Meta-analysis of psychological interventions for chronic low back pain.

The purpose of this meta-analysis of randomized controlled trials was to evaluate the efficacy of psychological interventions for adults with noncancerous chronic low back pain (CLBP). The authors updated and expanded upon prior meta-analyses by using broad definitions of CLBP and psychological intervention, a broad data search strategy, and state-of-the-art data analysis techniques. All relevant controlled clinical trials meeting the inclusion criteria were identified primarily through a computer-aided literature search. Two independent reviewers screened abstracts and articles for inclusion criteria and extracted relevant data. Cohen's d effect sizes were calculated by using a random effects model. Outcomes included pain intensity, emotional functioning, physical functioning (pain interference or pain-specific disability, health-related quality of life), participant ratings of global improvement, health care utilization, health care provider visits, pain medications, and employment/disability compensation status. A total of 205 effect sizes from 22 studies were pooled in 34 analyses. Positive effects of psychological interventions, contrasted with various control groups, were noted for pain intensity, pain-related interference, health-related quality of life, and depression. Cognitive-behavioral and self-regulatory treatments were specifically found to be efficacious. Multidisciplinary approaches that included a psychological component, when compared with active control conditions, were also noted to have positive short-term effects on pain interference and positive long-term effects on return to work. The results demonstrated positive effects of psychological interventions for CLBP. The rigor of the methods used, as well as the results that reflect mild to moderate heterogeneity and minimal publication bias, suggest confidence in the conclusions of this review. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reduced variability of postural strategy prevents normalization of motor changes induced by back pain: A risk factor for chronic trouble?

Variability is fundamental to biological systems and is important in posturomotor learning and control. Pain induces a protective postural strategy, although variability is normally preserved. If variability is lost, does the normal postural strategy return when pain stops? Sixteen subjects performed arm movements during control trials, when the movement evoked back pain and then when it did not. Variability in the postural strategy of the abdominal muscles and pain-related cognitions were evaluated. Only those subjects for whom pain induced a reduction in variability of the postural strategy failed to return to a normal strategy when pain stopped. They were also characterized by their pain-related cognitions. Ongoing perception of threat to the back may exert tighter evaluative control over variability of the postural strategy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Arousal of negative emotions and symptom-specific reactivity in chronic low back pain patients.

Anger may have greater effects on chronic pain severity than other negative emotions and may do so by increasing muscle tension near the site of injury (symptom-specific reactivity). For patients with chronic low back pain (CLBP), relevant muscles are lower paraspinals (LP). Ninety-four CLBP patients and 79 controls underwent anger and sadness recall interviews. EMG and cardiovascular activity were recorded. Patients exhibited greater LP tension increases during anger and slower recovery than controls. Only patients showed greater LP reactivity during anger than sadness. For both groups, trapezius reactivity during anger and sadness did not differ. LP reactivity to anger correlated with everyday pain severity for patients. Anger-induced symptom-specific LP reactivity may be linked to chronic pain aggravation among CLBP patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exposure to physical movement in low back pain patients: Restricted effects of generalization.

Whether the effects of exposure to 1 movement generalize to another dissimilar movement was investigated in 37 patients with low back pain (15 men, 22 women). Two movements were executed twice: bending forward while standing and lifting 1 leg while lying down. During each trial, baseline pain, expected pain, and experienced pain were recorded. Similar ratings for perceived harm were obtained. Analyses revealed an initial overprediction of pain, but after exposure the overprediction was readily corrected. This exposure effect did not generalize toward another dissimilar movement. These results were only characteristic for patients with catastrophic thinking about pain. Low pain catastrophizers did not overpredict pain. There were no effects of exposure on perceived harm. Exposure may profitably be conceived of as the learning of exceptions to a general rule. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Supportive colleague, unsupportive supervisor: The role of provider-specific constellations of social support at work in the development of low back pain.

In a 5-year longitudinal study, social support was investigated as a predictor of low back pain (LBP) in 46 initially asymptomatic individuals. Distinguishing between colleagues in general and the colleague one feels closest to, the authors analyzed constellations of support from supervisor (which had positive effects) and closest colleague (which had detrimental effects). Configural frequency analysis yielded a type characterized by high support from one's closest colleague and low support from one's supervisor at Time 1 and more LBP and disability at Time 2. Controlling for negative affectivity did not change findings. Results are interpreted in terms of being dependent on that one source of support in an unsupportive environment, which creates feelings of dependence, incompetence, and reciprocity obligations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of attentional strategies in moderating links between acute pain induction and subsequent psychological stress: Evidence for symptom-specific reactivity among patients with chronic pain versus healthy nonpatients.

Vulnerability to stressors after pain may depend on the degree to which the strategy used to process information about pain perpetuates thoughts of suffering and distress. Patients with chronic low back pain (CLBP) may show susceptibility to stress after pain through symptom-specific (lower paraspinal [LP]) muscle reactivity. Patients with CLBP (n = 100) and healthy nonpatients (n = 105) underwent a cold pressor, under sensory focus, distraction, suppression, or control conditions, and then performed mental arithmetic. Only patients under the suppression condition revealed increased LP tension during pain that was sustained during mental arithmetic and sustained systolic blood pressure after mental arithmetic. Patients with CLBP who suppress pain may detrimentally affect responses to the next noxious event, particularly through prolonged LP muscle tension, that may contribute to a cycle of pain-stress-pain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anger management style and emotional reactivity to noxious stimuli among chronic pain patients and healthy controls: The role of endogenous opioids.

Objective: Previous work suggests that elevated trait anger-out exacerbates pain responses in part through endogenous opioid dysfunction. The authors examined whether this opioid dysfunction affects not only perceived pain intensity, but also emotional responses to being hurt. Design: 79 chronic low back pain (LBP) patients and 46 healthy controls received opioid blockade (8 mg naloxone i.v.) and placebo in randomized, counterbalanced order in separate sessions. During each session, participants sequentially experienced finger pressure pain and ischemic forearm pain tasks, with emotional state assessed at baseline and postpain. Main Outcome Measures: Blockade effects indexing opioid modulation of emotional reactivity were derived by subtracting placebo from blockade condition emotional reactivity. Results: Significant Participant Type × Anger-Out interactions on blockade effects indicated that in LBP participants but not in controls, greater anger-out was associated with deficient opioid modulation of anxiety, anger, and fear reactivity to noxious stimulation. Across participant types, greater anger-in was associated with impaired opioid modulation of anxiety and fear reactivity. Anger-in opioid effects were partially due to overlap with general negative affect. Conclusions: Opioid dysfunction associated with trait anger-out may affect not only perceived pain intensity, but also pain-related suffering in individuals with chronic pain conditions. Implications for understanding the health effects of anger management styles are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A prospective analysis of acceptance of pain and values-based action in patients with chronic pain.

Objective: Acceptance of pain and values-based action appear important in the emotional, physical, and social functioning of individuals with chronic pain. The purpose of the current study was to prospectively investigate these combined processes. Method: 115 patients attending an assessment and treatment course for chronic pain in the U.K. completed a standard set of measures on two occasions separated by an average of 18.5 weeks. Results: Correlation analyses showed that acceptance of pain and values-based action measured at Time 1 were significantly correlated with pain, pain-related distress, pain-related anxiety and avoidance, depression, depression-related interference with functioning, and physical and psychosocial disability measured at Time 2. Multiple regression analyses, in which pain and relevant patient background variables were controlled, showed that the combined acceptance and values measures accounted for between 6.5% and 27.0% of variance in six key measures of patient functioning later in time. Conclusion: These results support the importance of acceptance and values-related processes in relation to chronic pain. These results also encourage continued applications of a functional contextual model of psychopathology, the model underlying Acceptance and Commitment Therapy and related approaches such as Contextual Cognitive-Behavioral Therapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Caregiver models of self and others, coping, and depression: Predictors of depression in children with chronic pain.

In a sample of 59 chronically ill pediatric patients and their maternal caregivers, both child-reported pain and caregiver-reported depression predicted child-reported depression. Results further suggested that the association between pain and depression in children is ameliorated by caregiver coping strategies and that how caregivers cope is a function of their attachment-related representations of the self and others. Caregivers with a negative model of the self were more depressed, and those with a negative model of others were more prone to use avoidant coping strategies, and, in turn, to be more depressed. However, the extent to which caregivers with negative models of self used more avoidant and less approach coping appeared to depend on whether they perceived that others were likely to respond to their needs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The convergence and predictive validity of the Multidimensional Pain Inventory and the Personality Assessment Inventory among individuals with chronic pain.

Objective: To explore the convergence, redundancy, and validity of the Multidimensional Pain Inventory (MPI) and the Personality Assessment Inventory (PAI) in a chronic pain treatment setting. Participants: Data from intake (N=235) and follow-up (N=187) for individuals with an average of 9 years of chronic pain who participated in a 20-day integrative treatment program were analyzed. Outcome Measures: Oswestry Disability Index, Beck Depression and Anxiety inventories, Rand Short-Form Health Survey, and clinician-rated ability to stand and carry. Results: Conjoint factor analyses suggested that the MPI and PAI combine to tap five orthogonal factors: Negative Affect, Support, Externalizing, Physical Dysfunction, and Impulsivity. MPI and PAI scales significantly related to various aspects of client functioning, although these scales were more limited in predicting clinician-rated markers and change during treatment. Conclusion: Results support the combined use of the MPI and PAI to understand patient heterogeneity and predict treatment outcome in chronic pain samples. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The association of parent behaviors, chronic pain, and psychological problems with venipuncture distress in infants: The Generation R study.

Objective: To examine the association of parent behavior with infant distress during a potentially painful medical procedure. A second aim was to investigate the association of parent chronic pain and psychological problems with parent behavior and infant distress during the procedure. Design: Population-based cohort study with both cross-sectional and prospective measurements. Main Outcome Measures: Video recordings of 275 parents and their 14-month-old infant undergoing venipuncture were coded with an observational instrument to yield measures of infant distress behaviors and parent behaviors, such as reassuring, showing empathy, praising, and distracting. Parent chronic pain and psychological problems were assessed through questionnaires. Results: Infants cried 58% of procedure duration. Parent reassuring occurred 34% of procedure duration, and parent distracting occurred 37% of procedure duration. Infant distress was positively related to parent reassuring and negatively related to parent praising. Parent chronic pain was related to increased parent distracting but not to parent reassuring. Parent psychological problems were not associated with parent behavior and infant distress. Conclusion: Parent behavior rather than psychological traits is related to increased venipuncture distress in young infants. This finding suggests that the focus should be on interventions based on behavior modification. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An epidemiological study of diagnostic and therapeutic strategies in office practice patients with subacute or chronic pain in the thoracic or low back. Comparison of practices in primary care and rheumatology settings

Mucin was purified by the gel filtration method on columns with high porous molecular sives in buffers with SDS and proteinase inhibitors. The addition of proteinase inhibitors distinctly inhibited proteolytic activity. It was found that the obtained mucin, after disulphide-bound reduction, is dissociated to mucin subunits and N-glycosylated glycoprotein of molecular weight about 75 kDa. This protein has carbohydrate and amino acid composition different from high molecular fraction. The 75 kDa protein is strongly associated with high molecular mass mucin subunits and can be separated either during electrophoresis or fractionation in buffers with 2-mercaptoethanol.