Patterns of brain activity during a set-shifting task linked to mild behavioral impairment in Parkinson's disease

Area of Science:

• Neuroscience
• Neurology
• Cognitive Science

Background:

• Mild behavioral impairment (MBI) is a syndrome of neuropsychiatric symptoms indicating increased risk for cognitive decline and dementia.
• Neuropsychiatric symptoms correlate with cognitive function in Parkinson's disease (PD).
• The neural basis of cognitive performance in PD with MBI remains unclear.

Purpose of the Study:

• To investigate the neural activity patterns associated with cognitive performance in non-demented PD patients with and without MBI.
• To identify differences in brain activation during a cognitive task between PD patients with MBI, PD patients without MBI, and healthy controls.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to scan 59 non-demented PD patients and 26 healthy controls.
• Participants performed a modified Wisconsin card sorting task.
• MBI was assessed using the MBI-checklist, dividing PD patients into PD-MBI and PD-noMBI groups.

Main Results:

• The PD-MBI group exhibited significantly less activation in the prefrontal and posterior parietal cortices compared to PD-noMBI and healthy control groups.
• Reduced deactivation was observed in the medial temporal region in the PD-MBI group.
• These findings indicate altered activity in the frontoparietal control network and hippocampal memory system in PD patients with MBI.

Conclusions:

• In Parkinson's disease, MBI is associated with functional brain deficits in critical networks supporting cognition.
• MBI in PD may reflect underlying impairments in the frontoparietal control network and hippocampal memory system.
• These neural differences may contribute to the increased risk of cognitive decline and dementia observed in PD with MBI.