Motor symptoms in Parkinson's disease (PD) are effectively managed by dopamine-based therapies, yet behavioral changes in patients can arise as an unintended consequence. Symptoms characterized by persistent participation in reward-driven activities result in significant morbidity to patients and caregivers. The descriptive term for these symptoms, impulsive and compulsive behaviors, captures the aberrant, goal- directed, decision-making phenomenology typified in this clinical condition. Symptoms range from hypersexuality to compulsive eating, gambling, shopping, and excessive participation in certain hobbies. Impulsive and compulsive behaviors are more commonly manifest in patients taking dopamine agonist therapy, and behaviors can abate with reduction or discontinuation of their use. Indeed, other therapeutic interventions, including deep brain stimulation and levodopa, are associated with the genesis of maladaptive behaviors, and overall, these symptoms appear to localize to a dysfunctional, or `overdosed', mesocorticolimbic dopamine system. This proposal will characterize the biological determinants of impulsive and compulsive behaviors in PD, with specific focus on the role of dopamine agonist therapy and the mesolimbic dopamine network. We propose a series of experiments that will determine distinct functional brain changes in response to dopamine agonist use in patients with and without impulsive and compulsive behaviors.
Our first aim i s to identify how the cerebral hemodynamic response to dopamine agonists distinguishes patients with impulsive and compulsive behaviors. We hypothesize that these patients have an exaggerated, or increased, mesolimbic hemodynamic response to dopamine agonist therapy. Hemodynamic changes will be linked to neurocognitive assessments of reward-based decision making and risk preference, emphasizing the coherence between physiologic brain changes and the behavioral response to medication. Next, we aim to determine how dopamine therapy can differentially alter inhibitory gamma-aminobutyric acid (GABA) neurotransmission in patients susceptible to impulsive and compulsive behaviors. Finally, we will test the hypothesis that releasable dopamine stores in the mesolimbic dopamine system are greater in patients susceptible these behaviors, thus linking a biological mechanism the etiology of these maladaptive behaviors. Completion of this study will pave the way for the use of non-invasive, quantitative outcomes in PD necessary for future target validation studies and early-phase drug discovery. Also, we will provide direct evidence that dopamine therapy acts on extra-striatal neural networks, linking regional changes in neural activity to dopamine-induced alterations to GABA levels. This work will advance the field to engaging novel therapeutic targets essential to effective treatment of impulsive and compulsive behaviors. Ultimately, this work will guide the development of improved, individualized therapies, advancing the therapeutic goals of personalized medicine, which is vital for patients suffering from PD.

Public Health Relevance

Impulsive and Compulsive Behaviors (ICB) in Parkinson's disease (PD) are characterized by maladaptive, reward-driven behaviors that occur in a subset of patients as a consequence of dopamine therapy. The work assesses the biophysical, physiological and molecular relationships determining susceptibility to medication- induced behavioral changes in PD. Completion of this study will provide the basis for a novel cognitive and imaging approach that will ultimately improve the quality and care of PD patients.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS097783-05
Application #
9928126
Study Section
Clinical Neuroscience and Neurodegeneration Study Section (CNN)
Program Officer
Babcock, Debra J
Project Start
2016-08-01
Project End
2021-05-31
Budget Start
2020-06-01
Budget End
2021-05-31
Support Year
5
Fiscal Year
2020
Total Cost
Indirect Cost
Name
Vanderbilt University Medical Center
Department
Type
DUNS #
079917897
City
Nashville
State
TN
Country
United States
Zip Code
37232
Hughes, Shelby; Claassen, Daniel O; van den Wildenberg, Wery P M et al. (2018) Action Control Deficits in Patients With Essential Tremor. J Int Neuropsychol Soc :1-9
Rane, Swati; Donahue, Manus J; Claassen, Daniel O (2018) Amnestic mild cognitive impairment individuals with dissimilar pathologic origins show common regional vulnerability in the default mode network. Alzheimers Dement (Amst) 10:717-725
Stark, Adam J; Smith, Christopher T; Lin, Ya-Chen et al. (2018) Nigrostriatal and Mesolimbic D2/3 Receptor Expression in Parkinson's Disease Patients with Compulsive Reward-Driven Behaviors. J Neurosci 38:3230-3239
Petersen, Kalen; Van Wouwe, Nelleke; Stark, Adam et al. (2018) Ventral striatal network connectivity reflects reward learning and behavior in patients with Parkinson's disease. Hum Brain Mapp 39:509-521
Petersen, Kalen J; Reid, Jacqueline A; Chakravorti, Srijata et al. (2018) Structural and functional connectivity of the nondecussating dentato-rubro-thalamic tract. Neuroimage 176:364-371
Stark, Adam J; Smith, Christopher T; Petersen, Kalen J et al. (2018) [18F]fallypride characterization of striatal and extrastriatal D2/3 receptors in Parkinson's disease. Neuroimage Clin 18:433-442
Trujillo, Paula; Summers, Paul E; Smith, Alex K et al. (2017) Pool size ratio of the substantia nigra in Parkinson's disease derived from two different quantitative magnetization transfer approaches. Neuroradiology 59:1251-1263
Van Wouwe, Nelleke C; Claassen, Daniel O; Neimat, Joseph S et al. (2017) Dopamine Selectively Modulates the Outcome of Learning Unnatural Action-Valence Associations. J Cogn Neurosci 29:816-826
Stark, Adam J; Claassen, Daniel O (2017) Positron emission tomography in Parkinson's disease: insights into impulsivity. Int Rev Psychiatry 29:618-627
Claassen, Daniel O; Stark, Adam J; Spears, Charis A et al. (2017) Mesocorticolimbic hemodynamic response in Parkinson's disease patients with compulsive behaviors. Mov Disord 32:1574-1583

Showing the most recent 10 out of 11 publications