Functional Abnormalities Underlying Pathological Gambling in Parkinson Disease

Background: Pathological gambling ( PG) may develop in patients with Parkinson disease (PD) during dopamine replacement therapy, but the underlying neural correlates are still unclear. Objective: To investigate resting state brain perfusion in PD patients with active PG compared with matched PD controls and healthy controls. Design: Case-control study. Setting: Outpatient tertiary clinic. Participants: Eleven right-handed PD patients with active PG according to Diagnostic and Statistical Manual of Mental Disorders ( Fourth Edition, Text Revision) criteria, 40 matched PD controls, and 29 age-matched healthy controls. Intervention: All the participants underwent resting state brain perfusion single-photon emission computed tomography using technetium TC 99m ethylcysteinate dimer bicisate. All PD subjects were taking dopaminer-gic medication. Main Outcome Measure: Statistical Parametric Mapping was used for data analysis (P <.005, false discovery rate corrected). Results: PD patients with PG showed resting state over-activity in a right hemisphere network that included the orbitofrontal cortex, the hippocampus, the amygdala, the insula, and the ventral pallidum. No areas of perfusion reduction were detected. Conclusions: We found that PD patients with PG have abnormal resting state dysfunction of the mesocortico-limbic network possibly associated with a drug-induced overstimulation of relatively preserved reward-related neuronal systems. These findings support the concept that PG is a "behavioral" addictive disorder.