Reliable digit span is unaffected by laboratory-induced pain: implications for clinical use

Reliable Digit Span (RDS) is an indicator used to assess the validity of cognitive test performance. Scores of 7 or lower suggest poor effort or negative response bias. The possibility that RDS scores are also affected by pain has not been addressed thus potentially threatening RDS specificity. The current study used cold pressor-induced pain to investigate the effect of pain on RDS scores. Sixty undergraduate volunteers randomly assigned to one of three conditions (control, simulator, pain) completed the Digit Span subtest from the Wechsler Adult Intelligence Scale-III from which the RDS is derived. No differences in RDS scores were found between the control and pain groups, and neither group scored below 8. Sixty-five percent of the simulator group scored 7 or below. These results suggest that RDS is not affected by pain, and scores of 7 or less in persons with pain can be more confidently attributed to negative response bias.     

Memory in traumatic brain injury: The effects of injury severity and effort on the Wechsler Memory Scale‐III

This study examined the effects of traumatic brain injury (TBI) on Wechsler Memory Scale‐III (WMS‐III) performance. Since poor effort potentially contaminates results, effort was explicitly assessed and controlled using two well‐validated cognitive validity indicators, the Portland Digit Recognition Test (PDRT) and Reliable Digit Span (RDS). Participants were 44 mild TBI patients with good effort, 48 mild TBI patients with poor effort, and 40 moderate–severe TBI patients with good effort. A dose–response relationship between injury severity and WMS‐III performance was demonstrated. Effect size calculations showed that the good effort mild TBI patients did not differ from normal (average Cohen's d= 0.07) while moderate–severe TBI had a moderate effect on WMS‐III scores (average Cohen's d=?0.52). Consistent with previous literature, the moderate–severe TBI group scored the lowest on WMS‐III Visual indices. Effort had a larger effect than injury severity on WMS‐III scores (average Cohen's d=?1.27). Clinical implications of these findings are discussed.     

Strategic and automatic threat processing in chronic musculoskeletal pain: a startle probe investigation

Attentional bias research with chronic pain samples has yielded conflicting results. In the present investigation the startle paradigm was used to test the postulate that fear-based mechanisms play an important role in attentional biases for pain-related threat in chronic pain. Participants, including 31 individuals with chronic musculoskeletal pain and 20 healthy controls, completed a startle task designed to measure attention to different types of words (neutral vs sensory pain vs affective pain vs health catastrophe) presented at different levels of cognitive processing (strategic vs automatic). Measures of fear-based individual difference variables, including anxiety sensitivity and fear of pain, were also completed. Startle amplitudes and latencies to acoustic startle probes that followed word presentations were recorded. Data were analyzed with repeated measures ANOVAs and correlational analysis. Significant between-group differences were found indicating that, relative to chronic pain participants, healthy controls had higher startle amplitude index scores for health catastrophe words. There was also a trend among patients with chronic pain for greater startle amplitude index scores for strategic presentations of sensory pain words. In the automatic condition, all participants demonstrated a lower startle latency index for sensory words relative to both affect and health catastrophe words, suggesting participants had more difficulty disengaging from affect and health catastrophe words or were more avoidant of sensory words. Correlational analyses indicated that startle response indices for words related to health catastrophe became more pronounced for chronic pain patients as anxiety sensitivity and fear of pain increased. Implications and directions for future research are discussed.     

Strategic and Automatic Threat Processing in Chronic Musculoskeletal Pain: A Startle Probe Investigation

Attentional bias research with chronic pain samples has yielded conflicting results. In the present investigation the startle paradigm was used to test the postulate that fear‐based mechanisms play an important role in attentional biases for pain‐related threat in chronic pain. Participants, including 31 individuals with chronic musculoskeletal pain and 20 healthy controls, completed a startle task designed to measure attention to different types of words (neutral vs sensory pain vs affective pain vs health catastrophe) presented at different levels of cognitive processing (strategic vs automatic). Measures of fear‐based individual difference variables, including anxiety sensitivity and fear of pain, were also completed. Startle amplitudes and latencies to acoustic startle probes that followed word presentations were recorded. Data were analyzed with repeated measures ANOVAs and correlational analysis. Significant between‐group differences were found indicating that, relative to chronic pain participants, healthy controls had higher startle amplitude index scores for health catastrophe words. There was also a trend among patients with chronic pain for greater startle amplitude index scores for strategic presentations of sensory pain words. In the automatic condition, all participants demonstrated a lower startle latency index for sensory words relative to both affect and health catastrophe words, suggesting participants had more difficulty disengaging from affect and health catastrophe words or were more avoidant of sensory words. Correlational analyses indicated that startle response indices for words related to health catastrophe became more pronounced for chronic pain patients as anxiety sensitivity and fear of pain increased. Implications and directions for future research are discussed.     

Malingering in toxic exposure: classification accuracy of reliable digit span and WAIS-III Digit Span scaled scores

This study examined the sensitivity and false-positive error rate of reliable digit span (RDS) and the WAIS-III Digit Span (DS) scaled score in persons alleging toxic exposure and determined whether error rates differed from published rates in traumatic brain injury (TBI) and chronic pain (CP). Data were obtained from the files of 123 persons referred for neuropsychological evaluation related to alleged exposure to environmental and industrial substances. Malingering status was determined using the criteria of Slick, Sherman, and Iverson (1999). The sensitivity and specificity of RDS and DS in toxic exposure are consistent with those observed in TBI and CP. These findings support the use of these malingering indicators in cases of alleged toxic exposure and suggest that the classification accuracy data of indicators derived from studies of TBI patients may also be validly applied to cases of alleged toxic exposure.     

Anxiety sensitivity and fear of pain in patients with recurring headaches.

Anxiety sensitivity (AS) plays an important role in the cognitive, affective and behavioral profiles of patients with chronic pain related to musculoskeletal injury. However, investigators have not considered whether these findings extend to patients with other classes of chronic pain. The primary purpose of this investigation was to address this issue in 72 patients with recurring headaches who completed a self-report questionnaire inventory during a treatment visit to an outpatient neurology clinic. The mean ASI score for the group (mean = 24; SD = 11) was relatively high. When patients were classified on the basis of ASI scores, 20 (28%) met criteria for high, 41 (57%) for medium and 11 (15%) for low AS. Multivariate analysis of variance confirmed that these groups differed on specific aspects of their cognitive, affective, and behavioral profiles. High AS patients reported greater depression, trait anxiety, pain-related escape/avoidance behavior and fearful appraisals of pain than did patients with medium or low AS. High AS patients also indicated greater cognitive disruption in response to pain than did patients with low AS. Groups did not differ in headache severity, physiological reactivity, change in lifestyle, anger, nor did they differ in use of over-the-counter or prescribed analgesics. Multiple regression analysis identified AS, pain-related cognitive disruption, and sensory pain experience as significant predictors of fear of pain. Lifestyle changes attributed to headache were, on the other hand, predicted by headache severity, physiological and cognitive anxiety and escape/avoidance behavior. These results provide further evidence of the important association between AS and fear responses of patients with chronic pain syndromes. Implications and future directions are discussed.     

Effects of active alert and relaxation hypnotic inductions on cold pressor pain

We contrasted relaxation and active alert hypnotic inductions with or without a specific suggestion for cold pressor pain analgesia. Groups of high (n = 38) and low (n = 27) hypnotizable subjects were tested; hypnotizability had been determined from results of the Stanford Hypnotic Susceptibility Scale, Form C. Cold pressor pain data were obtained after counterbalanced exposure to relaxation and active alert inductions. Highly hypnotizable subjects demonstrated lower pain scores than did low hypnotizable ones. Pain reports did not differ between induction conditions. Highly hypnotizable subjects given an analgesic suggestion showed lower pain scores than did those exposed only to hypnosis. The findings, conceptualized within E.R. Hilgard's (1977a) neodissociation theory, show that relaxation is not necessary for hypnotic analgesia.     

Gender Differences in Cognitive and Emotional Adjustment to Traumatic Brain Injury

This study examined gender differences in cognitive and emotional status after traumatic brain injury (TBI) among 262 men and 140 women with TBI referred for neuropsychological evaluations. In this cross-sectional study, cognition was measured in terms of both absolute level of functioning (i.e., raw/standard scores) and estimated decline from premorbid levels expressed as z-deficit scores in the following domains: intelligence [Wechsler Adult Intelligence Scale—Revised (WAIS-R)], memory and attention [Wechsler Memory Scale—Revised (WMS-R)], processing speed (Trails A), and cognitive flexibility (Trails B). Emotional functioning was measured in terms of depression (Beck Depression Inventory) and general emotional distress (Brief Symptom Inventory). Kruskal–Wallis nonparametric one-way ANOVAs indicated that women and men differed significantly on 2 of 8 raw/standard cognitive scores [men demonstrated lower WMS-R General Memory (p < .05) and Trails B scores (p < .0001) and 4 of 8 relative decline scores [women demonstrated more estimated change in VIQ (Verbal IQ) [p < .0001], FSIQ (Full Scale IQ) [p < .01], and Attention (p < .01)]; men demonstrated greater estimated z-decline scores on Trails B (p < .01)]. Women reported significantly higher levels of depression (p < .01), but men endorsed significantly greater general psychological distress (p < .05). Research and assessment recommendations are suggested.     

Cognitive reserve as a moderator of responsiveness to an online problem-solving intervention for adolescents with complicated mild-to-severe traumatic brain injury

Children and adolescents with traumatic brain injury (TBI) often experience behavior difficulties that may arise from problem-solving deficits and impaired self-regulation. However, little is known about the relationship of neurocognitive ability to post-TBI behavioral recovery. To address this question, we examined whether verbal intelligence, as estimated by Vocabulary scores from the Wechsler Abbreviated Scale of Intelligence, predicted improvements in behavior and executive functioning following a problem-solving intervention for adolescents with TBI. One hundred and thirty-two adolescents with complicated mild-to-severe TBI were randomly assigned to a six-month Web-based problem-solving intervention (CAPS; n = 65) or to an Internet resource comparison (IRC; n = 67) group. Vocabulary moderated the association between treatment group and improvements in metacognitive abilities. Examination of the mean estimates indicated that for those with lower Vocabulary scores, pre-intervention Metacognition Index scores from the Behavior Rating Inventory of Executive Function (BRIEF) did not differ between the groups, but post-intervention scores were significantly lower (more improved) for those in the CAPS group. These findings suggest that low verbal intelligence was associated with greater improvements in executive functioning following the CAPS intervention and that verbal intelligence may have an important role in response to intervention for TBI. Understanding predictors of responsiveness to interventions allows clinicians to tailor treatments to individuals, thus improving efficacy.     

Cerebral perfusion and neuropsychological follow up in mild traumatic brain injury: Acute versus chronic disturbances?

In a subgroup of patients with mild traumatic brain injury (TBI) residual symptoms, interfering with outcome and return to work, are found. With neuropsychological assessment cognitive deficits can be demonstrated although the pathological underpinnings of these cognitive deficits are not fully understood. As the admission computed tomography (CT) often is normal, perfusion CT imaging may be a useful indicator of brain dysfunction in the acute phase after injury in these patients.In the present study, directly after admission perfusion CT imaging was performed in mild TBI patients with follow-up neuropsychological assessment in those with complaints and a normal non-contrast CT. Neuropsychological tests comprised the 15 Words test Immediate Recall, Trailmaking test part B, Zoo Map test and the FEEST, which were dichotomized into normal and abnormal. Perfusion CT results of patients with normal neuropsychological test scores were compared to those with abnormal test scores.In total eighteen patients were included. Those with an abnormal score on the Zoo Map test had a significant lower CBV in the right frontal and the bilateral parieto-temporal white matter. Patients with an abnormal score on the FEEST had a significant higher MTT in the bilateral frontal white matter and a significant decreased CBF in the left parieto-temporal grey matter. No significant relation between the perfusion CT parameters and the 15 Words test and the Trailmaking test part B was present.In conclusion, impairments in executive functioning and emotion perception assessed with neuropsychological tests during follow up were related to differences in cerebral perfusion at admission in mild TBI. The pathophysiological concept of these findings is discussed.     

Predicting outcome of chronic pain treatment via a modified self-efficacy scale

This study utilized a modified self-efficacy scale and examined the relationship of perceived self-efficacy to treatment outcome in a chronic, intractable, benign pain population (N = 62). In two separate studies a self-efficacy scale was given to inpatients in a combined cognitive-behavioral and medical treatment program. The scale categories consisted of (1) walking distance, (2) lifting ability, (3) pain coping, (4) working ability, and (5) social and recreational engagement. Self-efficacy beliefs were found to be associated with the level of functioning of these patients and their response to treatment. Patients with higher self-efficacy scores following treatment rated themselves as more improved and demonstrated better overall functioning with greater reductions in chronic illness behavior at followup. These observations support the merits of self-efficacy measures as predictors of treatment outcome in chronic pain patients.     

Cognitive Factors in Fibromyalgia: The Role of Self-Concept and Identity Related Conflicts

Fibromyalgia is a syndrome characterized by the presence of diffuse and chronic musculoskeletal pain of unknown etiology. Clinical diagnosis and the merely palliative treatments considerably affect the patient's experience and the chronic course of the disease. Therefore, several authors have emphasized the need to explore issues related to self in these patients. The repertory grid technique (RGT), derived from personal construct theory, is a method designed to assess the patient's construction of self and others. A group of women with fibromyalgia (n = 30) and a control group (n = 30) were assessed using RGT. Women with fibromyalgia also completed the Fibromyalgia Impact Questionnaire and a visualanalogue scale for pain, and painful tender points were explored. Results suggest that these women had a higher present self-ideal self discrepancy and a lower perceived adequacy of others, and it was more likely to find implicative dilemmas among them compared to controls. These dilemmas are a type of cognitive conflict in which the symptom is construed as "enmeshed" with positive characteristics of the self. Finally, implications of these results for the psychological treatment of fibromyalgia are suggested to give a more central role to self-identity issues and to the related cognitive conflicts.     

Attention After Pediatric Traumatic Brain Injury: A Multidimensional Assessment

Attentional disturbance is a common complaint after TBI in children and adolescents, however, few studies have assessed post-traumatic attentional functions. The attentional constructs proposed by Mirsky, Anthony, Duncan, Ahearn, and Kellam (1991) provided a multidimensional framework for prospective assessment of late attentional disturbance after mild-moderate (n = 34) and severe (n = 57) traumatic brain injury (TBI). Attention was evaluated from 5 to 8 years after TBI in children ages 0 to 15 years at the time of injury. Children with severe TBI performed more poorly than children with mild-moderate TBI on tests comprising the focus/execute and shift constructs. Younger children scored below older children irrespective of injury severity on the Digit Span subtest and interstimulus interval scores from an adaptive rate continuous performance test reflecting the encode and sustain constructs of Mirsky et al. (1991). Age × Severity interaction effects were found for speeded perceptual-motor tests; scores were reduced following mild-moderate and severe TBI in younger children and following severe TBI in older patients. Results are discussed in terms of the vulnerability of skills in a rapid stage of development to disruption by acquired brain injury.     

Advanced clinical interpretation of the WAIS-IV and WMS-IV: prevalence of low scores varies by level of intelligence and years of education

Clinicians can use the base rates of low scores in healthy people to reduce the likelihood of misdiagnosing cognitive impairment. In the present study, base rates were developed for the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) and Wechsler Memory Scale-Fourth Edition (WMS-IV) using 900 healthy adults and validated on 28 patients with moderate or severe traumatic brain injuries (TBIs). Results indicated that healthy people obtain some low scores on the WAIS-IV/WMS-IV, with prevalence rates increasing with fewer years of education and lower predicted intelligence. When applying the base rates information to the clinical sample, the TBI patients were 13 times more likely to be identified as having a low cognitive profile compared with the controls. Using the base rates information is a psychometrically advanced method for establishing criteria to determine low cognitive abilities on the WAIS-IV/WMS-IV.     

Chronic Pain and Neuropsychological Functioning

This review article examines the effect of chronic pain on neuropsychological functioning. Primary attention is given to studies that include patient groups without a history of traumatic brain injury (TBI) or neurologic disorders. Numerous studies were identified that demonstrate neuropsychological impairment in patients with chronic pain, particularly on measures assessing attentional capacity, processing speed, and psychomotor speed. Despite suggestive findings, further studies are needed to clarify the variables that mediate the impact of pain on neuropsychological functioning and the unique role of various symptoms often associated with chronic pain.     

Automatic processing of pain: the change of implicit pain associations after psychotherapy

This study explores the utility of a pain IAT for the assessment of dysfunctional cognitive beliefs in chronic pain patients before and after a cognitive behaviour therapy. A patient group suffering from chronic pain (N=25) treated with a 4-week cognitive behavioural psychotherapy is compared with an untreated healthy control group (N=27) at two points in time. In addition, both groups completed a self-esteem questionnaire (Rosenberg-scale) and a self-esteem IAT. In the clinical group a questionnaire assessing self-reported pain cognitions was administered. The pain IAT was able to differentiate between chronic pain patients and healthy controls before the treatment. Most important, pain-related implicit associations could be shown to change over the course of treatment in the clinical group of chronic pain patients. Results provide first evidence for an application of the IAT in chronic pain research.     

Patients with chronic fatigue syndrome do not score higher on the autism‐spectrum quotient than healthy controls: Comparison with autism spectrum disorder

Clinically, there is an overlap of several symptoms of chronic fatigue syndrome (CFS ) and autism spectrum disorder (ASD ), including fatigue; brain “fog”; cognitive impairments; increased sensitivity to sound, light, and odour; increased pain and tenderness; and impaired emotional contact. Adults with CFS (n = 59) or ASD (n = 50) and healthy controls (HC ; n = 53) were assessed with the Autism‐Spectrum Quotient (AQ ) in a cross‐sectional study. Non‐parametric analysis was used to compare AQ scores among the groups. Univariate analysis of variance (ANCOVA ) was used to identify if age, sex, or diagnostic group influenced the differences in scores. Patients with ASD scored significantly higher on the AQ than the CFS group and the HC group. No differences in AQ scores were found between the CFS and HC groups. AQ results were influenced by the diagnostic group but not by age or sex, according to ANCOVA . Despite clinical observations of symptom overlap between ASD and CFS , adult patients with CFS report few autistic traits in the self‐report instrument, the AQ . The choice of instrument to assess autistic traits may influence the results.     

Evidence of a disposition toward fearfulness and vulnerability to posttraumatic stress in dysfunctional pain patients

Few investigations have addressed whether patient subgroups derived using the Multiaxial Assessment of Pain (MAP) [Turk, D. C., & Rudy, T. E. (1987). Towards a comprehensive assessment of chronic pain patients. Behaviour Research and Therapy, 25, 237-249; Turk, D. C., & Rudy, T. E. (1988). Toward an empirically derived taxonomy of chronic pain patients: integration of psychological assessment data. Journal of Consulting and Clinical Psychology, 56, 233-238.] differ with regard to fear and avoidance. It has, however, been reported that dysfunctional patients exhibit more pain-specific fear and avoidance than patients classified as interpersonally distressed or minimizers/adaptive copers [Asmundson, G. J. G., Norton, G. R., & Allerdings, M. D. (1997). Fear and avoidance in dysfunctional chronic back pain patients. Pain, 69, 231-236.]. We attempted to extend these findings by examining two fear constructs that are receiving increased attention in the chronic pain literature-anxiety sensitivity and PTSD. The sample comprised 115 patients with chronic pain. Of these, 14 (12.2%) were classified as dysfunctional, 21 (18.3%) as interpersonally distressed and 47 (40.8%) as minimizers/adaptive copers. Between-group differences were observed on the fear of cognitive and emotional dyscontrol dimension of anxiety sensitivity, total and symptom cluster scores on the PTSD measure, and depression. No differences were observed for the fear of somatic sensations dimension of anxiety sensitivity or agoraphobia, social phobia, and blood/injury fears. Dysfunctional patients generally exhibited elevated scores relative to one or both of the other MAP subgroups on fear of cognitive and emotional dyscontrol, depressed affect, PTSD symptom total score and PTSD symptom cluster scores. As well, a substantial proportion of dysfunctional and interpersonally distressed patients were classified as having PTSD (71.4 and 42.9%, respectively) when compared to minimizers/adaptive copers (21.3%). These results suggest that MAP subgroups differ with regard to their propensity to be(come) fearful and in their likelihood of having PTSD. Theoretical and clinical implications are discussed.     

Implicit and explicit memory bias for threat in post-traumatic stress disorder.

We investigated explicit (cued recall) and implicit (word completion) memory in Vietnam combat veterans with (n = 24) and without (n = 24) post-traumatic stress disorder (PTSD). Half of the subjects in each group encoded combat, social threat, positive, and neutral words elaboratively, whereas the others encoded these words nonelaboratively. On the cued recall test, under both encoding conditions, both groups recalled more combat words than other words. However, difference scores obtained by subtracting the mean recall for neutral words from the mean recall scores for the other words revealed that PTSD patients exhibited a relative explicit memory bias for combat words. That is, PTSD patients tended to exhibit poor memory for everything but combat words. On the word completion test, only PTSD subjects exhibited an implicit memory bias for combat words. This bias was greater for primed than for unprimed words, thereby ruling out a response bias. Such memory bias may underlie the 'reexperiencing' symptoms characteristic of PTSD (e.g. intrusive thoughts, nightmares).     

MBMD Coping Styles and Psychiatric Indicators and Response to a Multidisciplinary Pain Treatment Program

Psychosocial and personality factors are known to contribute to the maintenance of and recovery from chronic pain conditions but less is known about their influence on the efficacy of pain treatment programs. The purpose of the present study is to examine the ability of the Millon Behavioral Medicine Diagnostic (MBMD), a broadband measure of personality and psychosocial characteristics, to predict response to multidisciplinary pain treatment. 93 patients completed the MBMD, and ratings of current pain and average pain on an 11 point scale, prior to a multidisciplinary pain management program. Ratings of current and average pain were completed upon program completion. Participants were classified as “successful” or “unsuccessful” program completers based on pain reductions of ≥2 points. After program completion, 47 % of participants evidenced successful pain reductions. These successful participants had lower scores on depression and on coping style scales measuring introversive, inhibited, and dejected tendencies at baseline. Additionally, lower pre-treatment depression scores and lower scores on each of these coping style scales predicted lower pain ratings at discharge independent of educational level and pre-treatment pain ratings. The MBMD may be a useful tool to delineate patients who are likely to make significant treatment gains in intense, multidisciplinary pain treatment programs.