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Purpose: Event-related desynchronisation (ERD) and event-related synchronisation (ERS) reflect pain perception and integration of the nociceptive sensory inputs. This may contribute to the understanding of how neurophysiological markers of Knee Osteoarthritis (KOA) patients can differ from control individuals, which would improve aspects such as prediction and prognosis. We performed a cross-sectional analysis of our cohort study (DEFINE cohort), KOA arm, with 71 patients, compared with 65 control participants. The study aimed to examine possible differences between ERD and ERS in control participants compared to Knee Osteoarthritis (KOA) patients when adjusting for important covariates., Materials and Methods: We performed independent multivariate regression models considering as dependent variables the power value related to ERD and ERS for four different sensorimotor tasks (Motor Execution, Motor Imagery, Active Observation and Passive Observation) and four sensorimotor oscillations (Alpha, Beta, Low Beta, and High Beta), each model, controlled by age and sex., Results: We demonstrate that the differences between KOA and healthy subjects are frequency specific, as most differences are in the beta bandwidth range. Also, we observed that subjects in the KOA group had significantly higher ERD and ERS. This may be correlated to the amount of lack of brain organisation and a subsequent attempt at compensation induced by KOA., Conclusions: Our findings strengthen the notion that subjects with KOA have a higher degree of brain plasticity changes that are also likely correlated to the degree of compensation and behavioural dysfunction.

Objective: The study aimed to examine the clinical and neurophysiological predictors of motor event-related desynchronization (ERD) and synchronization (ERS) in patients with chronic pain due to knee osteoarthritis (KOA)., Methods: We performed a cross-sectional analysis of our cohort study (DEFINE cohort), KOA arm, with 71 patients, including demographic, functionality, genetic and neurophysiological measures. ERD/ERS was evaluated during hand motor tasks (motor execution, active and passive observation, and imagery). Multivariate regression models were used to explore predictors of ERD/ERS., Results: Although we found an altered ERD/ERS pattern during motor execution and active observation, the ERS pattern could only be clearly differentiated after passive observation.`. We found no predictors of ERD (excitatory biomarker). For ERS (inhibitory biomarker), our results showed that the main predictors differ across EEG frequency bands. Considering pain measures, we found that visual analogue scale (VAS, right knee) and chronicity of pain negatively predict low beta and high beta ERS, respectively. Pain threshold was positively correlated with alpha ERS, while 36-Item Short Form Survey (SF-36) emotional domain positively predicted beta ERS. Regarding transcranial magnetic stimulation (TMS) markers, intracortical inhibition (ICF) negatively predicted beta and low beta ERS, and left hemisphere cortical silent period (CSP) negatively predicted low beta ERS., Conclusion: Considering that higher power of ERS indicates a stronger cortical organization and inhibitory drive, our results show that limitation of activities due to emotional factors, lower pain threshold, higher VAS pain, and longer duration of pain are associated with lower ERS power (in alpha and beta frequencies), thus indicating a lower inhibitory drive. In the same direction, a lower inhibitory drive as indicated by higher ERS power is associated with higher ICF amplitude. Although there was a negative association between ERS and CSP, this may indicate that ICF values are adjusting CSP results. Our findings support the idea that a less organized cortical response as indicated by changes to the ERS is associated with higher pain correlates in subjects with KOA., Competing Interests: Conflict of interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier Masson SAS.)

Introduction: There is evidence that brain plasticity is the central mechanism involved in the functional recovery process of patients with knee osteoarthritis. Studies involving the analysis of central nervous system mechanisms of pain control and recovery could provide more data on future therapeutic approaches., Objective: The aim of the study was to explore possible functional changes in cortical activity of patients submitted to knee osteoarthritis standardized pain treatment using electroencephalography., Methodology: Ten patients with clinical and radiological diagnosis of painful knee unilateral or bilateral osteoarthritis were recruited to participate in clinical (Pain's Visual Analog Scale), radiological (Kellgren-Lawrence Scale), and neurophysiological (electroencephalography) assessments to evaluate cortical activity during cortical pain modulation activity. The clinical and neurophysiological analyses were performed before and after standardized pain treatment., Results: Eight patients participated in this study. A significant improvement in pain perception and relative increase in interhemispheric connectivity after therapies was observed. In electroencephalography analysis, tests with real movement showed a relative increase in density directed at Graph's analysis., Conclusions: Relative increase density directed measures at connectivity analysis in electroencephalography after pain treatment can be possible parameters to be explored in future research with a larger number of patients., Competing Interests: Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Knee osteoarthritis (OA) is associated with chronic inflammation in somatic structures, which alters sensory afferents and leads to plastic changes in the nervous system., Methods: A systematic literature review was carried out, without language restrictions, period, or status of publication. The database used were Medline, EMBASE, Cochrane Library and clinicaltrials.gov. Extra bibliographic references were extracted through the discussion with specialists, and through scientific researches in conference papers., Results: The electronic search found 938 articles. When excluding duplicates and applying the inclusion/exclusion criteria, 5 studies were considered: 2 using EEG and 3 using TMS. Significant reduction of EEG activity in the cingulate medium cortex, reduction of conditioned pain modulation (CPM) in studies with EEG, as well as the occurrence of an association between pain and motor response threshold/intracortical pain facilitation in studies with TMS were observed., Conclusions: The study contributes to a better understanding of the neurophysiological changes seen in the cingulate medium cortex, decrease in CPM and motor response threshold/intracortical pain facilitation. Advances in neuroplasticity studies may aid in the screening for early diagnosis of knee OA in the future. However, more studies are necessary., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.)

Worldwide, knee osteoarthritis (KOA) accounts for 2.2% of total years lived with disability. There is a low correlation between joint tissue damage and pain intensity. Periarticular structures may be involved and cannot be identified in X-rays. To describe the main ultrasonography (USG) changes in symptomatic patients with primary KOA; to correlate the number of USG findings with KOA severity assessed by Kellgren and Lawrence (K&L) radiological scores, with pain intensity measured by a visual analogue scale (VAS) and with functioning scores assessed with the Timed up and go test (TUG) and Western Ontario and McMaster Universities (WOMAC) questionnaire. 100 patients with primary symptomatic KOA were assessed with X-ray and USG. Quantitative and qualitative analyses were evaluated in a systematic manner. The most frequent findings were joint effusion, pes anserinus bursitis, quadriceps tendon enthesopathy, popliteal cyst, iliotibial band tendinitis and patellar tendinitis. Pearson's correlation analysis demonstrated a significant moderate positive association between VAS scores and the number of USG findings (r = 0.36; p < 0.0001). The number of USG findings was different between K&L grades I and III (p = 0.041), I and IV (p < 0.001), and II and IV (p = 0.001, analysis of variance with Bonferroni correction). There was significant association between number of USG findings and TUG (r = 0.18; p = 0.014) and WOMAC scores for pain (r = 0.16; p < 0.029) and physical function domains (r = 0.16; p < 0.028). The most frequent USG finding was joint effusion. Periarticular structures should be explored as potential sources of pain and disability., (© 2021. The Author(s).)

Therapeutic exercise and lifestyle changes (LS) are usually recommended for the treatment of knee osteoarthritis (OA)., Objectives: to compare the impact of an exercise program vs. exercise program plus LS education in individuals with knee OA., Materials and Methods: Single-blind randomized clinical trial with individuals of both sexes with clinical and radiological diagnosis of knee OA. Participants received the treatment 2 times/week for 8 weeks. Therapeutic exercise involved warm-up, flexibility, muscle strengthening, balance and proprioception. The exercise plus lifestyle education group (ELG) also participated in 8 sessions of lectures and discussion on disease self-management and healthy LS. Participants were assessed for pain intensity (visual analog scale), lifestyle, symptoms and physical disability (WOMAC) and pressure pain tolerance threshold (PPT)., Results: Sample consisted of 39 participants, divided into exercise group (EG, n=17) and ELG (n=22). Groups were homogeneous regarding regarding age, weight, height, initial pain perception (VAS) and gender predominance age and body mass index. After the interventions, reduction in pain perception and increase in PPT was observed in both groups. Despite the improvement in LS of both groups, only ELG exhibited a significant reduction in pain assessed by WOMAC. Therapeutic exercise programs may produce pain relief, but no improvements were observed in joint stiffness and funcionality.

Objective: To assess the influence of the body weight in functional capacity and pain of adult and elderly individuals with knee osteoarthritis., Methods: The sample consisted of 107 adult and elderly patients with knee osteoarthritis divided into two groups (adequate weight/adiposity and excessive weight/adiposity) according to body mass index and percent of body fat mass, assessed by electric bioimpedance. Subjects were evaluated for functional mobility (Timed Up and Go Test), pain, stiffness and function (Western Ontario and MacMaster Universities Osteoarthritis Index - WOMAC), pain intensity (Visual Analogue Scale - VAS) and pressure pain tolerance threshold (algometry in vastus medialis and vastus lateralis muscles). Data were analyzed with Statistical Package of the Social Sciences, version 22 for Windows. Comparisons between groups were made through Student's t test, with significance level set at 5%., Results: There was predominance of females in the sample (81.3%), and mean age was 61.8±10.1 years. When dividing the sample by both body mass index and adiposity, 89.7% of them had weight/adiposity excess, and 59.8% were obese. There was no difference between groups regarding age, pain intensity, pressure pain tolerance threshold, functional mobility, stiffness and function. However, pain (WOMAC) was higher (p=0.05) in the group of patients with weight or adiposity excess, and pain perception according to VAS was worse in the group of obese patients (p=0.05)., Conclusion: Excessive weight had negative impact in patients with osteoarthritis, increasing pain assessed by WOMAC or VAS, although no differences were observed in functionality and pressure pain tolerance.

Objective: To assess the efficacy and safety of radial extracorporeal shock wave therapy (rESWT) for disabling pain due to primary knee osteoarthritis., Design: Randomized, placebo-controlled trial (level of evidence, 1)., Subjects: A total of 105 women with disabling pain due to primary knee osteoarthritis lasting for a mean of 103 months (range 3-480 months)., Methods: Patients received either rESWT (3 sessions, each one week apart, 2,000 rESWT impulses per session, positive energy flux density 0.10-0.16 mJ/mm2) or placebo treatment. Primary outcome measure was pain on movement 3 months after the final treatment session. Secondary outcomes were pain, stiffness and limitations in physical function on the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index and the level of tolerance to pressure over muscles, tendons, ligaments and skin at both the treated and the untreated side at 1 week and 3 months follow-up examinations., Results: Compared with placebo treatment, rESWT led to a statistically significant improvement only in mean WOMAC scores for pain and a few of the pressure measurements., Conclusion: rESWT, as performed in the present study, is not efficient for treating patients with disabling pain due to primary knee osteoarthritis. Published data indicate that substantially higher energy flux densities are necessary for treatment success in this condition.

Introduction: Fibromyalgia and osteoarthritis may present a relationship with the concentration of cytokines. The aim of this study was to compare the serum concentrations of IL-12p70, tumor necrosis factor, IL-10, IL-6, IL-1β, and IL-8 in patients with knee osteoarthritis and fibromyalgia., Materials and Methods: The study included 53 women (71.2±7.6 years old) diagnosed with knee osteoarthritis with moderate-to-severe pain (visual analog scale >4) for at least 3 months. Sixty women (54.1±8.1 years old) diagnosed with fibromyalgia according to the American College of Rheumatology criteria and with moderate-to-severe pain (visual analog scale >4) also participated in this study. For the dosage of cytokines, blood was collected in the morning: 5 mL from the cubital vein. The material was centrifuged at 4°C, separated into 100 μL aliquots and stored at -80°C until processing. Serum concentrations of the studied cytokines were assessed using the BD Cytometric Bead Array method. Data were analyzed with Student's t-test and the Mann-Whitney U test., Results: We found higher levels of IL-6, IL-10, and IL-1β in fibromyalgia patients. After adjustment of age as a covariate, there was no statistically significant difference in the concentration of any cytokine between fibromyalgia and knee osteoarthritis patients., Conclusion: Patients with knee osteoarthritis and fibromyalgia with the same duration and intensity of pain demonstrate similar concentrations of cytokines. Aging may play a role in cytokine profile, a finding not so extensively addressed in the literature and one that should be further investigated.