Factorial analysis of the MMPI profiles of low back pain patients

To examine the interrelationships of MMPI scale scores among low back pain patients, 50 profiles were scored on the traditional 13 scales, Hanvik's Lb scale and seven subscales derived from Scales 1 and 3. The profiles were randomly divided into two equal samples and factor analyzed. Comparison of the two samples yielded three common factors. The first factor measured severity of the symptoms, the second assessed the level of anger and aggression and the third assessed the psychogenic components of the syndrome. The implications of the factors are discussed.     

Pain-related correlates of MMPI profile subgroups among back pain patients

The MMPI profiles of 96 male and 218 female patients attending a back pain clinic in a private university-affiliated, orthopedic hospital were analyzed by a hierarchical clustering procedure. The clustering procedure produced four male and four female profile subgroups. The subgroups were compared with one another on the basis of patients' responses to the Cornell Medical Index and revised McGill Pain Assessment Questionnaire. Within the male and female patient cohorts it was found that profile subgroups featuring elevated clinical scales showed greater disruptions of daily activities than did subgroups with relatively unelevated profiles. However, profile subgroups with elevations primarily on the neurotic triad scales reported greater affective disturbance and disruption of daily activities than did subgroups with elevations on both the neurotic triad and relatively psychotic scales. In addition, profile subgroups with subclinical elevations on the neurotic triad scales appeared to have adjusted to their pain experience more poorly than did subgroups that featured scores on nearly all clinical scales that were within one standard deviation of the mean. Suggestions are provided for the use of the MMPI in assessing chronic pain patients and future research regarding cluster analyses of patients' MMPI profiles.     

Musculoskeletal status and disability of MMPI profile subgroups among patients with low back pain

The Minnesota Multiphasic Personality Inventory (MMPI) profiles of 205 male and 157 female patients with acute and chronic low back pain (LBP) were studied for replicable homogeneous subgroups using three cluster-analysis procedures. Two normal and three clinically elevated profile subgroups were identified. The two normal subgroups were characterized by relatively normal musculoskeletal condition and were least disabled, but they differed somewhat from each other in duration of pain, presence of physical abnormalities, and daily functioning. The third subgroup had the following characteristics: an elevated neurotic triad, greatest duration of symptoms, most abnormal physical findings, greatest limitation of motion, most pain complaints during physical examination, and the fewest number of intact functional activities. The fourth subgroup, with an elevated neurotic triad plus subclinical elevations on other scales, had somewhat less musculoskeletal impairment but had extensive work disability, financial compensation, and previous surgeries. The fifth and most pathologic profile subgroup surprisingly consisted largely of acute-pain patients whose musculoskeletal condition and daily functioning were similar to those of the normal subgroups. Patients in the three abnormal MMPI subgroups were exposed to more LBP physical-risk factors in the workplace. Implications for psychological treatment with these different profile types are discussed.     

Rorschach and pain characteristics of patients with low back pain and "conversion V" MMPI profiles

Two studies examined the relationship between Rorschach determinants, MMPI scale scores, and pain reports in order to clarify the meaning of the MPI "conversion V" pattern among patients with low back pain. Study I showed that patients without demonstrable organic disease of the back produce Rorschach response summaries marked by lower F+%, lower Sum C, and higher F% than patients with demonstrable organic disease. Study 2 showed that only the increase in F% was associated with significant elevations of the MMPI Hs and Hy scales. The results suggest that elevated MMPI "conversion V" profiles are indicative of psychological disturbance among patients with low back pain. It is unlikely, however, that the disturbance is hysterical. Instead, the psychopathology is probably marked by tension and constraint rather than the over-reactivity of hysteria. The implications of these findings for diagnosis are discussed.     

The MMPI in evaluation of functional versus organic low back pain

This paper reviews the research literature on MMPI assessment of functional versus organic low back pain (LBP). Research is described in three categories: (a) the relationship between psychopathology as measured by the MMPI and low back pain, (b) MMPI speciality scales, and (c) surgical outcomes. Research, to date, has suffered from methodological problems which has limited generalizations to clinical population. It is suggested, however, that the MMPI can be effectively used with LBP patients, but should not be the only data used in such assessments. Cautions are noted regarding use of the speciality scales.     

Alexithymia among empirically derived subgroups of chronic back pain patients

A seeded cluster analysis procedure was applied to the Minnesota Multiphasic Personality Inventory (MMPI) profiles of 102 male and 63 female back-pain patients. For both men and women, the resulting subgroups were found to correspond closely to similar subgroups obtained in several previous investigations. New data on the psychometric properties of the MMPI Alexithymia scale (Kleiger & Kinsman, 1980) are presented. Significant differences in alexithymia among empirically derived MMPI subgroups were found in the male sample only.     

Impaired visual perception of hurtful actions in patients with chronic low back pain

Visually presented biological motion stimuli activate regions in the brain that are also related to musculo-skeletal pain. We therefore hypothesized that chronic pain impairs the perception of visually presented actions that involve body parts that hurt. In the first experiment, chronic back pain (CLBP) patients and healthy controls judged the lifted weight from point-light biological motion displays. An actor either lifted an invisible container (5, 10, or 15 kg) from the floor, or lifted and manipulated it from the right to the left. The latter involved twisting of the lower back and would be very painful for CLBP patients. All participants recognized the displayed actions, but CLBP patients were impaired in judging the difference in handled weights, especially for the trunk rotation. The second experiment involved discrimination between forward and backward walking. Here the patients were just as good as the controls, showing that the main result of the first experiment was indeed specific to the sensory aspects of the task, and not to general impairments or attentional deficits. The results thus indicate that the judgment of sensorimotor aspects of a visually displayed movement is specifically affected by chronic low back pain.     

Increased use of safety-seeking behaviors in chronic back pain patients with high health anxiety

Many patients with chronic pain also exhibit elevated levels of health anxiety. This study examined the effect of health anxiety on the use of safety-seeking behaviors (SSBs) in pain-provoking situations. Participants were 20 chronic back pain patients with high health anxiety (Group H), 20 with low health anxiety (Group L) and 20 pain-free controls (Group C). Two physical tasks were video recorded, and compared both for overt pain behavior (identified by blind observers following a standardized procedure) and for the occurrence of SSB (identified by showing the participants video playback and asking them to specify motivation for all actions/behaviors displayed during the tasks). While there were no differences in the display of overt pain behaviors, Group H deployed a greater number of SSBs than Groups L and C. This finding held true for both tasks and remained significant when concurrent pain and mood ratings were statistically controlled for. SSB was correlated with catastrophizing thoughts but not pain intensity; pain intensity was correlated with overt pain behavior but not catastrophizing. Taken together, these findings suggest that SSB is distinct from overt pain behavior and may be a defining characteristic of chronic pain patients reporting high levels of health anxiety.     

Use of verbal pain measurement in the detection of hidden psychological morbidity among low back pain patients with objective organic findings

Abstract

Patients with positive physical findings to explain low back pain arc believed lo belong to two organic subgroups. One group has organic disease alone: in the other, organic disease is accompanied by psychological disturbance. Separation of patients with medical findings into groups with varying levels of psychological disturbance is difficult, because emotional disturbance is often hidden. In this study, the pain report of 124 patients with organic findings alone, and 50 patients with organic and psychological findings was examined to determine whether pain measurement could he used to identify accurately patients belonging 10 the two groups. the pain groups differed in the use of 43 pain words from the Low Back Pain Symptom Check List. Using a set of weights derived From discriminant analysis. the 33 pain words predicted 99.2% of the patients with organic disease alone and 86.0% of the patients with organic disease and psychological disturbance. The results were replicated in a new sample of 140 patients. Cross-validation shrinkage in accuracy was 8.3%. The results of the two studies suggest that pain measurement may he a useful clinical indicator of psychological disturbance in patients with organic findings.     

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.     

Catastrophizing,locus of control,pain, and disability in chinese chronic low back pain patients

Abstract

The present study examined the associations of locus of control (LOC) and catastrophizing with pain intensity and disability in Chinese chronic low back pain (CLBP) patients. In the study, 56 respondents (21 men and 35 women) with a mean age of 36.98 years (SD= 12.22) completed measures assessing locus of control, catastrophizing tendency, pain intensity, disability, and psychological distress. Results showed that after partialling out the effects of gender, duration of pain, and psychological distress, internal LOC significantly explained the variance of disability. For pain intensity, only catastrophizing accounted for a large portion of the variance. Limitations of the study and suggestions for future work were discussed.     

Effects of pain acceptance and pain control strategies on physical impairment in individuals with chronic low back pain

Psychosocial treatments for chronic pain are effective. There is a need, however, to understand the processes involved in determining how these treatments contribute to behavior change. Control and acceptance strategies represent two potentially important processes involved in treatment, although they differ significantly in approach. Results from laboratory-based studies suggest that acceptance-oriented strategies significantly enhance pain tolerance and behavioral persistence, compared with control-oriented strategies. There is a need, however, to investigate processes of acceptance and control directly in clinical settings. The present study investigated the effects of three brief instructional sets (pain control, pain acceptance, continued practice) on demonstrated physical impairment in 74 individuals with chronic low back pain using an analogue experimental design. After controlling for baseline performance, the pain acceptance group demonstrated greater overall functioning on a set of 7 standardized physical tasks relative to the other two groups, which did not differ from one another. Further, the acceptance group exhibited a 16.3% improvement in impairment, whereas the pain control group worsened by 8.3% and the continued practice group improved by 2.5%. These results suggest that acceptance may be a key process involved in behavior change in individuals with chronic pain.     

The effect of chronic low back pain on tactile suppression during back movements

The aim of the present study was to examine whether tactile suppression, the phenomenon whereby tactile perception is suppressed during movement, would occur in the context of back movements. Of particular interest, it was investigated if tactile suppression in the back would be attenuated in those suffering from chronic low back pain. Individuals with chronic low back pain (N = 30) and a matched control group (N = 24) detected tactile stimuli on three possible locations (back, arm, chest) while performing a back or arm movement, or no movement. We hypothesized that the movements would induce tactile suppression, and that this effect would be largest for low-intense stimuli on the moving body part. We further hypothesized that, during back movements, tactile suppression on the back would be less pronounced in the chronic low back pain group than in the control group. The results showed the expected general tactile suppression effects. The hypothesis of back-specific attenuation of tactile suppression in the chronic low back pain group was not supported. However, back-specific tactile suppression in the chronic low back pain group was less pronounced in those who performed the back movements more slowly.     

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.     

Operant-behavioural and cognitive-behavioural treatment for chronic low back pain.

Fifty-eight outpatients with chronic low back pain were randomly allocated to one of six experimental conditions. Four conditions were designated as treatment conditions and two as control conditions. The four treatment groups consisted of: cognitive treatment (either with or without relaxation training) and behavioural treatment (either with or without relaxation training). The cognitive and behavioural groups also received physiotherapy. The two control conditions consisted of: attention (physiotherapy plus discussion sessions) and no-attention (physiotherapy-only) conditions. All conditions, including the two controls, received the same physiotherapy back-education and exercise program. For the sample as a whole, improvements were obtained on measures of affective distress, functional impairment, medication use, pain-related dysfunctional cognitions and use of active coping strategies. These improvements were generally maintained at 6- and 12-month follow-ups. The combined psychological/physiotherapy treatment conditions improved significantly more than the physiotherapy-only conditions from pre to posttreatment on measures of pain intensity, self-rated functional impairment and pain-related dysfunctional cognitions. However, these differences were only weakly maintained at 6- and 12-month follow-ups. The behavioural conditions improved significantly more than the cognitive conditions from pre to posttreatment on the self-rated measure of functional impairment, but this difference was not maintained at 6- and 12-month follow-ups. Progressive relaxation training was found to make little contribution to either cognitive or behavioural treatments.     

Reducing the threat value of chronic pain: A preliminary replicated single-case study of interoceptive exposure versus distraction in six individuals with chronic back pain

This paper describes a preliminary experimental evaluation of a technique intended to help people suffering from chronic back pain and low pain acceptance to alter the aversiveness or threat value of their persisting pain. Using a multiple baseline cross-over design six individuals with chronic back pain were taught to use a form of interoceptive exposure as well as a relaxation/distraction breathing-based technique in the presence of their pain. Half the participants used one method for three weeks, and then crossed over to the other method for a further three weeks. The other half did the reverse. Assessments were conducted at pre/post treatment and at a three month follow-up. Daily monitoring of pain-related distress was also completed. The results indicated moderately high improvements in pain acceptance across most participants and corresponding declines in pain-related distress. No clear differences occurred between conditions, but the changes on disability and catastrophising scales for most cases were consistent with those reported after more substantial interventions. The study raises some important clinical and methodological issues that could inform future research in this area.