By: Mallory Bachmann
Essential tremor, or ET, is the most common movement disorder that often causes small, rapid shaking, especially in the hands and head. While there is currently no cure, deep brain stimulation targeting the ventralis intermedius nucleus of the thalamus, or VIM DBS, has helped significantly reduce ET symptoms, particularly in the arms and hands.
With March recognized as ET Awareness Month, the Fixel Institute is proud to highlight the ongoing research aimed at better understanding ET and developing strategies to improve the quality of life for those living with the disease. This month also provides an opportunity to spotlight the scientists at Fixel who are working to translate research findings into meaningful improvements for patients.
In a recent collaborative study with the Norman Fixel Institute for Neurological Diseases at UF Health, published in Neuromodulation: Technology at the Neural Interface, researchers explored whether VIM DBS influences how the brain retains newly learned movements.
The study evaluated 16 individuals diagnosed with ET who are currently undergoing VIM DBS treatment, as well as 16 healthy controls matched by age and sex for baseline comparison. Researchers divided the 16 individuals with ET into two groups. The first group performed a controlled ankle movement task with VIM DBS turned off on day one, referred to as the “practice day,” and VIM DBS was turned on during day two, known as the “retention day.” The second group followed the opposite schedule.
“Participants performed a fast ‘toes up’ foot movement to hit a specific target. The study measured how steady and accurate the movement was and how the muscles worked to control it,” said Evangelos Christou, Ph.D., one of the study’s senior authors and professor in the UF Department of Applied Physiology and Kinesiology.
On day one, participants from both groups demonstrated similar performance as they learned and repeated the ankle movement. However, on day two, when researchers evaluated how well participants retained the movements, those who practiced with DBS turned on exhibited more accurate and controlled movements than those who practiced with DBS turned off.
The results were based on a comparison between participants’ performance in their last practice block and their performance in the first block on the retention day.
Researchers also noted that participants who had stronger tremor-related muscle activity tended to make jerkier movements, both during practice and on day two. In contrast, those who demonstrated greater movement stability during practice were more likely to maintain that stability and accuracy over time.
Together, these results suggest that movement stability is closely linked to tremor-related muscle activity patterns, helping explain how DBS may support more than tremor reduction. Overall, the study’s findings suggest that DBS not only reduces tremor but also strengthens the brain processes involved in learning and retaining movements.
“These findings are exciting because they open new possibilities for improving rehabilitation and quality of life for people with essential tremor,” said Professor Christou.
Access the full study publication here.