Altered Static and Dynamic Functional Motor Networks in Essential Tremor After Magnetic Resonance-Guided Focused...

Area of Science:

• Neuroscience
• Medical Imaging
• Neurological Disorders

Background:

• Essential tremor (ET) is a neurological condition often treated with medication.
• MR-guided focused ultrasound (MRgFUS) thalamotomy is an emerging treatment for medication-refractory ET.
• The impact of MRgFUS on the brain's motor network requires further investigation.

Purpose of the Study:

• To investigate the effects of MRgFUS on static and dynamic functional connectivity (FC) within the motor network in ET patients.
• To explore the relationship between changes in motor network properties and tremor improvement post-MRgFUS.

Main Methods:

• Resting-state fMRI data from 26 ET patients before and one year after MRgFUS, and from 26 healthy controls.
• Graph-theoretical analysis of motor network topology and sliding-window analysis for dynamic FC.
• Correlation analysis between network property changes and tremor severity (Clinical Rating Scale for Tremor).

Main Results:

• MRgFUS significantly altered motor network topology, increasing small-worldness and global efficiency.
• Two distinct dynamic connectivity states were identified; ET patients showed a shift towards a state of stronger connectivity post-procedure.
• Increased small-worldness and altered state occurrence rates correlated with tremor improvement.

Conclusions:

• MRgFUS effectively modifies both static and dynamic aspects of motor network connectivity in ET patients.
• These alterations reflect enhanced information transfer efficiency and functional integration within the motor network.
• The study provides insights into the neurobiological mechanisms underlying MRgFUS treatment for essential tremor.