bouhassira, Didier; Cruccu, Giorgio; Freeman, Roy; Hansson, Per; Nurmikko, Turo; Raja, Srinivasa N.; Rice, Andrew S.C.; Serra, Jordi; Smith, Blair H.; Treede, Rolf-Detlef; Jensen, Troels S.

    2016-01-01

    Abstract The redefinition of neuropathic pain as “pain arising as a direct consequence of a lesion or disease affecting the somatosensory system,” which was suggested by the International Association for the Study of Pain (IASP) Special Interest Group on Neuropathic Pain (NeuPSIG) in 2008, has been widely accepted. In contrast, the proposed grading system of possible, probable, and definite neuropathic pain from 2008 has been used to a lesser extent. Here, we report a citation analysis of the original NeuPSIG grading paper of 2008, followed by an analysis of its use by an expert panel and recommendations for an improved grading system. As of February, 2015, 608 eligible articles in Scopus cited the paper, 414 of which cited the neuropathic pain definition. Of 220 clinical studies citing the paper, 56 had used the grading system. The percentage using the grading system increased from 5% in 2009 to 30% in 2014. Obstacles to a wider use of the grading system were identified, including (1) questions about the relative significance of confirmatory tests, (2) the role of screening tools, and (3) uncertainties about what is considered a neuroanatomically plausible pain distribution. Here, we present a revised grading system with an adjusted order, better reflecting clinical practice, improvements in the specifications, and a word of caution that even the “definite” level of neuropathic pain does not always indicate causality. In addition, we add a table illustrating the area of pain and sensory abnormalities in common neuropathic pain conditions and propose areas for further research. PMID:27115670

  13. Interferon-γ Is a Critical Modulator of CB2 Cannabinoid Receptor Signaling during Neuropathic Pain

    PubMed Central

    Racz, Ildiko; Nadal, Xavier; Alferink, Judith; Baños, Josep E.; Rehnelt, Jennifer; Martín, Miquel; Pintado, Belén; Gutierrez-Adan, Alfonso; Sanguino, Elena; Bellora, Nicolas; Manzanares, Jorge

    2008-01-01

    Nerve injuries often lead to neuropathic pain syndrome. The mechanisms contributing to this syndrome involve local inflammatory responses, activation of glia cells, and changes in the plasticity of neuronal nociceptive pathways. Cannabinoid CB2 receptors contribute to the local containment of neuropathic pain by modulating glial activation in response to nerve injury. Thus, neuropathic pain spreads in mice lacking CB2 receptors beyond the site of nerve injury. To further investigate the mechanisms leading to the enhanced manifestation of neuropathic pain, we have established expression profiles of spinal cord tissues from wild-type and CB2-deficient mice after nerve injury. An enhanced interferon-γ (IFN-γ) response was revealed in the absence of CB2 signaling. Immunofluorescence stainings demonstrated an IFN-γ production by astrocytes and neurons ispilateral to the nerve injury in wild-type animals. In contrast, CB2-deficient mice showed neuronal and astrocytic IFN-γ immunoreactivity also in the contralateral region, thus matching the pattern of nociceptive hypersensitivity in these animals. Experiments in BV-2 microglia cells revealed that transcriptional changes induced by IFN-γ in two key elements for neuropathic pain development, iNOS (inducible nitric oxide synthase) and CCR2, are modulated by CB2 receptor signaling. The most direct support for a functional involvement of IFN-γ as a mediator of CB2 signaling was obtained with a double knock-out mouse strain deficient in CB2 receptors and IFN-γ. These animals no longer show the enhanced manifestations of neuropathic pain observed in CB2 knock-outs. These data clearly demonstrate that the CB2 receptor-mediated control of neuropathic pain is IFN-γ dependent. PMID:19005078

  14. Lysophosphatidic acid receptors (LPARs): Potential targets for the treatment of neuropathic pain.

    PubMed

    Velasco, María; O'Sullivan, Catherine; Sheridan, Graham K

    2017-02-01

    Neuropathic pain can arise from lesions to peripheral or central nerve fibres leading to spontaneous action potential generation and a lowering of the nociceptive threshold. Clinically, neuropathic pain can manifest in many chronic disease states such as cancer, diabetes or multiple sclerosis (MS). The bioactive lipid, lysophosphatidic acid (LPA), via activation of its receptors (LPARs), is thought to play a central role in both triggering and maintaining neuropathic pain. In particular, following an acute nerve injury, the excitatory neurotransmitters glutamate and substance P are released from primary afferent neurons leading to upregulated synthesis of lysophosphatidylcholine (LPC), the precursor for LPA production. LPC is converted to LPA by autotaxin (ATX), which can then activate macrophages/microglia and modulate neuronal functioning. A ubiquitous feature of animal models of neuropathic pain is demyelination of damaged nerves. It is thought that LPA contributes to demyelination through several different mechanisms. Firstly, high levels of LPA are produced following macrophage/microglial activation that triggers a self-sustaining feed-forward loop of de novo LPA synthesis. Secondly, macrophage/microglial activation contributes to inflammation-mediated demyelination of axons, thus initiating neuropathic pain. Therefore, targeting LPA production and/or the family of LPA-activated G protein-coupled receptors (GPCRs) may prove to be fruitful clinical approaches to treating demyelination and the accompanying neuropathic pain. This review discusses our current understanding of the role of LPA/LPAR signalling in the initiation of neuropathic pain and suggests potential targeted strategies for its treatment. This article is part of the Special Issue entitled 'Lipid Sensing G Protein-Coupled Receptors in the CNS'. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. N-palmitoylethanolamide in the treatment of neuropathic pain associated with lumbosciatica.

    PubMed

    Domínguez, C Morera; Martín, A Díaz; Ferrer, F Garibo; Puertas, Ma Ibáñez; Muro, A Leal; González, Jc Martí; Prieto, J Pombo; Taberna, I Rosselló

    2012-03-01

    SUMMARY  To investigate the effectiveness of N-palmitoylethanolamide (PEA) in the treatment of neuropathic pain due to lumbosciatica. Patients with neuropathic pain were assigned to standard treatment plus PEA (600 mg/day) or standard treatment for 30 days. Changes in visual analog scale, and score on Oswestry Disability Index and SF-12® Health Survey were assessed at baseline and follow-up. The mean age of the 118 patients evaluated was 48.4 years, and 47 (40.9%) were women. In the group comparison, significantly larger improvements were seen in the PEA group for visual analog scale and the physical component of the SF-12 Health Survey. The addition of PEA to standard treatment shows an improvement in pain relief in patients with neuropathic pain due to lumbosciatica. PEA was well tolerated. Future investigations of the role of PEA in the treatment of neuropathic pain might help to define novel therapeutic strategies for the treatment of this kind of neuropathic pain.

  16. Recent data on cannabinoids and their pharmacological implications in neuropathic pain.

    PubMed

    Coman, Oana Andreia; Paunescu, Horia; Coman, Laurentiu; Badarau, Anca; Fulga, Ion

    2008-01-01

    Natural cannabinoids have been used for centuries for their psychotropic properties, but their possible therapeutic implications in analgesia have been recently documented. The present review intended to make an analysis of the neuroanatomy and physiology of the cannabinoid system (receptors, functions, agents acting on these receptors) and of its implications in neuropathic pain. There were also described the complex phenomena implicated in the generation and maintenance of neuropathic pain, by high lightening the implications of endogenous cannabinoids in this complex of painful conditions. The pharmacological analgesia test proves of cannabinoid implication in neuropathic pain was sustained by many studies presented in this paper. Therapeutic approaches using natural and synthetic cannabinoid receptor agonists were reviewed. Therapeutic perspectives in neuropathic pain might involve the development of new agents that influence the cannabinoid system. Thus, peripheral acting cannabinoid 1 receptors agonists, selective cannabinoid 2 receptor agonists and also modulators of endocannabinoids metabolism might be a way to success in the treatment of this complex entity called neuropathic pain.

  17. Identification of an adenylyl cyclase inhibitor for treating neuropathic and inflammatory pain.

    PubMed

    Wang, Hansen; Xu, Hui; Wu, Long-Jun; Kim, Susan S; Chen, Tao; Koga, Kohei; Descalzi, Giannina; Gong, Bo; Vadakkan, Kunjumon I; Zhang, Xuehan; Kaang, Bong-Kiun; Zhuo, Min

    2011-01-12

    Neuropathic pain, often caused by nerve injury, is commonly observed among patients with different diseases. Because its basic mechanisms are poorly understood, effective medications are limited. Previous investigations of basic pain mechanisms and drug discovery efforts have focused mainly on early sensory neurons such as dorsal root ganglion and spinal dorsal horn neurons, and few synaptic-level studies or new drugs are designed to target the injury-related cortical plasticity that accompanies neuropathic pain. Our previous work has demonstrated that calcium-stimulated adenylyl cyclase 1 (AC1) is critical for nerve injury-induced synaptic changes in the anterior cingulate cortex. Through rational drug design and chemical screening, we have identified a lead candidate AC1 inhibitor, NB001, which is relatively selective for AC1 over other adenylate cyclase isoforms. Using a variety of behavioral tests and toxicity studies, we have found that NB001, when administered intraperitoneally or orally, has an analgesic effect in animal models of neuropathic pain, without any apparent side effects. Our study thus shows that AC1 could be a productive therapeutic target for neuropathic pain and describes a new agent for the possible treatment of neuropathic pain.

  18. TNFα is involved in neuropathic pain induced by nucleoside reverse transcriptase inhibitor in rats.

    PubMed

    Zheng, Xuexing; Ouyang, Handong; Liu, Shue; Mata, Marina; Fink, David J; Hao, Shuanglin

    2011-11-01

    In patients with HIV/AIDS, neuropathic pain is a common neurological complication. Infection with the HIV itself may lead to neuropathic pain, and painful symptoms are enhanced when patients are treated with nucleoside reverse transcriptase inhibitors (NRTIs). The mechanisms by which NRTIs contribute to the development of neuropathic pain are not known. In the current studies, we tested the role of TNFα in antiretroviral drug-induced neuropathic pain. We administered 2',3'-dideoxycytidine (ddC, one of the NRTIs) systemically to induce mechanical allodynia. We found that ddC induced overexpression of both mRNA and proteins of GFAP and TNFα in the spinal dorsal horn. TNFα was colocalized with GFAP in the spinal dorsal horn and with NeuN in the DRG. Knockdown of TNFα with siRNA blocked the mechanical allodynia induced by ddC. Intrathecal administration of glial inhibitor or recombinant TNF soluble receptor, reversed mechanical allodynia induced by ddC. These results suggest that TNFα is involved in NRTI-induced neuropathic pain. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. Antinociceptive effects of amiloride and benzamil in neuropathic pain model rats.

    PubMed

    Jeong, Seongtae; Lee, Seong Heon; Kim, Yeo Ok; Yoon, Myung Ha

    2013-08-01

    Amiloride and benzamil showed antinocicepitve effects in several pain models through the inhibition of acid sensing ion channels (ASICs). However, their role in neuropathic pain has not been investigated. In this study, we investigated the effect of the intrathecal amiloride and benzamil in neuropathic pain model, and also examined the role of ASICs on modulation of neuropathic pain. Neuropathic pain was induced by L4-5 spinal nerve ligation in male Sprague-Dawley rats weighing 100-120 g, and intrathecal catheterization was performed for drug administration. The effects of amiloride and benzamil were measured by the paw-withdrawal threshold to a mechanical stimulus using the up and down method. The expression of ASICs in the spinal cord dorsal horn was also analyzed by RT-PCR. Intrathecal amiloride and benzamil significantly increased the paw withdrawal threshold in spinal nerve-ligated rats (87%±12% and 76%±14%, P=0.007 and 0.012 vs vehicle, respectively). Spinal nerve ligation increased the expression of ASIC3 in the spinal cord dorsal horn (P=0.01), and this increase was inhibited by both amiloride and benzamil (P<0.001 in both). In conclusion, intrathecal amiloride and benzamil display antinociceptive effects in the rat spinal nerve ligation model suggesting they may present an alternative pharmacological tool in the management of neuropathic pain at the spinal level.

  20. [Altered expression of transporter and analgesic of morphine in neuropathic pain mice].

    PubMed

    Ochiai, Wataru; Sugiyama, Kiyoshi

    2015-01-01

    It is known that morphine is less effective for patients with neuropathic pain, accounting for approximately 70% of cancer patients with severe pain. One of the causes of the decline is reported as a decreased function of the μ-opioid receptor, which binds to the active metabolites of morphine in the mesencephalic ventral tegmental area. However, the details of this mechanism are not understood. We hypothesized that a decrease in the concentration of morphine in the brain reduces its analgesic effect on neuropathic pain, and found that the analgesic effect of morphine was correlated with its concentration in the brain. We examined the reason for the decreased concentration of morphine in the brain in case of neuropathic pain. We discovered increased P-glycoprotein (P-gp) expression in the small intestine, increased expression and activity of UGT2B in the liver, and increased P-gp expression in the brain under conditions of neuropathic pain. In this symposium, we argue that low brain morphine concentration is considered one of the causes of lower sensitivity to morphine in neuropathic pain patients.

  1. Intrathecal siRNA against GPNMB attenuates nociception in a rat model of neuropathic pain.

    PubMed

    Hou, Lili; Zhang, Yanfeng; Yang, Yong; Xiang, Kai; Tan, Qindong; Guo, Qulian

    2015-02-01

    Neuropathic pain is characterized by hyperalgesia, allodynia, and spontaneous pain. Recent studies have shown that glycoprotein nonmetastatic melanoma B (GPNMB) plays a pivotal role in neuronal survival and neuroprotection. However, the role of GPNMB in neuropathic pain remains unknown. The aim of the present study was to assess the role of GPNMB in neuropathic pain. In cultured spinal cord neurons, we used two small interfering RNAs (siRNAs) targeting the complementary DNA (cDNA) sequence of rat GPNMB that had potent inhibitory effects on GPNMB, and siRNA1-GPNMB was selected for further in vivo study as it had the higher inhibitory effect. After sciatic nerve injury in rats, the endogenous level of GPNMB was increased in a time-dependent manner in the spinal cord. Furthermore, the intrathecal injection of siRNA1-GPNMB inhibited the expression of GPNMB and pro-inflammatory factors (TNF-α, IL-1β, and IL-6) and alleviated mechanical allodynia and thermal hyperalgesia in the chronic constriction injury (CCI) model of rats. Taken together, our findings suggest that siRNA against GPNMB can alleviate the chronic neuropathic pain caused by CCI, and this effect may be mediated by attenuated expression of TNF-α, IL-1β, and IL-6 in the spinal cord of CCI rats. Therefore, inhibition of GPNMB may provide a novel strategy for the treatment of neuropathic pain.

  2. What is the efficacy of physical therapeutics for treating neuropathic pain in spinal cord injury patients?

    PubMed

    Fattal, C; Kong-A-Siou, D; Gilbert, C; Ventura, M; Albert, T

    2009-03-01

    Evaluate the place and level of proof of physical therapeutics for treating neuropathic pain in spinal cord injury (SCI) patients. Literature review from three databases: PubMed, Embase, Pascal. The following keywords were selected: chronic neuropathic pain/non-pharmacological treatment; transcutaneous electrical nerve stimulation, physiotherapy, acupuncture, physical therapy, transcranial magnetic stimulation, heat therapy, ice therapy, cold therapy, massage, ultrasound, alternative treatment, complementary treatment, occupational therapy. The articles were analyzed using the double-reading mode. Three techniques emerge from the literature: magnetic or electrical transcranial stimulation, transcutaneous electrical nerve stimulation and acupuncture. Even though the first method is not easily accessible on a daily basis it is the one that yields the most promising results validated by Grade B studies. Healthcare professionals remain faithful to pain-relieving transcutaneous neurostimulation for both segmental neuropathic pain and below-level central neuropathic pain. Acupuncture is advocated by Canadian teams and could offer some interesting options; however, to this day, it does not have the methodological support and framework required to validate its efficacy. All other physical therapies are used in a random way. Only below-level massages are advocated by the patients themselves. To this day, no study can validate the integration of physical therapy as part of the array of therapeutics used for treating neuropathic pain in SCI patients. In the future, it will require controlled and randomized therapeutic studies on homogenous groups of SCI patients, to control the various confusion factors.

  3. Maintaining efficacy in the treatment of diabetic peripheral neuropathic pain: role of duloxetine

    PubMed Central

    Zilliox, Lindsay; Russell, James W

    2010-01-01

    Introduction Neuropathy is one of the most frequent complications of diabetes. Of all the symptoms associated with diabetic neuropathy, pain has the largest impact on sleep and quality of life. In the past few years further medications have been added to the available therapies for neuropathic pain. One of these medications, duloxetine hydrochloride (duloxetine), is a balanced and potent selective serotonin and norepinephrine reuptake inhibitor. Methods Medline was searched from January 2005 to September 2009 using the key words duloxetine and peripheral neuropathy for clinical trials limited to human research published in English and duloxetine and pharmacology in the nervous system. Results Duloxetine has been shown to effectively reduce diabetic peripheral neuropathic pain compared to placebo at doses of 60 mg/day and 120 mg/day with minimal to moderate side effects. This effect is seen with minimal effects on glycemic control and without any clinically relevant effects on lipid control, or cardiovascular parameters. In addition, its efficacy and tolerability is comparable to other medications commonly used in the management of neuropathic pain. Furthermore, duloxetine performs favorably both in terms of quality of life and in cost utility analyses. Discussion and conclusion This article reviewed the issues related to management of diabetic peripheral neuropathic pain, the pharmacology and rationale for use of duloxetine, efficacy studies, and the safety and tolerability of treatment with duloxetine. Duloxetine is an acceptable initial or alternative treatment for patients with diabetic neuropathic pain. PMID:21437071

  4. 5% lidocaine medicated plaster double effect in a case of orofacial localized neuropathic pain

    PubMed Central

    Casale, Roberto; Romanenko, Yuriy; Allegri, Massimo

    2014-01-01

    Localized neuropathic pain (LNP) is a type of neuropathic pain that is characterized by “consistent and limited area(s) of maximum pain associated with negative or positive sensory signs and/or spontaneous symptoms characteristic of neuropathic pain”. This definition encompasses a huge number of neuropathic orofacial pain syndromes. We present a case report of a patient who was affected with sleep apnea syndrome treated with nocturnal oxygen mask delivery, in whom orofacial LNP hampered the wearing of a mask due to unbearable burning and throbbing pain. The application of 5% lidocaine medicated plaster during the night led to an impressive reduction of both the pain level and the size of the painful area due to the plaster’s pharmacological mechanisms, which were associated with a secondary benefit due to its mechanical protective action. This case report shows how these two factors could be of clinical value and have to be considered more systematically in the treatment of LNP in reducing pain and the size of the painful area. PMID:25473307

  5. Platelet-Derived Growth Factor Receptor-β Antagonism Restores Morphine Analgesic Potency against Neuropathic Pain

    PubMed Central

    Donica, Courtney L.; Cui, Yan; Shi, Shanping; Gutstein, Howard B.

    2014-01-01

    Background Chronic, intractable pain is a problem of pandemic proportions. Pain caused by nerve injuries (neuropathic pain) is extremely difficult to treat. For centuries, opiates such as morphine have been the first-line treatment for severe chronic pain. However, opiates are often ineffective against neuropathic pain, leaving few options for suffering patients. We previously demonstrated that platelet-derived growth factor- β (PDGFR-β) inhibition completely eliminated morphine tolerance. In these studies, we determined whether PDGFR-β inhibition could improve the effectiveness of morphine for neuropathic pain treatment. Results and Findings Spinal nerve ligation was performed in male Sprague-Dawley rats. The clinically used PDGFR antagonist imatinib did not relieve mechanical pain in a nerve injury model as determined by Von Frey assay. Surprisingly, combining imatinib with a previously ineffective dose of morphine led to complete pain relief. Scavenging released PDGF-B also markedly augmented the analgesic effect of morphine. Conclusions These findings suggest the novel hypothesis that PDGF-B released by injured nerves renders animals resistant to morphine, implying that PDGFR-β inhibition could potentially eliminate the tremendous suffering caused by neuropathic pain. PMID:24820332

  6. Towards a definition of refractory neuropathic pain for epidemiological research. An international Delphi survey of experts

    PubMed Central

    2012-01-01

    Background Best current estimates of neuropathic pain (NeuP) prevalence come from studies using various screening detecting pain with probable neuropathic features; the proportion experiencing significant, long-term NeuP, and the proportion not responding to standard treatment are unknown. These “refractory” cases are the most clinically important to detect, being the most severe, requiring specialist treatment. Methods We report an international Delphi survey of experts in NeuP, aiming for consensus on the features required to define, for epidemiological research: (1) neuropathic pain; and (2) when NeuP is “refractory”. A web-based questionnaire was developed and data collected from three rounds of questionnaires from nineteen experts. Results There was good consensus on essential inclusion of six items to identify NeuP (“prickling, tingling, pins & needles”, “pain evoked by light touch”, “electric shocks or shooting pain”, “hot or burning” pain, “brush allodynia on self-examination”, and “relevant history”) and on some items that were non-essential. Consensus was also reached on components of a “refractory NeuP” definition: minimum duration (one year); number of trials of drugs of known effectiveness (four); adequate duration of these trials (three months / maximum tolerated); outcomes of treatment (pain severity, quality of life). Further work needs to validate these proposed criteria in general population research. Conclusions This paper presents an international consensus on measuring the epidemiology of refractory neuropathic pain. This will be valuable in reaching an agreed estimate of the prevalence of neuropathic pain, and the first estimate of refractory neuropathic pain prevalence. PMID:22640002

  7. Quantitative sensory testing in the German Research Network on Neuropathic Pain (DFNS): somatosensory abnormalities in 1236 patients with different neuropathic pain syndromes.

    PubMed

    Maier, C; Baron, R; Tölle, T R; Binder, A; Birbaumer, N; Birklein, F; Gierthmühlen, J; Flor, H; Geber, C; Huge, V; Krumova, E K; Landwehrmeyer, G B; Magerl, W; Maihöfner, C; Richter, H; Rolke, R; Scherens, A; Schwarz, A; Sommer, C; Tronnier, V; Uçeyler, N; Valet, M; Wasner, G; Treede, R-D

    2010-09-01

    Neuropathic pain is accompanied by both positive and negative sensory signs. To explore the spectrum of sensory abnormalities, 1236 patients with a clinical diagnosis of neuropathic pain were assessed by quantitative sensory testing (QST) following the protocol of DFNS (German Research Network on Neuropathic Pain), using both thermal and mechanical nociceptive as well as non-nociceptive stimuli. Data distributions showed a systematic shift to hyperalgesia for nociceptive, and to hypoesthesia for non-nociceptive parameters. Across all parameters, 92% of the patients presented at least one abnormality. Thermosensory or mechanical hypoesthesia (up to 41%) was more frequent than hypoalgesia (up to 18% for mechanical stimuli). Mechanical hyperalgesias occurred more often (blunt pressure: 36%, pinprick: 29%) than thermal hyperalgesias (cold: 19%, heat: 24%), dynamic mechanical allodynia (20%), paradoxical heat sensations (18%) or enhanced wind-up (13%). Hyperesthesia was less than 5%. Every single sensory abnormality occurred in each neurological syndrome, but with different frequencies: thermal and mechanical hyperalgesias were most frequent in complex regional pain syndrome and peripheral nerve injury, allodynia in postherpetic neuralgia. In postherpetic neuralgia and in central pain, subgroups showed either mechanical hyperalgesia or mechanical hypoalgesia. The most frequent combinations of gain and loss were mixed thermal/mechanical loss without hyperalgesia (central pain and polyneuropathy), mixed loss with mechanical hyperalgesia in peripheral neuropathies, mechanical hyperalgesia without any loss in trigeminal neuralgia. Thus, somatosensory profiles with different combinations of loss and gain are shared across the major neuropathic pain syndromes. The characterization of underlying mechanisms will be needed to make a mechanism-based classification feasible. Copyright (c) 2010 International Association for the Study of Pain. Published by Elsevier B.V. All rights

  8. The painDETECT project - far more than a screening tool on neuropathic pain.

    PubMed

    Freynhagen, Rainer; Tölle, Thomas R; Gockel, Ulrich; Baron, Ralf

    2016-06-01

    Background and objectives The painDETECT questionnaire (PD-Q), a simple and reliable screening questionnaire of neuropathic pain, was developed in 2004 in cooperation with the German Research Network on Neuropathic Pain. The initial aim was to implement quality management and to improve the situation of neuropathic pain (NeP) patients in Germany. The PD-Q proved immediately successful and was translated into and validated in multiple languages. Subsequently a comprehensive electronic system (PD) comprising various validated questionnaires with regard to pain typical comorbidities, such as function, sleep, mood or anxiety, was implemented Germany wide. We aimed to provide a comprehensive overview about the development and validation as well as the application of the PD-Q in various clinical conditions. Methods This overview is based on a literature search on English full-text papers using the term 'painDETECT' in Medline and PubMed covering the time period from 2006 to September 2015, amended with further publications cited in the retrieved publications or provided by the questionnaire developers. Results PD-Q as screening tool for NeP described in patients with lower back pain (8 studies), rheumatoid arthritis and osteoarthritis (10), thoracotomy (2 studies), tumor diseases (4 studies), fibromyalgia (4 studies), diverse musculoskeletal conditions (12 studies) and diverse other conditions (10 studies). In addition, the PD-Q was used in 9 studies that investigated the effect of drugs for the treatment of patients with a NeP component. Conclusion To date more than 300,000 patients were assessed, providing the basis for one of the world's largest datasets for chronic pain. Among others the extensive pool of PD-Q data triggered the idea of subgrouping patients on the basis of their individual sensory profiles which might in the future lead to a stratified treatment approach and ultimately to personalized therapy. Started as a healthcare utilization project in Germany

  9. Safety and efficacy of prolonged outpatient ketamine infusions for neuropathic pain.

    PubMed

    Webster, Lynn R; Walker, Mary Jean

    2006-01-01

    Ketamine has demonstrated usefulness as an analgesic to treat nonresponsive neuropathic pain; however, it is not widely administered to outpatients due to fear of such side effects as hallucinations and other cognitive disturbances. This retrospective chart review is the first research to study the safety and efficacy of prolonged low-dose, continuous intravenous (IV) or subcutaneous ketamine infusions in noncancer outpatients. Thirteen outpatients with neuropathic pain were administered low-dose IV or subcutaneous ketamine infusions for up to 8 weeks under close supervision by home health care personnel. Using the 10-point verbal analog score (VAS), 11 of 13 patients (85%) reported a decrease in pain from the start of infusion treatment to the end. Side effects were minimal and not severe enough to deter treatment. Prolonged analgesic doses of ketamine infusions were safe for the small sample studied. The results demonstrate that ketamine may provide a reasonable alternative treatment for nonresponsive neuropathic pain in ambulatory outpatients.

  10. A Mangifera indica L. extract could be used to treat neuropathic pain and implication of mangiferin.

    PubMed

    Garrido-Suárez, Bárbara B; Garrido, Gabino; Delgado, Rene; Bosch, Fe; del C Rabí, María

    2010-12-09

    It has been accepted that neuroinflammation, oxidative stress and glial activation are involved in the central sensitization underlying neuropathic pain. Vimang is an aqueous extract of Mangifera indica L. traditionally used in Cuba for its analgesic, anti-inflammatory, antioxidant and immunomodulatory properties. Several formulations are available, and also for mangiferin, its major component. Preclinical studies demonstrated that these products prevented tumor necrosis factor α -induced IκB degradation and the binding of nuclear factor κB to DNA, which induces the transcription of genes implicated in the expression of some mediators and enzymes involved in inflammation, pain, oxidative stress and synaptic plasticity. In this paper we propose its potential utility in the neuropathic pain treatment. This hypothesis is supported in the cumulus of preclinical and clinical evidence around the extract and mangiferin, its major component, and speculates about the possible mechanism of action according to recent advances in the physiopathology of neuropathic pain.

  11. Relationship between electrodiagnostic severity and neuropathic pain assessed by the LANSS pain scale in carpal tunnel syndrome

    PubMed Central

    Gürsoy, Azize Esra; Kolukısa, Mehmet; Yıldız, Gülsen Babacan; Kocaman, Gülşen; Çelebi, Arif; Koçer, Abdülkadir

    2013-01-01

    Objective The aim of the study was to investigate the relationship between the presence of neuropathic pain assessed by the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) scale and electrophysiological findings in patients with carpal tunnel syndrome (CTS). Methods We studied 124 hands with idiopathic CTS with pain complaints involving hand and wrist. All hands were assessed by the LANSS with which a score of 12 or more is defined as pain dominated by neuropathic mechanisms. These hands were assigned to minimal, mild, moderate, severe, or extreme severe groups according to the results of the median nerve conduction studies. Results A LANSS score ≥ 12, suggestive of pain dominated by neuropathic mechanisms, was defined in 59 (47.6%) CTS hands. Pain intensity was significantly higher in CTS hands with a LANSS score ≥ 12 (P < 0.001). Among electrophysiological findings, compound muscle action potential amplitude was significantly lower in hands with a LANSS score ≥ 12 compared with hands with a LANSS score < 12 (P = 0.020). Severity of CTS was not significantly different between LANSS ≥ 12 and LANSS < 12 groups. Electrophysiological severity was significantly higher in CTS hands with evoked pain (P = 0.005) and allodynia (P < 0.001) in LANSS subscore analysis. Conclusion We suggest that the presence of pain dominated by neuropathic mechanisms in CTS is not related to electrophysiological CTS severity. Neuropathic pain should be assessed carefully in patients with CTS, and an appropriate treatment plan should be chosen, taking into account the clinical and electrophysiological findings together with the true pain classification. PMID:23326196

  12. Non-invasive Brain Stimulation, a Tool to Revert Maladaptive Plasticity in Neuropathic Pain

    PubMed Central

    Naro, Antonino; Milardi, Demetrio; Russo, Margherita; Terranova, Carmen; Rizzo, Vincenzo; Cacciola, Alberto; Marino, Silvia; Calabro, Rocco S.; Quartarone, Angelo

    2016-01-01

    Neuromodulatory effects of non-invasive brain stimulation (NIBS) have been extensively studied in chronic pain. A hypothetic mechanism of action would be to prevent or revert the ongoing maladaptive plasticity within the pain matrix. In this review, the authors discuss the mechanisms underlying the development of maladaptive plasticity in patients with chronic pain and the putative mechanisms of NIBS in modulating synaptic plasticity in neuropathic pain conditions. PMID:27512368

  13. Expression profiling of genes modulated by minocycline in a rat model of neuropathic pain

    PubMed Central

    2014-01-01

    Background The molecular mechanisms underlying neuropathic pain are constantly being studied to create new opportunities to prevent or alleviate neuropathic pain. The aim of our study was to determine the gene expression changes induced by sciatic nerve chronic constriction injury (CCI) that are modulated by minocycline, which can effectively diminish neuropathic pain in animal studies. The genes associated with minocycline efficacy in neuropathic pain should provide insight into the etiology of neuropathic pain and identify novel therapeutic targets. Results We screened the ipsilateral dorsal part of the lumbar spinal cord of the rat CCI model for differentially expressed genes. Out of 22,500 studied transcripts, the abundance levels of 93 transcripts were altered following sciatic nerve ligation. Percentage analysis revealed that 54 transcripts were not affected by the repeated administration of minocycline (30 mg/kg, i.p.), but the levels of 39 transcripts were modulated following minocycline treatment. We then selected two gene expression patterns, B1 and B2. The first transcription pattern, B1, consisted of 10 mRNA transcripts that increased in abundance after injury, and minocycline treatment reversed or inhibited the effect of the injury; the B2 transcription pattern consisted of 7 mRNA transcripts whose abundance decreased following sciatic nerve ligation, and minocycline treatment reversed the effect of the injury. Based on the literature, we selected seven genes for further analysis: Cd40, Clec7a, Apobec3b, Slc7a7, and Fam22f from pattern B1 and Rwdd3 and Gimap5 from pattern B2. Additionally, these genes were analyzed using quantitative PCR to determine the transcriptional changes strongly related to the development of neuropathic pain; the ipsilateral DRGs (L4-L6) were also collected and analyzed in these rats using qPCR. Conclusion In this work, we confirmed gene expression alterations previously identified by microarray analysis in the spinal cord and

  14. Traumatic peripheral nerve injuries: epidemiological findings, neuropathic pain and quality of life in 158 patients.

    PubMed

    Ciaramitaro, Palma; Mondelli, Mauro; Logullo, Francesco; Grimaldi, Serena; Battiston, Bruno; Sard, Arman; Scarinzi, Cecilia; Migliaretti, Giuseppe; Faccani, Giuliano; Cocito, Dario

    2010-06-01

    The objectives of this study were (1) epidemiological analysis of traumatic peripheral nerve injuries; (2) assessment of neuropathic pain and quality of life in patients affected by traumatic neuropathies. All consecutive patients with a diagnosis of traumatic neuropathies from four Italian centres were enrolled. Electromyography confirmed clinical level and site diagnosis of peripheral nerve injury. All patients were evaluated by disability scales, pain screening tools, and quality of life tests. 158 consecutive patients for a total of 211 traumatic neuropathies were analysed. The brachial plexus was a frequent site of traumatic injury (36%) and the radial, ulnar, and peroneal were the most commonly involved nerves with 15% of iatrogenic injuries. Seventy-two percent of the traumatic neuropathies were painful. Pain was present in 66% and neuropathic pain in 50% of all patients. Patients had worse quality of life scores than did the healthy Italian population. Moreover, there was a strong correlation between the quality of life and the severity of the pain, particularly neuropathic pain (Short Form-36 [SF-36] p < 0.005; Beck Depression Inventory [BDI] p < 0.0001). Traumatic neuropathies were more frequent in young males after road accidents, mainly in the upper limbs. Severe neuropathic pain and not only disability contributed to worsening the quality of life in patients with traumatic neuropathies.

  15. Micronized palmitoylethanolamide reduces the symptoms of neuropathic pain in diabetic patients.

    PubMed

    Schifilliti, Chiara; Cucinotta, Lelio; Fedele, Viviana; Ingegnosi, Carmela; Luca, Salvatore; Leotta, Carmelo

    2014-01-01

    The present study evaluated the effectiveness of micronized palmitoylethanolamide (PEA-m) treatment in reducing the painful symptoms experienced by diabetic patients with peripheral neuropathy. PEA-m, a fatty acid amide of the N-acylethanolamine family, was administered (300 mg twice daily) to 30 diabetic patients suffering from painful diabetic neuropathy. Before treatment start, after 30 and 60 days the following parameters were assessed: painful symptoms of diabetic peripheral neuropathy using the Michigan Neuropathy Screening instrument; intensity of symptoms characteristic of diabetic neuropathic pain by the Total Symptom Score; and intensity of different subcategories of neuropathic pain by the Neuropathic Pain Symptoms Inventory. Hematological and blood chemistry tests to evaluate metabolic control and safety were also performed. Statistical analysis (ANOVA) indicated a highly significant reduction in pain severity (P < 0.0001) and related symptoms (P < 0.0001) evaluated by Michigan Neuropathy Screening instrument, Total Symptom Score, and Neuropathic Pain Symptoms Inventory. Hematological and urine analyses did not reveal any alterations associated with PEA-m treatment, and no serious adverse events were reported. These results suggest that PEA-m could be considered as a promising and well-tolerated new treatment for symptomatology experienced by diabetic patients suffering from peripheral neuropathy.

  16. Micronized Palmitoylethanolamide Reduces the Symptoms of Neuropathic Pain in Diabetic Patients

    PubMed Central

    Schifilliti, Chiara; Cucinotta, Lelio; Fedele, Viviana; Ingegnosi, Carmela; Luca, Salvatore; Leotta, Carmelo

    2014-01-01

    The present study evaluated the effectiveness of micronized palmitoylethanolamide (PEA-m) treatment in reducing the painful symptoms experienced by diabetic patients with peripheral neuropathy. PEA-m, a fatty acid amide of the N-acylethanolamine family, was administered (300 mg twice daily) to 30 diabetic patients suffering from painful diabetic neuropathy. Before treatment start, after 30 and 60 days the following parameters were assessed: painful symptoms of diabetic peripheral neuropathy using the Michigan Neuropathy Screening instrument; intensity of symptoms characteristic of diabetic neuropathic pain by the Total Symptom Score; and intensity of different subcategories of neuropathic pain by the Neuropathic Pain Symptoms Inventory. Hematological and blood chemistry tests to evaluate metabolic control and safety were also performed. Statistical analysis (ANOVA) indicated a highly significant reduction in pain severity (P < 0.0001) and related symptoms (P < 0.0001) evaluated by Michigan Neuropathy Screening instrument, Total Symptom Score, and Neuropathic Pain Symptoms Inventory. Hematological and urine analyses did not reveal any alterations associated with PEA-m treatment, and no serious adverse events were reported. These results suggest that PEA-m could be considered as a promising and well-tolerated new treatment for symptomatology experienced by diabetic patients suffering from peripheral neuropathy. PMID:24804094

  17. Role of PAR2 in regulating oxaliplatin-induced neuropathic pain via TRPA1.

    PubMed

    Tian, Liujun; Fan, Tianren; Zhou, Nan; Guo, Hui; Zhang, Weijie

    2015-01-01

    Oxaliplatin (OXL) is a third-generation chemotherapeutic agent commonly used to treat metastatic digestive tumors; however, one of the main limiting complications of OXL is neuropathic pain. In this study, the underlying mechanisms responsible for OXL evoked-neuropathic pain were examined. Using a rat model, the results demonstrated that intraperitoneal (i.p.) injection of OXL significantly increased mechanical pain and cold sensitivity as compared with control animals (P < 0.05 vs. control rats). Blocking proteinase-activated receptor 2 (PAR2) significantly attenuated mechanical pain and cold sensitivity observed in control rats and OXL rats (P < 0.05 vs. vehicle control). The attenuating effect of PAR2 on mechanical pain and cold sensitivity were significantly smaller in OXL-rats than in control rats. The role played by PAR2 downstream signaling pathways [namely, transient receptor potential ankyrin 1 (TRPA1)] in regulating OXL evoked-neuropathic pain was also examined. The data shows that TRPA1 expression was upregulated in the lumbar dorsal root ganglion (DRG) of OXL rats and blocking TRPA1 inhibited mechanical pain and heightened cold sensitivity (P < 0.05 vs. control rats). Blocking PAR2 also significantly decreased TRPA1 expression in the DRG. Findings in this study show that OXL intervention amplifies mechanical hyperalgesia and cold hypersensitivity and PAR2 plays an important role in regulating OXL-induced neuropathic pain via TRPA1 pathways.

  18. Ultrasound-Guided Nerve Block with Botulinum Toxin Type A for Intractable Neuropathic Pain

    PubMed Central

    Moon, Young Eun; Choi, Jung Hyun; Park, Hue Jung; Park, Ji Hye; Kim, Ji Hyun

    2016-01-01

    Neuropathic pain includes postherpetic neuralgia (PHN), painful diabetic neuropathy (PDN), and trigeminal neuralgia, and so on. Although various drugs have been tried to treat neuropathic pain, the effectiveness of the drugs sometimes may be limited for chronic intractable neuropathic pain, especially when they cannot be used at an adequate dose, due to undesirable severe side effects and the underlying disease itself. Botulinum toxin type A (BoNT-A) has been known for its analgesic effect in various pain conditions. Nevertheless, there are no data of nerve block in PHN and PDN. Here, we report two patients successfully treated with ultrasound-guided peripheral nerve block using BoNT-A for intractable PHN and PDN. One patient had PHN on the left upper extremity and the other patient had PDN on a lower extremity. Due to side effects of drugs, escalation of the drug dose could not be made. We injected 50 Botox units (BOTOX®, Allergan Inc., Irvine, CA, USA) into brachial plexus and lumbar plexus, respectively, under ultrasound. Their pain was significantly decreased for about 4–5 months. Ultrasound-guided nerve block with BoNT-A may be an effective analgesic modality in a chronic intractable neuropathic pain especially when conventional treatment failed to achieve adequate pain relief. PMID:26761032

  19. The antiallodynic action of pregabalin in neuropathic pain is independent from the opioid system.

    PubMed

    Kremer, Mélanie; Yalcin, Ipek; Nexon, Laurent; Wurtz, Xavier; Ceredig, Rhian Alice; Daniel, Dorothée; Hawkes, Rachael Aredhel; Salvat, Eric; Barrot, Michel

    2016-01-01

    Clinical management of neuropathic pain, which is pain arising as a consequence of a lesion or a disease affecting the somatosensory system, partly relies on the use of anticonvulsant drugs such as gabapentinoids. Therapeutic action of gabapentinoids such as gabapentin and pregabalin, which act by the inhibition of calcium currents through interaction with the α2δ-1 subunit of voltage-dependent calcium channels, is well documented. However, some aspects of the downstream mechanisms are still to be uncovered. Using behavioral, genetic, and pharmacological approaches, we tested whether opioid receptors are necessary for the antiallodynic action of acute and/or long-term pregabalin treatment in the specific context of neuropathic pain. Using the cuff model of neuropathic pain in mice, we show that acute pregabalin administration at high dose has a transitory antiallodynic action, while prolonged oral pregabalin treatment leads to sustained antiallodynic action, consistent with clinical observations. We show that pregabalin remains fully effective in μ-opioid receptor, in δ-opioid receptor and in κ-opioid receptor deficient mice, either female or male, and its antiallodynic action is not affected by acute naloxone. Our work also shows that long-term pregabalin treatment suppresses tumor necrosis factor-α overproduction induced by sciatic nerve constriction in the lumbar dorsal root ganglia. We demonstrate that neither acute nor long-term antiallodynic effect of pregabalin in a context of neuropathic pain is mediated by the endogenous opioid system, which differs from opioid treatment of pain and antidepressant treatment of neuropathic pain. Our data are also supportive of an impact of gabapentinoid treatment on the neuroimmune aspect of neuropathic pain. © The Author(s) 2016.

  20. The antiallodynic action of pregabalin in neuropathic pain is independent from the opioid system

    PubMed Central

    Yalcin, Ipek; Nexon, Laurent; Wurtz, Xavier; Ceredig, Rhian Alice; Daniel, Dorothée; Hawkes, Rachael Aredhel; Salvat, Eric; Barrot, Michel

    2016-01-01

    Background Clinical management of neuropathic pain, which is pain arising as a consequence of a lesion or a disease affecting the somatosensory system, partly relies on the use of anticonvulsant drugs such as gabapentinoids. Therapeutic action of gabapentinoids such as gabapentin and pregabalin, which act by the inhibition of calcium currents through interaction with the α2δ-1 subunit of voltage-dependent calcium channels, is well documented. However, some aspects of the downstream mechanisms are still to be uncovered. Using behavioral, genetic, and pharmacological approaches, we tested whether opioid receptors are necessary for the antiallodynic action of acute and/or long-term pregabalin treatment in the specific context of neuropathic pain. Results Using the cuff model of neuropathic pain in mice, we show that acute pregabalin administration at high dose has a transitory antiallodynic action, while prolonged oral pregabalin treatment leads to sustained antiallodynic action, consistent with clinical observations. We show that pregabalin remains fully effective in μ-opioid receptor, in δ-opioid receptor and in κ-opioid receptor deficient mice, either female or male, and its antiallodynic action is not affected by acute naloxone. Our work also shows that long-term pregabalin treatment suppresses tumor necrosis factor-α overproduction induced by sciatic nerve constriction in the lumbar dorsal root ganglia. Conclusions We demonstrate that neither acute nor long-term antiallodynic effect of pregabalin in a context of neuropathic pain is mediated by the endogenous opioid system, which differs from opioid treatment of pain and antidepressant treatment of neuropathic pain. Our data are also supportive of an impact of gabapentinoid treatment on the neuroimmune aspect of neuropathic pain. PMID:27030724

  1. Intravenous Ketamine Infusions for Neuropathic Pain Management: A Promising Therapy in Need of Optimization.

    PubMed

    Maher, Dermot P; Chen, Lucy; Mao, Jianren

    2017-02-01

    Intravenous ketamine infusions have been used extensively to treat often-intractable neuropathic pain conditions. Because there are many widely divergent ketamine infusion protocols described in the literature, the variation in these protocols presents a challenge for direct comparison of one protocol with another and in discerning an optimal protocol. Careful examination of the published literature suggests that ketamine infusions can be useful to treat neuropathic pain and that certain characteristics of ketamine infusions may be associated with better clinical outcomes. Increased duration of relief from neuropathic pain is associated with (1) higher total infused doses of ketamine; (2) prolonged infusion durations, although the rate of infusion does not appear to be a factor; and (3) coadministration of adjunct medications such as midazolam and/or clonidine that mitigate some of the unpleasant psychomimetic side effects. However, there are few studies designed to optimize ketamine infusion protocols by defining what an effective infusion protocol entails with regard to a respective neuropathic pain condition. Therefore, despite common clinical practice, the current state of the literature leaves the use of ketamine infusions without meaningful guidance from high-quality comparative evidence. The objectives of this topical review are to (1) analyze the available clinical evidence related to ketamine infusion protocols and (2) call for clinical studies to identify optimal ketamine infusion protocols tailored for individual neuropathic pain conditions. The Oxford Center for Evidence-Based Medicine classification for levels of evidence was used to stratify the grades of clinical recommendation for each infusion variable studied.

  2. A long noncoding RNA contributes to neuropathic pain by silencing Kcna2 in primary afferent neurons

    PubMed Central

    Zhao, Xiuli; Tang, Zongxiang; Zhang, Hongkang; Atianjoh, Fidelis E.; Zhao, Jian-Yuan; Liang, Lingli; Wang, Wei; Guan, Xiaowei; Kao, Sheng-Chin; Tiwari, Vinod; Gao, Yong-Jing; Hoffman, Paul N.; Cui, Hengmi; Li, Min; Dong, Xinzhong; Tao, Yuan-Xiang

    2013-01-01

    Neuropathic pain is a refractory disease characterized by maladaptive changes in gene transcription and translation within the sensory pathway. Long noncoding RNAs (lncRNAs) are emerging as new players in gene regulation, but how lncRNAs operate in the development of neuropathic pain is unclear. Here we identify a conserved lncRNA for Kcna2 (named Kcna2 antisense RNA) in first-order sensory neurons of rat dorsal root ganglion (DRG). Peripheral nerve injury increases Kcna2 antisense RNA expression in injured DRG through activation of myeloid zinc finger protein 1, a transcription factor that binds to Kcna2 antisense RNA gene promoter. Mimicking this increase downregulates Kcna2, reduces total Kv current, increases excitability in DRG neurons, and produces neuropathic pain symptoms. Blocking this increase reverses nerve injury-induced downregulation of DRG Kcna2 and attenuates development and maintenance of neuropathic pain. These findings suggest native Kcna2 antisense RNA as a new therapeutic target for the treatment of neuropathic pain. PMID:23792947

  3. Antiepileptic drugs for the treatment of neuropathic pain: A systematic review

    PubMed Central

    Vargas-Espinosa, Maríam L.; Sanmartí-García, Gemma; Vázquez-Delgado, Eduardo

    2012-01-01

    Many therapies have been proposed for the management of neuropathic pain, and they include the use of different antiepileptic drugs. However, the lack of high quality studies indicates that results on the different neuropathic disorders under study do not recommend a particular drug treatment. This study makes a systematic review of the published literature on the use of several antiepileptic drugs to treat neuropathic pain, and has the objective of considering both its clinical characteristics and pharmacological use, which will depend on their level of scientific evidence and will follow the principles of evidence-based dentistry. The articles were stratified according to their scientific evidence using the SORT criteria (Strength of Recommendation Taxonomy), and it included those articles that only have level 1 or 2. Randomized clinical trials were stratified according to their level of quality using the JADAD scale, an instrument described by Jadad et al. (7). to assess the quality of clinical trials, while studies with a level below 3 were discarded. Recently, type A or B recommendations are given in favor or against the use of antiepileptic drugs to treat neuropathic pain on the basis of their scientific quality. Key words:Neuropathic pain, antiepileptic drugs (AEDs), trigeminal neuralgia, glossopharyngeal neuralgia, post- herpetic neuralgia, burning mouth syndrome, persistent idiopathic facial pain. PMID:22549682

  4. Calcium-Permeable AMPA Receptors in the Nucleus Accumbens Regulate Depression-Like Behaviors in the Chronic Neuropathic Pain State

    PubMed Central

    Goffer, Yossef; Xu, Duo; Eberle, Sarah E.; D'amour, James; Lee, Michelle; Tukey, David; Froemke, Robert C.; Ziff, Edward B.

    2013-01-01

    Depression is a salient emotional feature of chronic pain. Depression alters the pain threshold and impairs functional recovery. To date, however, there has been limited understanding of synaptic or circuit mechanisms that regulate depression in the pain state. Here, we demonstrate that depression-like behaviors are induced in a rat model of chronic neuropathic pain. Using this model, we show that chronic pain selectively increases the level of GluA1 subunits of AMPA-type glutamate receptors at the synapses of the nucleus accumbens (NAc), a key component of the brain reward system. We find, in addition, that this increase in GluA1 levels leads to the formation of calcium-permeable AMPA receptors (CPARs). Surprisingly, pharmacologic blockade of these CPARs in the NAc increases depression-like behaviors associated with pain. Consistent with these findings, an AMPA receptor potentiator delivered into the NAc decreases pain-induced depression. These results show that transmission through CPARs in the NAc represents a novel molecular mechanism modulating the depressive symptoms of pain, and thus CPARs may be a promising therapeutic target for the treatment of pain-induced depression. More generally, these findings highlight the role of central glutamate signaling in pain states and define the brain reward system as an important region for the regulation of depressive symptoms of pain. PMID:24285907

  5. Dorsal Root Ganglionic Field Stimulation Relieves Spontaneous and Induced Neuropathic Pain in Rats.

    PubMed

    Pan, Bin; Yu, Hongwei; Fischer, Gregory J; Kramer, Jeffery M; Hogan, Quinn H

    2016-12-01

    Dorsal root ganglion (DRG) electrical stimulation (ganglionic field stimulation [GFS]) is effective in relieving clinical pain, but its mechanism is unknown. We therefore developed a rat model for GFS to test analgesic effects in the context of neuropathic pain. GFS was applied with a bipolar electrode at L4, using parameters replicating clinical use (20 Hz, 150-μs pulse width, current at 80% of motor threshold). Neuropathic pain was generated by tibial nerve injury (TNI). Pain behavior was monitored by determining the threshold for withdrawal from punctate mechanical stimuli, by identifying hyperalgesic responses to noxious mechanical stimuli, and by hypersensitivity to cold. The affective dimension of pain was measured using conditioned place preference. We found that electrode insertion caused no behavioral evidence of pain and produced no histological evidence of DRG damage. GFS reversed TNI-induced hypersensitivity to cold and mechanical hyperalgesia and allodynia. Allodynia remained diminished 15 minutes after GFS. Conditioned place preference showed that GFS was not rewarding in uninjured control animals but was rewarding in animals subjected to TNI, which reveals analgesic efficacy of GFS for spontaneous pain. We conclude that GFS relieves neuropathic pain in rats. This model may provide a platform for identifying mechanisms and novel applications of GFS. We show that electrical stimulation of the DRG in rats reverses neuropathic pain behavior and provides a rewarding effect to animals with spontaneous neuropathic pain. This confirms analgesic efficacy of DRG stimulation in an animal model, and provides a platform for preclinical exploration. Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.

  6. Treatment of neuropathic pain with 5% lidocaine-medicated plaster: Five years of clinical experience

    PubMed Central

    Delorme, Claire; Navez, Marie L; Legout, Valérie; Deleens, Rodrigue; Moyse, Dominique

    2011-01-01

    BACKGROUND: Neuropathic pain is often severe and adversely affects patients’ quality of life. OBJECTIVE: To perform a retrospective, observational study investigating the efficacy and safety of treating refractory chronic neuropathic pain with 5% lidocaine-medicated plaster, in patients attending pain centres. METHODS: Medical records from 467 patients treated with 5% lidocaine-medicated plaster were evaluated for efficacy (maximum and minimum pain intensities and coanalgesic consumption) and adverse events. Data from an initial assessment and at least one follow-up visit had to be available, and separate analyses were conducted for the general population and the subpopulation older than 70 years of age. RESULTS: Of the patients enrolled, 25.0% were older than 70 years of age. While 20.6% had postherpetic neuralgia, 76.3% had other types of peripheral pain. Approximately 78.1% of cases of peripheral neuropathic pain followed surgery, and 23% were post-traumatic pain. The time from onset to referral was more than one year in two-thirds of cases. All patients experienced pain of at least moderate severity (mean [± SD] 11-point numerical rating scale score 5.2±2.4 to 8.2±1.6). Treatment with 5% lidocaine-medicated plaster reduced pain intensity by more than 50% in 45.5% of patients, and by at least 30% in 82.2%. Of note, the consumption of analgesics and coanalgesics was significantly reduced. Results were similar in both the general population and the subpopulation older than 70 years of age, at high risk and often receiving multiple medications. CONCLUSIONS: Treatment of refractory neuropathic pain with 5% lidocaine-medicated plaster clearly demonstrated efficacy and an excellent safety profile in patients with refractory neuropathic pain. PMID:22059196

  7. Alternative treatment strategies for neuropathic pain: Role of Indian medicinal plants and compounds of plant origin-A review.

    PubMed

    Singh, Hasandeep; Bhushan, Sakshi; Arora, Rohit; Singh Buttar, Harpal; Arora, Saroj; Singh, Balbir

    2017-08-01

    Neuropathic pain is a complex, chronic pain state accompanied by tissue injury and nerve damage. This important health issue constitutes a challenge for the modern medicine worldwide. The management of neuropathic pain remains a major clinical challenge, pertaining to an inadequate understanding of pathophysiological mechanisms of neuropathic pain. Various classes of drugs have been reported effective for the management of neuropathic pain viz. opiates, tricyclic antidepressants, and antiepileptic agents. However, association of adverse effects with these drugs hinders their confident prescription in people with neuropathic pain. Recently, various medicinal plants have been reported effective for the management of neuropathic pain. So, it may be prudent to look beyond synthetic drugs pertaining to their unprecedented pharmacotherapeutic effects with lesser adverse effects. The extensive literature review has been carried out from databases such as Science direct, Scifinder, Wiley online library, PubMed, Research gate, Google scholar and Chemical Abstracts. The list of Traditional Indian Medicinal plants (TIMPs) and isolated compounds have been compiled which have been reported effective as an alternative therapy for the management of neuropathic pain. This helps the researchers to discover some novel therapeutic agents against neuropathic pain. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  8. Neuropathic ocular pain: an important yet underevaluated feature of dry eye

    PubMed Central

    Galor, A; Levitt, R C; Felix, E R; Martin, E R; Sarantopoulos, C D

    2015-01-01

    Dry eye has gained recognition as a public health problem given its prevalence, morbidity, and cost implications. Dry eye can have a variety of symptoms including blurred vision, irritation, and ocular pain. Within dry eye-associated ocular pain, some patients report transient pain whereas others complain of chronic pain. In this review, we will summarize the evidence that chronicity is more likely to occur in patients with dysfunction in their ocular sensory apparatus (ie, neuropathic ocular pain). Clinical evidence of dysfunction includes the presence of spontaneous dysesthesias, allodynia, hyperalgesia, and corneal nerve morphologic and functional abnormalities. Both peripheral and central sensitizations likely play a role in generating the noted clinical characteristics. We will further discuss how evaluating for neuropathic ocular pain may affect the treatment of dry eye-associated chronic pain. PMID:25376119

  9. Spinal Cord Stimulation for Treatment of Neuropathic Pain Associated With Erythromelalgia.

    PubMed

    Matzke, Laura L; Lamer, Tim J; Gazelka, Halena M

    2016-01-01

    Erythromelalgia is a rare disorder associated with neuropathic pain that commonly affects the lower extremities. This pain is often refractory to multimodal treatment. Both pharmacologic management and interventional anesthetic blocks have been used with varying and often limited success. To date, little experience has been gained with the use of spinal cord stimulation in treating pain associated with erythromelalgia. We present a case of successful treatment of pain secondary to erythromelalgia with a spinal cord stimulator in an 80-year-old woman. This patient had severe pain and debility secondary to erythromelalgia, having undergone trials of multiple medical therapies before presenting to our clinic. Dual-lead percutaneous spinal cord stimulation was successfully implanted without complication, leading to excellent pain control, now 18 months postimplant. Spinal cord stimulation may be a promising treatment of neuropathic pain associated with erythromelalgia.

  10. Revised definition of neuropathic pain and its grading system: an open case series illustrating its use in clinical practice.

    PubMed

    Geber, Christian; Baumgärtner, Ulf; Schwab, Rainer; Müller, Harald; Stoeter, Peter; Dieterich, Marianne; Sommer, Clemens; Birklein, Frank; Treede, Rolf-Detlef

    2009-10-01

    The definition of neuropathic pain has recently been revised by an expert committee of the Neuropathic Pain Special Interest Group of the International Association for the Study of Pain (NeuPSIG) as "pain arising as direct consequence of a lesion or disease affecting the somatosensory system," and a grading system of "definite," "probable," and "possible" neuropathic pain has been introduced. This open case series of 5 outpatients (3 men, 2 women; mean age 48 +/- 12 years) demonstrates how the grading system can be applied, in combination with appropriate confirmatory testing, to diagnosis neuropathic conditions in clinical practice. The proposed grading system includes a dynamic algorithm that enhances the physician's ability to determine with a greater level of certainty whether a pain condition is neuropathic. Its clinical use should be further validated in prospective studies.

  11. Neuropathic pain after breast cancer treatment: characterization and risk factors.

    PubMed

    Pereira, Susana; Fontes, Filipa; Sonin, Teresa; Dias, Teresa; Fragoso, Maria; Castro-Lopes, José; Lunet, Nuno

    2017-08-07

    Neuropathic pain (NP) may be an important contributor to the morbidity burden of breast cancer. We aimed to quantify the incidence of NP in the first year after diagnosis of breast cancer, and to identify its main determinants. We performed a prospective cohort study including 506 patients with incident breast cancer, recruited at the Portuguese Institute of Oncology of Porto, and followed for one year; patients with incident NP were additionally evaluated when this condition was diagnosed and after six months, to identify chronic NP. During the first year, 156 patients were diagnosed with NP [30.8%, 95% confidence interval (95%CI): 27.0-35.0]. Anxiety [relative risk (RR)=1.50; 95%CI: 1.06-2.13], arm symptoms (RR=1.44; 95%CI: 1.02-2.05), cancer stage III/IV (RR=2.47; 95%CI: 1.66-3.66), breast-conserving surgery with axillary lymph node dissection (ALND) (RR=3.13; 95%CI: 1.51-6.48), mastectomy with ALND (RR=2.52; 95%CI: 1.25-5.11) and damaging of the intercostobrachial nerve (RR=2.05; 95%CI:1.25-3.37) were predictors of a higher risk of NP. A total of 97 patients (62.2%, 95%CI: 54.4-69.4) diagnosed with NP remained symptomatic after six months. NP and chronic NP were frequent in this population, being associated with anxiety and arm symptoms prior to breast cancer treatments, as well as type of surgical management. These results highlight the need for monitoring the occurrence of this neurological side effect of treatments and to develop strategies for reducing the morbidity burden of breast cancer. Copyright © 2017. Published by Elsevier Inc.

  12. Persistent post-surgical pain and neuropathic pain after total knee replacement

    PubMed Central

    Drosos, Georgios I; Triantafilidou, Triantafilia; Ververidis, Athanasios; Agelopoulou, Cristina; Vogiatzaki, Theodosia; Kazakos, Konstantinos

    2015-01-01

    AIM: To study the prevalence of persistent post-surgical pain (PPSP) and neuropathic pain (NP) after total knee replacement (TKR). METHODS: MEDLINE and Embase databases were searched for articles published until December 2014 in English language. Published articles were included if they referred to pain that lasts at least 3 mo after primary TKR for knee osteoarthritis, and measured pain with pain specific instruments. Studies that referred to pain caused by septic reasons and implant malalignment were excluded. Both prospective and retrospective studies were included and only 14 studies that match the inclusion criteria were selected for this review. RESULTS: The included studies were characterized by the heterogeneity on the scales used to measure pain and pre-operative factors related to PPSP and NP. The reported prevalence of PPSP and NP seems to be relatively high, but it varies among different studies. There is also evidence that the prevalence of post-surgical pain is related to the scale used for pain measurement. The prevalence of PPSP is ranging at 6 mo from 16% to 39% and at 12 mo from 13.1% to 23% and even 38% of the patients. The prevalence of NP at 6 mo post-operatively is ranging from 5.2% to 13%. Pre-operative factors related to the development of PPSP also differ, including emotional functioning, such as depression and pain catastrophizing, number of comorbidities, pain problems elsewhere and operations in knees with early grade of osteoarthritis. CONCLUSION: No firm conclusions can be reached regarding the prevalence of PPSP and NP and the related factors due to the heterogeneity of the studies. PMID:26301182

  13. Prevalence and incidence of chronic pain with or without neuropathic characteristics in patients with cancer.

    PubMed

    Bouhassira, Didier; Luporsi, Elisabeth; Krakowski, Ivan

    2017-06-01

    This prospective national multicenter study was carried out to estimate the prevalence and incidence of chronic pain with or without neuropathic characteristics in patients with cancer in France. All consecutive outpatients (n = 1885) seen over 2 weeks for cancer treatment in 12 oncology units were invited to participate in the study, and 1805 were included. Patients underwent a clinical examination during visit 1, and a questionnaire was completed to detect chronic pain (defined as daily pain for at least 3 months), and to characterize its intensity, location, and neuropathic characteristics (ie, DN4 score ≥4). The impact of pain on quality of life was assessed with the Brief Pain Inventory. Patients without pain at visit 1 were included in the incidence study and were seen at 3 and 6 months after visit 1. The overall prevalence of chronic pain was 28.2% (95% CI: 26.3-30.5), ranging from 22.5% to 35.4%, depending on the location of the primary tumor. Neuropathic characteristics were present in 20.9% of these patients, with a prevalence of 2.9% to 9.7%, depending on primary tumor location. Pain intensity and interference were higher in patients with neuropathic characteristics. In total, 1285 patients were included in the incidence study, 873 of whom were seen at least once, 3, or 6 months after the first visit. The incidence of chronic pain during the 6-month follow-up period ranged from 13% to 28%, depending on primary tumor location, and neuropathic characteristics were found in 19.9% of patients with chronic pain.

  14. The refined biomimetic NeuroDigm GEL™ model of neuropathic pain in a mature rat

    PubMed Central

    Hannaman, Mary R.; Fitts, Douglas A.; Doss, Rose M.; Weinstein, David E.; Bryant, Joseph L.

    2017-01-01

    Background: Many humans suffering with chronic neuropathic pain have no objective evidence of an etiological lesion or disease. Frequently their persistent pain occurs after the healing of a soft tissue injury. Based on clinical observations over time, our hypothesis was that after an injury in mammals the process of tissue repair could cause chronic neural pain. Our objectives were to create the delayed onset of neuropathic pain in rats with minimal nerve trauma using a physiologic hydrogel, and characterize the rats’ responses to known analgesics and a targeted biologic. Methods: In mature male Sprague Dawley rats (age 9.5 months) a percutaneous implant of tissue-derived hydrogel was placed in the musculofascial tunnel of the distal tibial nerve. Subcutaneous morphine (3 mg/kg), celecoxib (10 mg/kg), gabapentin (25 mg/kg) and duloxetine (10 mg/kg) were each screened in the model three times each over 5 months after pain behaviors developed. Sham and control groups were used in all screenings. A pilot study followed in which recombinant human erythropoietin (200 units) was injected by the GEL™ neural procedure site. Results: The GEL group gradually developed mechanical hypersensitivity lasting months. Morphine, initially effective, had less analgesia over time. Celecoxib produced no analgesia, while gabapentin and duloxetine at low doses demonstrated profound analgesia at all times tested. The injected erythropoietin markedly decreased bilateral pain behavior that had been present for over 4 months, p ≤ 0.001. Histology of the GEL group tibial nerve revealed a site of focal neural remodeling, with neural regeneration, as found in nerve biopsies of patients with neuropathic pain. Conclusion: The refined NeuroDigm GEL™ model induces a neural response resulting in robust neuropathic pain behavior. The analgesic responses in this model reflect known responses of humans with neuropathic pain. The targeted recombinant human erythropoietin at the ectopic neural

  15. Prevalence of neuropathic features of back pain in clinical populations: implications for the diagnostic triage paradigm.

    PubMed

    Hush, Julia M; Marcuzzi, Anna

    2012-07-01

    SUMMARY Contemporary clinical assessment of back pain is based on the diagnostic triage paradigm. The most common diagnostic classification is nonspecific back pain, considered to be of nociceptive etiology. A small proportion are diagnosed with radicular pain, of neuropathic origin. In this study we review the body of literature on the prevalence of neuropathic features of back pain, revealing that the point prevalence is 17% in primary care, 34% in mixed clinical settings and 53% in tertiary care. There is evidence that neuropathic features of back pain are not restricted to typical clinical radicular pain phenotypes and may be under-recognized, particularly in primary care. The consequence of this is that in the clinic, diagnostic triage may erroneously classify patients with nonspecific back pain or radicular pain. A promising alternative is the development of mechanism-based pain phenotyping in patients with back pain. Timely identification of contributory pain mechanisms may enable greater opportunity to select appropriate therapeutic targets and improve patient outcomes.

  16. SIP30 Is Regulated by ERK in Peripheral Nerve Injury-induced Neuropathic Pain*

    PubMed Central

    Peng, Guangdun; Han, Mei; Du, Yimin; Lin, Anning; Yu, Lei; Zhang, Yuqiu; Jing, Naihe

    2009-01-01

    ERK plays an important role in chronic neuropathic pain. However, the underlying mechanism is largely unknown. Here we show that in chronic constriction injury-treated rat spinal cords, up-regulation of SIP30 (SNAP25-interacting protein 30), which is involved in the development and maintenance of chronic constriction injury-induced neuropathic pain, correlates with ERK activation and that the up-regulation of SIP30 is suppressed by intrathecal delivery of the MEK inhibitor U0126. In PC12 cells, up-regulation of SIP30 by nerve growth factor is also dependent on ERK activation. We found that there is an ERK-responsive region in the rat sip30 promoter. Activation of ERK promotes the recruitment of the transcription factor cyclic AMP-response element-binding protein to the sip30 gene promoter. Taken together, our results provide a potential downstream target of ERK activation-mediated neuropathic pain. PMID:19723624

  17. [Chemotherapy-induced peripheral neuropathy and neuropathic pain].

    PubMed

    Schuler, U; Heller, S

    2017-03-14

    The perception of the media is that chemotherapy is mainly associated with nausea, vomiting and hair loss. In the longer term the development of peripheral neuropathy, i.e. chemotherapy-induced peripheral neuropathy (CIPN) is often more important for patients. The CIPN represents a side effect of many antineoplastic substances with severe functional impairment and its prevention and treatment is an important task. In addition to many interventions, which have been shown to be ineffective, physiotherapeutic measures and possibly the prophylactic application of cold are helpful for prevention. Randomized studies on the treatment of painful CIPN provided positive data for duloxetine and to a lesser extent for venlafaxine.

  18. Challenges in translational drug research in neuropathic and inflammatory pain: the prerequisites for a new paradigm.

    PubMed

    Taneja, A; Della Pasqua, O; Danhof, M

    2017-09-11

    Despite an improved understanding of the molecular mechanisms of nociception, existing analgesic drugs remain limited in terms of efficacy in chronic conditions, such as neuropathic pain. Here, we explore the underlying pathophysiological mechanisms of neuropathic and inflammatory pain and discuss the prerequisites and opportunities to reduce attrition and high-failure rate in the development of analgesic drugs. A literature search was performed on preclinical and clinical publications aimed at the evaluation of analgesic compounds using MESH terms in PubMed. Publications were selected, which focused on (1) disease mechanisms leading to chronic/neuropathic pain and (2) druggable targets which are currently under evaluation in drug development. Attention was also given to the role of biomarkers and pharmacokinetic-pharmacodynamic modelling. Multiple mechanisms act concurrently to produce pain, which is a non-specific manifestation of underlying nociceptive pathways. Whereas these manifestations can be divided into neuropathic and inflammatory pain, it is now clear that inflammatory mechanisms are a common trigger for both types of pain. This has implications for drug development, as the assessment of drug effects in experimental models of neuropathic and chronic pain is driven by overt behavioural measures. By contrast, the use of mechanistic biomarkers in inflammatory pain has provided the pharmacological basis for dose selection and evaluation of non-steroidal anti-inflammatory drugs (NSAIDs). A different paradigm is required for the identification of relevant targets and candidate molecules whereby pain is coupled to the cause of sensorial signal processing dysfunction rather than clinical symptoms. Biomarkers which enable the characterisation of drug binding and target activity are needed for a more robust dose rationale in early clinical development. Such an approach may be facilitated by quantitative clinical pharmacology and evolving technologies in brain

  19. Long-term treatment of neuropathic pain with a 5% lidocaine medicated plaster.

    PubMed

    Wilhelm, Ilca Ricarda; Tzabazis, Alexander; Likar, Rudolf; Sittl, Reinhard; Griessinger, Norbert

    2010-02-01

    The 5% lidocaine medicated plaster is a topical treatment for peripheral neuropathic pain symptoms (e.g. burning, shooting and stabbing pain) and is registered for the treatment of postherpetic neuralgia. This study examined the efficacy and tolerability of long-term treatment with the 5% lidocaine medicated plaster in patients with localized neuropathic pain conditions. Twenty patients with localized neuropathic pain [postoperative neuropathic pain (n = 14); complex regional pain syndrome (n = 2); and postherpetic neuralgia (n = 4)], who had been successfully treated with 5% lidocaine medicated plaster, were followed up by telephone interview after 3 and 5 years. Questions were related to the efficacy, development of tolerance, tolerability, wear time and comfort of the plaster. At 3 years, 10 out of 20 (50%) initial responders were still using the plasters with no decline in analgesic efficacy. After 5 years, eight of the original 20 responders (40%) maintained treatment and continued to experience effective pain relief. The 12 responders who discontinued treatment did so because they no longer required analgesic therapy (n = 4); their health insurer refused to fund treatment (n = 2); they were lost to follow-up (n = 1); or had died from an illness unrelated to plaster treatment (n = 5). No patient discontinued because of inadequate analgesia or intolerable side effects. Reversible erythema occurred in two patients wearing the plaster for more than 16 h. There were no systemic side effects. The 5% lidocaine medicated plaster provides sustained pain relief over long-term treatment in patients with neuropathic pain of various causes and is well tolerated.

  20. Cell transplants to treat the "disease" of neuropathic pain and itch.

    PubMed

    Basbaum, Allan I; Bráz, João M

    2016-02-01

    Among many mechanisms implicated in the development of neuropathic pain after nerve damage is a profound dysfunction of GABAergic inhibitory controls, manifested by ongoing pain, mechanical hypersensitivity, and thermal hyperalgesia. In some respects, neuropathic pain can be considered a "disease" of the nervous system, with features in common with trauma-induced seizures. Indeed, first-line management involves anticonvulsant therapy. An alternative to pharmacotherapy for neuropathic pain is an approach that reestablishes the inhibitory tone that is lost after nerve damage. To this end, we have transplanted embryonic cortical GABAergic precursor neurons into the spinal cord of nerve-injured mice. Using a combination of light and electron microscopic analyses, and also in vitro electrophysiological recordings from spinal cord slice preparations, we demonstrated remarkable integration of the transplants into the host, adult spinal cord. Most importantly, transplants produced a complete reversal of the hypersensitivity in a sciatic nerve injury model and in a paclitaxel-generated chemotherapy model of neuropathic pain. In related studies, we demonstrated that medial ganglionic eminence cell transplants are also effective in a chronic neuropathic itch model in which there is a significant loss of dorsal horn inhibitory interneurons. Most importantly, in contrast to systemic or intrathecal pharmacological therapies, adverse side effects are minimized when the inhibitory control, namely, γ-aminobutyric acid release, occurs in a spinal cord circuit. These studies suggest that therapy targeted at repairing the GABAergic dysfunction is a viable and novel alternative to the management of neuropathic pain and itch, particularly those that are or become refractory to traditional pharmacotherapy.

  1. A single trial of transcutaneous electrical nerve stimulation reduces chronic neuropathic pain following median nerve injury in rats.

    PubMed

    Cho, Hwi-Young; Suh, Hye Rim; Han, Hee Chul

    2014-01-01

    Neuropathic pain is a devastating chronic condition and is often induced in the upper limb following nerve injury or damage. Various drugs or surgical methods have been used to manage neuropathic pain; however, these are frequently accompanied by undesirable side effects. Transcutaneous electrical nerve stimulation (TENS) is a safe and non-invasive intervention that has been used to alleviate different types of pain in the clinic, but it is unclear whether TENS can improve chronic neuropathic pain in the upper limb. Thus, the aim of this study was to investigate the effects of a single trial of TENS on chronic neuropathic pain following median nerve injury. Male rats weighing 200-250 g received median nerve-ligation of the right forearm, while the control group received only skin-incision without nerve-ligation. Neuropathic pain-behaviors, including mechanical, cold, and thermal allodynia, were measured for 4 weeks. After the development of chronic neuropathic pain, TENS (100 Hz, 200 µs, sub-motor threshold) or placebo-TENS (sham stimulation) was applied for 20 min to the ipsilateral or contralateral side. Neuropathic pain behavior was assessed before and after intervention. Median nerve-ligation significantly induced and maintained neuropathic pain in the ipsilateral side. TENS application to the ipsilateral side effectively attenuated the three forms of chronic neuropathic pain in the ipsilateral side compared to sham-treated rats (peripheral and central effects), while TENS application to contralateral side only reduced mechanical allodynia in the ipsilateral side (central effect). Our findings demonstrate that TENS can alleviate chronic neuropathic pain following median nerve injury.

  2. [Experience in treatment of patients with neuropathic facial pain using ziconotide].

    PubMed

    Lux, E A; Rasche, D

    2011-08-01

    We report on the intrathecal use of ziconotide in three patients with idiopathic facial pain after surgery of the mouth, jaw or face and one patient with neuropathic pain after damage of the lingual nerve. The therapy was successful in three patients but one patient with idiopathic facial pain had pain relief only during the test phase of ziconotide with an external pump and not after implanting the Synchromed® pump. With intrathecal morphine therapy this patient achieved good pain relief. We recommend that patients with neuropathic facial pain should be treated with ziconotide after implementation of guideline-based therapy. In the test phase the ziconotide dose should be increased by 0.6 µg/day per week after an initial dose of 0.6-1.2 µg/day to avoid side-effects.

  3. Neuropathic Pain in Low Back-Related Leg Pain Patients: What Is the Evidence of Prevalence, Characteristics, and Prognosis in Primary Care? A Systematic Review of the Literature.

    PubMed

    Harrisson, Sarah A; Stynes, Siobhán; Dunn, Kate M; Foster, Nadine E; Konstantinou, Kika

    2017-06-12

    This systematic review synthesizes literature describing prevalence, characteristics, and prognosis of low back-related leg pain (LBLP) patients with neuropathic pain in primary care and/or similar settings. Inclusion and exclusion criteria were developed and used by independent reviewers to screen citations for eligibility. The initial search yielded 24,948 citations; after screening 12 studies were included. Neuropathic pain was identified using case ascertainment tools (n = 5), clinical history with examination (n = 4), and using LBLP samples assumed neuropathic (n = 3). Neuropathic pain prevalence varied from 19% to 80%. There was consistent evidence for higher back-related disability (n = 3), poorer health-related quality of life (n = 2), and some evidence for more severe depression (n = 2), anxiety (n = 3), and pain intensity (n = 4) in patients with neuropathic pain. Results were less consistent when cases were identified through clinical history with examination than those identified using case ascertainment tools. Prognosis (n = 1) of LBLP patients with neuropathic pain was worse compared with those without, in all outcomes (leg pain intensity, leg and back-related disability, self-reported general health) except back pain intensity. No studies described prognostic factors. This systematic review highlights the evidence gap in neuropathic pain in LBLP in primary care, especially with respect to prognosis. Patients with LBLP may have neuropathic pain. This systematic review emphasizes the paucity of evidence describing the characteristics and prognosis of neuropathic pain in this patient population. Future research investigating prognosis of these patients with neuropathic pain is likely to contribute to better understanding and management. Copyright © 2017 American Pain Society. Published by Elsevier Inc. All rights reserved.

  4. Enduring Reversal Of Neuropathic Pain By A Single Intrathecal Injection Of Adenosine 2A Receptor Agonists: A Novel Therapy For Neuropathic Pain

    PubMed Central

    Loram, Lisa C; Harrison, Jacqueline A; Sloane, Evan M; Hutchinson, Mark R; Sholar, Paige; Taylor, Frederick R; Berkelhammer, Debra; Coats, Benjamen D; Poole, Stephen; Milligan, Erin D; Maier, Steven F; Rieger, Jayson; Watkins, Linda R

    2009-01-01

    Previous studies of peripheral immune cells have documented that activation of adenosine 2A receptors (A2AR) decrease pro-inflammatory cytokine release and increase release of the potent anti-inflammatory cytokine, interleukin-10 (IL-10). Given the growing literature supporting that glial proinflammatory cytokines importantly contribute to neuropathic pain, and that IL-10 can suppress such pain, we evaluated the effects of intrathecally (i.t.) administered A2AR agonists on neuropathic pain using the chronic constriction injury (CCI) model. A single i.t. injection of the A2AR agonists ATL313 or CGS21680, 10-14 d after CCI versus sham surgery, produced a long-duration reversal of mechanical allodynia and thermal hyperalgesia for at least 4 wk. Neither drug altered the nociceptive responses of sham-operated controls. An A2AR antagonist (ZM241385) co-administered i.t. with ATL313 abolished the action of ATL313 in rats with neuropathy-induced allodynia, but had no effect on allodynia in the absence of the A2AR agonist. ATL313 attenuated CCI-induced upregulation of spinal cord activation markers for microglia and astrocytes in the L4-L6 spinal cord segments both 1 wk and 4 wk after a single i.t. ATL313 administration. Neutralizing IL-10 antibodies administered i.t. transiently abolished the effect of ATL313 on neuropathic pain. In addition, IL-10 mRNA was significantly elevated in the CSF cells collected from the lumbar region. Activation of A2ARs following i.t. administration may be a novel, therapeutic approach for the treatment of neuropathic pain by increasing IL-10 in the immunocompetent cells of the CNS. PMID:19890011

  5. Physical therapy modalities and rehabilitation techniques in the management of neuropathic pain.

    PubMed

    Akyuz, Gulseren; Kenis, Ozge

    2014-03-01

    Neuropathic pain is an important problem because of its complex natural history, unclear etiology, and poor response to standard physical therapy agents. It causes severe disability unrelated to its etiology. The primary goals of the management of neuropathic pain are to detect the underlying cause, to define the differential diagnosis and eliminate risk factors, and to reduce the pain. The physician should also know the functional and psychologic conditions of the patient. Therefore, a multimodal management plan in neuropathic pain is essential. This review aimed to reflect a diverse point of view about various physical therapy modalities and rehabilitation techniques. Physical therapy modalities and rehabilitation techniques are important options and must be considered when pharmacotherapy alone is not sufficient. In addition, psychosocial support and cognitive behavioral therapy could also be taken into consideration. It has been suggested that the importance of pain rehabilitation techniques will increase in time and these will take a larger part in the management of neuropathic pain. However, it is now early to comment on these methods because of the lack of adequate publications.

  6. Therapeutic Strategies for Neuropathic Pain: Potential Application of Pharmacosynthetics and Optogenetics

    PubMed Central

    Lee, Gum Hwa; Kim, Sang Seong

    2016-01-01

    Chronic pain originating from neuronal damage remains an incurable symptom debilitating patients. Proposed molecular modalities in neuropathic pain include ion channel expressions, immune reactions, and inflammatory substrate diffusions. Recent advances in RNA sequence analysis have discovered specific ion channel expressions in nociceptors such as transient receptor potential (TRP) channels, voltage-gated potassium, and sodium channels. G protein-coupled receptors (GPCRs) also play an important role in triggering surrounding immune cells. The multiple protein expressions complicate therapeutic development for neuropathic pain. Recent progress in optogenetics and pharmacogenetics may herald the development of novel therapeutics for the incurable pain. Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) facilitate the artificial manipulation of intracellular signaling through excitatory or inhibitory G protein subunits activated by biologically inert synthetic ligands. Expression of excitatory channelrhodopsins and inhibitory halorhodopsins on injured neurons or surrounding cells can attenuate neuropathic pain precisely controlled by light stimulation. To achieve the discrete treatment of injured neurons, we can exploit the transcriptome database obtained by RNA sequence analysis in specific neuropathies. This can recommend the suitable promoter information to target the injury sites circumventing intact neurons. Therefore, novel strategies benefiting from pharmacogenetics, optogenetics, and RNA sequencing might be promising for neuropathic pain treatment in future. PMID:26884648

  7. A central neuropathic pain model by DSP-4 induced lesion of noradrenergic neurons: preliminary report.

    PubMed

    Kudo, Takashi; Kushikata, Tetsuya; Kudo, Mihoko; Kudo, Tsuyoshi; Hirota, Kazuyoshi

    2010-09-06

    Neuropathic pain models are classified as central and peripheral pain models. Although various peripheral neuropathic pain models are established, central pain models are based only on spinal cord injury. DSP-4 is a competitive inhibitor of norepinephrine uptake that selectively degenerates the locus coeruleus (LC)-noradrenergic neurons projection to the cerebral cortex and hippocampus. In the present study, we have tested whether lesion of LC-noradrenergic neurons by ip DSP-4 (0, 10, 30, 50 mg/kg, n=7 each) could provide a new central neuropathic pain model in rats using a hot-plate and tail-flick tests. DSP-4 significantly reduced the hot-plate latency and norepinephrine contents especially in the coerulean regions. However, DSP-4 did not change tail-flick latency. There are significant correlations of the latency in the hot-plate test with norepinephrine contents in the cerebral cortex (r=0.432, p=0.022), the hippocampus (r=0.465, p=0.013) and the pons (r=0.400, p=0.035) but not with those in the hypothalamus and the spinal cord. As response to hot-plate and tail-flick implies supra-spinal process and spinal reflex, respectively, central neuropathic pain may be facilitated by DSP-4 depleting LC-noradrenergic neurons although the present data are preliminary.

  8. Therapeutic Strategies for Neuropathic Pain: Potential Application of Pharmacosynthetics and Optogenetics.

    PubMed

    Lee, Gum Hwa; Kim, Sang Seong

    2016-01-01

    Chronic pain originating from neuronal damage remains an incurable symptom debilitating patients. Proposed molecular modalities in neuropathic pain include ion channel expressions, immune reactions, and inflammatory substrate diffusions. Recent advances in RNA sequence analysis have discovered specific ion channel expressions in nociceptors such as transient receptor potential (TRP) channels, voltage-gated potassium, and sodium channels. G protein-coupled receptors (GPCRs) also play an important role in triggering surrounding immune cells. The multiple protein expressions complicate therapeutic development for neuropathic pain. Recent progress in optogenetics and pharmacogenetics may herald the development of novel therapeutics for the incurable pain. Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) facilitate the artificial manipulation of intracellular signaling through excitatory or inhibitory G protein subunits activated by biologically inert synthetic ligands. Expression of excitatory channelrhodopsins and inhibitory halorhodopsins on injured neurons or surrounding cells can attenuate neuropathic pain precisely controlled by light stimulation. To achieve the discrete treatment of injured neurons, we can exploit the transcriptome database obtained by RNA sequence analysis in specific neuropathies. This can recommend the suitable promoter information to target the injury sites circumventing intact neurons. Therefore, novel strategies benefiting from pharmacogenetics, optogenetics, and RNA sequencing might be promising for neuropathic pain treatment in future.

  9. Aromatherapy Massage for Neuropathic Pain and Quality of Life in Diabetic Patients.

    PubMed

    Gok Metin, Zehra; Arikan Donmez, Ayse; Izgu, Nur; Ozdemir, Leyla; Arslan, Ismail Emre

    2017-07-01

    This study aimed to examine the effects of aromatherapy massage on neuropathic pain severity and quality of life (QoL) in patients suffering from painful diabetic neuropathy. This open-label randomized controlled clinical study was conducted in a university hospital endocrine outpatient clinic in Turkey. The study sample consisted of 46 patients, randomly allocated to an intervention group (n = 21) and a control group (n = 25). The intervention group received aromatherapy massage three times per week for a period of 4 weeks. The control group received only routine care. Data were collected from patients using the Douleur Neuropathique questionnaire, the visual analog scale, and the Neuropathic Pain Impact on Quality of Life questionnaire. Neuropathic pain scores significantly decreased in the intervention group compared with the control group in the fourth week of the study. Similarly, QoL scores significantly improved in the intervention group in the fourth week of the study. Aromatherapy massage is a simple and effective nonpharmacological nursing intervention that can be used to manage neuropathic pain and improve QoL in patients with painful neuropathy. Aromatherapy massage is a well-tolerated, feasible, and safe nonpharmacological method that can be readily integrated into clinical settings by nursing staff. The essential oils rosemary, geranium, lavender, eucalyptus, and chamomile can be safely used by nurses in the clinical setting, if applicable. However, training and experience of nurses in aromatherapy massage is critical to achieving positive results. © 2017 Sigma Theta Tau International.

  10. Inhibition of MicroRNA-221 Alleviates Neuropathic Pain Through Targeting Suppressor of Cytokine Signaling 1.

    PubMed

    Xia, Li; Zhang, Yunlong; Dong, Tieli

    2016-07-01

    Neuropathic pain results in considerable trouble to people's physical and mental health. The pathophysiological mechanisms underlying its occurrence and development remain unclear. A large number of experiments show that microRNAs (miRNAs) play a major role in the pathogenesis of neuropathic pain and neuroinflammation resulting from nerve injury. Among various miRNAs, microRNA-221 (miR-221) overexpression has been reported in a chronic constrictive injury (CCI)-induced rat model of neuropathic pain. However, the role of miR-221 in the regulation of neuropathic pain is unknown. In this study, we investigated the potential role and underlying mechanism of miR-221 in regulating neuropathic pain. Our findings show that miR-221 is overexpressed in the spinal cord and the isolated microglia of CCI rats. Intrathecal injection of a miR-221 inhibitor attenuated CCI-induced mechanical allodynia and thermal hyperalgesia, and reduced proinflammatory cytokine expression, including tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 in CCI rats. Using a dual-luciferase reporter assay, we show that suppressor of cytokine signaling 1 (SOCS1), an important regulator of inflammation, is a direct target of miR-221. Treatment with the miR-221 inhibitor significantly inhibited the expression of SOCS1. Furthermore, the miR-221 inhibitor markedly suppressed the activation of nuclear factor-kappa B (NF-κB) and the p38 mitogen-activated protein kinase (p38 MAPK) signaling pathway. Knockdown of SOCS1 in CCI rats abrogated the inhibitory effect of the miR-221 inhibitor on CCI-induced neuropathic pain and the NF-κB and p38 MAPK signaling pathways. Together, these results suggest that inhibition of miR-221 alleviates neuropathic pain and neuroinflammation through increasing SOCS1 and by inhibiting the NF-κB and p38 MAPK signaling pathways, indicating that miR-221 may be a promising molecular target for the treatment of neuropathic pain.

  11. Osteoarthritis pain has a significant neuropathic component: an exploratory in vivo patient model.

    PubMed

    Duarte, Rui V; Raphael, Jon H; Dimitroulas, Theodoros; Sparkes, Elizabeth; Southall, Jane L; Ashford, Robert L; Kitas, George D

    2014-03-01

    Osteoarthritis is the most common form of arthritis and includes manifestations of both nociceptive and neuropathic mechanisms. Intravenous lignocaine, a sodium channel blocker and neuronal membrane stabiliser, has been shown in controlled trials to be effective in neuropathic pain; however, the outcome of intravenous lignocaine in osteoarthritis patients has not been assessed yet. The existence of a neuropathic component to the pain of osteoarthritis was investigated by examining possible benefits upon sensory aspects of pain in osteoarthritis patients receiving intravenous lignocaine therapy. Retrospective observational study was carried out using health data routinely collected for non-research purposes. Patients with generalised osteoarthritis who had not responded to more conservative treatments were recruited sequentially and scheduled for intravenous lignocaine therapy either in the rheumatology or pain relief departments. Assessment of efficacy was carried out through a questionnaire including sensory, psychological and social aspects of pain. The sample consisted of 17 women (60.7%) and 11 men (39.3%) with an average age at the time of treatment of 59 ± 11 years. The average pain relief calculated from the NRS scores was 30.2 ± 21.4%, and the mean duration of pain relief was 10 ± 6 weeks. Pain intensity (p < 0.001), pain relief (p < 0.003) and mobility (p < 0.003) were all significantly improved after administration of lignocaine intravenous infusion therapy. Pain was significantly reduced in a group of osteoarthritis patients after administration of intravenous lignocaine. This suggests that part of the pain mechanism in this patient group may be neuropathic, appears to contribute significantly to the patients' pain, and requires further investigation in studies designed specifically for the purpose.

  12. Expectations and positive emotional feelings accompany reductions in ongoing and evoked neuropathic pain following placebo interventions.

    PubMed

    Petersen, Gitte L; Finnerup, Nanna B; Grosen, Kasper; Pilegaard, Hans K; Tracey, Irene; Benedetti, Fabrizio; Price, Donald D; Jensen, Troels S; Vase, Lene

    2014-12-01

    Research on placebo analgesia and nocebo hyperalgesia has primarily included healthy subjects or acute pain patients, and it is unknown whether these effects can be obtained in ongoing pain in patients with chronic pain caused by an identifiable nerve injury. Eighteen patients with postthoracotomy neuropathic pain were exposed to placebo and nocebo manipulations, in which they received open and hidden administrations of pain-relieving (lidocaine) or pain-inducing (capsaicin) treatment controlled for the natural history of pain. Immediately after the open administration, patients rated their expected pain levels on a mechanical visual analogue scale (M-VAS). They also reported their emotional feelings via a quantitative/qualitative experiential method. Subsequently, patients rated their ongoing pain levels on the M-VAS and underwent quantitative sensory testing of evoked pain (brush, pinprick, area of hyperalgesia, wind-up-like pain). There was a significant placebo effect on both ongoing (P=.009 to .019) and evoked neuropathic pain (P=.0005 to .053). Expected pain levels accounted for significant amounts of the variance in ongoing (53.4%) and evoked pain (up to 34.5%) after the open lidocaine administration. Furthermore, patients reported high levels of positive and low levels of negative emotional feelings in the placebo condition compared with the nocebo condition (P⩽.001). Pain increases during nocebo were nonsignificant (P=.394 to 1.000). To our knowledge, this is the first study to demonstrate placebo effects in ongoing neuropathic pain. It provides further evidence for placebo-induced reduction in hyperalgesia and suggests that patients' expectations coexist with emotional feelings about treatments. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  13. Validation of a New Arabic Version of the Neuropathic Pain Diagnostic Questionnaire (DN4).

    PubMed

    Chatila, Nadwa; Pereira, Bruno; Maarrawi, Joseph; Dallel, Radhouane

    2017-01-01

    The "Douleur Neuropathique 4 (DN4) questionnaire" was developed for screening neuropathic pain. The purpose of this work was to validate the DN4 questionnaire in the sta