The Role of Dopamine in the Central Neural Signature of Chronic Pain
University of Rochester
Summary
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 at baseline (no drug administration) and three times after treatment with the two drugs or placebo. The protocol will follow a randomized double-blind approach.
Description
The proposed study is a single center study investigating the effect of dopamine modulation on the brain signature of chronic pain. The patients will undergo 4 scanning visits (baseline, placebo, LD/CD, and MP) the order of the drug visits will be randomized by the investigational drug pharmacy (IDP). In addition, both patients and experimenters will be blind to the intervention given. The patients would have therefore received all the 3 different treatments by the end of the study. Chronic pain patients will be asked to come to the PI's Lab for 4 visits. On visit 1, after consenting and doin…
Eligibility
- Age range
- 18+ years
- Sex
- All
- Healthy volunteers
- No
Inclusion Criteria: The following inclusion criteria must be met for all subjects to be considered eligible to participate: 1. 18 years old or older 2. Equal numbers of men and women, as well as racial and ethnic makeup representative of surrounding area 3. Able to speak, read, and understand English 4. In generally stable health 5. Sign informed consent document The following inclusion criteria must be met for chronic pain patients to be considered eligible to participate: 1. Patients must report chronic pain for more than 1 year. 2. The reported pain should be rated at ≥ 40/100 Exclusio…
Interventions
- DrugMethylphenidate
0.5 mg/kg
- Drugcarbidopa-levodopa
25 mg/100 mg
- DrugPlacebo
oral pill
Location
- University of Rochester Medical CenterRochester, New York