Symptom-Specific Networks and the DBS-Modulated Network in Parkinson's Disease: A Connectivity-Based Review

Area of Science:

• Neuroscience
• Neurology
• Medical Imaging

Background:

• Parkinson's disease (PD) is increasingly understood as a complex brain network disorder.
• Advanced neuroimaging techniques like resting-state functional MRI and diffusion tensor imaging are crucial for this understanding.

Purpose of the Study:

• To review research on brain networks in PD.
• To elucidate network abnormalities underlying PD's four major motor symptoms.
• To identify brain networks modulated by deep brain stimulation (DBS).

Main Methods:

• Systematic literature search of PubMed and Web of Science.
• Inclusion of studies on general PD networks, symptom-specific networks (tremor, postural instability/gait disorder, freezing of gait, akinetic-rigidity), and DBS-modulated networks.
• Integration of findings and network visualization using BrainNet Viewer.

Main Results:

• Symptom-specific PD networks share abnormalities within the sensorimotor network.
• DBS therapeutic effects correlate with motor cortex modulation via functional and structural connectivity.
• Distinct network features characterize each motor symptom: tremor (cortico-thalamic-cerebellar), postural instability/gait disorder (striatum, visual cortex), freezing of gait (midbrain, pedunculopontine nucleus), and akinetic-rigidity (default mode network).

Conclusions:

• PD motor symptoms have both unique network signatures and common sensorimotor alterations.
• DBS modulates large-scale motor networks, alleviating symptoms.
• Characterizing symptom-specific networks can guide precision DBS target selection and optimization.