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It is important to consider how we conceptualize pain. Our views
of pain will influence our evaluations of patients who report pain
and the nature of the interventions that we use to treat them. The way
in which we conceptualize pain depends largely on the nature of
the information acquired and the models we were exposed to during
our training. In the first section of this chapter, we review the
traditional conceptualizations of pain. Although these models are
not necessarily inaccurate, they are incomplete. We propose that
a broader, multidimensional perspective is required to understand
pain and to treat patients appropriately. We describe the role of
behavioral, cognitive, and affective factors that have been shown
to be relevant to the experience of pain, disability, and response
to treatment. We provide data demonstrating that these psychological
factors may have an effect on both patients’ behavior and
physiology. Finally, we raise the issue of the “patient
uniformity myth” and describe the subgroups of pain patients
based on psychosocial and behavioral characteristics. We provide
preliminary data suggesting that knowledge of such patient subgroups
may serve as a basis for matching patients to treatments based on
their characteristics.
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[Preparation of this manuscript was supported by grants
from the National Institute of Child Health and Development (P01
HD33989) and the National Institute of Arthritis and Musculoskeletal
and Skin Diseases (R01 AR 44724) awarded to the first author and
the National Institutes of Health/Shannon Director’s
Award (R55 AR44230) awarded to the second author.]
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Historically, pain has been understood from the perspective of
Cartesian dualism wherein pain was viewed as purely sensory, reflecting
the degrees of incoming noxious sensory stimuli. This perspective
assumes that there are two ends to a pain pathway. At the periphery
are sensory receptors where noxious information is received; at
the other end, regions located in the brain where information is
registered passively. From this perspective, noxious stimulation
inevitably results in the sensation of pain, as if pulling a string
at the periphery activates a bell located in the brain. Variations
of this model have been prominent since first proposed by Aristotle.
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A central belief of sensory models is that the amount of pain
experienced is a direct result of the amount, degree, or nature
of sensory input or physical damage and is explained in terms of
specific physiologic mechanisms. Clinically, it is expected that
the report of pain will be directly proportional to the amount of
pathology. This model dictates that assessment should focus on identifying
the cause of the pain. Once identified, treatment should involve
removal of the cause or severing the specific pain pathways by surgical
or pharmacologic means.
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Sensory models continued to maintain a prominent position in
medicine despite the inability of this model to account for a number
of observations. For example:
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- Patients with equivalent degrees and types of objectively
determined tissue pathology vary widely in their reports of pain ...