Functional abnormalities underlying pathological gambling in Parkinson disease

Pathological gambling (PG) may develop in patients with Parkinson disease (PD) during dopamine replacement therapy, but the underlying neural correlates are still unclear.

To investigate resting state brain perfusion in PD patients with active PG compared with matched PD controls and healthy controls.

Case-control study.

Outpatient tertiary clinic.

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.

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 dopaminergic medication.

Statistical Parametric Mapping was used for data analysis (P<.005, false discovery rate corrected).

PD patients with PG showed resting state overactivity 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.

We found that PD patients with PG have abnormal resting state dysfunction of the mesocorticolimbic 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.