Wearable peripheral nerve stimulator reduces essential tremor symptoms through targeted brain modulation

Area of Science:

• Neuroscience
• Movement Disorders
• Neuromodulation

Background:

• Essential tremor (ET) is a common adult movement disorder linked to cerebello-thalamo-cortical network dysfunction.
• Transcutaneous afferent patterned stimulation (TAPS) is a novel non-invasive treatment for medication-refractory ET, but its mechanism is not fully understood.

Purpose of the Study:

• To investigate the hypothesis that TAPS reduces ET by modulating the VIM thalamus within the cerebello-thalamo-cortical network.
• To explore the neurophysiological underpinnings of TAPS's therapeutic effects in ET patients.

Main Methods:

• Evaluated clinical tremor reduction in ET patients undergoing TAPS before deep brain stimulation (DBS).
• Performed intra-operative microelectrode recordings in the contralateral thalamus during TAPS (on/off) in ET patients.

Main Results:

• TAPS significantly reduced upper limb tremor, particularly kinetic tremor, with an asymmetric effect favoring the treated limb.
• Tremor reduction correlated with modulation of alpha and beta band LFPs in the VIM thalamus.
• TAPS suppressed VIM spiking activity, with maximal modulation near the optimal DBS lead placement site.

Conclusions:

• TAPS likely alleviates ET by modulating neural activity in the VIM thalamus and connected brain regions.
• Findings suggest TAPS influences the cerebello-thalamo-cortical pathway, providing a potential mechanism for its therapeutic effect in ET.