Subthalamic-Cortical Network Reorganization during Parkinson's Tremor

Area of Science:

• Neuroscience
• Movement Disorders
• Systems Neuroscience

Background:

• Tremor is a primary symptom of Parkinson's disease (PD).
• Pathophysiology involves basal ganglia and cerebello-thalamic-cortical circuits.
• Functional interactions producing tremor remain unclear.

Purpose of the Study:

• Identify neurophysiologic correlates of tremor onset versus sustained tremor in PD.
• Examine subthalamic nucleus and cortical dynamics during tremor.
• Clarify short-timescale subcortical-cortical interactions in PD tremor.

Main Methods:

• Acquired intraoperative cortical and subthalamic nucleus recordings from 10 PD patients.
• Patients performed a naturalistic visual-motor task.
• Analyzed tremor onset and sustained tremor epochs.

Main Results:

• Subthalamic nucleus drove motor cortical activity and tremor output during tremor onset.
• Cortical control of tremor emerged once tremor became sustained.
• Directed functional connectivity changes in sensorimotor cortex distinguished sustained tremor.

Conclusions:

• Reconciles models of Parkinson's tremor pathophysiology.
• Describes short-timescale subcortical-cortical dynamics during tremor.
• Provides a framework for developing targeted neurostimulation for tremor treatment.