Pain in severe dementia: A comparison of a fine-grained assessment approach to an observational checklist designed for clinical settings.

BACKGROUND: Fine-grained observational approaches to pain assessment (e.g. the Facial Action Coding System; FACS) are used to evaluate pain in individuals with and without dementia. These approaches are difficult to utilize in clinical settings as they require specialized training and equipment. Easy-to-use observational approaches (e.g. the Pain Assessment Checklist for Limited Ability to Communicate-II; PACSLAC-II) have been developed for clinical settings. Our goal was to compare a FACS-based fine-grained system to the PACSLAC-II in differentiating painful from non-painful states in older adults with and without dementia. METHOD: We video-recorded older long-term care residents with dementia and older adult outpatients without dementia, during a quiet baseline condition and while they took part in a physiotherapy examination designed to identify painful areas. Videos were coded using pain-related behaviours from the FACS and the PACSLAC-II. RESULTS: Both tools differentiated between painful and non-painful states, but the PACSLAC-II accounted for more variance than the FACS-based approach. Participants with dementia scored higher on the PACSLAC-II than participants without dementia. CONCLUSION: The results suggest that easy-to-use observational approaches for clinical settings are valid and that there may not be any clinically important advantages to using more resource-intensive coding approaches based on FACS. We acknowledge, as a limitation of our study, that we used as baseline a quiet condition that did not involve significant patient movement. In contrast, our pain condition involved systematic patient movement. Future research should be aimed at replicating our results using a baseline condition that involves non-painful movements. SIGNIFICANCE: Examining older adults with and without dementia, a brief observational clinical approach was found to be valid and accounted for more variance in differentiating pain-related and non-pain-related states than did a detailed time-consuming fine-grained approach.

Repeated exposure to others' pain reduces vicarious pain intensity estimation.

BACKGROUND: Pain perception in others can be influenced by different contextual factors. In clinical settings, the repeated exposure to others' pain has been proposed as a factor that could explain underestimation of patients' pain by health care providers. Previous research supported this idea by showing that repeated exposure to persons in pain biases the subsequent willingness to impute pain in others. However, it remains unclear if the effect of repeated exposure on the detection of pain extends to deliberate pain estimation of stimuli presented for a longer period. METHOD: Therefore, in a first experiment, healthy participants were either exposed to clips of facial expressions of intense pain or neutral expressions before estimating the intensity of other individuals' pain expressions. To test the specificity of this effect with regard to the pain content, a second study was conducted with healthy adults, which compared the effect of exposure to fear, pain and neutral videos on subsequent pain assessment in others. RESULTS: Results from the first experiment indicated that repeated exposure to others' pain diminished the subsequent estimation of the intensity of pain in others. Results from the second experiment suggested that exposure to fear could bias pain estimation in a similar manner. However, the absence of difference in ratings between the exposure to fear and neutral groups warrants caution in the interpretation of these findings. CONCLUSION: By demonstrating that repeated exposure to others' pain diminished subsequent pain estimation in others, this study adds relevant information on the factors that could contribute to pain underestimation in health care professionals. WHAT DOES THIS STUDY ADD?: Repeated exposure to facial expressions of intense pain not only biases pain detection, but also pain estimation in others. Prior exposure to facial expressions of pain compared to exposure to neutral ones leads to a reduced estimation of others' pain. This effect is not specific to pain as exposure to another negative emotion (fear) also biases subsequent pain estimation. These results support the interpretation that the underestimation of patients' pain by health care professionals could be related to repeated exposure to other's pain.

Emotional contagion for pain is intact in autism spectrum disorders.

Perceiving others in pain generally leads to empathic concern, consisting of both emotional and cognitive processes. Empathy deficits have been considered as an element contributing to social difficulties in individuals with autism spectrum disorders (ASD). Here, we used functional magnetic resonance imaging and short video clips of facial expressions of people experiencing pain to examine the neural substrates underlying the spontaneous empathic response to pain in autism. Thirty-eight adolescents and adults of normal intelligence diagnosed with ASD and 35 matched controls participated in the study. In contrast to general assumptions, we found no significant differences in brain activation between ASD individuals and controls during the perception of pain experienced by others. Both groups showed similar levels of activation in areas associated with pain sharing, evidencing the presence of emotional empathy and emotional contagion in participants with autism as well as in controls. Differences between groups could be observed at a more liberal statistical threshold, and revealed increased activations in areas involved in cognitive reappraisal in ASD participants compared with controls. Scores of emotional empathy were positively correlated with brain activation in areas involved in embodiment of pain in ASD group only. Our findings show that simulation mechanisms involved in emotional empathy are preserved in high-functioning individuals with autism, and suggest that increased reappraisal may have a role in their apparent lack of caring behavior.

Assessing pain behaviour of low-back pain patients in real time: concurrent validity and examiner sensitivity.

Several systems for measuring pain behaviour have been developed for clinical settings. The present study reports on a real-time system for coding five categories of pain behaviour for low-back pain patients: guarding, touching, sounds, words, and facial expression. Unique features of the system are the use of refined measures of facial expression and integration of the measurements with a standardized physical examination. 176 sub-acute and chronic low-back pain patients underwent a physical examination while their pain behaviour was coded. Concurrent measures of subjective pain, medically-incongruent signs, and independent global ratings of pain behaviour were taken. Analyses indicated that the pain behaviours, particularly guarding and facial expression, varied systematically with the alternative measures, supporting the concurrent validity of the behaviour observation system. While pain behaviours, especially use of words and facial expressions, were significantly associated with the examiners' independent ratings, the strength of the associations suggested that, in the absence of direct training, examiners' performance was relatively poor. Implications for training of clinicians in detecting pain behaviour are discussed.

Comparison of hemodynamic responses to social and nonsocial stress: evaluation of an anger interview.

Hemodynamic responses to an anger interview and cognitive and physical stressors were compared, and the stability of associated hemodynamic reactions examined. Participants experienced control, handgrip, counting, and mental arithmetic tests and an anger interview on two occasions. Systolic and diastolic blood pressure, heart rate, stroke volume, and cardiac output were measured. Total peripheral resistance was also derived. The anger interview produced larger, more sustained changes in blood pressure in both sessions than the other stressors. These changes were largely a consequence of increased peripheral resistance. Consistent with previous findings, handgrip was associated with a resistance-type reaction whereas arithmetic was associated with a cardiac output-type reaction. There was low-to-modest stability of hemodynamic reactions to the interview. Further research is necessary to optimize its utility in studies of cardiovascular function. Nevertheless, the findings underscore the ability of ecologically relevant stressors to provoke unique configurations of cardiovascular activity.

Does experience influence judgments of pain behaviour? Evidence from relatives of pain patients and therapists.

OBJECTIVE: Judgments about an individual's pain can be profoundly important to sufferers. Relatively few studies have examined variables that may affect observers' judgments of the pain of others. The present article reports two studies investigating the relationship between different kinds of exposure to pain problems and observers' ratings of the pain intensity of patients. DESIGN: In the first study, 82 observers were classified into groups with positive and negative family histories of chronic pain. They viewed a videotape showing the facial expressions of shoulder pain patients undergoing physiotherapy assessments and rated the pain experienced by the subjects. In the second study, the data from observers having no experience with pain problems were compared with data collected from therapists having considerable experience with pain problems. RESULTS: Observers with a positive family history of chronic pain attributed greater pain to the patients than those with a negative family history of chronic pain. Professionals' pain judgments were lower than those of control subjects. CONCLUSIONS: Together, the findings imply that one's experiences with the different problems of pain patients may affect pain judgments. Alternative interpretations of the findings are considered.

Cardiovascular changes during induced emotion: an application of lang's theory of emotional imagery.

Studies of emotion have provided occasional support for physiological differentiation of affective states; however, the evidence has been inconsistent. The aims of the present study were to investigate cardiovascular changes associated with relived experiences of happiness, sadness, anger, fear, and disgust and to examine the utility of methods designed to optimize the induction of emotional responses. Thirty-four undergraduates who scored 0.5 sd above the mean on Larsen and Diener's Affect Intensity Measure described their most intense experiences of five emotions. These descriptions were then used to induce those emotions while blood pressure and other hemodynamic measures were monitored. Systolic blood pressure, diastolic blood pressure, and stroke volume differentiated among emotions. The results support the suggestion that cardiovascular activity differentiates emotional states and provide some insight into the physiological adjustments subserving such effects. The study demonstrates a method that may be applied to studies of discrete emotions.

Enhancing sensitivity to facial expression of pain.

Clinicians have long appreciated the information communicated by a patient's facial expression. Advances in the measurement of facial movements, using the Facial Action Coding System (FACS) have allowed for identification of a universal expression of pain, which is primarily encoded in four facial movements. While the FACS provides a rigorous assessment of facial expression, the time required to learn the system and to analyze the facial expression by use of slow motion video recording, makes its use impractical in the clinical setting. The purpose of this research was to examine whether exposure to a brief training procedure, based on orienting subjects to the four facial movements, would increase sensitivity to pain communicated by facial expression. Seventy-five occupational and physical therapy student volunteers were randomly assigned to training or control groups. The trained group was exposed to a 30-min training session. Both groups were then asked to rate a videotape of patients undergoing assessment of a painful shoulder and rate the amount of discomfort the patients appeared to be experiencing. Analyses indicated that the trained group was significantly more sensitive to subtle facial movements associated with low levels of pain. Relative to the patients' ratings, there was a tendency for raters to underestimate pain particularly when these were at a high level. The findings lend hope to the feasibility of developing a tool which would be clinically useful though this may be more difficult for observers judging more complex facial expressions associated with high levels of pain.

Bias in assessment of nonverbal pain in compensation patients: does it exist?

This study examined whether providing information to rehabilitation professionals, on the compensation status of patients, would influence their rating of nonverbal expressions of pain. In an experimental design two groups of physiotherapists and occupational therapists were asked to view videotapes of 10 patients with shoulder pain undergoing a total of 88 pain induction tests. They were asked to rate the amount of pain the patients were experiencing based solely on the facial expression of pain. Bias was instilled in one group (n = 18) by informing them that the patients originated from a workers' compensation facility. Sixteen therapists served as a control group. Results indicate that the therapists rated the nonverbal expression of pain similarly regardless of their perceived compensation status. These findings suggest that the mistrust that is commonly experienced by patients on workers' compensation does not come from rehabilitation professionals but from other sources within the system. Alternative explanations for the findings and directions for future research are explored.

Comparison of three theories relating facial expressiveness to blood pressure in male and female undergraduates.

We examined differing predictions of how emotional expressions and blood pressure are related. Spontaneous positive and negative facial expressions, resting systolic blood pressure (SBP), and reactive SBP were each measured for 148 male and female undergraduates. The discharge theory of emotions proposes that few expressions will predict higher baseline SBP, and this was found for men. A mismatch theory of emotions proposes that an imbalance between positive and negative expressions will predict higher baseline SBP, and this was supported for women. Finally, coactivation theory proposes that many expressions will predict higher reactive SBP, and this was found for both men and women. These results reconcile previous conflicting findings by clarifying the conditions under which each of these theories may be supported.

Psychological stress reverses antiaggregatory effects of dietary fish oil.

Effect of acute psychological stress on the inhibition of in vitro platelet aggregation by dietary long-chain n-3 fatty acids was studied in 20 adult males. Subjects were randomly divided into groups receiving either olive oil or fish oil (2.4 g long-chain n-3 fatty acids/day) for 4 weeks. In vitro aggregation responses to two doses of ADP collagen, and epinephrine were measured immediately prior to and following exposure to three psychological stressors (2 min each), before and after the supplementation period. Olive oil had no effect on baseline aggregatory responses, while fish oil reduced aggregatory responses to ADP and epinephrine. Exposure to the stressors had no effect upon presupplementation aggregation in either group or in the olive oil group postsupplementation. However, stress abolished antiaggregatory effects of fish oil. This reversal of the antiaggregatory effects of fish oil by mild stress suggests possible limitations of low-dose fish oil supplementation in clinical situations.

Effects of acute exercise on cardiovascular reactivity.

Although exercise may modulate cardiovascular reactivity to stress, its acute effects have not been studied extensively. The purpose of this study was to examine over time the acute effects of different durations of aerobic exercise on cardiovascular reactivity to stressors. Twenty-four sedentary men underwent minimal exercise, 1 or 2 hr of stationary cycling at 55% VO2max. Heart rate, blood pressure, and blood catecholamines were measured during cold pressor, Stroop, and public speech tasks 1, 3, and 24 hr after exercise. One or two hours of exercise attenuated blood pressure responses to stress. The attenuation was evident 3 hr following exercise and was most apparent on the cold pressor task. These effects were independent of epinephrine level and stress appraisal. The role of central sympathetic processes in the effects of exercise and methodologic implications are discussed.

The expression and perception of facial emotion in alexithymia: a pilot study.

The term alexithymia denotes a cluster of traits including a marked difficulty in finding words to describe emotions. Despite a rapidly growing literature, the construct has not been validated adequately. The present study addressed the validity of the construct. Twenty males assessed as alexithymic or not, on the basis of the Schalling-Sifneos Personality Scale, were videotaped during tasks designed to elicit spontaneous and posed facial expressions of emotion. They also rated the emotional impact of the tasks and prototypic displays of emotion. Results showed that alexithymics were comparable to controls in judgments of the impact of provocative slides and in their ability to label posed expressions. With the exception of expressions of anger and happiness, they were also comparable in the ability to pose emotions. Alexithymics showed a deficit in spontaneous displays of negative affect. Results support the validity of the concept and suggest that deficits in nonverbal expression are central to the phenomenon. Implications for conceptualizations of alexithymia and emotion are discussed.

Dietary fatty acid supplementation alters stress reactivity and performance in man.

Certain dietary polyunsaturated fatty acids, gamma linolenic (18:3n-6) and eicosapentaenoic (20:5n-3) acid, attenuate cardiovascular reactivity to stress in rats. To study their effects on cardiovascular reactivity to acute stress in man, 30 men were randomly assigned to one of three groups and given 28 day supplements of borage oil (containing 18:3n-6), fish oil (containing 20:5n-3), or olive oil (placebo). Reactivity to the Stroop colour-word conflict test was assessed prior to and following treatment. Borage oil alone attenuated blood pressure and heart rate responses to stress, increased skin temperature, and improved task performance. These data suggest that diet may be used to alter stress reactivity in man.

Observer judgments of acute pain: facial action determinants.

We provided a microanalytic description of facial reactions to a series of painful and nonpainful electric shocks and examined the impact of these as discrete facial cues for observer judgments of acute pain. Thirty female volunteers were videotaped and reported their discomfort in response to electric shocks after earlier exposure to one of three social influence conditions: a tolerant model, an intolerant model, or neutral peer presence. We coded the videotapes for facial activity using the Facial Action Coding System (Ekman & Friesen, 1978b), and peer judges rated them for painful discomfort. Subjects exposed to a tolerant model reported no more discomfort than did subjects exposed to an intolerant model, despite receiving more intense levels of shock, but were judged by observers to be in more pain. Analyses of facial activity yielded consistent findings: Tolerant-model subjects, though reporting discomfort equivalent to that reported in other groups, displayed more pain-related facial activity (brow lowering, narrowing of the eye aperture from below, raising the upper lip, and blinking). There was a substantial direct relation between observer judgments of distress and discrete, pain-related facial actions (mean multiple R = .74 for the various shock levels rated). These data indicate that nonverbal expression yields information about the response to noxious stimulation that is non-redundant with self-report.

Social influences on factored dimensions of the McGill Pain Questionnaire.

The McGill Pain Questionnaire (MPQ) was administered to 268 subjects following electrical stimulation to pain-tolerance limits. Subjects received stimulation under four social modeling conditions: tolerant, intolerant, control, and no model. The number of factors and degree of obliqueness most appropriate for the MPQ scores were determined using multiple criteria. Five factors, reflecting 46.6% of the total variance, were derived and labelled as follows: affective-arousal, sensory-pressure, perception of harm, somesthetic pressure, and cutaneous sensitivity. The various modeling conditions did not produce any significant between-group differences on the factors. The repeated demonstration that the MPQ assesses substantially more than the three components originally proposed suggests that considerable caution is warranted with respect to using the 'sensory-evaluative-affective' method of scoring this test. Considered in relation to previous research, the present findings are consistent with the conclusion that social influences affect fundamental components of subjective reactions to pain.

Social modeling influences on sensory decision theory and psychophysiological indexes of pain.

Subjects exposed to social models dissimulating tolerance or intolerance generally exhibit matching behavior in their verbal ratings of painful stimulation. It has been unclear, however, whether these changes reflect voluntary alteration of evidence or genuine changes in distress. This study used alternative measures and controlled for methodological limitations of earlier studies by examining nonpalmar skin potential in addition to palmar skin conductance and heart rate indexes of psychophysiological response to electric shock, and by evaluating verbal expressions of pain with sensory decision theory methodology. Of 20 female volunteer subjects, half served as controls, and half were exposed to a tolerant female model. Both the subject and the model verbalized ratings of discomfort provoked by a series of electric shocks of increasing intensity. Subjects then underwent a series of preselected random shocks. Sensory decision theory analyses revealed lower discriminability of the shocks among subjects exposed to a tolerant model. Several indexes of nonpalmar skin potential and heart rate reactivity exhibited lower reactivity in the tolerant group. Tolerant modeling was also associated with decreases in subjective stress. The results were consistent with the position that changes in pain indexes associated with exposure to a tolerant model represented variations in fundamental characteristics of painful experiences as opposed to suppression of information.