Steps toward developing an EEG biofeedback treatment for chronic pain.

Chronic pain, usually refractory to analgesics, is a significant problem for many individuals with spinal cord injury (SCI). Preliminary studies suggest that electroencephalography (EEG) biofeedback (also known as neurofeedback, NF) has the potential to help patients with otherwise refractory chronic pain. However, there remain many unanswered questions about the effects and mechanisms of this treatment. We studied 13 individuals with SCI and chronic pain with NF. Ten of the 13 individuals completed 4 sessions each of three different neurofeedback protocols assigned in random order for a total of 12 NF sessions. All three protocols had similar immediate effects on pain intensity. In addition, the participants reported modest pre- to post-treatment decreases in worst pain and pain unpleasantness following completion of the 12 NF sessions. These improvements were maintained at 3-month follow-up. The majority of the participants felt they benefited from and were satisfied with the treatment. No significant effects on measures of other outcome domains (sleep quality, pain interference and fatigue) were observed, although there was a non-significant trend for an increase in fatigue. Finally, pre- to post-treatment changes in EEG bandwidth activity, consistent with the training protocols, were observed in θ and α but not ß frequencies. The findings provide preliminary support for the potential efficacy of NF for the treatment of SCI-related pain, and suggest that further clinical studies are warranted.

Pain self-efficacy mediates the relationship between depressive symptoms and pain severity.

OBJECTIVES: We examined the relationships between depressive symptoms, pain severity, and pain self-efficacy (PSE) in patients with chronic low back pain (CLBP). We hypothesized that change in depressive symptoms would significantly influence change in pain severity, and that PSE indirectly affects this relationship. MATERIALS AND METHODS: Participants were 109 CLBP patients in a 4-week multidisciplinary rehabilitation program for CLBP. They completed measures of PSE, depression, and pain severity at admission and discharge. Structural equation modeling was used to test the significant direct and indirect effects from pretreatment to posttreatment. RESULTS: Change in depressive symptoms significantly predicted change in pain severity in affective (ß=0.358; 95% confidence interval [CI], 0.206-0.480; P=0.006), sensory (ß=0.384; 95% CI, 0.257-0.523; P=0.002), and evaluative pain (ß=0.456; 95% CI, 0.285-0.605; P=0.002). The indirect effects of change in PSE partially accounted for the relationship between change in depressive symptoms and change in sensory (ß=0.105; 95% CI, 0.016-0.241; P=0.023) and evaluative pain (ß=0.121; 95% CI, 0.010-0.249; P=0.040). The relationship between change in depressive symptoms and change in affective pain was fully accounted for by the indirect effect of change in PSE (ß=0.203; 95% CI, 0.082-0.337; P=0.002). DISCUSSION: These findings suggest that pain management and rehabilitation programs for CLBP should specifically target PSE as a key aspect of treatment.

Predicting illness behavior: health anxiety mediated by locus of control.

OBJECTIVE: To examine the role of 3 dimensions of Health Locus of Control (HLOC) on the relationship between health anxiety and illness behavior. METHODS: Cross-sectional survey study of 202 college women. Path analysis and bootstrapping techniques were used to test the significance of mediated models. RESULTS: The indirect effect of Powerful Others HLOC was significant (ß = .06, p < .001), and together health anxiety and Powerful Others HLOC explained 27% of the variance in illness behavior. CONCLUSION: Health anxiety and illness behavior are common problems in college women, and that Powerful Others HLOC is a key mechanism underlying the relationship between health anxiety and illness behavior.

Biopsychosocial functioning and pain self-efficacy in chronic low back pain patients.

The aim of this study was to examine the relationship between biopsychosocial functioning and pain severity and to evaluate whether pain self-efficacy (PSE) mediates this relationship. This study used archival data from a multidisciplinary pain management program. Participants were 99 individuals (69% female) with chronic low back pain who completed measures of biological, psychological, and social functioning, pain severity, and PSE at admission. They ranged in age from 18 to 72 yr (mean = 42.6, standard deviation = 12.1). Structural equation modeling and bootstrapping techniques were used to test the significance of the mediated model. As we predicted, lower biological functioning (beta = -0.011; 95% confidence interval [CI] = -0.019 to -0.004, p = 0.002) and social functioning (beta = -0.009; 95% CI = -0.016 to -0.003, p = 0.007) were found to significantly predict higher pain severity, and lower social functioning was found to significantly predict lower PSE (beta = 0.196; 95% CI = -0.130 to 0.273, p = 0.002). PSE did not mediate the relationship between biopsychosocial functioning and pain severity, and psychological functioning did not significantly predict pain severity or PSE. These findings suggest that social functioning is an important factor in predicting outcomes and has a number of treatment implications.

Cognitive testing and revision of the pain quality assessment scale.

OBJECTIVE: To revise the Pain Quality Assessment Scale (PQAS) using feedback from patients to further increase its validity. METHODS: This project involved 3 cognitive interviewing studies. In Study 1, a group of patients with chronic pain (N=20) were asked a series of questions regarding the PQAS's understandability, and invited to make suggestions regarding how the measure could be improved. In Study 2, a second group of patients (N=21) responded to questions about a modified version of the PQAS. The PQAS was further modified on the basis of the findings of Study 2, and in Study 3 the participants were asked to indicate whether the changes made improved the understandability of the PQAS further. RESULTS: The participants in Studies 1 and 2 identified portions of the PQAS instructions and some of the PQAS items that could be modified to increase their understandability. Modifications resulted in a revised PQAS that was deemed by patients with chronic pain to be more understandable than the original PQAS by the majority of participants. DISCUSSION: testing can be used to improve the understandability of pain measures. The results of cognitive testing with the PQAS indicated that much of the content of the original instructions and items were understandable as written, but that minor changes could be made to make them even clearer to patients with chronic pain. The changes made resulted in a revised PQAS that is more understandable and may therefore be even more useful than with the original PQAS.

Frequency of chronic pain descriptors: implications for assessment of pain quality.

The current study interviewed patients with chronic pain to: (1) identify the most common words used by patients in the samples to describe the "quality" of their pain (i.e. sharp, dull) and (2) evaluate the validity of existing pain quality measures. Two-hundred and thirteen individuals with pain associated with spinal cord injury (SCI) or multiple sclerosis (MS) were asked to describe their pain. Consistent with previous research that has shown that patients with different types of pain problems describe their pain using different pain quality descriptors, there was variability in the frequency of pain descriptors used by the study participants. For example, patients with SCI and below injury level pain used "burning" more often than patients with SCI and shoulder, arm, or neck pain or patients with MS. Regarding the validity of existing pain measures, only one pain quality measure assessed all 14 of the most common pain descriptors volunteered by the sample. Also, although a number of pain quality measures have been developed to discriminate neuropathic from nociceptive pain, there was surprisingly little overlap in descriptors between these measures. The results of the current study and other studies using similar procedures would be useful for evaluating and developing existing and future pain quality measures.

Psychosocial factors and adjustment to pain in individuals with postpolio syndrome.

OBJECTIVE: The purpose of the current study was to examine the associations among measures of psychosocial factors, pain, and adjustment in persons with postpoliomyelitis syndrome. DESIGN: A cross-sectional survey design was used. Sixty-three community-dwelling individuals with postpoliomyelitis syndrome returned completed questionnaires (71% response rate) that included measures of pain intensity and interference, psychological functioning, pain catastrophizing, social support, and pain-related beliefs and coping. RESULTS: After controlling for demographic variables, the group of psychosocial variables accounted for an additional 23% of the variance in pain intensity. These variables explained an additional 35% and 50% of the variance in pain interference and psychological functioning, respectively, after accounting for demographic variables and pain intensity. Social support was associated with both psychological functioning and pain interference, whereas catastrophizing was most closely related to psychological functioning. Individual pain beliefs and coping strategies were variably related to the three criterion measures. CONCLUSIONS: The overall results of the current study are consistent with a biopsychosocial framework for understanding pain and functioning in individuals with postpoliomyelitis syndrome. Although additional research is needed to clarify the nature of the relationships between individual psychosocial variables and functional indices, the findings suggest the need for a multidisciplinary approach to pain management in individuals with postpoliomyelitis syndrome.