Pain complaint and the weather: weather sensitivity and symptom complaints in chronic pain patients.

Chronic pain patients frequently report that weather conditions affect their pain; however, no standardized measures of weather sensitivity have been developed. We describe the development and use of the Weather and Pain Questionnaire (WPQ) which assess patient sensitivity to meteorologic variables defined by the National Weather Service (e.g., temperature, precipitation). Seventy chronic pain patients (59% females) with an average age of 43 years completed the WPQ. The instrument was revised using factor analysis to produce a Weather Sensitivity Index (WSI) (48% of variance) with high internal consistency (0.93) and test-retest reliability (r = 0.89). Reporting patterns suggested that patients could reliably identify which meteorologic variables influenced their pain but could not reliably determine which physical symptoms were consistently affected. The most frequently reported meteorologic variables which affect pain complaint were temperature (87%) and humidity (77%). The most frequently reported physical complaints associated with the weather were joint and muscle aches (82% and 79%, respectively). Patients labeled as being 'weather sensitive', defined by greater than median scores on the WPQ, reported significantly greater pain intensity, greater chronicity of pain problems, and more difficulties sleeping than patients with low scores on the WPQ. No differences in gender, education level, disability status, or global psychological distress were found. Results are discussed with respect to physiological and psychological mediating variables.     

Multiple Response Comparison of Parietal EEG and Frontalis EMG Biofeedback

In Study I parietal EEG and frontalis EMG were simultaneously recorded from 20 normal subjects while half of the subjects received 45 min of eyes-closed alpha EEG enhancement feedback and the other half received a similar amount of EMG suppression feedback. EMG feedback resulted in a significant reduction in frontalis EMG activity accompanied by a reliable increase in parietal alpha density, while EEG feedback produced only an increase in alpha without corresponding EMG reduction. In Study II, each of 8 subjects underwent four separate feedback contingencies in two 40-min sessions—one session with eyes open and the other with eyes closed. The four types of feedback were: a) alpha-up (alpha enhancement), b) alpha-down (alpha suppression), c) EMG-down (frontalis tension decrease), and d) EMG-up (frontalis tension increase). EMG feedback, up and down, resulted in the more consistent pattern of generalized arousal changes reflected in heart rate and respiratory rate as well as EEG and EMG activity. Within the constraints of a limited training period, the results suggest that frontalis EMG feedback is the more efficient procedure for producing a generalized relaxation response. However, since fingertip vasoconstriction accompanied all four types of feedback, caution must be exercised to avoid the oversimplification of generalized organism effects.     

Effect of EMG Biofeedback and Progressive Muscle Relaxation Training on Awareness of Frontalis Muscle Tension

Awareness of muscle tension, as estimated by a modification of the Kinsman et al. (1975) procedure for determining probability of correct estimation (P(c)) of absolute differences in muscle tension between adjacent trials, was examined before and after volunteer subjects underwent 4 sessions of either: 1) EMG biofeedback (BF) training, 2) progressive muscle relaxation (PMR) training, or 3) a placebo-control (MC) procedure which involved listening to music as an alleged guide for relaxation. The subjects were 30 females (mean age = 28.3 yrs) responding to an offering of experimental treatment for anxiety and tension. Measurements of frontalis muscle tension (EMG) and P(c) were made before and after training. The results showed that EMG was significantly reduced by BF and PMR training but not by the MC procedure. Increases in P(c) after training were significantly greater for BF than for PMR or MC training. There were no group differences for subjective report of tension. Correlations between pre- to post-training EMG and P(c) change scores were significant only for the BF group and the combined group of BF and PMR subjects. These results suggest that: 1) both BF and PMR training were effective in producing frontalis EMG reductions, 2) the following relationship may exist among training groups in terms of relative influence upon awareness of tension—BF training > PMR training > MC training, and 3) awareness of tension appears to be related to the ability to reduce EMG although the exact nature of this relationship remains unclear.     

The Balans chair and its semi-kneeling position: an ergonomic comparison with the conventional sitting position

Recently, the Balans chair has been introduced with claims that, because of its semi-kneeling position, individuals will experience decreased low-back pain (LBP) as well as improvement in circulation. This study investigated the validity of these claims. Twenty healthy subjects were randomly assigned to one of two groups. Group 1 subjects sat in the Balans chair for a 30-minute study period and then sat in a conventional office chair for an additional 30-minute period. Group 2 subjects were studied in the reverse seating order. Parameters studied were cervical and lumbar paraspinous surface EMG, and pedal cutaneous blood flow measured by laser-Doppler flowimetry. In addition, a questionnaire comparing the comfort of the two chairs was completed at the end of the study session. Comfort ratings showed an overall preference for the conventional chair. Increased cervical (P = .004) and lumbar muscle EMG measurements were noted after sitting in the Balans chair. Pedal cutaneous blood flow was increased by 15% in the Balans chair (P = .001). The data do not support the manufacturer's claim that the Balans chair is likely to decrease complaints of LBP.     

Self-reported alcohol and nicotine use and the ability to control occipital EEG in a biofeedback situation

Forty college-aged males, identified as either users or non-users of alcohol and nicotine, underwent four, 40-min eyes-closed occipital alpha (8–13 Hz, 10μV) biofeedback sessions over a 4-week period. One-half of the subjects attempted to enhance their alpha density while the other half attempted to suppress it. Analyses of the alpha control scores indicated that non-users of alcohol and nicotine were superior to users of these substances in the self-regulation of occipital alpha density. The possibility that individuals with poor cortical regulatory ability might be predisposed to use such cortically active substances as alcohol and nicotine was discussed, as were several limitations of the present data.     

A comparison of health locus of control beliefs in low-back patients from the U.S. and New Zealand

In order to study differences in health control attitudes between chronic low-back patients from the U.S. and New Zealand, the Health Locus of Control (HLC) was administered to 284 consecutive admissions to pain clinics in those countries: 96 patients seen at the Auckland (New Zealand) Pain Clinic and 188 seen at the University of Virginia (U.S.) Pain Clinic. The HLC is an 11-item instrument [23] that assesses general control over health matters. Principal component factor analyses indicated 3 distinct subscales for the low back patients: (a) personal health control, (b) external health control, and (c) control by powerful others (physicians). HLC responses were analyzed with univariate analyses of variance using subscale scores as dependent measures and country and sex as independent variables. New Zealanders rated themselves as less dependent on physicians' orders (F (1,280)=3.92, P less than 0.05), and women were seen as having less personal control over their pain conditions than men (F (1,280)=6.29, P less than 0.02). The differences related to sex and country are discussed within a social learning framework. Suggestions are made for future cross-cultural research, especially related to issues of dependency on others for health control and outcomes in the treatment of chronic pain.     

Effects of Alpha Feedback Training on Occipital EEG, Heart Rate, and Experiential Reactivity to a Laboratory Stressor

The intent of this study was to examine whether brief alpha biofeedback training would alter the degree of physiological and experiential stress evidenced in an aversive laboratory situation. While occipital alpha and heart rate were monitored, 36 subjects underwent 8 presentations of a warning tone preceding fingertip electric shock by 30 sec. Subjects were then placed into one of three treatments taking place in dim light with eyes open. Group 1 received 24 min of contingent feedback. Group 2 received an equivalent amount of non-contingent feedback and Group 3, a no-feedback control condition, listened to music. Following the treatment period, 12 additional tone-shock pairings were presented, equally divided between eyes-open and eyes-closed trials, also with and without continuation of the treatment period “signal” (i.e. contingent, non-contingent feedback, or music). The results revealed that, in general, enhanced alpha density was maintained by the contingent feedback group during the post-treatment aversive situation. However, the reduction in alpha suppression was not systematically accompanied by corresponding heart rate and self-report reductions in situational reactivity. It was concluded that alpha feedback training was not sufficient to produce a generalized relaxation to the aversive situation. Alternative accounts of the results, focusing primarily on independence of response systems, are discussed.     

A comparison of low back pain patients in the United States and New Zealand: Psychosocial and economic factors affecting severity of disability

One hundred and ninety-eight patients suffering from chronic low back pain seen at the University of Virginia (U.S.) Pain Center and 117 similar patients seen at the Auckland Hospital, Auckland, New Zealand (N.Z.) Pain Clinic completed a self-report questionnaire prior to beginning comparable outpatient treatment programs. Approximately 55% of the sample from each country returned a follow-up questionnaire 1 year later. Analyses of the results indicated that despite nearly similar between-country reports of pain frequency and intensity, the U.S. patients, both at pre- and post-testing, reported greater emotional and behavioral disruption as a correlate of their pain. U.S. patients consistently used more medication, experienced more disphoric mood states, and were more hampered in social-sexual, recreational, and vocational functioning. Patients from both countries demonstrated a nearly equal degree of pre- to post-improvement; however, the relative initial differences favoring the New Zealanders remained constant across both questionnaire administrations. At the onset of treatment, 49% of the U.S. sample and only 17% of the N.Z. patients were receiving pain-related financial compensation. At follow-up, patients from both countries receiving pretreatment compensation were less likely to report a return to full activity, although the relationship appeared more pronounced in U.S. patients. Seemingly, compared to the U.S., the N.Z. compensation-disability system is used less, or for shorter durations of time, resulting in less severe life-style disruption than appears to be the case in the U.S. patients. Seemingly, compared to the U.S., the N.Z. compensation-disability system is used less, or for shorter durations of time. resulting in less severe life-style disruption than appears to be the case in the U.S.     

Chronic pain patients' beliefs about their pain and treatment outcomes

A novel assessment procedure measuring chronic pain patients' agreement with information presented on a clinic orientation videotape was evaluated as a predictor of short-term treatment outcome. One hundred randomly selected outpatients viewed a 15-minute videotape detailing conservative approaches to pain management and completed a questionnaire measuring factual recall of the videotape presentation and their acceptance or rejection (ie, agreement) of this information. Patient ratings of satisfaction with treatment were assessed one month after treatment. Multivariate analyses revealed that extent of agreement with the videotape content was significantly associated with lower pain ratings, increased ratings of physical ability, and higher treatment satisfaction. Prognostic use of this procedure for identifying patients at risk for nonadherence to treatment is discussed.