Objective:

To study the influence of circadian rhythms on local field potentials (LFPs) recorded from the ventral intermediate nucleus (VIM) of the thalamus of essential tremor (ET) patients and develop an adaptive deep brain stimulation (aDBS) strategy.

Background:

Deep brain stimulation (DBS) in the VIM is an effective therapy for individuals with ET. However, over time, the benefits of DBS often wane due to disease progression and/or habituation to stimulation. Sleep disturbances are also common in ET patients and may be exacerbated by continuous DBS. Automatically turning off DBS during sleep may reduce sleep difficulties while potentially prolonging the therapeutic effects of stimulation. 

Design/Methods:

This restospetcive study includes data from 33 ET patients with VIM DBS lead(s) attached to a Percept (Medtronic Inc.®) pulse generator capable of chronic brain sensing. VIM activity was recorded over 5 consecutive days. LFP power was averaged across two time windows: daytime (3 PM-8 PM) and nighttime (12 AM-5 AM), and the values were compared using a t-test to detect circadian fluctuations.

Results:

In most cases, circadian fluctuations in LFP power were observed. Alpha (8-12Hz) and low beta (13-20Hz) frequencies were either increased or decreased (50%) at night, while high beta (20-30Hz) frequencies were consistently decreased at night.

Conclusions:

VIM LFP activities exhibit circadian fluctuations that may be utilized to develop an aDBS system capable of turning off stimulation during sleep. Our next step is a prospective, single-center, crossover pilot trial to evaluate the feasibility, safety, and non-inferiority of this aDBS strategy in ET patients with stable VIM DBS settings.