Central Pain Research Articles

Promoting multidisciplinary pain management in low- and middle-income countries—challenges and achievements

Abstract The burden of pain in low- and middle income countries (LMICs) is high and expected to rise further with their ageing populations. Multidisciplinary pain management approaches based on the biopsychosocial model of pain have been shown to be effective in reducing pain-related distress and disability, but these approaches are still lacking in many LMICs due to various factors, including low levels of awareness about the role of multidisciplinary pain clinics, lack of prioritisation for pain services, and lack of healthcare professionals trained in pain management. The International Association for the Study of Pain (IASP) has several educational programs to promote multidisciplinary pain management in LMICs, in the form of education grants, pain fellowships, pain camps and, most recently, the development of a Multidisciplinary Pain Centre Toolkit. This article describes the various educational programs, focusing on Southeast Asia, that demonstrate how targeted educational programs which include skills training, follow-up and mentorship, can translate into the formation of new multidisciplinary pain management services in settings with limited resources.

Prescription time trends in patients with high-impact chronic pain: A National Patient Registry Study.

High-impact chronic pain (HICP), defined as chronic pain with a significant impact on daily function, affects approximately 8% of the Western population. In Denmark, HICP still remains to be described at the population level. Some patients with HICP are referred to the Danish pain centres, where they are registered with a procedural code. We conducted a nationwide registry-based study of all Danish patients registered with a visit to a pain centre from January 2005 to March 2022, to explore time trends in the prescription of analgesics and sedatives in this HICP subpopulation. Furthermore, data on socioeconomics and hospital diagnoses are reported. We used data from the Central Person Registry, the Danish National Patient Registry, the Danish National Prescription Registry, combined with data on socioeconomic information from Statistics Denmark. Data was collected on prescriptions 3 months before the first visit to a pain centre. Prescriptions were stratified into five calendar periods: before 2011, 2011-2013, 2014-2016, 2017-2019, and 2020-2022. We identified 66,577 patients referred to a pain centre. Over 15 years, prescriptions before referral declined for opioids (from 53.2% to 31.7%), NSAIDs (from 28.3% to 23.5%), antidepressants (from 20.5% to 16.8%), anxiolytics (from 12.3% to 3.2%), and sleep medication (from 15.8% to 7.6%). In contrast, prescriptions increased for paracetamol (from 31.1% to 48.9%) and gabapentinoids (from 19.2% to 27.7%). In patients with HICP visiting Danish pain centres, prescriptions before referral decreased for opioids over 15 years, with a simultaneously increased prescription of gabapentinoids (gabapentin and pregabalin). This nationwide study of 66,577 Danish patients with high-impact chronic pain reveals a significant decrease in filled opioid prescriptions over the past 15 years, with a simultaneous rise in gabapentinoid use before referral to pain centres. These findings suggest a shift in clinical practice towards alternative pain management strategies. The study underscores the need for continued research into the long-term effects of these changes and their impact on patient outcomes.

Low ambient temperature and incident myocardial infarction with or without obstructive coronary arteries: a Chinese nationwide study.

Although non-optimum ambient temperature is a major non-traditional risk factor for acute myocardial infarction, there is no prior knowledge on whether non-optimum ambient temperature could differentially affect myocardial infarction with obstructive coronary artery disease (MI-CAD) and myocardial infarction with non-obstructive coronary arteries (MINOCA). Using the Chinese Cardiovascular Association database-Chest Pain Center Registry, a nationwide, time-stratified, case-crossover investigation was conducted from 2015 to 2021. Meteorological data were obtained from an established satellite-based model, and daily exposures were assigned according to the onset of myocardial infarction in each patient. A conditional logistic regression model combined with distributed lag non-linear models (10 days) was used to estimate the exposure-response relationships. A total of 83 784 MINOCA patients and 918 730 MI-CAD patients were included. The risk of MINOCA and MI-CAD associated with low temperature occurred at lag 2 day and lasted to 1 week. Extremely low temperature was associated with a substantially greater odds ratio (OR) of MINOCA [OR 1.58, 95% confidence interval (CI) 1.31-1.90] than MI-CAD (unmatched: OR 1.32, 95% CI 1.23-1.43; equally matched by age and sex: OR 1.25, 95% CI 1.04-1.50), compared with the corresponding reference temperatures (30°C, 35°C, and 30°C). Stronger associations were observed for patients who were aged ≥65 years, female, or resided in the south. There was no significant difference for the impacts of high temperature on MINOCA and MI-CAD. This nationwide study highlights the particular susceptibility of MINOCA patients to ambient low temperature compared with that of MI-CAD patients.

Non-surgical spinal cord infarction: case series & long-term follow-up of functional outcome

IntroductionSpinal cord infarction is a rare but often devastating disorder. The pathogenesis of most non-surgical cases involves atherothrombosis and treatment with anticoagulation and antiplatelet agents may be indicated. Functional recovery in most cases is poor. We describe five cases of spinal cord infarction and provide details on their functional outcomes after long-term (>10 years) follow-up.Case presentationA 28-year-old female presented at 16 weeks gestation with chest and back pain and paraesthesia in her fingers. Magnetic resonance imaging on admission revealed a spinal cord lesion extending from C5-T8. She was treated with anticoagulation and rehabilitation. Six years following presentation she was able to return to work. A 42-year-old male experiencing central chest pain and leg weakness was initially diagnosed as having acute coronary syndrome. Following discharge, he was re-admitted with urinary retention and leg weakness. Magnetic resonance imaging revealed a spinal cord lesion extending from T4 to T7. He was treated with anticoagulation, and eight months following presentation he regained full muscle strength but required intermittent self-catherisation. Three further cases are described.DiscussionThe aetiology of non-surgical spinal cord infarction is not always evident, but is commonly associated with atherothrombosis. There are often delays in making a diagnosis, but early recognition and prompt treatment of spinal cord infarction is essential. Long-term functional outcomes are often poor and typically reflect the severity of initial presentation. This case series is unique as it has one of the longest follow-up periods described in the literature.

Bedside Neuromodulation of Persistent Pain and Allodynia with Caloric Vestibular Stimulation.

Caloric vestibular stimulation (CVS) is a well-established neurological diagnostic technique that also induces many phenomenological modulations, including reductions in phantom limb pain (PLP), spinal cord injury pain (SCIP), and central post-stroke pain. We aimed to assess in a variety of persistent pain (PP) conditions (i) short-term pain modulation by CVS relative to a forehead ice pack cold-arousal control procedure and (ii) the duration and repeatability of CVS modulations. The tolerability of CVS was also assessed and has been reported separately. We conducted a convenience-based non-randomised single-blinded placebo-controlled study. Thirty-eight PP patients were assessed (PLP, n = 8; SCIP, n = 12; complex regional pain syndrome, CRPS, n = 14; non-specific PP, n = 4). Patients underwent 1-3 separate-day sessions of iced-water right-ear CVS. All but four also underwent the ice pack procedure. Analyses used patient-reported numerical rating scale pain intensity (NRS-PI) scores for pain and allodynia. Across all groups, NRS-PI for pain was significantly lower within 30 min post-CVS than post-ice pack (p < 0.01). Average reductions were 24.8% (CVS) and 6.4% (ice pack). CRPS appeared most responsive to CVS, while PLP and SCIP responses were less than expected from previous reports. The strongest CVS pain reductions lasted hours to over three weeks. CVS also induced substantial reductions in allodynia in three of nine allodynic CRPS patients, lasting 24 h to 1 month. As reported elsewhere, only one patient experienced emesis and CVS was widely rated by patients as a tolerable PP management intervention. Although these results require interpretative caution, CVS was found to modulate pain relative to an ice pack control. CVS also modulated allodynia in some cases. CVS should be examined for pain management efficacy using randomised controlled trials.

Ostial left main disease tackled with a percutaneous coronary intervention using a second-generation drug-eluting stent: A case report

Abstract: The hospital emergency admitted a middle-aged male who had previously undergone stenting in the left anterior descending (LAD) and right coronary arteries due to severe central chest pain radiating to both arms. A two-dimensional color Doppler echocardiogram showed septal hypokinesia, and coronary angiography showed a 70% ostial left main (LM) stenosis. The LAD coronary artery had a patent stent, but the mid-right coronary artery had a totally occluded stent. The chest pain increased during coronary angiography, and the patient consented to percutaneous coronary intervention (PCI) with a second-generation drug-eluting stent. The patient was discharged in a stable condition. The evolution and the current approach of PCI compared to coronary artery bypass grafting surgery for LM coronary disease based on randomized trials are discussed.

Low-dose methadone added to another opioid for cancer pain: a multicentre prospective study

ContextThe use of methadone for cancer pain management is gaining wider acceptance. However, switching to methadone treatment can still pose challenges. Consequently, there is ongoing development of its use in low doses in combination with other opioids, despite a lack of clinical evidence regarding its efficacy and safety.ObjectivesThis study aimed to evaluate the efficacy and tolerability of low-dose methadone in combination with another opioid in patients with moderate-to-severe cancer-related pain in a clinical setting.Patients and methodsThis was a prospective, open-label study conducted in 19 pain and/or palliative care centres treating patients with cancer-related pain. Pain intensity, patients' global impression of change, and adverse effects were assessed on day 7 and day 14. The main outcome measure was the proportion of responders.ResultsThe study included 92 patients. The daily dose of methadone was 3 [3–6] mg at baseline, 9 [4–10] mg on day 7 and 10 [6–15] mg on day 14. The NRS pain ratings significantly decreased from 7 [6–8] at baseline to 5 [3–6] on visit 2 (p < .0001) and 4 [3–6] on visit 3 (p < .0001). Similarly, the VRS pain ratings decreased from 3 [3–3] at baseline to 2 [2–3] on visit 2 (p = 0.026) and 2 [1–3] (p < 0.001) on visit 3. At Visits 1 and 2, half of the patients were considered Responders. Of those responders, 73.5% were High-Responders at Visit 1 and 58.7% were High-Responders at Visit 2. No adverse events related to the risk of QT prolongation, overdose, or drug interactions were reported.ConclusionFor patients experiencing moderate to severe cancer-related pain despite initial opioid treatment, our study found that low-dose methadone, when used in combination with another opioid, was both safe and effective. This supports the use of methadone as an adjunct to opioid-based treatment for cancer pain.

Interpretation of a clinical practice guideline on the management of chronic pain associated with temporomandibular joint disorders

Temporomandibular disorders (TMD) are a heterogeneous group of diseases that affect the temporomandibular joint, chewing muscle system, dental occlusion, and even various structures throughout the body, with significant characteristics of biological-psychological-social pattern. TMD related chronic pain, as the most important clinical symptom, can result in negative emotions seriously affecting patients' quality of life and physical and mental health. Although a variety of therapies have been previously reported to treat TMD related chronic pain, there is a lack of widely recognized therapies. Professor Jason W Busse (from Michael G DeGroote National Pain Centre, McMaster University, Hamilton ON, Canada) took the lead and collaborated with multiple internationally renowned schools/hospitals of stomatology to develop an international consensus on the management of chronic pain associated with TMD, a clinical practice guideline, which took two years and was published in December 15th, 2023 in a global top journal of clinical research The British Medical Journal. This clinical practice guideline explored the comparative effectiveness of available therapies for chronic pain associated with TMD, conditionally recommended the specific intervention for different treatment or pain relief, proposed a comprehensive, agreed, and standardized clinical practice guideline. This present article describes the methodology and key elements of the clinical practice guideline to help clinicians fully understand and appropriately apply this guidance, which could provide the references for clinical practice of TMD associated chronic pain in China.

The role of environmental sensitivity, traumatic experiences, defense mechanisms and mental pain on central sensitivity: testing a path analysis model in chronic headache on quality of life.

Central pain sensitivity (CS) is defined as an increased responsiveness of nociceptive neurons in the central nervous system to normal or subthreshold inputs. The main aim of this paper is to investigate if and how specific psychological constructs are related with CS burden in patients with chronic headache (CH). Specifically, research question 1 explores the association of temperament, personality, childhood adversities, defense mechanisms and mental pain with CS burden. Research question 2 aims to test the role of the best predictors of CS burden in affecting the quality of life (QoL) using path analysis. A total of 508 women with CH completed a psycho-diagnostic survey. Results showed that higher levels of low sensory threshold (β = 0.200), bodily threat traumatic experiences (β = 0.156), neurotic defenses (β = 0.109) and mental pain (β = 0.343) emerged as the best predictors of higher CS burden. The model presented demonstrated a satisfactory fit (GFI = 0.984; NFI = 0.966; CFI = 0.979; RMSEA = 0.056 [95% CI 0.028-0.085]) with large and medium effect sizes on physical (-0.654) and psychological QoL (-0.246). The study showed a key role of psychological dimensions in CS burden levels and their relationships with QoL in CH patients. From a clinical perspective, these results suggest the importance of evaluating the level of CS burden during the clinical assessment for chronic pain conditions such as CH, since it may contribute to guide patients to tailored psychological and medical treatments, thereby saving time and costs on diagnostic procedures for chronic pain.

Effect of continuous improvement of standardized construction of China Chest Pain Center on treatment time and mortality of acute ST-segment elevation myocardial infarction: A population-based study.

Standardized construction of China Chest Pain Center improves outcomes in patients with acute ST-segment elevation myocardial infarction (STEMI). A total 778 patients with a definite diagnosis of STEMI who underwent percutaneous coronary intervention (PCI) in our hospital from March 2017 to November 2022 were selected. Among them, 194 patients admitted from March 2017 to December 2019 were included as the pre-continuous improvement period (control group), and 584 patients admitted from January 2020 to November 2022 were included as the continuous improvement period (study group). Major quality control indicators were compared between the 2 groups. In continuous improvement period, the time of electrocardiograph (ECG) diagnosis, time of dual antiplatelet drug administration, troponin I return time, catheter activation time, and door to wire (D2W) were all significantly shorter than those in the pre-continuous improvement period (P < .05). The reperfusion rate of patients in the continuous improvement period was 98.12%, which was significantly higher than that in the pre-continuous improvement period (92.78%; P < .001). The mortality rate of STEMI patients in continuous improvement period was 3.42%, lower than 4.64% in the pre-continuous improvement period with no statistical difference (P = .439). Age, previous history of coronary artery disease, and high Killip class (Killip III-IV) were derived as independent risk factors for death by logistic regression analysis (OR＞1, P < .05). Continuous improvement of the chest pain center can effectively shorten the treatment time of STEMI patients, improve the reperfusion rate, and improve myocardial blood supply by restoring TIMI blood flow as early as possible.

Central Neuropathic Pain

ABSTRACT OBJECTIVE This article provides an approach to the assessment, diagnosis, and treatment of central neuropathic pain. LATEST DEVELOPMENTS Recent studies of the pathophysiology of central neuropathic pain, including evidence of changes in the expression of voltage-gated sodium channels and N-methyl-d-aspartate (NMDA) receptors, may provide the basis for new therapies. Other areas of current research include the role of cannabinoid-receptor activity and microglial cell activation in various animal models of central neuropathic pain. New observations regarding changes in primary afferent neuronal activity in central neuropathic pain and the preliminary observation that peripheral nerve blocks may relieve pain due to central neuropathic etiologies provide new insights into both the mechanism and treatment of central neuropathic pain. ESSENTIAL POINTS In the patient populations treated by neurologists, central neuropathic pain develops most frequently following spinal cord injury, multiple sclerosis, or stroke. A multimodal, individualized approach to the management of central neuropathic pain is necessary to optimize pain relief and may require multiple treatment trials to achieve the best outcome.

Usefulness of Mirogabalin in Central Neuropathic Pain After Stroke: Post Hoc Analysis of a Phase3 Study by Stroke Type and Location.

Central post-stroke pain (CPSP) is a common type of central neuropathic pain (CNeP) that can occur following the onset of stroke. The oral gabapentinoid mirogabalin besylate (mirogabalin) is a selective α2δ ligand that is effective for the treatment of CNeP, including CPSP. However, it is unknown whether the analgesic effect of mirogabalin on CPSP varies in patients with different background factors. This was a post hoc subgroup analysis of a multinational, open-label, long-term phase3 study of mirogabalin for the treatment of CNeP conducted between March 2019 and December 2020. Data from patients with CPSP were stratified by type of stroke (ischemic or hemorrhagic), stroke location (thalamus, putamen, brainstem, or other), presence/absence of motor weakness, median time since stroke (≥ 59 or < 59months), and median duration of CPSP (≥ 55.5 or < 55.5months). Efficacy was assessed with the short-form McGill Pain Questionnaire (SF-MPQ), and treatment-emergent adverse events (TEAEs) and adverse drug reactions (ADRs) were recorded. This subanalysis included all 94 patients with CPSP from the phase3 study; all were Japanese, and the mean age was 65.3years. The least squares mean change [95% confidence interval] in SF-MPQ visual analog scale (VAS) score from baseline at week52 (last observation carried forward) was - 17.0 [- 22.1, - 11.9] mm. Among the subgroups, least squares mean changes in SF-MPQ VAS scores were not different. Most TEAEs were mild or moderate; severe TEAEs occurred in six patients (6.4%). Somnolence (25.5%), peripheral edema (13.8%), dizziness (11.7%), and weight gain (6.4%) were the most common ADRs, and the types and frequencies of ADRs were similar among subgroups. Mirogabalin was generally effective and well tolerated in patients with CPSP, regardless of background factors such as stroke type or location, presence/absence of motor weakness, time since stroke, and duration of CPSP. Trial registration number NCT03901352.

Peripheral Neuropathic Pain.

This article synthesizes current knowledge on neuropathic pain, with a brief review of mechanisms, diagnostic approaches, and treatment strategies to help neurologists provide effective and individualized care for patients with this complex condition. The most promising developments in peripheral neuropathic pain are related to the molecular biology of the peripheral nervous system. Systematic molecular and genetic analyses of peripheral nerve terminals and dorsal root ganglia have advanced our understanding of the genetics of function and disease of peripheral nerves, as well as their physiology and clinical manifestations. Peripheral neuropathic pain, similar to central neuropathic pain, is primarily influenced by the biology and pathophysiology of the underlying structures, peripheral sensory nerves, and their central pathways. The clinical course is widely variable in sensory symptoms and intensities, natural history, and response to treatments.

Pediatric Pain

ABSTRACT OBJECTIVE This article reviews pain disorders encountered in pediatric neurology practice and provides current information regarding the assessment and treatment of pediatric chronic pain. LATEST DEVELOPMENTS Data about pediatric pain management remain sparse, owing to a dearth of controlled trials and longitudinal studies in these patients. However, the field of pain management and understanding of central and peripheral pain processing has expanded to allow more effective treatment of a broad group of children and adolescents with pain associated with neurologic disease. Neuroimaging visualizes sensory and nonsensory systems, and genetic markers of sensitivity and disease may guide specific therapy. The concept of central sensitization in chronic pain disorders has supported the development of multidisciplinary paradigms for the comprehensive care of these patients. ESSENTIAL POINTS Pain involves sensory activation and central nervous system modulation in pediatric patients. Pediatric neurologists should be prepared to define, investigate, and treat pain disorders in this complex patient population. Appropriate interventions during childhood may attenuate or prevent chronic pain later in life. Current interventions include behavioral, physical, and pharmacologic approaches, as well as potential noninvasive tools for neuromodulation. Research is progressing in sensory measurement, neuroimaging, genetics, and neuroinflammation to guide future targeted therapies.

Discriminating fingerprints of chronic neuropathic pain following spinal cord injury using artificial neural networks and mass spectrometry analysis of female mice serum

Spinal cord injury (SCI) often leads to central neuropathic pain, a condition associated with significant morbidity and is challenging in terms of the clinical management. Despite extensive efforts, identifying effective biomarkers for neuropathic pain remains elusive. Here we propose a novel approach combining matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with artificial neural networks (ANNs) to discriminate between mass spectral profiles associated with chronic neuropathic pain induced by SCI in female mice. Functional evaluations revealed persistent chronic neuropathic pain following mild SCI as well as minor locomotor disruptions, confirming the value of collecting serum samples. Mass spectra analysis revealed distinct profiles between chronic SCI and sham controls. On applying ANNs, 100% success was achieved in distinguishing between the two groups through the intensities of m/z peaks. Additionally, the ANNs also successfully discriminated between chronic and acute SCI phases. When reflexive pain response data was integrated with mass spectra, there was no improvement in the classification. These findings offer insights into neuropathic pain pathophysiology and underscore the potential of MALDI-TOF MS coupled with ANNs as a diagnostic tool for chronic neuropathic pain, potentially guiding attempts to discover biomarkers and develop treatments.

ID: 334170 Case Report: Spinal cord stimulation in the treatment of central pain syndrome ()

ID: 334170 Case Report: Spinal cord stimulation in the treatment of central pain syndrome ()

The effects of C-tactile stimulation on temporal summation of second pain: A study of the central and peripheral neural correlates

Affective touch is mediated by specialized receptors sensitive to gentle and slow touch called C-tactile afferents (CT). The activation of these receptors has shown promise in reducing subjective pain ratings, however, how this type of touch can affect central sensitization processes is poorly studied. This work aimed to investigate if affective touch is able to modulate pain sensitization and its electrophysiological correlates during Temporal Summation of Second Pain (TSSP), a phenomenon characterized by an increase in pain perception due to repeated noxious stimuli.Thirty-seven participants underwent a TSSP protocol involving three conditions: TSSP alone, TSSP during vibrotactile stimulation, and TSSP during CT stimulation (administered with a brush mounted in a robot arm). We measured subjective pain ratings, electroencephalographic (N2-P2 complex) and electrocardiographic activity during these conditions.Participants reported a significantly lower increase of pain during CT stimulation compared to vibrotactile stimulation, but not to TSSP alone. In addition, TSSP was reduced when administered in the ipsilateral arm compared to the other somatosensory stimulation. Subjective reports of attention towards painful stimuli, amplitude of the N2-P2 complex, and heart rate were also reduced during CT stimulation. Conclusion: Our results indicated that the activation of CT receptors may reduce sensitization compared to other types of somatosensory stimulation, which is possibly related to the reduction of the attention devoted to nociceptive stimulation. Our results suggest that activation of CT receptors may alleviate the occurrence of central pain sensitization.

Neurotensin-expressing lateral hypothalamic neurons alleviate neuropathic and inflammatory pain via neurotensin receptor signaling

Persistent, severe pain negatively impacts health and wellbeing, but half of patients do not receive adequate relief from current treatments. Understanding signals that modulate central pain processing could point to new strategies to manage severe pain. Administering Neurotensin (Nts) or Nts receptor (NtsR) agonists into the brain provides analgesia comparable to pharmacologic opioids. However, the endogenous sources of Nts that modify pain processing and might be leveraged for pain relief remained unknown. We previously characterized a large population of Nts-expressing neurons in the lateral hypothalamic area (LHANts neurons) that project to brain regions that participate in descending control of pain processing. We hypothesized that LHANts neurons are an endogenous source of Nts and activating them would alleviate pain dependent on Nts signaling via NtsRs. To test this, we injected NtsCre mice in the LHA with AAVs to cre-dependently express either mCherry (Control) or the excitatory hM3Dq in LHANts neurons, permitting their stimulation after treatment with the hM3Dq ligand clozapine N-oxide (CNO). Activating LHANts neurons had no effect on thermal pain and mechanical responses in naïve mice. By contrast, both spared nerve injury- (SNI) and complete Freund’s adjuvant (CFA)-induced mechanical hypersensitivity was completely reversed by CNO-stimulation of LHANts neurons. Pretreatment with the Nts receptor antagonist SR142948 reduced CNO-mediated analgesia, indicating that LHANts neurons alleviate chronic pain in an Nts receptor-dependent manner. Taken together these data identify LHANts neurons as an endogenous source of Nts that modulates central pain processing and may inform future development of Nts-based targets to treat severe pain.

Postsurgical tactile-evoked pain: a role for brain-derived neurotrophic factor-tropomyosin receptor kinase B-dependent novel tactile corpuscles.

Millions of people undergo surgical procedures each year with many developing postsurgical pain. Dynamic allodynia can arise when, for example, clothing brushing close to the surgical site elicits pain. The allodynia circuits that enable crosstalk between afferent tactile inputs and central pain circuits have been studied, but the peripheral tactile drive has not been explored. Investigate the innervation of the skin in the rat plantar hindpaw skin-muscle incision model. Incision increased epidermal thickness and cell layers and reduced intraepidermal nerve fibre density, identified with PGP9.5 immunostaining. Strikingly, Collagen IV immunostaining revealed the development of dermal protrusions, oriented towards the incision site, that were reminiscent of the dermal papillae that exist in glabrous footpads. S100 immunostaining for lamellar Schwann cells revealed the presence of novel tactile corpuscles (S100-positive bulb) within incision-induced putative dermal papillae. The occurrence of these novel tactile corpuscles coincided with behavioural observations of dynamic allodynia. Tactile corpuscles require brain-derived neurotrophic factor- tropomyosin receptor kinase B (BDNF-TrkB) signalling to form during development, and an increase in BDNF-immunostaining intensity was observed close to the incision site. Local acute administration of TrkB-Fc, to block BDNF-TrkB signalling, reduced, by approximately 50%, both tactile corpuscle size (S100+ bulb area) and dynamic allodynia. Surgery induces the development of novel tactile corpuscles in the incision surround, in a BDNF-TrKB-dependent manner, that contributes to postsurgical tactile-evoked pain.

CENTRAL POST-STROKE PAIN: A SCOPING REVIEW

Introduction: Central post-stroke pain (CPSP) is a neuropathic pain syndrome that can affect individuals who have suffered a stroke and which is still under-recognized by doctors. CPSP has an estimated prevalence of 11% and is more common in lesions involving the thalamus. Diagnosis is challenging due to the variable clinical manifestations and the lack of specific diagnostic criteria. The study aims to gather up-to-date information on this condition and highlight the importance of its early recognition. Methodology: This is a descriptive review of the literature in Medline databases, including articles from 2014 to 2024. A total of 468 articles were initially found, of which 43 were selected after applying inclusion and exclusion criteria. Results and discussion: Risk factors were identified as involvement of the spinothalamic pathway, presence of sensory deficits, female gender, young age, and initial stroke severity. The clinical characteristics of CPSP include pain and sensory abnormalities in the regions corresponding to the injured brain territory. The differential diagnosis includes other etiologies, such as post-stroke spasticity, complex regional pain syndrome, headache and shoulder pain. CPSP has a significant impact on quality of life and is associated with psychological disorders and functional limitations. Conclusion: It is understood that early recognition and appropriate management of CPSP are essential for improving patients' quality of life, highlighting the need for clear diagnostic criteria and effective treatments.