# Balance and Gait in Essential Tremor:  Effects of Thalamic DBS

> **NIH NIH R21** · UNIVERSITY OF FLORIDA · 2021 · $419,375

## Abstract

PROJECT SUMMARY
Here, our multidisciplinary group with expertise in movement disorders and motor physiology, proposes to study
the effects of deep brain stimulation of the ventralis intermedius nucleus (VIM DBS) on balance and gait tasks
of patients with Essential Tremor (ET). Although VIM DBS is effective in controlling upper limb tremor, it does
not address balance and gait disturbances in ET. This is a significant problem because balance and gait
disturbances occur in >40% of ET patients, who exhibit lower quality of life and increased risk for falls and
mortality. The inability to mitigate balance and gait disturbances may be a consequence of the DBS targeting a
location within the VIM that reduces hand tremor but not tremor relevant to balance and gait. Our preliminary
data show that only when VIM DBS reduced midline tremor, balance and gait improved. These findings are
based on measurements of midline tremor with sensitive accelerometers during balance and gait tasks. In
contrast, current measures of midline tremor are based on qualitative clinical assessments and have never been
performed during balance and gait tasks. Thus, current measures of midline tremor are not task-relevant and
lack sensitivity. In this proposal, therefore, we will determine if midline tremor is a marker for balance and gait
impairments using sensitive accelerometry and electromyography (EMG) of postural muscles and innovative
analyses. We will test the central hypothesis that when thalamic neurostimulation reduces midline tremor
amplitude, balance and gait improve and risk for falls decreases. In Aim 1, we propose to characterize the effects
of neurostimulation on tremor at multiple body locations during static and dynamic balance tasks and during
straight and obstacle overground walking tasks (task-relevant tremor). We will quantify tremor using sensitive
accelerometers and EMG when ET patients perform balance and gait tasks with their DBS ON or OFF. We test
the hypothesis that only the VIM DBS-induced reduction of midline tremor will relate to balance and gait
improvements. In Aim 2, we examine the association between the change in risk for falls (pre/post DBS surgery)
and the change in tremor quantified at various locations during balance and gait tasks (DBS ON/OFF). We will
quantify the risk for falls before and after DBS surgery by using the Activities Specific Balance Confidence scale
(ABC), a validated and sensitive scale for risk for falls. In addition, we will quantify performance during the Berg
Balance Test (BBS) and Timed Up and Go Test (TUG) with DBS ON and OFF. We will test the hypothesis that
a greater VIM DBS-induced reduction in midline tremor amplitude will relate to decreased risk for falls. If
successful, the outcomes of this proposal are clinically impactful because they will advance the use of DBS
for treating balance and gait disturbances in ET and in other disorders.

## Key facts

- **NIH application ID:** 10217581
- **Project number:** 1R21NS119849-01A1
- **Recipient organization:** UNIVERSITY OF FLORIDA
- **Principal Investigator:** Evangelos A Christou
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $419,375
- **Award type:** 1
- **Project period:** 2021-05-01 → 2023-10-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10217581

## Citation

> US National Institutes of Health, RePORTER application 10217581, Balance and Gait in Essential Tremor:  Effects of Thalamic DBS (1R21NS119849-01A1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10217581. Licensed CC0.

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