This reference file was created as part of the Massage Medical Applications Project (MMAP). It contains selected articles from the medical literature on pain and pain perception. These form a meta-context for massage medical applications. Last modified 22 January 2006. Kimberly K Trout author text continuing periodical academic journal 1526-9523 2004 49 6 482 488 Women experience the pain of labor differently, with many factors contributing to their overall perception of pain. The neuromatrix theory of pain provides a framework that may explain why selected nonpharmacologic methods of pain relief can be quite effective for the relief of pain for the laboring woman. The concept of a pain "neuromatrix" suggests that perception of pain is simultaneously modulated by multiple influences. The theory was developed by Ronald Melzack and represents an expansion beyond his original "gate theory" of pain, first proposed in 1965 with P. D. Wall. This article reviews several nonpharmacologic methods of pain relief with implications for the practicing clinician. Providing adequate pain relief during labor and birth is an important component of caring for women during labor and birth. Trout2004 10.1016/j.jmwh.2004.07.009 Partap S Khalsa author 2004-Feb text continuing periodical academic journal 1050-6411 2004-Feb 14 1 109 120 Pain, due to mechanical stimuli, is a normal, indeed healthy, response of animals to potential or actual damage to tissues. Mammals in general, and humans in particular, have evolved a highly sophisticated system of pain perception, which is characterized in humans by complementary but distinct neural processing of the intensity and location of a noxious stimulus, and a motivational/emotional or affective response to the stimulus. The peripheral and central neurons that comprise this system, which has been called the 'neuromatrix', dynamically (temporally) respond and adapt to noxious biomechanical stimuli. However, phenotypic variability of the neuromatrix can be large, which can result in a host of musculoskeletal conditions that are characterized by altered pain perception, which can and often does alter the course of the condition. This neural plasticity has been well recognized in the central nervous system, but it has only more recently become known that peripheral nociceptors also adapt to their altered extracellular matrix environment. This work reviews the biomechanics of pain focusing on the relevant stimulus that initiates responses by nociceptors to the cognitive perception of pain. Khalsa2004 10.1016/j.jelekin.2003.09.020 G L Moseley author 2003-Aug text continuing periodical academic journal 1356-689X 2003-Aug 8 3 130 140 This paper presents an approach to rehabilitation of pain patients. The fundamental principles of the approach are (i) pain is an output of the brain that is produced whenever the brain concludes that body tissue is in danger and action is required, and (ii) pain is a multisystem output that is produced when an individual-specific cortical pain neuromatrix is activated. When pain becomes chronic, the efficacy of the pain neuromatrix is strengthened via nociceptive and non-nociceptive mechanisms, which means that less input, both nociceptive and non-nociceptive, is required to produce pain. The clinical approach focuses on decreasing all inputs that imply that body tissue is in danger and then on activating components of the pain neuromatrix without activating its output. Rehabilitation progresses to increase exposure to threatening input across sensory and non-sensory domains. Moseley2003 Laurence A Bradley author Nancy L McKendree-Smith author 2002-Jan text continuing periodical academic journal 1040-8711 2002-Jan 14 1 45 45 Pain is one of the most important and challenging consequences of musculoskeletal disorders. This article examines the role of central nervous system structures in the physiology of pain. It also describes the neuromatrix, a construct that provides a framework for understanding the interaction between physiologic mechanisms and psychosocial factors in the development and maintenance of chronic pain. This construct suggests that behavioral and psychologic interventions may alter the pain experience primarily through their effects on emotional states and cognitive processes. The literature on cognitive-behavioral interventions for patients with rheumatoid arthritis and osteoarthritis indicates that they are well-established treatments for these disorders. However, the efficacy of these interventions for patients with fibromyalgia has not been established. It is anticipated that the development of valid measures of readiness for behavioral change may allow investigators to identify the patients with musculoskeletal disorders who are most likely to benefit from cognitive-behavioral intervention. Bradley2002 R Melzack author 2001-Dec text continuing periodical academic journal 0022-0337 2001-Dec 65 12 1378 1382 The neuromatrix theory of pain proposes that pain is a multidimensional experience produced by characteristic "neurosignature" patterns of nerve impulses generated by a widely distributed neural network-the "body-self neuromatrix"-in the brain. These neurosignature patterns may be triggered by sensory inputs, but they may also be generated independently of them. Acute pains evoked by brief noxious inputs have been meticulously investigated by neuroscientists, and their sensory transmission mechanisms are generally well understood. In contrast, chronic pain syndromes, which are often characterized by severe pain associated with little or no discernible injury or pathology, remain a mystery. Furthermore, chronic psychological or physical stress is often associated with chronic pain, but the relationship is poorly understood. The neuromatrix theory of pain provides a new conceptual framework to examine these problems. It proposes that the output patterns of the body-self neuromatrix activate perceptual, homeostatic, and behavioral programs after injury, pathology, or chronic stress. Pain, then, is produced by the output of a widely distributed neural network in the brain rather than directly by sensory input evoked by injury, inflammation, or other pathology. The neuromatrix, which is genetically determined and modified by sensory experience, is the primary mechanism that generates the neural pattern that produces pain. Its output pattern is determined by multiple influences, of which the somatic sensory input is only a part, that converge on the neuromatrix. Melzack2001 S W Derbyshire author 2000 text continuing periodical academic journal 1069-5850 2000 4 6 467 477 A considerable number of functional imaging studies have demonstrated the involvement of multiple central regions during the experience of pain. These regions process information in circuits that can broadly be assumed to process the affective, sensory, cognitive, motor, inhibitory, and autonomic responses stimulated by a noxious event. The concept of a "neuromatrix" for pain processing is, therefore, well supported. There is, however, scant evidence for any particular regional or circuit dysfunction during clinical pain. To be clinically useful, functional imaging may have to step beyond the generalities of the neuromatrix. Derbyshire2000 R Melzack author 1999-Oct text continuing periodical academic journal 0001-5172 1999-Oct 43 9 880 884 The neuromatrix theory of pain proposes that pain is a multidimensional experience produced by characteristic "neurosignature" patterns of nerve impulses generated by a widely distributed neural network--the "body-self neuromatrix"--in the brain. These neurosignature patterns may be triggered by sensory inputs, but they may also be generated independently of them. Pains that are evoked by noxious sensory inputs have been meticulously investigated by neuroscientists, and their sensory transmission mechanisms are generally well understood. In contrast, chronic pain syndromes, which are often characterized by severe pain associated with little or no discernible injury or pathology, remain a mystery. The neuromatrix theory of pain, however, provides a new conceptual framework that is consistent with recent clinical evidence. It proposes that the output patterns of the neuromatrix activate perceptual, homeostatic and behavioral programs after injury or pathology, or as a result of multiple other inputs that act on the neuromatrix. Pain, then, is produced by the output of a widely distributed neural network in the brain rather than directly by sensory input evoked by injury, inflammation or other pathology. The neuromatrix, which is genetically determined and modified by sensory experience, is the primary mechanism that generates the neural pattern that produces pain. Its output pattern is determined by multiple influences, of which the somatic sensory input is only a part, that converge on the neuromatrix. Melzack1999b R Melzack author 1999-Aug text continuing periodical academic journal 0304-3959 1999-Aug Suppl 6 S121 S126 The gate control theory's most important contribution to understanding pain was its emphasis on central neural mechanisms. The theory forced the medical and biological sciences to accept the brain as an active system that filters, selects and modulates inputs. The dorsal horns, too, were not merely passive transmission stations but sites at which dynamic activities (inhibition, excitation and modulation) occurred. The great challenge ahead of us is to understand brain function. I have therefore proposed that the brain possesses a neural network--the body-self neuromatrix--which integrates multiple inputs to produce the output pattern that evokes pain. The body-self neuromatrix comprises a widely distributed neural network that includes parallel somatosensory, limbic and thalamocortical components that subserve the sensory-discriminative. affective-motivational and evaluative-cognitive dimensions of pain experience. The synaptic architecture of the neuromatrix is determined by genetic and sensory influences. The 'neurosignature' output of the neuromatrix--patterns of nerve impulses of varying temporal and spatial dimensions--is produced by neural programs genetically build into the neuromatrix and determines the particular qualities and other properties of the pain experience and behavior. Multiple inputs that act on the neuromatrix programs and contribute to the output neurosignature include. (1) sensory inputs (cutaneous, visceral and other somatic receptors); (2) visual and other sensory inputs that influence the cognitive interpretation of the situation; (3) phasic and tonic cognitive and emotional inputs from other areas of the brain; (4) intrinsic neural inhibitory modulation inherent in all brain function; (5) the activity of the body's stress-regulation systems, including cytokines as well as the endocrine, autonomic, immune and opioid systems. We have traveled a long way from the psychophysical concept that seeks a simple one-to-one relationship between injury and pain. We now have a theoretical framework in which a genetically determined template for the body-self is modulated by the powerful stress system and the cognitive functions of the brain, in addition to the traditional sensory inputs. Melzack1999a 10.1016/S0304-3959(99)00145-1 J D Loeser author R Melzack author 1999-May-08 text continuing periodical academic journal 0140-6736 1999-May-8 353 9164 1607 1609 Until the 1960s, pain was considered an inevitable sensory response to tissue damage. There was little room for the affective dimension of this ubiquitous experience, and none whatsoever for the effects of genetic differences, past experience, anxiety, or expectation. In recent years, great advances have been made in our understanding of the mechanisms that underlie pain and in the treatment of people who complain of pain. The roles of factors outside the patient's body have also been clarified. Pain is probably the most common symptomatic reason to seek medical consultation. All of us have headaches, burns, cuts, and other pains at some time during childhood and adult life. Individuals who undergo surgery are almost certain to have postoperative pain. Ageing is also associated with an increased likelihood of chronic pain. Health-care expenditures for chronic pain are enormous, rivalled only by the costs of wage replacement and welfare programmes for those who do not work because of pain. Despite improved knowledge of underlying mechanisms and better treatments, many people who have chronic pain receive inadequate care. Loeser1999 10.1016/S0140-6736(99)01311-2 L Gagliese author R Melzack author 1997-Mar text continuing periodical academic journal 0304-3959 1997-Mar 70 1 3 3 Chronic pain in elderly people has only recently begun to receive serious empirical consideration. There is compelling evidence that a significant majority of the elderly experience pain which may interfere with normal functioning. Nonetheless, a significant proportion of these individuals do not receive adequate pain management. Three significant factors which may contribute to this are (1) lack of proper pain assessment; (2) potential risks of pharmacotherapy in the elderly; and (3) misconceptions regarding both the efficacy of nonpharmacological pain management strategies and the attitudes of the elderly towards such treatments. In this review the most commonly used assessment instruments and patterns of age differences in the experience of chronic pain are described and evidence for the efficacy of psychological pain management strategies for this group is reviewed. Gagliese1997 10.1016/S0304-3959(96)03266-6 R Melzack author 1993-Dec text continuing periodical academic journal 1196-1961 http://www.alternatives.com/raven/cpain/melzack2.html 1993-Dec 47 4 615 629 Descartes' concept that pain is produced by a direct, straight-through transmission system from injured tissues in the body to a pain centre in the brain has dominated pain research and therapy until recently. The gate control theory of pain, published in 1965, proposes that a mechanism in the dorsal horns of the spinal cord acts like a gate which inhibits or facilitates transmission from the body to the brain on the basis of the diameters of the active peripheral fibers as well as the dynamic action of brain processes. As a result, psychological variables such as past experience, attention and other cognitive activities have been integrated into current research and therapy on pain processes. The gate control theory, however, is not able to explain several chronic pain problems, such as phantom limb pain, which require a greater understanding of brain mechanisms. A new theory of brain function, together with recent research that has derived from it, are described. They throw light on complex pain problems and have important implications for basic assumptions in psychology. Melzack1993 R Melzack author text continuing periodical academic journal 0031-2991 1992 4 52 54 A phantom limb is universally experienced after a limb has been amputated or its sensory roots have been destroyed. A complete break of the spinal cord also often leads to a phantom body below the level of the break. Furthermore, phantom breasts, genitals and other body areas occur in a substantial number of people after surgical removal or denervation of the body part. The most astonishing feature of a phantom limb (or other body area) is its incredible "reality" to the person. An examination of phantom limb phenomena has led to a new theory. It is proposed that we are born with a widespread neural network--the "neuromatrix"--for the body-self, which is subsequently modified by experience. The neuromatrix imparts a pattern--the "neurosignature"--on all inputs from the body, so that experiences of one's own body have a quality of self and are imbued with affective tone and cognitive meaning. The theory is presented with supporting evidence as well as implications for research. Melzack1992 R Melzack author 1990-Mar text continuing periodical academic journal 0166-2236 1990-Mar 13 3 88 88 The phenomenon of a phantom limb is a common experience after a limb has been amputated or its sensory roots have been destroyed. A complete break of the spinal cord also often leads to a phantom body below the level of the break. Furthermore, a phantom of the breast, the penis, or of other innervated body parts is reported after surgical removal of the structure. A substantial number of children who are born without a limb feel a phantom of the missing part, suggesting that the neural network, or 'neuromatrix', that subserves body sensation has a genetically determined substrate that is modified by sensory experience. Melzack1990