Decision-making performance in Parkinson's disease correlates with lateral orbitofrontal volume

Area of Science:

• Neuroscience
• Neurology
• Cognitive Science

Background:

• Parkinson's disease (PD) is associated with deficits in decision-making.
• The specific neural underpinnings of impaired decision-making in PD remain unclear.

Purpose of the Study:

• To investigate the neural correlates of poor decision-making in Parkinson's disease patients.
• To examine the relationship between brain structure, decision-making performance, and clinical factors in PD.

Main Methods:

• Voxel-based morphometry was used to analyze gray matter volume.
• Decision-making was assessed using the Iowa Gambling Task (IGT) in 20 PD patients and 37 healthy controls (HCs).
• Correlations were examined between gray matter volume and IGT performance, disease duration, severity, and medication dose.

Main Results:

• PD patients performed worse on the IGT compared to HCs.
• Reduced gray matter volume was observed in the medial orbitofrontal cortex, left inferior temporal cortex, and right middle frontal gyrus in PD patients.
• Lateral orbitofrontal cortex volume significantly correlated with IGT performance in PD patients.

Conclusions:

• The lateral and medial orbitofrontal cortex are crucial for decision-making in Parkinson's disease.
• Impairments in reward monitoring (medial orbitofrontal cortex) and punishment evaluation (lateral orbitofrontal cortex) likely contribute to decision-making deficits in PD.
• Individual differences in decision-making performance in PD may be influenced by the lateral orbitofrontal cortex's role in evaluating punishment.