ABSTRACT
BACKGROUND: Chronic, unexplained pain is a common, ill-understood clinical problem. Increased sensitivity for pain and other stimuli is often implied as an underlying mechanism. Attentional processes influence central pain processing and might mediate hypersensitivity at a cerebral level. AIMS: To study patients with chronic, unexplained pain with respect to (a) subjective pain experience; (b) effects of attentional manipulation; (c) level at which alterations in pain processing occur: locally (symptomatic body region), or generalised. METHODS: We compared 16 patients with chronic, unexplained limb pain with 16 matched healthy controls. Pain thresholds to electrical stimuli were recorded. Subjects then received individually thresholded painful and non-painful stimuli, with manipulation of attention towards or away from pain. The intensity of pain perception was recorded by means of visual analogue scales (VAS). Pain thresholds and effects of Attention and Laterality on VAS scores were compared between groups by means of general linear modelling (restricted to 12 patients with unilateral pain and 12 controls). RESULTS: Distraction increased thresholds for pain in healthy volunteers, but this effect was significantly attenuated in patients. Significant interactions between attention-effects, stimulus laterality and stimulus intensity indicated that VAS scores for painful stimuli were attenuated during distraction in healthy controls, but not in pain patients. CONCLUSIONS: Results support the notion that pain processing is enhanced in chronic, unexplained pain, and that the influence of attentional modulation on pain processing is attenuated. Potential cerebral mechanisms are changes in either attentional allocation or attention-mediated descending pain modulation. The changes seem to occur at a generalised level.
Subject(s)
Attention/physiology , Pain Threshold/psychology , Pain/psychology , Adult , Aged , Analysis of Variance , Case-Control Studies , Chronic Disease , Electric Stimulation , Female , Humans , Male , Middle Aged , Pain Measurement , Surveys and QuestionnairesABSTRACT
BACKGROUND: Knowledge on fundamental aspects of the influence of 'stress' on animal and human organisms is accumulating. In clinical situations, however, psychiatrists still do not use apropriate instruments to recognize and handle the impact of daily life stress. DSM-IV is insufficient in this respect. OBJECTIVE: A different approach is sketched for clinicians to be able to integrate knowledge from research more effectively. METHOD: Application of a 'broad' biological view may reveal the significance of interpretation, emotion, impulse and reaction as stages of a 'mental tract', which is involved in processing the input of stressful situations. RESULT: This may lead to a more rational 'targeting' of pharmacological and psychotherapeutic strategies in clinical practice. CONCLUSION: A re-orientation of clinical psychiatry from mere classification towards a 'broad' biological approach may pave the way for a more rational and purposeful application of research findings to therapy.
