Chronic pain is associated with plasticity in the brain limbic system composed mainly of the
amygdala, hippocampus, ventral striatum, and cingulate cortex (ACC) /medial prefrontal cortex
(mPFC). These brain areas, especially the ventral striatum, receive dopaminergic input from
the ventral-tegmental area (VTA). Although there is a significant literature now showing that
limbic brain tracks chronic pain intensity and predicts the risk of transition from sub-acute
to chronic pain, the role of dopaminergic input to the limbic brain and the change thereof
which occurs in chronic pain, is still not clear.
Given the role of dopamine in motivational control and the loss of motivation associated with
chronic pain understanding how dopaminergic transmission is altered in the limbic brain of
chronic pain patients is critical to the understanding of the pathophysiology of chronic
pain. Therefore, the overall aim of this project is to use brain imaging to study how
dopaminergic transmission through the oral administration of pro-dopaminergic medications
carbidopa/levodopa (CD/LD) and methylphenidate will modulate the brain signature of chronic
pain. Chronic pain subjects will be scanned twice before and after treatment with the two
drugs or placebo. The protocol will follow a randomized double-blind approach.
Phase:
Phase 2
Details
Lead Sponsor:
University of Rochester
Treatments:
Carbidopa Carbidopa, levodopa drug combination Levodopa Methylphenidate