Differences in white matter structure and cortical thickness between patients with traumatic and idiopathic chronic neck pain: Associations with cognition and pain modulation?

Brain alterations are hypothesized to be present in patients with chronic whiplash-associated disorders (CWAD). The aim of this case-control study was to examine alterations in cortical thickness and white matter (WM) structure, and the presence of brain microhemorrhages in a patient group encountering chronic neck pain of traumatic origin (i.e., CWAD) when compared with a patient group characterized by nontraumatic chronic neck pain [i.e., chronic idiopathic neck pain (CINP)], and healthy controls. Furthermore, we aimed to investigate associations between brain structure on one hand and cognitive performance and central sensitization (CS) on the other hand. T1-weighted, diffusion-weighted and T2*-weighted magnetic resonance images of the brain were acquired in 105 women (31 controls, 37 CINP, 37 CWAD) to investigate regional cortical thickness, WM structure, and microhemorrhages, respectively. Next, cognitive performance, and CS encompassing distant hyperalgesia and conditioned pain modulation (CPM) efficacy were examined. Cortical thinning in the left precuneus was revealed in CWAD compared with CINP patients. Also, decreased fractional anisotropy, together with increased values of mean diffusivity and radial diffusivity could be observed in the left cingulum hippocampus and tapetum in CWAD compared with CINP, and in the left tapetum in CWAD patients compared with controls. Moreover, the extent of WM structural deficits in the left tapetum coincided with decreased CPM efficacy in the CWAD group. This yields evidence for associations between decreased endogenous pain inhibition, and the degree of regional WM deficits in CWAD. Our results emphasize the role of structural brain alterations in women with CWAD compared with CINP.

Validity and Test-Retest Reliability of the Dutch Modified Perceived Deficits Questionnaire to Examine Cognitive Symptoms in Women with Chronic Whiplash, Chronic Idiopathic Neck Pain, and Fibromyalgia.

INTRODUCTION: Until now, only reliability and validity of the English version of the modified Perceived Deficits Questionnaire (mPDQ) have been investigated. OBJECTIVE: The aim of this study was to translate the mPDQ into Dutch and evaluate its validity and reliability as an assessment tool for self-perceived cognitive problems in patients with chronic whiplash-associated disorders (CWAD), chronic idiopathic neck pain (CINP), and fibromyalgia (FM). METHODS: A case-control study was performed with a volunteer sample of 13 women with CWAD, 18 with CINP, and 33 with FM, and 33 women who were healthy and free of pain. The mPDQ was first translated into Dutch, and its test-retest reliability, internal consistency, and discriminative power were examined. RESULTS: The intraclass correlation coefficients were higher than 0.74. Cronbach's α values ranged between 0.71 and 0.95. Total mPDQ scores were significantly higher (P < 0.017) in FM and CWAD patients compared to healthy controls. Furthermore, participants performed the Stroop task and the psychomotor vigilance task (PVT), 2 neuropsychological computer-based cognitive performance tests. Correlations between the mPDQ total score and the cognitive performance tests were evaluated. Significant moderate to high correlations were found in all study samples between total mPDQ score and objective cognitive tests (Spearman correlation coefficient = 0.35 to 0.80; P < 0.05). CONCLUSION: Therefore, the Dutch version of the mPDQ showed high test-retest reliability and high internal consistency, and was able to distinguish CWAD and FM patients from healthy controls. PERSPECTIVE: This article presents the validity and test-retest reliability of the Dutch mPDQ. This measure could help clinicians who seek a reliable and user-friendly way to assess cognitive symptoms in chronic pain patients.

Do sociodemographic features, pain sensitivity or pain catastrophizing relate to clinic-based adherence to physiotherapy in people suffering from chronic spinal pain? Secondary analysis of a randomized clinical trial.

PURPOSE: Examining whether socio-demographic variables, pain or functionality are related to the degree of clinic-based therapy adherence in patients suffering from nonspecific chronic spinal pain (nCSP). DESIGN: Secondary analysis of a randomized clinical trial. SETTING: University hospital of Ghent and Brussels. METHODS: Dutch speakers, 18-65 years old, experiencing nCSP for at least 3 months. 120 participants were randomly allocated to two interventional groups, of which 94 completed all therapy sessions. MAIN OUTCOME MEASURES: Degree of clinic-based adherence, defined as the amount of completed therapy sessions. RESULTS: Demographic data (sex, age or education) were not significantly associated with adherence in the total sample or the neuroscience group. For the traditional physiotherapy group, educational level was associated with attendance of at least 50% of the therapy sessions. Regarding pain-, belief- and function-related measures, only the association between change in kinesiophobia and adherence was significant for the traditional physiotherapy group. CONCLUSIONS: Factors related to therapy adherence in the total group or the neuroscience group could not be found. Educational level and change in kinesiophobia were however related to therapy adherence in the traditional physiotherapy group.

Brain changes associated with cognitive and emotional factors in chronic pain: A systematic review.

An emerging technique in chronic pain research is MRI, which has led to the understanding that chronic pain patients display brain structure and function alterations. Many of these altered brain regions and networks are not just involved in pain processing, but also in other sensory and particularly cognitive tasks. Therefore, the next step is to investigate the relation between brain alterations and pain related cognitive and emotional factors. This review aims at providing an overview of the existing literature on this subject. Pubmed, Web of Science and Embase were searched for original research reports. Twenty eight eligible papers were included, with information on the association of brain alterations with pain catastrophizing, fear-avoidance, anxiety and depressive symptoms. Methodological quality of eligible papers was checked by two independent researchers. Evidence on the direction of these associations is inconclusive. Pain catastrophizing is related to brain areas involved in pain processing, attention to pain, emotion and motor activity, and to reduced top-down pain inhibition. In contrast to pain catastrophizing, evidence on anxiety and depressive symptoms shows no clear association with brain characteristics. However, all included cognitive or emotional factors showed significant associations with resting state fMRI data, providing that even at rest the brain reserves a certain activity for these pain-related factors. Brain changes associated with illness perceptions, pain attention, attitudes and beliefs seem to receive less attention in literature. SIGNIFICANCE: This review shows that maladaptive cognitive and emotional factors are associated with several brain regions involved in chronic pain. Targeting these factors in these patients might normalize specific brain alterations.

Does muscle morphology change in chronic neck pain patients? - A systematic review.

BACKGROUND: Neck pain is a common disabling worldwide health problem with a high socio-economic burden. Changes underlying the transition to, or the maintenance of a chronic state are still barely understood. Increasing evidence suggests that morphological muscle changes, including changes in cross-sectional area (CSA) or fatty infiltration, play a role in chronic neck pain. However, a structured overview of the current evidence of morphological changes is lacking. OBJECTIVE: To systematically review the morphological muscle changes in patients with chronic neck pain, including those with whiplash-associated disorders (WAD) and chronic idiopathic neck pain. STUDY DESIGN & METHODS: A systematic review using the PRISMA-guidelines. RESULTS: Fourteen of 395 papers were included after extensive screening. Most studies were of moderate methodological quality. A higher CSA was found in all flexor muscles in both patients with WAD and patients with chronic idiopathic neck pain, except for the deeper flexor muscles in patients with chronic idiopathic neck pain. The cervical extensor muscles show an increased CSA at the highest cervical segments in patients with WAD, while most studies in patients with chronic idiopathic neck pain report a decreased CSA in all extensor muscles. Fatty infiltration, which could be accountable for an increased CSA, of both cervical extensors and flexors seems to occur only in patients with WAD. CONCLUSION: Some evidence is available for changes in muscle morphology, however more high quality prospective and cross-sectional research is needed to confirm these changes and to identify potential underlying causes that need yet to be discovered.