Neuropathic Pain
Central neuropathic pain (CNP) is a
devastating, unrelenting pain that can significantly impact sleep,
work and quality of life, and partially accounts for depression and
suicide among people with spinal cord injury (SCI). A major
roadblock to effective CNP treatment is the inability to identify,
within an individual, the specific neurobiological mechanism(s)
responsible for the pain. The first step towards mechanism-based
treatment is to precisely characterize the somatosensory profile of
patients using psychophysical methods such as quantitative sensory
testing (QST).
Patients suffering from CNP almost always
have thermal sensory deficits within the painful area that is
unmistakingly similar to the Thermal Grill Illusion
(TGI), in which burning pain is felt while reduced
warm/cold sensation is reported. A Thermal Grill (TG) device is
used, in which innocuous cool (20°C) and innocuous warm (40°C)
stimuli are presented together in a spatial pattern causing the
subject to experience this TGI of burning pain. If the hypothesis
that the fundamental neural dysfunction causing CNP is the same
mechanism that underlies the TGI, then any agent that blocks the TGI
could be efficacious for alleviating central pain, and the absence
of the thermal grill effect would be a diagnostic for CNP.
Despite its potential value for studying
pain mechanisms in humans, there are few studies evaluating the
psychophysical properties of the TGI or its application as an
investigative tool for patients with CNP. The main objective of my
thesis is to design and oversee the development of a standardized
diagnostic TG device; determine the optimal stimulation pattern that
produces the TGI in individuals; and prepare the TG device for use
in a clinical setting.
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