Neuromodulation in Treatment Resistant Essential Tremor in Early Habituation - Investigating Low and High Frequencies / Waveform Shaping / Pulse and Bursts / Combination Therapy in Deep Brain Stimulation Utilizing the Boston Scientific® Chronos™ Software

The goal of this observational study is to learn whether a new way of programming Deep Brain Stimulation (DBS) can improve and maintain tremor control in adults with essential tremor (ET) who stopped responding to standard DBS therapy.

The main questions it aims to answer are:

• 1. Can advanced DBS settings, using varied stimulation patterns, frequencies, and pulses, restore tremor control in people with ET who lost benefit from standard Ventral Intermedius Deep Brain Stimulation (VIM-DBS)?
• 2. Do these advanced settings provide more stable, longer-lasting tremor improvement over time?

Researchers will compare six different stimulation settings to see if any of them can improve tremor symptoms when standard DBS programming no longer works.

Participants will:

• Complete a clinic visit where they try six different DBS stimulation settings using specialized Chronos software.
• Be randomly assigned to one of these settings to use at home.
• Receive a follow-up phone call at 4 weeks to check on symptoms and device use.
• Return to the clinic at 3 months for a full tremor evaluation.
• Have the option to return for an additional follow-up visit at 1 year.

This study will include 5 participants with essential tremor who previously lost benefit quickly after receiving standard VIM-DBS treatment.