Functional inhibitory control dynamics in impulse control disorders in Parkinson's disease

Area of Science:

• Neuroscience
• Neurology
• Psychiatry

Background:

• Impulse control disorders (ICDs) are linked to dopamine network alterations in Parkinson's disease (PD).
• Understanding the neural basis of reward processing and inhibitory control in PD with ICDs is crucial.

Purpose of the Study:

• To investigate the functional neural substrates of reward processing and inhibitory control in Parkinson's disease patients with impulse control disorders.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to scan 18 PD patients with ICDs, 17 PD patients without ICDs, and 18 healthy controls.
• Participants performed a gambling task with positive, negative, and mixed feedback conditions.
• Analyses included whole-brain contrasts, regions of interest, time courses, functional connectivity, and brain-behavior associations.

Main Results:

• PD patients with ICDs exhibited hyperactivation in reward and inhibitory control regions compared to controls.
• Hyperactivation in right-lateralized frontostriatal areas during negative feedback correlated with ICD severity.
• Functional connectivity between the right ventral striatum and frontal regions mediated the association between ICD severity and regional activation.

Conclusions:

• PD patients with ICDs display hyperactivation in a right-lateralized network during reward-based tasks, associated with ICD severity.
• The right ventral striatum plays a critical role in modulating inhibitory control networks in PD patients with ICDs when facing negative feedback.