VISTA-Rehab: a resource for stroke rehabilitation trials.

BACKGROUND: Stroke rehabilitation is a complex intervention. Many factors influence the interaction between the patient and the elements of the intervention. Rehabilitation interventions are aimed at altering different domains of patient outcome including body functions, activity and participation. As a consequence, randomised clinical trials in this area are difficult to design. We developed an archive of stroke rehabilitation trials (VISTA-Rehab) to act as a resource to help trialists model and design future rehabilitation studies. METHODS: We developed specific eligibility criteria for the entry of stroke rehabilitation trials into the archive. We established a Steering Committee to oversee projects and publications and commenced the recruitment of rehabilitation trials into this resource. RESULTS: As of August 2009, VISTA-Rehab contains data from 23 stroke rehabilitation trials (>3400 patients). Demographic data, including age [median=73, interquartile range (63,79)], gender (male=53%) and initial dependency [median baseline Barthel index score=6, interquartile range (9,19)], are available for all patients. Outcome measures include the modified Rankin Scale, Barthel Index, Rivermead Motor Assessment, Fugl-Meyer Assessment, General Health Questionnaire and Nottingham Extended Activities of Daily Living Scale. CONCLUSION: VISTA-Rehab expands the Virtual International Stroke Trials Archive to include rehabilitation trials. Anonymised data can be used to examine questions specific to stroke rehabilitation and to generate novel hypotheses.

Reflecting upon line bisection: mirror reversal increases the magnitude of pseudoneglect.

In order to investigate the effect of congruent and non-congruent motor actions upon pseudoneglect, 'real' lines and mirror reversed 'virtual' lines were bisected in left and right hemispaces by 50 right handed subjects, 25 males, 25 females, with both left and right hands. Statistical analysis revealed significantly greater pseudoneglect for the non-congruent motor condition (virtual > real), hand (left > right), gender (male > female) and hemispace for virtual lines (left > right). These results are explained in terms of the interaction between three factors whose influence can jointly and severally result in pseudoneglect: right hemisphere specialization for spatial attention, right hemisphere activation resulting from hand use and sensorimotor discrepancies and the allocation of visual attention.

Accuracy of patient recall of preoperative symptom severity (angina and breathlessness) at one year following aorta-coronary artery bypass grafting.

AIM AND OBJECTIVE: The accuracy with which patients recall their cardiac symptoms prior to aorta-coronary artery bypass grafting is assessed approximately one year after surgery together with patient-related factors potentially influencing accuracy of recall. BACKGROUND: This is a novel investigation of patient's rating of preoperative symptom severity before and approximately one year following aorta-coronary artery bypass grafting. DESIGN: Patients undergoing aorta-coronary artery bypass grafting (n = 208) were recruited preoperatively and 177 of these were successfully followed up at 16.4 (SD 2.1) months after surgery and asked to describe current and recalled preoperative symptoms using a 15-point numerical scale. METHOD: Accuracy of recall was measured and correlated (Pearson's correlation) with current and past symptoms, health-related quality of life and coronary artery disease risk factors. Hypothesis tests used Student's t-test and the chi-squared test. RESULTS: Respective angina and breathlessness scores were recalled accurately by 16.9% and 14.1% while 59% and 58% were inaccurate by more than one point. Although the mean preoperative and recalled scores for severity of both angina and breathlessness and were not statistically different, patients who recalled most accurately their preoperative scores had, on average, significantly higher preoperative scores than those with less accurate recall. Patients whose angina and breathlessness symptoms were relieved by operation had significantly better accuracy of recall than patients with greater levels of symptoms postoperatively. CONCLUSION: Patient's rating of preoperative symptom severity before and one year following aorta-coronary artery bypass grafting was completely accurate in approximately one sixth of patients with similar proportions of the remaining patients overestimating and underestimating symptoms. The extent to which angina and breathlessness was relieved by operation was a significant factor in improving accuracy of recall. RELEVANCE TO CLINICAL PRACTICE: Factors associated with accuracy of recall of symptoms provide useful insights for clinicians when interpreting patients' views of the effectiveness of aorta-coronary artery bypass grafting for the relief of symptoms associated with coronary heart disease.

Memory for pain? A comparison of nonexperiential estimates and patients' reports of the quality and intensity of postoperative pain.

UNLABELLED: Prior research has questioned the extent to which postoperative retrospective ratings of acute pain actually reflect memory of that pain. To investigate this issue, pain ratings provided by patients who had undergone vascular surgery were compared with estimates of this pain provided by 2 groups of healthy, nonpatient participants with no personal experience of the surgery. Patient participants rated postoperative pain while actually experiencing it and again 4 to 6 weeks after surgery. Nonpatient groups read either a comprehensive information leaflet describing postoperative pain after vascular surgery, or a short general information leaflet about the surgery and provided 2 estimates of the likely nature of the pain, 4 to 6 weeks apart. Compared with patients, both nonpatient groups overestimated pain severity, and nonpatients provided with the comprehensive information leaflet were less consistent in their estimates compared with the other 2 groups. However, qualitative descriptions of the pain provided by the 3 groups shared many similarities. Our findings highlight limitations of inferring pain memory accuracy by comparing ratings given while in pain with those provided retrospectively and demonstrate the need to consider the phenomenological awareness accompanying recollections of prior pain events to advance our understanding of memory for pain. PERSPECTIVE: The observed similarities between pain ratings made by individuals who have experienced a particular pain and estimates made by those without personal experience question whether retrospective pain ratings can be assumed to reflect memory of that pain. The need to adopt new approaches to assess memory for pain is highlighted.

Hand and hand preferences in use of a visual analogue scale.

Visual analogue scales are commonly used to measure the intensity of sensations, and their validity and reliability have been reported. However, biases similar to those found in visual line bisection have not been investigated. 23 right-handed and 19 left-handed participants, with a mean age of 30.1 yr., marked three points on a visual analogue scale representing imagined pain, using both the left and right hands, corresponding to 1/4, 1/2, and 3/4 of the way across the scale. In keeping with visual line bisection literature, both right- and left-handed participants marked the scale with the left hand significantly leftward of the point marked with the right hand, thereby underreporting the intensity. Right-handed participants marked 1/4 significantly leftward and 3/4 significantly rightward of veridical points, thereby underreporting and overreporting, respectively, the intensity. However, left-handed participants did not display this bias and consistently erred leftward for 1/4, 1/2, and 3/4 positions, underreporting intensity. These findings were explained in terms of hemispheric specialisation and activation for a manual response to a visuospatial task, with the conclusion that scoring the visual analogue scale to millimetre accuracy is subject to a potential confound of these factors.

Exploring the phenomenology of memory for pain: is previously experienced acute pain consciously remembered or simply known?

UNLABELLED: Whether or not acute pain is recalled by consciously remembering it or by simply knowing about that past pain as an autobiographical fact, and the degree to which it can be accurately anticipated ("precalled") was investigated using the remember/know paradigm. Cold Pressor (CP) pain was induced in 97 healthy participants who precalled CP pain and then reported their actual experiences of CP pain, using the McGill Pain Questionnaire (MPQ) and a Visual Analogue Scale (VAS). Two weeks later, participants recalled the CP pain and indicated whether each retrospectively selected MPQ descriptor reflected their "remembering" or "knowing" about the pain. Whereas precall ratings significantly underestimated the severity of actual CP pain, recall ratings did not differ significantly from actual CP ratings. Almost three quarters of the MPQ descriptors chosen at recall reflected sensations of CP pain that were clearly, consciously remembered. The proportions of "correct" MPQ descriptors and categories at recall were significantly greater when judged as remembered than when judged as known. These findings suggest that recollections of acute pain at 2 weeks involve episodic memory and to a lesser extent semantic memory, with the former being more accurate. PERSPECTIVE: Whether previously experienced pain is clearly, consciously remembered or merely recalled as semantic knowledge about one's personal past has never been empirically investigated. Establishing the relative contribution of different types of memory will allow a better understanding of the phenomenological experience of recalling acute pain.

Analgesia through the looking-glass? A randomized controlled trial investigating the effect of viewing a 'virtual' limb upon phantom limb pain, sensation and movement.

The extent to which viewing a 'virtual' limb, the mirror image of an intact limb, modifies the experience of a phantom limb, was investigated in 80 lower limb amputees before, during and after repeated attempts to simultaneously move both intact and phantom legs. Subjects were randomly assigned to one of two conditions, a control condition in which they only viewed the movements of their intact limb and a mirror condition in which they additionally viewed the movements of a 'virtual' limb. Although the mirror condition elicited a significantly greater number of phantom limb movements than the control condition, it did not attenuate phantom limb pain and sensations any more than the control condition. The potential of a 'virtual' limb as a treatment for phantom limb pain was discussed in terms of its ability to halt and/or reverse the cortical re-organisation of motor and somatosensory cortex following acquired limb loss.

A comparison of the effects of preferred music, arithmetic and humour on cold pressor pain.

Research studies of 'audioanalgesia', the ability of music to affect pain perception, have significantly increased in number during the past two decades. Listening to preferred music in particular may provide an emotionally engaging distraction capable of reducing both the sensation of pain itself and the accompanying negative affective experience. The current study uses experimentally induced cold pressor pain to compare the effects of preferred music to two types of distracting stimuli found effective within the previous studies; mental arithmetic, a cognitive distraction, and humour, which may emotionally engage us in a similar manner to music. Forty-four participants (24 females, 20 males) underwent three cold pressor trials in counterbalanced order. The Paced Auditory Serial Addition Task provided the cognitive distraction and a choice was given from three types of audiotaped stand-up comedy. Participants provided their own preferred music. A circulating and cooling water bath administered cold pressor stimulation. Tolerance time, pain intensity on visual analogue scale and the pain rating index and perceived control were measured. Preferred music listening was found to significantly increase tolerance in comparison to the cognitive task, and significantly increase perceived control in comparison to humour. Ratings of pain intensity did not significantly differ. The results suggest preferred music listening to offer effective distraction and enhancement of control as a pain intervention under controlled laboratory conditions.

Visual line bisection in sinistrals and dextrals as a function of hemispace, hand, and scan direction.

Visual line bisection was investigated in 26 sinistral and 24 dextral subjects as a function of hemispace, hand and scan direction. An ANOVA revealed significant main effects for hand preference, due to the mean bisection errors of dextral subjects being significantly leftward of those of sinistral subjects; for hand, due to the bisection errors of the left hand being significantly to the left of the right hand; and for scan, due to the bisection errors following a left scan being significantly to the left of a right scan. One significant interaction was found, that between hand and direction of scan, due to a significant difference between left and right hands following a scan from the left but not following a scan from the right. For dextral subjects the leftward bisection errors of the left and right hands following a scan from the left, but not for a scan from the right, differed significantly from the midpoint. For sinistral subjects the leftward bisection errors following a scan from the left and rightward bisection errors following a scan from the right differed significantly from the midpoint for the left hand but not for the right hand. No significant main effect or interactions for hemispace were found. This confirms that both sinistral and dextral subjects display pseudoneglect when using their preferred hand and scanning from the left. However, sinistrals, but not dextrals, will display reversed pseudoneglect when using their preferred hand and adopting a scan direction from the right. These results are discussed in terms of the interaction between three factors, whose influence can jointly and severally produce misbisections, hemispheric specialisation for visuospatial function, hemispheric activation for a manual response, and the allocation of visual attention.

Temperature and the cold pressor test.

UNLABELLED: As a method of experimental pain induction, the cold pressor test is thought to mimic the effects of chronic conditions effectively. A survey of previous studies using the cold pressor, however, revealed a lack of standardization and control of water temperature, questioning comparability and reliability. This study reports the influence of temperature on pain tolerance and intensity by using a commercially available circulating water bath. Twenty-six participants (12 men, 14 women) underwent 4 cold pressor trials with temperature order counterbalanced across 1 degrees C, 3 degrees C, 5 degrees C, and 7 degrees C, temperatures representative of the range used in previous literature. After each cold immersion participants rated pain intensity on a visual analogue scale and the McGill Pain Questionnaire. Tolerance times were recorded for each trial. Significant main effects of temperature were found for tolerance time, with higher temperatures resulting in longer times, and pain intensity, with lower temperatures resulting in higher intensities. Gender differences were found, with men tolerating the stimulus for significantly longer than women. It was concluded that small differences in water temperature have a significant effect on pain intensity and tolerance time. The use of cold pressor equipment that ensures a precise constant temperature of circulating water is necessary to ensure comparable and reliable results. PERSPECTIVE: The cold pressor method of experimental pain induction has been widely used in the evaluation of psychological and physiological pain treatments. This article highlights the need for clear methodologic guidelines for the technique and demonstrates that very minor changes in experimental protocol can produce significant differences.

Increased motor control of a phantom leg in humans results from the visual feedback of a virtual leg.

Although previous research reported that the visual feedback of a 'virtual arm' increased the control of a phantom arm, it did not consider that the repeated attempt to move the phantom may have contributed to the effect. Twenty-one lower limb amputees reported the response of their phantom leg during repeated attempts to move both legs in one of two conditions, a control condition in which the amputee only viewed the movements of their intact leg and an experimental condition in which the amputee additionally viewed the movements of a 'virtual' leg. It was found that viewing a virtual leg resulted in amputees reporting a significantly greater number of movements of their phantom leg than with attempted movement alone. The implications were discussed in terms of visuo-motor adaptation and theories of motor control.

Remembering an everyday pain: the role of knowledge and experience in the recall of the quality of dysmenorrhoea.

The ability to describe the quality of a previous pain may be thought to be better if one had experienced that particular pain because information stored in episodic and/or semantic memory is available rather than if one had not and could only guess what the pain may be like on the basis of information stored in semantic memory. However research has shown that not only is the quality of labour pain poorly recalled by women who have given birth but also it is no better described by them than by women who have never given birth at all. In order to replicate this effect for an everyday pain, the ability to recall the quantity and the quality of dysmenorrhoea was measured in two groups of women. One group regularly experienced dysmenorrhoea, the other had never experienced it. Analysis of the pain intensity scores revealed that the 'pain' group reported significantly less pain 2 weeks later whereas the 'no-pain' group did not significantly differ in their rating over time. Analysis of the MPQ Descriptors chosen by subjects using Cohen's kappa resulted in 'fair' recall for both groups with no significant advantage for the 'pain' group. These results suggest that the episodic memory system plays a limited role in facilitating the recall of the quality of an often experienced pain. However the semantic memory system allows both previous pain sufferers and pain guessers to describe the core qualities of a pain to the same extent. Further research is required to explain why remembering the quality of a pain experience is not advantaged by episodic memory and what facilitates the transfer of a pain experience into semantic event memory.