Contralesional motor-related functional networks following MR-guided focused ultrasound thalamotomy for essential tremor.

Motivation: To understanding how MR-guided focused ultrasound (MRgFUS)-thalamotomy affects motor network connectivity over time in essential tremor. Goal(s): To explore if long-term motor network reorganization, outside of the targeted nucleus, occurs after MRgFUS thalamotomy in essential tremor. Approach: Dentate nucleus connectivity changes in 25 essential tremor patients were tracked via fMRI at three intervals: pre-operation, one day post-operation, and twelve months post-MRgFUS. Results: Initially, the right DN showed diminished local connectivity. By one year, both DNs showed enhanced connectivity with right sensorimotor cortex (contralateral to the targeted motor network), compared to pre-MRgFUS thalamotomy. Impact: MRgFUS thalamotomy for essential tremor induces lasting motor network reorganization, suggesting that long-term tremor relief may arise from adaptive connectivity changes. These findings could inform strategies to enhance neuromodulatory treatments for essential tremor or movement disorders.