Is traumatic and non-traumatic neck pain associated with brain alterations? : a systematic review

Background: Chronic neck pain affects 50% - 85% of people who have experienced an acute episode. This transition and the persistence of chronic complaints are believed to be mediated by brain alterations among different central mechanisms. Objectives: This study aimed to systematically review and critically appraise the current existing evidence regarding structural and functional brain alterations in patients with whiplash associated disorders (WAD) and idiopathic neck pain (INP). Additionally, associations between brain alterations and clinical symptoms reported in neck pain patients were evaluated. Study Design: Systematic review. Methods: The present systematic review was performed according to the PRISMA guidelines. PubMed, Web of Science, and Cochrane databases were searched. First, the obtained articles were screened based on title and abstract. Secondly, the screening was based on the full text. Risk of bias in included studies was investigated. Results: Twelve studies met the inclusion criteria. Alterations in brain morphology and function, including perfusion, neurotransmission, and blood oxygenation level dependent-signal, were demonstrated in chronic neck pain patients. There is some to moderate evidence for both structural and functional brain alterations in patients with chronic neck pain. In contrast, no evidence for structural brain alterations in acute neck pain patients was found. Limitations: Only 12 articles were included, which allows only cautious conclusions to be drawn. Conclusion: Brain alterations were observed in both patients with chronic WAD and chronic INP. Furthermore, more evidence exists for brain alterations in chronic WAD, and different underlying mechanisms might be present in both pathologies. In addition, pain and disability were correlated with the observed brain alterations. Accordingly, morphological and functional brain alterations should be further investigated in patients with chronic WAD and chronic INP with newer and more sensitive techniques, and associative clinical measurements seem indispensable in future research

Influence of concrete composition on chloride ingress and carbonation : analysis by means of an extended data-set

In 2015 an IWT-TETRA project, called DurOBet, was initiated focusing on service life design assessment according to different chloride diffusion and carbonation models applied on Belgian concrete mixtures. The main purpose of this research project is to develop a quantitative method for a service-life based design of concrete structures, more particular applicable for the Belgian concrete industry. In this way an improvement of the deemed-to-satisfy approach of the EN206-1 code can be established which is more reliable with regards to service life predictions of concrete structures. In the framework of this DurOBet project it was decided to develop an extensive database incorporating concrete related results on i) fresh properties, ii) hardened properties and iii) durability related properties such as porosity, permeability and more specifically on chloride ingress and carbonation. The data originate from numerous journal articles and conference papers, doctoral research projects and master thesis studies. At this time more than 100 papers or studies were investigated, reported between 1992 and 2016, generating a dataset of over a thousand unique concrete recipes, geographically spread but with focus on the concrete mixes applicable for the Belgian industry. Both traditional and self-compacting concrete mixes are incorporated into the database. This database is being used for the analysis of the durability related properties, such as the chloride diffusion and carbonation coefficient, and their relation with mix proportioning parameters of the concrete mixtures (cement or binder content, type of binder, water-to-binder ratio,…). The main focus of this paper is to highlight the framework of the database: the mix proportioning of the concrete mixes is being discussed and the origin of the concrete data (country, reference info, etc.). By means of data mining and some known relations with respect to the durability related properties, e.g. correlation between w/b-ratio and chloride diffusion coefficient, are being evaluated

Evaluation of the migration coefficient, diffusion coefficient and the ageing factor according to the chloride ingress model described in the fib bulletin 34 applied to Belgian concrete mixtures

In this contribution the chloride diffusion model according to fib bulletin 34 is applied and evaluated on Belgian concrete [1]. The service life estimation according to chloride-induced corrosion is, inter alia, affected by the chloride migration coefficient or chloride diffusion coefficient. In addition, the time dependency of these parameters, reflected in the ageing exponent, has an even greater influence on the model. In a first part the different diffusion coefficients will be discussed. In a second part the parameters are calibrated to the Belgian concrete compositions. The chloride migration coefficient and chloride diffusion coefficient depend on the type of cement and vary according to different types of cement and w/c ratios. The ageing exponent is also dependent on the exposure class. Such a calibration is performed on the most commonly used types of cement in Belgium, which are Portland cement (CEM I) and blended cements (CEM III/A and CEM III/B). Distributions are proposed and evaluated based on available Belgian data and results from laboratory experiments. Finally the time dependency of the instantaneous diffusion coefficients and the time dependency of the apparent diffusivities are investigated

Cognitive performance is related to central sensitization and health-related quality of life in patients with chronic whiplash-associated disorders and fibromyalgia

Background: A growing body of research has demonstrated that impaired central pain modulation or central sensitization (CS) is a crucial mechanism for the development of persistent pain in chronic whiplash-associated disorders (WAD) and fibromyalgia (FM) patients. Furthermore, there is increasing evidence for cognitive dysfunctions among these patients. In addition, chronic WAD and FM patients often report problems with health-related quality of life (QoL). Yet, there is limited research concerning the interrelations between cognitive performance, indices of CS, and health-related QoL in these patients. Objectives: (1) Examining the presence of cognitive impairment, CS, and limitations on health-related QoL in patients with chronic WAD and FM compared to healthy controls. (2) Examining interrelations between performance-based cognitive functioning, CS, and self-reported health-related QoL in these 3 study groups. Study Design: A case-control study was conducted. Setting: The present study took place at the University Hospital Brussels, the University of Brussels, and the University of Antwerp. Methods: Fifty-nine patients (16 chronic WAD patients, 21 FM patients, and 22 pain-free volunteers) filled out the Short Form 36 item Health Survey (SF-36), a self-reported psychosocial questionnaire, to assess health-related QoL. Next, they were subjected to various pain measurements (pressure hyperalgesia, deep-tissue hyperalgesia, temporal summation [TS], and conditioned pain modulation [CPM]). Finally, participants completed a battery of performance-based cognitive tests (Stroop task, psychomotor vigilance task [PVT], and operation span task [OSPAN]). Results: Significant cognitive impairment, bottom-up sensitization, and decreased health-related QoL were demonstrated in patients with chronic WAD and FM compared to healthy controls (P < 0.017). CPM was comparable between the 3 groups. Cognitive performance was significantly related to central pain modulation (deep-tissue hyperalgesia, TS, CPM) as well as to self-reported health-related QoL (P < 0.05). Decreased cognitive performance was related to deficient central pain modulation in healthy controls. Further, significant correlations between decreased cognitive performance and reduced health-related QoL were revealed among all study groups. Additionally, FM patients showed correlations between cognitive impairment and increased health-related QoL. Remarkably, impaired selective attention and working memory were related to less TS, whereas impaired sustained attention was correlated with dysfunctional CPM in FM patients. Limitations: Based on the current cross-sectional study no firm conclusions can be drawn on the causality of the relations. Conclusion: In conclusion, this paper has demonstrated significant cognitive deficits, signs of CS, and reduced health-related QoL in chronic WAD and FM patients compared to healthy individuals. Significant relations between cognitive performance and CS as well as health-related QoL were demonstrated. These results provide preliminary evidence for the clinical importance of objectively measured cognitive deficits in patients with chronic WAD and FM

Effects of stress and relaxation on central pain modulation in chronic whiplash and fibromyalgia patients compared to healthy controls

Background: Compelling evidence has demonstrated that impaired central pain modulation contributes to persistent pain in patients with chronic whiplash associated disorders (WAD) and fibromyalgia (FM). However, there is limited research concerning the influence of stress and relaxation on central pain modulation in patients with chronic WAD and FM. Objectives: The present study aims to investigate the effects of acute cognitive stress and relaxation on central pain modulation in chronic WAD and FM patients compared to healthy individuals. Study Design: A randomized crossover design was employed. Setting: The present study took place at the University of Brussels, the University Hospital Brussels, and the University of Antwerp. Methods: Fifty-nine participants (16 chronic WAD patients, 21 FM, 22 pain-free controls) were enrolled and subjected to various pain measurements. Temporal summation (TS) of pain and conditioned pain modulation (CPM) were evaluated. Subsequently, participants were randomly allocated to either a group that received progressive relaxation therapy or a group that performed a battery of cognitive tests (= cognitive stressor). Afterwards, all pain measurements were repeated. One week later participant groups were switched. Results: A significant difference was found between the groups in the change in TS in response to relaxation (P = 0.008) and cognitive stress (P = 0.003). TS decreased in response to relaxation and cognitive stress in chronic WAD patients and controls. In contrast, TS increased after both interventions in FM patients. CPM efficacy decreased in all 3 groups in response to relaxation (P = 0.002) and cognitive stress (P = 0.001). Limitations: The obtained results only apply for a single session of muscle relaxation therapy and cognitive stress, whereby no conclusions can be made for effects on pain perception and modulation of chronic cognitive stress and long-term relaxation therapies. Conclusions: A single relaxation session as well as cognitive stress may have negative acute effects on pain modulation in patients with FM, while cognitive stress and relaxation did not worsen bottom-up sensitization in chronic WAD patients and healthy persons. However, endogenous pain inhibition, assessed using a CPM paradigm, worsened in chronic WAD and FM patients, as well as in healthy people following both interventions

Does conservative treatment change the brain in patients with chronic musculoskeletal pain? : a systematic review

Background: Chronic musculoskeletal pain is characterized by maladaptive central neuroplastic changes. Many observational studies have demonstrated that chronic pain states are associated with brain alterations regarding structure and/or function. Rehabilitation of patients with chronic musculoskeletal pain may include cognitive, exercise, or multimodal therapies. Objective: The current review aims to provide a constructive overview of the existing literature reporting neural correlates, based on brain magnetic resonance imaging (MRI) techniques, following conservative treatment in chronic musculoskeletal pain patients. Study Design: Systematic review of the literature. Methods: The current review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Literature was searched from 3 databases and screened for eligibility. Methodological quality across studies was assessed with Cochrane Collaboration's tool for assessing risk of bias and quality of evidence was determined applying the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach. Results: A total of 9 eligible studies were identified with a predominant high risk of bias. Cognitive behavioral therapy induced several structural and functional changes predominantly in prefrontal cortical regions and a shift from affective to sensory-discriminative brain activity after behavioral extinction training. Multidisciplinary treatment in pediatric complex regional pain syndrome facilitated normalization of functional connectivity of resting-state networks and the amygdala, and increased gray matter in prefrontal and specific subcortical areas. Exercise therapy led to specific for resting-state functional connectivity and a trend towards pressure-induced brain activity changes. Limitations: A very small number of studies was available, which furthermore exhibited small study samples. Moreover, only 2 of the included studies were randomized controlled trials. Conclusions: It is likely that conservative treatments may induce mainly functional and structural brain changes in prefrontal regions in patients with chronic musculoskeletal pain. Due to the relatively high risk of bias across the included studies, future studies with randomized designs are needed to confirm the current findings. In addition, more research evaluating

Decreased regional grey matter volume in women with chronic whiplash-associated disorders: Relationships with cognitive deficits and disturbed pain processing

Background: Patients with chronic whiplash-associated disorders (CWAD) are characterized by pain of traumatic origin, cognitive deficits, and central sensitization (CS). Previous neuroimaging studies revealed altered grey matter volume (GMV) in mild traumatic brain injury patients and chronic pain conditions also characterized by CS. It can therefore be hypothesized that GMV alterations also play a role in the persistent complaints of CWAD. However, brain alterations remain poorly investigated in these patients. Objectives: This study examined regional GMV alterations in patients with CWAD compared to patients with non-traumatic chronic idiopathic neck pain (CINP), who normally do not show CS at a group level, and healthy controls. Additionally, in both patient groups, relationships between regional GMV and measures of cognition as well as pain processing were assessed. Study Design: A cross-sectional case-control study. Setting: This study was performed at the Department of Rehabilitation Sciences and Physiotherapy of Ghent University in cooperation with the Ghent Institute for Functional and Metabolic Imaging. Methods: Ninety-three women (28 healthy controls, 34 CINP patients, and 31 CWAD patients) were enrolled. First, T1-weighted magnetic resonance images (MRIs) were acquired to examine GMV alterations in the brain regions involved in processing cognition and pain. Next, cognitive performance, pain cognitions, and CS symptoms were assessed. Finally, hyperalgesia and conditioned pain modulation efficacy were examined. Results: Regional GMV of the right lateral orbitofrontal cortex, left supramarginal cortex, and left posterior cingulate cortex was decreased in CWAD patients compared to healthy controls (P = 0.023; P = 0.012; P = 0.047, respectively). Additionally, GMV of the right superior parietal cortex and left posterior cingulate cortex was decreased in CWAD patients compared to CINP patients (P = 0.008; P = 0.035, respectively). Decreased regional GMV correlated with worse cognitive performance, higher maladapted pain cognitions, CS symptoms, and hyperalgesia in CWAD patients (rs = -0.515 to -0.657; P < 0.01). In CINP patients, decreased regional GMV correlated only with worse cognitive performance (rs = -0.499 to -0.619; P < 0.01), and no GMV differences compared with the controls could be revealed. Limitations: No conclusions about the causality of the observed relationships can be drawn. Conclusions: These results provide the first evidence for reduced GMV in cortical regions involved in processing cognition and pain in patients with CWAD. Accordingly, it is recommended that therapy approaches for CWAD patients should address the brain and take into account neuroplasticity of the central nervous system (CNS)