Dopamine medications are effective in treating the motor symptoms of Parkinson’s Disease (PD), but dopamine agonists can trigger impulsive and compulsive behaviors, such as compulsive gambling, eating or shopping, in a subset of patients. Impulsive and compulsive behaviors are thought to be caused by overstimulation of the mesocorticolimbic dopamine network, which regulates reward learning and executive function.

In a collaborative effort with Manus Donahue PhD, Daniel Claassen, MD, and colleagues explored the neural underpinnings of ICBs in PD using a noninvasive imaging technique called arterial-spin-labeling (ASL)-MRI. ASL-MRI quantitatively measures cerebral blood flow (CBF), an indirect measure of brain metabolism and activity.

Comparing PD patients with and without impulsive and compulsive behaviors, the researchers found that dopamine agonists increase CBF in brain regions of the mesocorticolimbic network only in patients with impulsive and compulsive behaviors. They also found a link between dopamine agonist-induced changes in the mesocorticolimbic network and the expression of impulsive and compulsive behaviors as well as their severity across all PD patients.

This study, published in the journal Movement Disorders, highlights the potential of using ASL-MRI to predict impulsive and compulsive behaviors susceptibility in patients and improve clinical treatment plans.