Neuropathic pain component and its association with time elapsed since pain onset in patients with low back pain.

BACKGROUND: Time elapsed since pain onset might affect the likelihood of neuropathic component in low back pain. The aim of this study was to investigate the relationship between neuropathic pain component and pain duration in patients with low back pain and to identify factors associated with neuropathic pain component. METHODS: Patients with low back pain who received treatment at our clinic were enrolled. Neuropathic component was assessed using the painDETECT questionnaire at the initial visit. PainDETECT scores and the results for each item were compared according to pain duration category (< 3 months, 3 months to 1 year, 1 year to 3 years, 3 years to 10 years, and ≥ 10 years). A multivariate analysis was used to identify factors associated with neuropathic pain component (painDETECT score ≥ 13) in low back pain. RESULTS: A total of 1957 patients, including 255 patients who reported neuropathic-like pain symptoms (13.0%), fully satisfied the study criteria for analysis. No significant correlation between painDETECT score and pain duration was observed (ρ = -0.025, p = 0.272), and there were no significant differences between median painDETECT score or trend of change in the proportion of patients with neuropathic component and the pain duration category (p = 0.307, p = 0.427, respectively). The electric shock-like pain symptom was frequently reported in patients with acute low back pain, and the persistent pain pattern with slight fluctuations was predominant in chronic low back pain. The pattern of attacks with pain between them was much less common in patients with pain for 10 years or longer. Multivariate analysis revealed that a history of lumbar surgery, severe maximum pain, opioid use, lumbosacral radiculopathy, and sleep disturbance were significantly associated with a neuropathic component in low back pain. CONCLUSION: Time elapsed since current pain onset did not correlate with neuropathic pain component in patients with low back pain. Therefore, diagnostic and therapeutic approaches for this condition should be based on a multidimensional evaluation at assessment and not on pain duration alone.

Heart rate and heart rate variability in patients with chronic inflammatory joint disease: the role of pain duration and the insular cortex.

BACKGROUND: Chronic inflammatory joint diseases (CIJD) have been linked to increased cardiovascular morbidity and mortality. A decisive reason could be a dysregulation of the autonomic nervous system, which is responsible for the control of cardiovascular function. So far, the cause of changes in autonomic nervous system functions remains elusive. In this study, we investigate the role of chronic pain and the insular cortex in autonomic control of cardiac functioning in patients with CIJD. METHODS: We studied the autonomic nervous system through the assessment of heart rate and heart rate variability (HRV) at rest and under cognitive stimulation. Furthermore, we investigated insular cortex volume by performing surface-based brain morphometry with FreeSurfer. For this study, 47 participants were recruited, 22 individual age- and sex-matched pairs for the magnetic resonance imaging analyses and 14 for the HRV analyses. All available patients' data were used for analysis. RESULTS: Pain duration was negatively correlated with the resting heart rate in patients with chronic inflammatory joint diseases (n = 20). In a multiple linear regression model including only CIJD patients with heart rate at rest as a dependent variable, we found a significant positive relationship between heart rate at rest and the volume of the left insular cortex and a significant negative relationship between heart rate at rest and the volume of the right insular cortex. However, we found no significant differences in HRV parameters or insular cortex volumes between both groups. CONCLUSIONS: In this study we provide evidence to suggest insular cortex involvement in the process of ANS changes due to chronic pain in CIJD patients. The study was preregistered with the German Clinical Trials Register ( https://www.drks.de ; DRKS00012791; date of registration: 28 July 2017).

Combination of Pain Location and Pain Duration is Associated with Central Sensitization-Related Symptoms in Patients with Musculoskeletal Disorders: A Cross-Sectional Study.

OBJECTIVES: Increased evidence indicates that pain location affects central sensitization (CS)-related symptoms. In addition, pain location and pain duration may be intricately related to CS-related symptoms. However, these factors have been investigated separately. This study aimed to investigate the association between CS-related symptoms and pain location and/or pain duration in patients with musculoskeletal disorders. METHODS: Six hundred thirty-five participants with musculoskeletal disorders were included in this cross-sectional study. All participants were assessed for pain location, pain duration, central sensitization inventory (CSI), EuroQol-5 dimension, and brief pain inventory. The participants were categorized into 3 groups based on pain location (spinal, limb, and both spinal and limb pain) and into 2 groups based on pain duration (acute and chronic pain). RESULTS: The interaction between pain location and pain duration were not significant on CSI score (P > 0.05). The odds ratio for higher CSI score (≥ 40) in patients with both spinal and limb pain vs. those with spinal or limb pain was 2.64 (P < 0.01) and that in patients with chronic pain vs. those with acute pain was 1.31 (P = 0.52). In addition, the prevalence of higher CSI scores in the combination of chronic and "both spinal and limb" pain was high (23.1%, adjusted residual = 4.48). CONCLUSIONS: Pain location independently influenced CSI scores, and the combination of both spinal and limb pain and chronic pain indicated high CSI scores. The combination of pain location and pain duration is an important clue that points to CS-related symptoms.

[The Mainz Pain Staging System is also suitable for grading chronic pain in inpatient geriatric patients]. / Das Mainzer Stadienmodell der Schmerzchronifizierung ist auch bei stationären geriatrischen Patienten zur Graduierung chronischer Schmerzen geeignet.

INTRODUCTION: The Mainz Pain Staging System (MPSS), which has been validated primarily in middle-aged and chronic low back pain patients, is designed to predict prognosis and control the use of resources at baseline. In multi-morbid and functionally impaired patients (geriatric patients) with multiple causes of pain, it is unclear whether this instrument can be implemented at all and whether it permits statements to be made on the severity of pain chronification. MATERIALS AND METHODS: Therefore, 173 consecutive patients with pain were classified in the second week of inpatient geriatric treatment according to the MPSS. For validation, the questions from the "Pain interview for geriatric patients" (SgP) were used. In addition, the MPSS was compared with the personal history of the duration of the main pain. RESULTS: With the exception of the questions on medication intake, the items in the MPSS could be collected predominantly by self-assessment. Even with current analgesic therapy, MPSS has significant correlations with sensory, affective, and emotional dimensions of pain from the SgP. The data on duration correlated with only one category of MPSS (spatial aspects of pain). CONCLUSION: MPSS can be used in multi-morbid and functionally impaired elderly patients undergoing inpatient treatment. Chronification features are more pronounced at higher stages than at lower levels. Only one category of the MPSS cannot be collected by self-assessment. The possibilities of prognosis estimation and resource control using the MPSS should be further investigated for these patients.

Oral health-related quality of life in patients with temporomandibular disorders: A case-control study considering psychological aspects.

OBJECTIVES: This case-control study aimed to compare patients with temporomandibular disorders (TMD) and healthy controls in terms of oral health-related quality of life (OHRQoL) considering Graded Chronic Pain Scale (GCPS) scores, pain duration, psychological impairment and demographic characteristics. METHODS: A total of 75 patients with TMD and 75 healthy controls were recruited. The short version of Oral Health Impact Profile (OHIP-14) was administered for evaluating the OHRQoL. Psychosocial impairments were assessed using the General Health Questionnaire-28 (GHQ-28). The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) axis I and II were also used for patient diagnosis and collecting GCPS scores, pain duration, age and gender. Independent-sample t tests, Pearson's chi-square tests and multiple logistic and linear regression models were applied for statistical analysis. RESULTS: The mean age of the patients was 34.3±12.4 years. A female-to-male ratio of 6:1 was seen in the TMD group. The prevalence and severity of the OHIP were significantly different between the TMD and control groups (66.7% vs 12.0% and 18.0 vs 9.2, respectively). According to multiple logistic regression for OHIP prevalence and multiple linear regression for OHIP severity in the TMD group, GCPS scores and pain duration, followed by psychological impairment, were the most important predictors of the OHRQoL. CONCLUSION: TMD negatively affected the OHRQoL, particularly in patients with psychological impairments. Meanwhile, age and gender did not seem to have a serious effect. Hence, promoting the quality of life of patients with TMD requires emphasis on chronic pain management and maintaining good mental health.

Does Duration of Neuropathic Pain Impact the Effectiveness of Pregabalin?

BACKGROUND: Patients with chronic pain conditions such as neuropathic pain frequently experience delays in diagnosis and treatment. Ideally, all patients should be treated in a timely manner, but in those patients with more established disease it is important to know that approved treatments remain effective. METHODS: This was a pooled analysis of 19 randomized placebo-controlled trials of pregabalin for peripheral neuropathic pain conditions, including diabetic peripheral neuropathy, postherpetic neuralgia, and post-traumatic/postsurgical pain. Patients were divided into 5 pain duration categories based on time since onset of pain (< 6 months, 6 months to < 1 year, 1 year to < 2 years, 2 years to < 5 years, and ≥ 5 years). Mean change in pain score at endpoint, vs. placebo, was assessed for each category, together with changes in Patient Global Impression of Change (PGIC) responders ("very much" or "much" improved at endpoint). RESULTS: The analysis included 5,783 patients (n = 3,619 pregabalin; n = 2,164 placebo). Mean baseline pain scores were similar across the pain duration categories (range 6.3 to 6.5). Pregabalin significantly improved pain score at endpoint, vs. placebo, in all patients together (treatment difference [95% confidence interval], -0.59 [-0.67, -0.52], P < 0.0001) and similarly in each pain duration category (P < 0.0001 for each). There were significantly more PGIC responders with pregabalin, vs. placebo, for all patients (45.0% vs. 30.9%, P < 0.0001) and each category separately (P < 0.001 for each). There were no consistent, significant differences in treatment response between the different pain duration categories. CONCLUSIONS: Pregabalin significantly improves pain irrespective of the length of time since onset of neuropathic pain.

BODY AWARENESS, STRESS AND SYMPTOMS IN AUTONOMIC DYSFUNCTION IN PATIENTS WITH CHRONIC PAIN: AN EXPLORATIVE STUDY.

Objective: To assess pain outcomes, stress levels and body awareness among patients with chronic pain and explore potential associations between these variables. Design: An explorative study. Methods: Patients with chronic pain in primary and specialist care were assessed regarding pain intensity using the Numerical Rating Scale (NRS; 0-10 point scale) and stress levels using the Stress and Crisis Inventory (SCI-93; 0-140). To assess body awareness, multidimensional assessment of interoceptive awareness (MAIA; 0-5), a widely used self-report measure of interoceptive bodily awareness was used. Results: Participants (n = 42) reported an average NRS of 4.4, elevated stress levels and low body awareness. Stress levels were moderately correlated with pain intensity (r = 0.53; p < 0.001; 95% confidence interval [CI] 0.25-0.72) and number of pain sites (r = 0.58; p < 0.001; 95% CI 0.32-0.76). The regression analysis showed that pain outcomes predicted stress level scores and explained almost 50% of variance (R 2 = 0.47, p < 0.001). Moreover, shorter pain duration predicted a higher body awareness (p = 0.04). Conclusion: In patients with chronic pain, high pain intensity and multiple painful sites seem to be associated with impaired stress regulation. The patients had low body awareness, which was negatively influenced by pain duration.

The Duration of Chronic Pain Can Affect Brain Functional Changes of the Pain Matrix in Patients with Chronic Back Pain: A Resting-State fMRI Study.

Purpose: This study was conducted to explore the differences in functional changes in the pain matrix in patients with chronic back pain (CBP) at different stages and identify whether these brain changes were related to the pain duration. Patients and Methods: In this study, 29 healthy individuals and 54 patients with CBP were recruited. According to the pain duration, 25 patients (3 to 12 months) were divided into the CBP-S group and 29 patients (≥ 24 months) were divided into the CBP-L group. All subjects completed clinical pain-related measurement and functional magnetic resonance imaging (fMRI) scans. Moreover, the amplitude of low-frequency fluctuation (ALFF), functional connectivity (FC), and correlation analysis were conducted in this study. Results: Compared with healthy controls, patients in the CBP-L group showed significantly decreased ALFF in the left precuneus. In the FC analysis, patients in the CBP-S and CBP-L groups showed significantly decreased FC in several regions in the bilateral orbitofrontal cortices (OFC) and the left ventral posterior insula. Moreover, there were significant differences in the FC between the left hyper granular insula and the probabilistic area in OFC in pairwise group comparisons. The correlation analysis results demonstrated that pain duration was correlated with these functional brain changes, and the ANCOVA results revealed that pain intensity and pain interference scores did not affect the FC analysis results. Conclusion: There are different changes in the pain neural matrix in patients with chronic pain at different stages. Furthermore, the pain duration is related to brain functional changes.

Effect of duration of preoperative pain on outcomes of total temporomandibular joint replacement.

The purpose of the study was to determine whether the duration of preoperative pain affects outcomes of temporomandibular joint replacement (TMJR). Twenty-seven patients who underwent primary TMJR between 1 July 2020 and 31 October 2022 were retrospectively assessed for duration of preoperative pain, level of preoperative and postoperative pain on a visual analogue scale (VAS; 0, none; 10, severe), preoperative and postoperative range of motion (ROM), and net change in quality of life (much better, better, same, worse, much worse), reporting the longest available follow up for each patient. Surgical success was defined as postoperative pain of ≤4 and postoperative ROM of ≥30 mm, or net change (Δ) in ROM of ≥10 mm. Regression analyses evaluated associations between independent variables and postoperative pain and ROM. At a mean follow-up of 17.8 (SD: 6.8, range 3-32) months , pain (5.1, SD: 2.2, p < 0.001) and ROM (9.3 mm, SD: 8.0, p<0.001) significantly improved. Quality of life was much better in 16 patients, better in eight, the same in one, and worse in two. Longer duration of preoperative pain tended to be negatively associated with postoperative ROM (ß = -0.27; 95% CI -0.6 to 0.0; p = 0.078) but was not associated with severity of postoperative pain. Surgical success was achieved in 23/27 patients. The successful group tended to have lower pain on VAS preoperatively (5.9, SD: 1.9) vs 7.5, SD: 1.3) and postoperatively (0.4, SD: 0.8 vs 4.8, SD: 2.6), and greater improvement in quality of life (much better: 14/23 vs 2/4). In conclusion, longer duration of preoperative pain tended to be associated with worse postoperative ROM following TMJR. Higher preoperative pain may be a predictor for unsuccessful surgery.

Predictive models of pain following root canal treatment: a prospective clinical study.

AIM: To determine the probability of the incidence, intensity, duration and triggering of post-endodontic pain, considering factors related to the patient (age, gender, medical evaluation) and to the affected tooth (group, location, number of canals, pulp vitality, preoperative pain, periapical radiolucencies, previous emergency access, presence of occlusal contacts with antagonist). METHODOLOGY: A total of 500 one-visit root canal treatments (RCTs) were performed on patients referred to an endodontist. Shaping of root canals was performed manually with Gates-Glidden drills and K-Flexofiles, and apical patency was maintained with a size 10 file. A 5% NaOCl solution was used for irrigation, and canals were filled with lateral compaction and AH-Plus sealer. Independent factors were recorded during the treatment, and characteristics of post-endodontic pain (incidence, intensity, type and duration) were later surveyed through questionnaires. Of the 500 questionnaires, 374 were properly returned and split in two groups for two different statistical purposes: 316 cases were used to adjust the logistic regression models to predict each characteristic of post-endodontic pain using predictive factors, and the remaining 58 cases were used to test the validity of each model. RESULTS: The predictive models showed that the incidence of post-endodontic pain was significantly lower when the treated tooth was not a molar (P = 0.003), demonstrated periapical radiolucencies (P = 0.003), had no history of previous pain (P = 0.006) or emergency endodontic treatment (P = 0.045) and had no occlusal contact (P < 0.0001). The probability of experiencing moderate or severe pain was higher with increasing age (P = 0.09) and in mandibular teeth (P = 0.045). The probability of pain lasting more than 2 days was increased with age (P = 0.1) and decreased in males (P = 0.007) and when a radiolucent lesion was present on radiographs (P = 0.1). CONCLUSIONS: Predictive formulae for the incidence, the intensity and the duration of post-endodontic pain were generated and validated taking account of the interrelation of multiple concomitant clinical factors. A predictive model for triggering post-endodontic pain could not be established.

Clinical indicators for recommending continued care to patients with neck pain in chiropractic practice: a cohort study.

BACKGROUND: Chiropractors' clinical indicators for recommending preventive continued care to patients with low back pain include previous pain episodes, a history of long pain duration and improvement after initial treatment. Our objectives were, in a cohort of patients with neck pain, to examine whether these clinical indicators were associated with being recommended continued care beyond 4 weeks, and if so whether this recommendation was dependent of chiropractor characteristics, as well as if the number of clinical indicators influenced this recommendation. METHODS: In this multi-center observational study, 172 patients seeking care for a new episode of neck pain in chiropractic practice in Norway were included between September 2015 and May 2016. The chiropractors treated their patients as per usual, and for this study, baseline data and 4-week follow-up data were used. Patient data included the clinical indicators (1) previous episodes of neck pain, (2) a history of long duration neck pain and (3) improvement four weeks after initial treatment. The recruiting chiropractors were asked at 4-week follow-up if each patient was recommended continued care, defined as care planned beyond the first 4 weeks. Univariate and multivariable logistic regression models investigated the association between clinical indicators and the continued care recommendation, as well as the influence of chiropractor characteristics on this recommendation. Cross tabulations investigated the relationship between the number of indicators present and recommendation of continued care. RESULTS: Long duration of neck pain was the strongest clinical indicator for being recommended continued care 4 weeks after the initial treatment. Chiropractor characteristics were not associated with this recommendation. In patients with all three clinical indicators present, 39% were recommended continued care. When two and one indicators were present, the percentages of those recommended continued care were 25% and 10%, respectively. CONCLUSION: Chiropractors recommended continued care for patients experiencing neck pain based on their history of long pain duration, and this was not influenced by characteristics of the chiropractor. This differs from previous studies of indicators for maintenance care in patients with low back pain.

Intramuscular injection of nerve growth factor as a model of temporomandibular disorder: nature, time-course, and sex differences characterising the pain experience.

Background: Temporomandibular disorder (TMD) is a common condition that frequently transitions to chronic symptoms. Experimental pain models that mimic the symptoms of clinical TMD may be useful in understanding the mechanisms, and sex differences, present in this disorder. Here we aimed to comprehensively characterise the nature and time-course of pain, functional impairment and hyperalgesia induced by repeated intramuscular injection of nerve growth factor (NGF) into the masseter muscle, and to investigate sex differences in the NGF-induced pain experience. Methods: 94 healthy individuals participated in a longitudinal study with 30-day follow-up. NGF was injected into the right masseter muscle on Day 0 and Day 2. Participants attended laboratory sessions to assess pain (Numerical Rating Scale; NRS), functional limitation (mouth opening distance, Jaw Functional Limitation Scale; JFLS) and mechanical sensitization (pressure pain thresholds; PPTs) on Days 0, 2 and 5 and completed twice daily electronic pain dairies from Day 0 to day 30. Results: Peak pain averaged 2.0/10 (95 % CI: 1.6-2.4) at rest and 4.3/10 (95 % CI: 3.9-4.8) on chewing. Pain-free mouth opening distance reduced from 5.0 cm (95 % CI: 4.8-5.1 cm) on Day 0 to 3.7 cm (95 % CI: 3.5-3.9 cm) on Day 5. The greatest reduction in PPTs was observed over the masseter muscle. Females experienced higher pain, greater functional impairment, and greater sensitivity to mechanical stimuli than males. Conclusion: Intramuscular injection of NGF is a useful model with which to explore the mechanisms, and sex differences, present in clinical TMD.

Postural sway does not differentiate individuals with chronic low back pain, single and multisite chronic musculoskeletal pain, or pain-free controls: a cross-sectional study of 229 subjects.

BACKGROUND CONTEXT: Physical activity in its various forms are the most recommended prevention and treatment strategy for chronic low back pain (CLBP). Standing postural stability is a prerequisite for many types of physical activities. Systematic reviews have investigated the evidence for an association between CLBP and postural stability but results remain inconclusive. PURPOSE: Our primary objective was to compare postural stability between pain-free controls and subjects with CLBP with or without leg pain and single and multisite chronic musculoskeletal pain subjects. The secondary objectives were to evaluate the association between postural stability with CLBP intensity and duration, demographics, physical characteristics and validated health and pain-related patient-reported outcome measures (PROMs). STUDY DESIGN/SETTING: Cross-sectional study in a private chiropractic clinic setting PATIENT SAMPLE: Subjects included 42 pain-free controls and 187 patients with chronic musculoskeletal pain divided into CLBP with or without leg pain and single and multisite pain groups. OUTCOME MEASURES: Pain intensity was measured using the numerical pain rating scale, PROMs Central Sensitization Inventory, Tampa Scale of Kinesiophobia, The Depression Scale, EuroQol-5D, Roland-Morris Disability Questionnaire, and Pain and Sleep Questionnaire Three-Item Index disability. Group differences were measured using area and velocity of sway on the force plate. METHODS: Postural stability was assessed using a force plate on four 60-second bipedal quiet stance tests: eyes open on a stable surface, eyes closed on a stable surface, eyes open on an unstable foam surface, eyes closed on an unstable foam surface. Following the clinic visit, subjects completed an online web-based data entry detailing pain history, demographic data, physical characteristics, pain intensity via the numerical pain rating scale, and PROMS. RESULTS: Postural sway parameters did not differ between pain-free controls and subjects with CLBP with or without leg pain and single and multisite chronic musculoskeletal pain subjects. Furthermore, severity and duration of CLBP pain in addition to central sensitization, kinesiophobia, depression, quality of life, disability, and effect of pain on sleep only had very weak associations with postural stability. CONCLUSIONS: Chronic musculoskeletal pain appears not to influence bipedal postural stability.

Do intensity of pain alone or combined with pain duration best reflect clinical signs in the neck, shoulder and upper limb?

OBJECTIVES: It is important to validate self-reported musculoskeletal pain used in epidemiological studies for evaluation of pain outcome measures. The main objective of this paper was to assess the association between self-reported neck/shoulder/upper limb pain and clinical signs of disorders in the region, especially by comparing a measure that only used pain intensity with a measure that combined pain intensity and pain duration. METHODS: Four hundred and twenty technical school students of both genders were included with a median age of 17 years (16-28). The students stated the pain in four intensity grades and the pain duration in four period lengths within the preceding four weeks period. A pain severity index was calculated by multiplying the pain intensity (0-3) and the duration (1-4). A clinical examination was performed within a week after completing the form. The associations were evaluated by agreement, correlation and symmetric strength of association (contingency). RESULTS: The study found low correlation and low positive agreement for neck/shoulder and upper limb pain related to clinical signs of disorders in the region. However, the relationship showed high negative agreement and high contingency. The negative agreement increased for the neck/shoulder region with higher cut-off points for dichotomization, but not for the upper limb region. The index combining reports of pain intensity with pain duration, do not improve agreement, correlation or contingency with clinical signs compared to use of pain intensity alone. CONCLUSIONS: This study showed an association between self-reported neck/shoulder/upper limb pain intensity and clinical signs of musculoskeletal disorders of the region. An index combining pain intensity and duration (Pain Severity Index) did not increase this association. From the results we suggest using pain intensity reports alone and if dichotomizing is wanted, choosing a cut-off point at high pain levels, especially for neck and shoulder pain.

Resting-state functional connectivity patterns are associated with worst pain duration in community-dwelling older adults.

INTRODUCTION: An individual's chronic pain history is associated with brain morphometric alterations; but little is known about the association between pain history and brain function. OBJECTIVES: This cross-sectional study aimed at determining how worst musculoskeletal pain intensity (WPINT) moderated the association between worst musculoskeletal pain duration (WPDUR) and brain resting-state magnetic resonance imaging functional connectivity (RSFC) in community-dwelling older adults (60-94 years, 75% females, 97% right-handed). METHODS: Resting-state magnetic resonance imaging functional connectivity between region of interests was linearly regressed on WPDUR and WPINT. Predictions were compared with a control group's average RSFC (61-85 years, 47% females, 95% right-handed). RESULTS: Three significant patterns emerged: (1) the positive association between WPDUR and RSFC between the medial prefrontal cortex, in the anterior salience network (SN), and bilateral lateral Brodmann area 6, in the visuospatial network (VSN), in participants with more severe chronic pain, resulting in abnormally lower RSFC for shorter WPDUR; (2) the negative association between WPDUR and RSFC between right VSN occipitotemporal cortex (lateral BA37 and visual V5) and bilateral VSN lateral Brodmann area 6, independently of WPINT, resulting in abnormally higher and lower RSFC for shorter and longer WPDUR, respectively; and (3) the positive association between WPDUR and the left hemisphere's salience network-default mode network connectivity (between the hippocampus and both dorsal insula and ventral or opercular BA44), independently of WPINT, resulting in abnormally higher RSFC for longer WPDUR. CONCLUSION: Musculoskeletal effects on brain functional networks of general healthy individuals could accumulate until being observable at older ages. Results invite to examinations of these effects' impact on function and memory.

High Attention-Deficit/Hyperactivity Disorder Scale Scores Among Patients with Persistent Chronic Nonspecific Low Back Pain.

BACKGROUND: Associations between attention-deficit/hyperactivity disorder (ADHD) and chronic pain disorders, such as fibromyalgia, have been reported. However, associations between persistent chronic nonspecific low back pain (CNLBP) and ADHD have not yet been investigated. OBJECTIVES: This study aimed to investigate the positive rates of possible ADHD, as assessed by self-reported ADHD scales, in patients with persistent CNLBP, using data from self-reported questionnaires completed by patients and their families. This study also aimed to compare the self-reported scores obtained from existing standardized data for healthy individuals, and to examine whether the ADHD scale scores of patients with persistent CNLBP are associated with pain variables. STUDY DESIGN: Cross-sectional study. SETTING: The specialized pain clinic at our university hospital. METHODS: This cross-sectional study included 60 consecutive patients with persistent CNLBP who were diagnosed with a possible somatic symptom disorder and were referred to a psychiatrist in our pain clinic. The Conners' Adult ADHD Rating Scales (CAARS) self-report (CAARS-S) and observer-rated (CAARS-O) questionnaires were utilized. We investigated the CAARS scores, and the association between the CAARS subscale scores and pain variables (pain duration and pain Numeric Rating Scale) in patients with persistent CNLBP. RESULTS: Of the 60 patients, 19 (31.7%) were positive on both CAARS-S and CAARS-O questionnaires (T-score > 65). The ADHD indices, which comprised subscales of the CAARS estimating the necessity of treatment for ADHD, were significantly higher in both male and female patients with persistent CNLBP than in the Japanese standardized sample (P < 0.005). CAARS-S hyperactivity/restlessness, CAARS-O hyperactivity/restlessness, and the Diagnostic and Statistical Manual of Mental Disorders, fourth edition hyperactive-impulsive symptom subscale scores also correlated with the pain intensity (P < 0.05). LIMITATIONS: In this study, ADHD tendency was evaluated using only a self-reported questionnaire. Hence in the future, accurate and precise assessments of ADHD symptoms using structured clinical interviews conducted by ADHD experts are warranted. Additionally, the study only included patients with persistent CNLBP. Therefore in the future, it will be valuable to investigate ADHD scale scores (e.g., CAARS) among patients with CNLBP and nonspecific low back pain with larger sample sizes. CONCLUSIONS: Our findings revealed that the subscale scores on an ADHD scale were considerably high in patients with persistent CNLBP. As a previous study of our clinical experience indicates that persistent CNLBP can be substantially relieved by administering ADHD medications, ADHD screening is warranted in the treatment of persistent CNLBP.

Alterations of Dynamic Regional Homogeneity in Trigeminal Neuralgia: A Resting-State fMRI Study.

Accumulating evidence from neuroimaging studies has supported that chronic pain could induce changes in brain function. However, few studies have focused on the dynamic regional homogeneity (dReHo) of trigeminal neuralgia (TN). In this study, twenty-eight TN patients and 28 healthy controls (HC) were included. Based on the resting-state fMRI (rsfMRI), we detected abnormalities in dReHo in the TN patients. Patients with TN had decreased dReHo in the left middle temporal gyrus, superior parietal lobule, and precentral gyrus, and increased dReHo in the thalamus. Furthermore, the increase in dReHo in the thalamus was positively correlated with duration of TN (r = 0.485, p = 0.012). These results provide compelling evidence for abnormal resting-state brain activity in TN and suggest that the duration of TN may play a critical role in brain function.

Chronic pain intervention using pulsed shortwave therapy: the relationship between pain demographics and central sensitization inventory.

Aim: The central sensitization inventory (CSI) is a validated, patient-reported questionnaire that quantifies symptoms of hypersensitivity disorders such as chronic pain, for which central sensitization (CS) may be the etiology. Objective: To investigate the analgesic effectiveness of ActiPatch and analyze the relationship between baseline CSI scores and demographics of chronic pain sufferers. Methods: Upon completing a 7-day ActiPatch trial, baseline CSI scores along with other assessment measures were obtained via e-mail from 174 chronic pain sufferers. Conclusion: CSI scores were positively correlated with gender (higher for women), baseline visual analog scale scores and pain duration. ActiPatch was found to be effective in reducing baseline pain for all subjects by an average of 4.3 visual analog scale points.

Treatment of painful radiculopathies with capsaicin 8% cutaneous patch.

BACKGROUND AND OBJECTIVE: The treatment of neuropathic pain due to low-back (lumbosacral) radiculopathies, a common source of neuropathic pain, is challenging and often requires a multimodal therapeutic approach. The capsaicin 8% patch is the first topical analgesic licensed for peripheral neuropathic pain. To evaluate this treatment, a subset of patients with painful radiculopathy (lumbar and cervical, including ventral and dorsal rami) enrolled into the multicenter, non-interventional QUEPP study (Qutenza 2 - safety and effectiveness in peripheral neuropathic pain) was analyzed. METHODS: Of the 1044 study participants, 50 were diagnosed with painful radiculopathy as only peripheral neuropathic pain syndrome and were eligible for evaluation. Patients received a single treatment (visit 1) with follow-up visits 2-5 at weeks 1-2, 4, 8 and 12. Parameters assessed at all visits included pain intensity, neuropathy symptoms and side effects. Quality of life (SF-12) and painDETECT 1 questionnaires were completed at baseline and final visit. Data was analyzed by patch application site and duration of pain. RESULTS: Topical treatment led to a significant decrease of pain intensity between weeks 1/2 and week 12 versus baseline at the application sites representing dermatomes of ventral (N = 26) and dorsal rami (N = 13) of spinal nerves. A significant decline (p ≤ .001) of numeric pain rating scale scores was observed between weeks 1/2 following patch application and the end of observation (week 12) in the overall radiculopathy group (N = 50), and the groups with either 3 months to 2 years (N = 14) or >2 years (N = 23) duration of pain. Pain relief of at least 30% was observed in 50.0%, 71.4% and 39.1% of patients in the respective groups. Four patients experienced in total seven adverse drug reactions (application site pain or pruritus). CONCLUSION: Effective neuropathic pain relief was observed after patch application within the innervation territories of both dorsal and ventral branches of the spinal nerve. Further controlled randomized trials are indicated.

Efficient conditioned pain modulation despite pain persistence in painful diabetic neuropathy.

INTRODUCTION: Alleviation of pain, by either medical or surgical therapy, is accompanied by transition from less efficient, or pro-nociceptive, to efficient conditioned pain modulation (CPM). Spontaneous decrease or resolution of pain with disease progression is reported for some patients with painful diabetic neuropathy (PDN). OBJECTIVES: To explore whether CPM changes similarly in parallel to spontaneous resolution of pain in PDN patients. METHODS: In this cross-sectional study, thirty-three patients with PDN underwent psychophysical assessment of pain modulation on the forearm, remote from the clinical pain. RESULTS: Pain duration was not correlated with neuropathic pain intensity, yet, it correlated with CPM efficiency; patients with longer pain duration had same pain level, but more efficient CPM than those with short-pain duration (ρ = -0.417; P = 0.025, Spearman correlation). Patients with pain more than 2 years (median split) expressed efficient CPM that was not different from that of healthy controls. These patients also had lower temporal summation of pain than the short-pain duration patients group (P < 0.05). The 2 patient groups did not differ in clinical pain characteristics or use of analgesics. CONCLUSION: Pro-nociception, expressed by less efficient CPM and high temporal summation that usually accompanies clinical painful conditions, seems to "normalize" with chronicity of the pain syndrome. This is despite continuing pain, suggesting that pro-nociceptivity in pain syndromes is multifactorial. Because the pain modulation profile affects success of therapy, this suggests that different drugs might express different efficacy pending on duration of the pain in patients with PDN.