Neuroimaging Advances in Neuropsychiatric Symptoms Associated with Parkinson’s Disease

Parkinson’s disease (PD) is a prevalent neurodegenerative disorder traditionally defined by its motor symptoms yet increasingly recognized for its wide spectrum of neuropsychiatric symptoms (NPS) including anxiety, depression, apathy, impulse-control behaviors, and hallucinations. Recent neuroimaging advances have provided crucial insights into the neural substrates underlying these comorbidities. Structural imaging studies, using voxel-based morphometry and T1-weighted magnetic resonance imaging, have revealed regional atrophy in the frontal cortex, striatum, limbic areas, and occipital regions. In comparison, functional imaging using positron emission tomography, single-photon emission computed tomography, and resting-state functional MRI have identified abnormal network connectivity in circuits implicated in fear processing, reward regulation, and cognitive control. Overall, these imaging studies suggest shared and distinct pathophysiology of PD-related NPS, emphasizing the need for longitudinal, multimodal investigations to inform targeted therapeutic strategies and to improve clinical outcomes.