Neuropathic and Nociplastic Pain Profiles are Common in Adult Chronic Nonbacterial Osteitis (CNO).

Chronic nonbacterial osteitis (CNO) is a rare musculoskeletal disease causing chronic bone pain. It is known that chronic musculoskeletal pain may involve other mechanisms than nociceptive pain only. We investigate the prevalence of neuropathic and nociplastic pain in adult CNO and their association with clinical characteristics and treatment outcomes. Survey study among the Dutch adult CNO cohort (n = 84/195 participated), including PAIN-detect for neuropathic pain, and the Central Sensitization Inventory (CSI), Fibromyalgia Rapid Screening Tool (FiRST), and ACTTION-APS Pain Taxonomy (AAPT) for nociplastic pain. Clinical characteristics and CNO-related bone pain scores were compared between patients with exclusive nociceptive pain and those with nociceptive pain plus neuropathic and/or nociplastic pain (mixed pain). 31% (95% CI 21-41) of patients classified as likely having neuropathic pain according to PAIN-detect. 53% (41-64) of patients displayed central sensitization on CSI, 61% (50-72) screened positive for fibromyalgia on FiRST and 14% (7-23) of patients fulfilled the AAPT criteria, all indicative of nociplastic pain. Mixed pain was associated with longer diagnostic delay (mean difference 2.8 years, 95% CI 0.4-5.2, p = 0.023), lower educational level (72% versus 20%, p < 0.001), and opioid use (37% versus 13%, p = 0.036). Despite comparable disease severity and extent, patients with mixed pain reported significantly higher CNO-related bone pain scores. This study demonstrates the high prevalence of mixed pain in adult CNO, in which neuropathic and nociplastic pain exist alongside nociceptive inflammatory bone pain. Disease burden in CNO may extend beyond inflammatory activity, highlighting the need for a multifaceted management approach.

Translation and cross-cultural adaptation of Polish version of Neuropathic Pain Questionnaire (NPQ-PL) and its comparisons with different questionnaires.

AIM OF THE STUDY: The aim of this study was to assess the validity and reliability of the Polish version of the Neuropathic Pain Questionnaire (NPQ-PL), and to compare it to other diagnostic tools. CLINICAL RATIONALE FOR THE STUDY: Neuropathic pain is a burdensome condition, of which the exact prevalence is difficult to estimate. During initial screening, pain questionnaires are helpful in alerting clinicians about the need for further evaluation. MATERIAL AND METHODS: The NPQ-PL has been developed following the guidelines for translation and cultural adaptation. A total of 140 patients with chronic pain (ChP), 90 with neuropathic pain (NP), and 50 with nociceptive pain (NoP), were enrolled into this study. RESULTS: The study group consisted of 60.71% women and 39.29% men; the mean age of patients (standard deviation, SD) was 53.22 years (15.81), and the average NPQ-PL score (SD) was 0.49 (1.27). Statistically significant relationships were found between higher age distribution and greater pain intensity in the NP group compared to the NoP group. There were also significant differences in pain levels between people of different ages, with the predominance in the elderly. Cronbach's alpha coefficient of the whole questionnaire was 0.85 and the intraclass correlation coefficient (ICC) for test-retest reliability was 0.635. Using receiver-operating characteristic (ROC) curve analysis, the area under the curve (AUC) was 0.97 and the best cut-off value was 0.002, which resulted in the highest sensitivity (93.3%) and specificity (96.0%). CONCLUSIONS AND CLINICAL IMPLICATIONS: The NPQ-PL is a valid tool for discriminating between neuropathic and nociceptive pain. It can be used by physicians of various disciplines when assessing patients with ChP of various origins.

Nociplastic pain: towards an understanding of prevalent pain conditions.

Nociplastic pain is the semantic term suggested by the international community of pain researchers to describe a third category of pain that is mechanistically distinct from nociceptive pain, which is caused by ongoing inflammation and damage of tissues, and neuropathic pain, which is caused by nerve damage. The mechanisms that underlie this type of pain are not entirely understood, but it is thought that augmented CNS pain and sensory processing and altered pain modulation play prominent roles. The symptoms observed in nociplastic pain include multifocal pain that is more widespread or intense, or both, than would be expected given the amount of identifiable tissue or nerve damage, as well as other CNS-derived symptoms, such as fatigue, sleep, memory, and mood problems. This type of pain can occur in isolation, as often occurs in conditions such as fibromyalgia or tension-type headache, or as part of a mixed-pain state in combination with ongoing nociceptive or neuropathic pain, as might occur in chronic low back pain. It is important to recognise this type of pain, since it will respond to different therapies than nociceptive pain, with a decreased responsiveness to peripherally directed therapies such as anti-inflammatory drugs and opioids, surgery, or injections.

Comparison of the serum brain-derived neurotrophic factor (BDNF) between fibromyalgia and nociceptive pain groups; and effect of duloxetine on the BDNF level.

BACKGROUND: The primary objective was to compare the serum brain-derived neurotrophic factor (BDNF) level in the patients with two types of pain: fibromyalgia (FM) and non-FM nociceptive pain (non-FM NP). The secondary objective was to investigate the effect of duloxetine on serum BDNF in FM patients and assess the direction of BDNF changes' relation to clinical parameters' alterations. METHODS: This is a study on 73 patients (50 FM and 23 non-FM chronic non-inflammatory pain patients). Serum BDNF was first compared between both groups. Patients with FM, then prospectively, underwent standardized FM treatment with duloxetine maximized to 60 mg/day. The Revised Fibromyalgia Impact Questionnaire (FIQR), Short-Form Health Survey (SF-12), pain visualized analog scale (pain VAS), Beck Depression Inventory-II (BDI-II), polysymptomatic distress scale (PSD) and serum BDNF were measured and compared at baseline and 4 weeks after treatment in FM group. RESULTS: The mean of adjusted BDNF level in the FM group had no significant difference than the non-FM NP group ((5293.5 ± 2676.3 vs. 6136.3 ± 4037.6; P value = 0.77). Using linear mixed model, we showed that duloxetine reduced BDNF level significantly in FM patients, even after adjusting for depression, pain and severity of the disease (P < 0.01). The FIQR, BDI-II, PSD, and pain VAS improved significantly after duloxetine treatment. CONCLUSIONS: Non-significant BDNF level difference between FM and non-FM nociceptive pain suggested that peripheral BDNF is not a pathophysiological feature of FM. The decreased BDNF level parallel with improvement of PSD/pain scores after duloxetine treatment indicates BDNF alteration in the pain modulation process, regardless of cause and effect.

Angiotensin (1-7) Attenuates the Nociceptive Behavior Induced by Substance P and NMDA via Spinal MAS1.

The intrathecal (i.t.) injection of substance P (SP) and N-methyl-D-aspartate (NMDA) induce transient nociceptive response by activating neurokinin (NK) 1 and NMDA receptors, respectively. We have recently reported that angiotensin (Ang) (1-7), an N-terminal fragment of Ang II, could alleviate several types of pain including neuropathic and inflammatory pain by activating spinal MAS1. Here, we investigated whether Ang (1-7) can inhibit the SP- and NMDA-induced nociceptive response. The nociceptive response induced by an i.t. injection of SP or NMDA was assessed by measuring the duration of hindlimb scratching directed toward the flank, biting and/or licking of the hindpaw or the tail for 5 min. Localization of MAS1 and either NK1 or NMDA receptors in the lumbar superficial dorsal horn was determined by immunohistochemical observation. The nociceptive response induced by SP and NMDA was attenuated by the i.t. co-administration of Ang (1-7) (0.03-3 pmol) in a dose-dependent manner. The inhibitory effects of Ang (1-7) (3 pmol) were attenuated by A779 (100 pmol), a MAS1 antagonist. Moreover, immunohistochemical analysis showed that spinal MAS1 co-localized with NK1 receptors and NMDA receptors on cells in the dorsal horn. Taken together, the i.t. injection of Ang (1-7) attenuated the nociceptive response induced by SP and NMDA via spinal MAS1, which co-localized with NK1 and NMDA receptors. Thus, the spinal Ang (1-7)/MAS1 pathway could represent a therapeutic target to effectively attenuate spinal pain transmission caused by the activation of NK1 or NMDA receptors.

Can the Nociception Coma Scale-Revised Be Used in Patients With a Tracheostomy?

OBJECTIVE: To investigate the influence of the presence of a tracheostomy tube to assess pain with the Nociception Coma Scale-Revised (NCS-R) in patients with disorders of consciousness (DOC). DESIGN: A cohort study in which patients were evaluated at a single time point. SETTING: Patients were evaluated in a tertiary care hospital. PARTICIPANTS: Patients (N=125) (unresponsive wakefulness syndrome [UWS]: 46 patients, minimally conscious state [MCS]: 74 patients, emerging from MCS [eMCS]: 5 patients, mean age: 46±16y, time since injury: 817±1280d) in a convenience sample were evaluated with the NCS-R after noxious stimulation. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: We compared the NCS-R scores of patients with and without tracheostomy with a Mann-Whitney U test. A secondary outcome was to evaluate the influence of the presence of a tracheostomy on the previously described cutoff score of 2. RESULTS: The presence of a tracheostomy was associated with lower verbal subscores (P=.002) as well as total scores (P=.039). The cutoff score of 2 remained valid for the group of patients with tracheostomy with a high sensitivity (71.43%) and specificity (89.29%), as well as when we excluded the verbal subscore of the NCS-R (sensitivity=83.2% and specificity=92.4%). CONCLUSION: Our study confirms the validity of the NCS-R in DOC patients with a tracheostomy. However, the presence of a nonspeaking tracheostomy should be clearly mentioned when applying the NCS-R, because it significantly lowers the verbal subscore.

Objective monitoring of nociception: a review of current commercial solutions.

Nociception, in contrast to pain, is not a subjective feeling, but the physiological encoding and processing of nociceptive stimuli. However, monitoring nociception remains a challenge in attempts to lower the incidence of acute postoperative pain and the move towards a more automated approach to analgesia and anaesthesia. To date, several commercialised devices promise a more accurate reflection of nociception than the traditionally used vital signs, blood pressure and heart rate. This narrative review presents an overview of existing technologies and commercially available devices, and offers a perspective for future research. Although firm conclusions about individual methods may be premature, none currently appears to offer a sufficiently broad applicability. Furthermore, there is currently no firm evidence for any clinically relevant influence of such devices on patient outcome. However, the available monitors have significantly aided the understanding of underlying mechanisms and identification of potential pitfalls.

Multiple types of somatic pain increase suicide attempts and depression: A nationwide community sample of Korean adults.

OBJECTIVE: Somatic pain is an important risk factor for suicide and suicidal behaviors. However, the association between the number of somatic pain conditions and lifetime suicide attempts (LSA) has not been well established yet. Therefore, the objective of this study was to examine associations between LSA and multiple somatic pain (MSP), singe pain, and no pain in a nationwide survey. METHODS: A total of 12,532 adults were randomly selected from the population using the one-person-per-household method. Each participant completed a face-to-face interview using the Korean Composite International Diagnostic Interview (K-CIDI) with Suicide Module, and the Barratt Impulsiveness Scale 11 (BIS-11). The MSP was defined as pain in two or more parts of one's body, including abdominal pain, back pain, arthralgia, arm or leg pain, chest pain, headache, menstrual pain, dysuria, genital pain, and other pain. RESULTS: Among 12,532 subjects, 858 (6.85%) had MSP. Among the three groups (MSP, single pain, and no pain) of subjects, the MSP group had higher percentages of females, those with lower education, and divorced/widowed/separated individuals. However, there were no significant differences in monthly income or residence among the three groups. The MSP group showed four times higher suicide attempts and six times higher multiple attempts than did the no pain group. The BIS total score of the MSP group was the highest among the three groups. Genital pain showed the highest odds ratio for LSA. The higher the number of somatic pain, the higher the odds ratios were for LSA, major depressive disorder (MDD), and anxiety disorders. Subjects having both MSP and MDD showed a significant association with LSA (AOR = 14.78, 95% CI 10.08-21.67, p < 0.001) compared to those having neither somatic pain nor MDD. CONCLUSIONS: MSP was significantly associated with LSA. It had greater prevalence among individuals reporting a higher number of somatic pain conditions and comorbid MDD.

Pain assessment with the revised nociception coma scale and outcomes of patients with unresponsive wakefulness syndrome: results from a pilot study.

The aim of this study was to evaluate whether standardized responses to nociceptive pain, assessed with the revised Nociception Coma Scale (NCS-R), were correlated with the outcomes of patients with unresponsive wakefulness syndrome (UWS) 6 months after admission to a rehabilitation department. We recruited 24 consecutive patients with UWS. Patients' consciousness levels were assessed with the revised Coma Recovery Scale (CRS-R) at admission and 6 months later, and their CRS-R scores were correlated with the NCS-R scores at admission. Ten of the 24 patients with UWS recovered consciousness after 6 months. The NCS-R score at admission was correlated with the CRS-R score at admission (P = 0.02), but not after 6 months (P = 0.6). Patients with and without consciousness improvement after 6 months showed no significant difference in the NCS-R total score and sub-scores at admission (P values > 0.05). In conclusion, the correlation between NCS-R and CRS-R scores at admission suggests that the standardized assessment of pain parallels patients' levels of consciousness, and may be helpful in the clinical evaluation of patients with UWS. Pain response assessed with the NCS-R was not related to the 6-month outcomes of patients with UWS.

Evidence of altered pressure pain thresholds in persons with disorders of consciousness as measured by the Nociception Coma Scale-Italian version.

Pain assessment in patients with disorders of consciousness (DoC) is a controversial issue for clinicians, who require tools and standardised procedures for testing nociception in non-communicative patients. The aims of the present study were, first, to analyse the psychometric properties of the Italian version of the Nociception Coma Scale and, second, to evaluate pressure pain thresholds in a group of patients with DoC. The authors conducted a multi-centre study on 40 healthy participants and 60 DoC patients enrolled from six hospitals in Italy. For each group an electronic algometer was used to apply all nociceptive pressure stimuli. Our results show that the Italian version of the NCS retains the good psychometric properties of the original version and is therefore suitable for standardised pain assessment in clinical practice. In our study, pressure pain thresholds measured in a group of patients in vegetative and minimally conscious state were relatively lower than pain threshold values found in a group of healthy participants. Such findings motivate additional investigation on possible pain sensitisation in patients with severe brain injury and multiple co-morbidities, and on application of tailored therapeutic approaches useful for pain management in patients unable verbally to communicate their feelings.

Hyperacusis in chronic pain: neural interactions between the auditory and nociceptive systems.

OBJECTIVE: Sensory disturbances are common in chronic pain patients. Hyperacusis can be an especially debilitating experience. Here, we review published work on how the auditory and nociceptive systems might interact in chronic pain syndromes to produce pain-hyperacusis. DESIGN: Literature review. STUDY SAMPLE: The PubMed and Scopus databases were searched for relevant articles published between 2000 and 2017 using the primary search terms "hyperacusis"/"hyperacousis" and "pain". Ten papers were found using this strategy. Supplementary sources were identified by browsing textbooks and the reference lists of identified articles. RESULTS: The importance of central mechanisms in pain-hyperacusis was highlighted in the 10 selected papers. Hyperacusis is a significant but under-recognised symptom in conditions such as complex regional pain syndrome and fibromyalgia, and an integral feature of migraine. CONCLUSIONS: Nociceptive circuits become hypersensitive in acute and chronic pain; this sensitivity spreads from the periphery to spinal neurons and higher centres in the brain, leading to hyperalgesia or spontaneous pain even in the absence of peripheral nociceptive input. This "central sensitisation" may alter activity at sensory convergence points in the thalamus and brainstem centres such as the locus coeruleus, and give rise to hyperacusis in certain pain syndromes.

Staged decrease of physical ability on the locomotive syndrome risk test is related to neuropathic pain, nociceptive pain, shoulder complaints, and quality of life in middle-aged and elderly people - The utility of the locomotive syndrome risk test.

OBJECTIVES: A locomotive syndrome (LS) risk test for evaluation of physical ability is recently proposed. The objective of this study is to evaluate the utility of this test by examining physical ability, neuropathic pain, nociceptive pain, shoulder complaints, and quality of life (QOL). METHODS: A prospective cohort study was conducted in 523 subjects (240 males, 283 females; mean age: 63.3 years) at a health checkup. Data collected using visual analog scales (VAS) for shoulder pain, low back pain, sciatica, and knee pain, neuropathic pain, shoulder complaint, body mass index (BMI), osteoporosis, and SF-36 were compared among three LS risk stages. RESULTS: Subjects in LS risk stage 1 (24%) had significantly more osteoporosis, slower gait speed, weaker muscle strength and higher VAS, with no difference in age and BMI compared to those with no LS risk (50%). Subjects in stage 2 (26%) had significantly poorer results for all items. Shoulder complaint, neuropathic pain and QOL differed significantly among all three groups and worsened with decline in mobility on the LS risk test. CONCLUSIONS: LS risk test is easy and useful screening tool for evaluation of mobility and for screening for pain and complaint associated with activity of daily living and QOL.

Pain following cancer treatment: Guidelines for the clinical classification of predominant neuropathic, nociceptive and central sensitization pain.

BACKGROUND: In addition to fatigue, pain is the most frequent persistent symptom in cancer survivors. Clear guidelines for both the diagnosis and treatment of pain in cancer survivors are lacking. Classification of pain is important as it may facilitate more specific targeting of treatment. In this paper we present an overview of nociceptive, neuropathic and central sensitization pain following cancer treatment, as well as the rationale, criteria and process for stratifying pain classification. MATERIAL AND METHODS: Recently, a clinical method for classifying any pain as either predominant central sensitization pain, neuropathic or nociceptive pain was developed, based on a large body of research evidence and international expert opinion. We, a team of 15 authors from 13 different centers, four countries and two continents have applied this classification algorithm to the cancer survivor population. RESULTS: The classification of pain following cancer treatment entails two steps: (1) examining the presence of neuropathic pain; and (2) using an algorithm for differentiating predominant nociceptive and central sensitization pain. Step 1 builds on the established criteria for neuropathic pain diagnosis, while Step 2 applies a recently developed clinical method for classifying any pain as either predominant central sensitization pain, neuropathic or nociceptive pain to the cancer survivor population. CONCLUSION: The classification criteria allow identifying central sensitization pain following cancer treatment. The recognition of central sensitization pain in practice is an important development in the integration of pain neuroscience into the clinic, and one that is relevant for people undergoing and following cancer treatment.

Interface Pressure Behavior During Painful Cuff Algometry.

OBJECTIVE: Cuff algometry is used for the psychophysical assessment of deep-tissue pain sensitivity. The cuff pressure homogeneity may affect the pain sensitivity assessment and potentially be improved by alternative cuff designs optimizing the pressure distribution. The aim of this study was to investigate the relationship between pain sensitivity, inflation pressure, and distribution of interface pressure between the skin and cuff during stimulation with a conventional air tourniquet and a novel tourniquet including a water tube interfacing the air cuff with the skin. METHODS: Air and water cuff stimulations were applied separately on the right lower leg of 12 subjects until the tolerance pain threshold. The inflation pressure was controlled and recorded by a computer-control program, while the interface pressure distribution was measured by a flexible pressure sensor mat located between the cuff and skin. RESULTS: The mean interface pressure across the entire stimulation surface was not significantly different from inflating pressure during air-cuff algometry. For the water cuff there was a significant reduction in the mean interface pressure compared with the inflating pressure at both the detection and tolerance pain levels (P < 0.002). The interface pressure distribution of the water cuff around the limb was significantly more homogeneous compared with the air cuff (P < 0.03). This homogeneity showed a significant correlation with pain sensitivity (P < 0.008). CONCLUSION: Cuff systems with a liquid medium optimize the homogeneity of the interface pressure distribution. However, the deviation of the interface pressure from the inflating pressure is crucial as it counteracts the effects of pressure homogeneity on pain sensitivity in water-cuff algometry.

Monitoring heart rate variability to assess experimentally induced pain using the analgesia nociception index: A randomised volunteer study.

BACKGROUND: Pain assessment using a numerical rating scale (NRS) is considered good clinical practice, but objective assessment in noncommunicating patients is still a challenge. A potential solution is to monitor changes in heart rate variability transformed into the analgesia nociception index (ANI), that offers a noninvasive means of pain quantification. OBJECTIVES: The aim was to measure magnitudes, descending slopes and time courses of ANI following expected and unexpected painful, nonpainful and sham experimental stimuli and compare these with pain intensity as assessed by NRS in conscious human volunteers. We expected a negative correlation between ANI and NRS after painful stimuli. DESIGN: Randomised stimuli and placebo-controlled, single-blinded study. SETTING: Experimental pain simulation laboratory, Bochum, Germany. PARTICIPANTS: Twenty healthy male students, (mean ±â€Šstandard deviation; 24.2 ±â€Š1.9 years) recruited via local advertising, were consecutively included. INTERVENTION: ANI values were continuously recorded. After resting, four stimuli were applied in a random order on the right forearm (unexpected and expected electrical pain, expected nonpainful and sham stimuli). Blinded volunteers were asked to rate all four stimuli on NRS. MAIN OUTCOME MEASURES: ANI means (0-100), amplitudes, maxima, minima and slopes with NRS pain intensity scores (0-10). RESULTS: Resting alert volunteers showed ANI values of 82.05 ±â€Š10.71. ANI decreased after a random stimulus (maximal decrease of 25.0 ±â€Š7.3%), but different kinds of stimuli evoked similar results. NRS scores (median; interquartiles) were significantly (P = 0.008) higher after expected (5.25; 3.5-6.75) compared with unexpected (4.50; 3.0-5.0) pain stimuli. No correlation was found between ANI and NRS. CONCLUSION: ANI did not allow a differentiation of painful, nonpainful or sham stimuli in alert volunteers. Therefore, ANI does not exclusively detect nociception, but may be modified by stress and emotion. Thus, we conclude that ANI is not a specific, robust measure for assessment of pain intensity.

Translation, Cultural Adaptation, and Validation of Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) and Self-Complete Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) Questionnaires into the Greek Language.

BACKGROUND: The LANSS and S-LANSS questionnaires represent two widely accepted and validated instruments used to assist the identification of neuropathic pain worldwide. OBJECTIVE: The aim of this study was to translate, culturally adapt, and validate the LANSS and S-LANSS questionnaires into the Greek language. METHODS: Forward and backward translations of both questionnaires were performed from the English to Greek language. The final versions were assessed by a committee of clinical experts, and they were then pilot-tested in 20 patients with chronic pain. Both questionnaires were validated in 200 patients with chronic pain (100 patients for each questionnaire), using as the "gold standard" the diagnosis of a clinical expert in pain management. Sensitivity and specificity of questionnaires were assessed, as well as the internal consistency (using Cronbach's alpha coefficient) and correlation with the "gold standard" diagnosis (using Pearson correlation coefficient). RESULTS: Sensitivity and specificity of the LANSS questionnaire were calculated to be 82.76% and 95.24%, while for the S-LANSS 86.21% and 95.24%, respectively. Positive predictive value for neuropathic pain was 96% for the LANSS and 96.15% for the S-LANSS. Cronbach's alpha was revealed to be acceptable for both questionnaires (0.65 for LANSS and 0.67 for the S-LANSS), while a significant correlation was observed compared to the "gold standard" diagnosis (rLANSS   = 0.79 και tSLANSS   = 0.77, respectively, P = 0.01). CONCLUSIONS: The LANSS and the S-LANSS diagnostic tools have been translated and validated into the Greek language and can be adequately used to assist the identification of neuropathic pain in everyday clinical practice.

A study of the reliability of the Nociception Coma Scale.

OBJECTIVE: In this study, we investigated the reliability of the Nociception Coma Scale which has recently been developed to assess nociception in non-communicative, severely brain-injured patients. DESIGN: Prospective cross-sequential study. SETTING: Semi-intensive care unit and long-term brain injury care. SUBJECTS: Forty-four patients diagnosed as being in a vegetative state (n=26) or in a minimally conscious state (n=18). INTERVENTIONS: Patients were assessed by two experts (rater A and rater B) on two consecutive weeks to measure inter-rater agreement and test-retest reliability. MAIN MEASURES: Total scores and subscores of the Nociception Coma Scale. RESULTS: We performed a total of 176 assessments. The inter-rater agreement was moderate for the total scores (k = 0.57) and fair to substantial for the subscores (0.33 ≤ k ≤ 0.62) on week 2. The test-retest reliability was substantial for the total scores (k = 0.66) and moderate to almost perfect for the subscores (0.53 ≤ k ≤ 0.96) for rater A. The inter-rater agreement was weaker on week 1, whereas the test-retest reliability was lower for the least experienced rater (rater B). CONCLUSIONS: This study provides further evidence of the psychometric qualities of the Nociception Coma Scale. Future studies should assess the impact of practical experience and background on administration and scoring of the scale.

Evaluation of quality of life and neuropathic pain in patients with low back pain using the Japanese Orthopedic Association Back Pain Evaluation Questionnaire.

PURPOSE: To examine the impact that neuropathic or nociceptive pain has on the quality of life (QOL) in patients with low back pain (LBP) using the Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and the Japanese version of the PainDETECT Questionnaire (PDQ-J). METHODS: Between June 2012 and December 2013, 650 new patients were treated at our institution for LBP. All patients between the ages of 20 and 79 were asked to complete a set of questionnaires including the PDQ-J, a pain visual analog scale (VAS), the JOABPEQ, and the Short Form 36 (SF-36). Based on the PDQ-J scores, participants were classified into three groups: a neuropathic pain group, a nociceptive pain group, and an intermediate mixed pain group. Among them, patients with clear neuropathic and nociceptive LBP were selected. To investigate the differences between neuropathic and nociceptive LBP, diagnosis of spinal disorder, prevalence, age, gender, duration of symptoms, VAS scores, and self-reported general health (SF-36 and JOABPEQ) were compared between the neuropathic and nociceptive pain groups. RESULTS: Of 650 patients with LBP, 331 completed the questionnaires and were enrolled in the study. There were 193 men (58.3 %) and 138 women (41.7 %) with a mean age of 54.5 years (range 20-79 years). From the PDQ-J survey, 49 patients (15 %) were classified as having neuropathic pain, and 190 (58 %) were categorized as having nociceptive pain. Patients in the neuropathic pain group had significantly higher VAS scores and lower SF-36 and JOABPEQ scores compared to the nociceptive pain group. CONCLUSION: We examined the impact of nociceptive or neuropathic LBP on QOL. A comparison of JOABPEQ scores between LBP patients assessed by PDQ-J as having neuropathic pain or nociceptive pain suggests that neuropathic pain affects the social and psychological well-being of LBP patients.

Cross-cultural Adaptation and Linguistic Validation of the Korean Version of the Leeds Assessment of Neuropathic Symptoms and Signs Pain Scale.

Distinction between neuropathic pain and nociceptive pain helps facilitate appropriate management of pain; however, diagnosis of neuropathic pain remains a challenge. The aim of this study was to develop a Korean version of the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) pain scale and assess its reliability and validity. The translation and cross-cultural adaptation of the original LANSS pain scale into Korean was established according to the published guidelines. The Korean version of the LANSS pain scale was applied to a total of 213 patients who were expertly diagnosed with neuropathic (n = 113) or nociceptive pain (n = 100). The Korean version of the scale had good reliability (Cronbach's α coefficient = 0.815, Guttman split-half coefficient = 0.800). The area under the receiver operating characteristic curve was 0.928 with a 95% confidence interval of 0.885-0.959 (P < 0.001), suggesting good discriminate value. With a cut-off score ≥ 12, sensitivity was 72.6%, specificity was 98.0%, and the positive and negative predictive values were 98% and 76%, respectively. The Korean version of the LANSS pain scale is a useful, reliable, and valid instrument for screening neuropathic pain from nociceptive pain.

The effects of low-dose ketamine on the analgesia nociception index (ANI) measured with the novel PhysioDoloris™ analgesia monitor: a pilot study.

The PhysioDoloris™ analgesia monitor assesses nociception effects on the autonomic nervous system by analyzing changes in heart rate variability (HRV). This non-invasive device analyses ECG signals and determines the analgesia nociception index (ANI), allowing for quantitative assessment of the analgesia/nociception balance in anesthetized patients. Ketamine, an analgesic adjuvant with sympathomimetic properties, has been shown to improve perioperative pain management. The purpose of this pilot study was to evaluate whether low-dose ketamine, due to its intrinsic effect on the sino-atrial node, affects HRV and, therefore, interferes with ANI measurements. This pilot study included 20 women undergoing abdominal hysterectomies. Anesthesia and analgesia were maintained with sevoflurane and fentanyl respectively, in a standardized manner. Five minutes after intubation, 0.5 µg kg(-1) of intravenous (i.v.) ketamine was administered. ANI, bispectral index (BIS), heart rate and blood pressure were recorded from the induction of anesthesia until 5 min after skin incision. There was not any significant decrease in mean (±SD) ANI values after intubation (2.11±20.11, p=0.35) or i.v. ketamine administration (1.31±15.26, p=0.28). The mean (±SD) reduction in ANI values after skin incision was statistically significant (13.65±15.44, p=0.01), which is consistent with increased nociception. A single i.v. bolus of 0.5 µg kg(-1) ketamine did not influence the ANI values of 20 women under standardized general anesthesia conditions and absent noxious stimulation. These results suggest that the ANI derived from the PhysioDoloris™ analgesia monitor is feasible under such clinical conditions.