# Role of Subthalamic nucleus in Speech and Movement among people with Parkinson’s as Revealed by Intraoperative Recordings and Deep Brain Stimulation

> **NIH NIH R01** · UNIVERSITY OF IOWA · 2021 · $611,099

## Abstract

PROJECT SUMMARY / ABSTRACT
 Parkinson's disease (PD) is an increasingly prevalent progressive neurodegenerative disorder that
leads to disabling motor, speech, and cognitive symptoms that reduce quality of life for patients and their
families. As the prevalence of PD increases, so too does the use of deep brain stimulation (DBS) as a
surgical treatment option when medications fail to control motor fluctuations or side effects from
medications limit their efficacy. As many as 15% of the more than 1 million American PD patients are felt
to be candidates for DBS.
 The subthalamic nucleus (STN) is the most common target utilized for DBS and limb motor outcomes
after STN-DBS show reliable and consistent improvement in properly selected patients. On the other
hand speech motor outcomes after STN-DBS are unpredictable and more patients experience
deterioration of speech than those that notice improved speech. An estimated 40% of STN-DBS patients
notice worsened speech and with declines significant enough to reduce quality of life. Furthermore, few
effective treatments exist to provide sustained improvement in speech performance for those with
impaired speech.
 In order to optimize and develop better treatments for those living with PD, it is necessary to better
understand the role of STN in speech as contemporary mechanistic models of human speech production
omit STN. Here we study 80 PD patients undergoing bilateral STN-DBS along with 40 non-surgical PD
control subjects to address existing critical knowledge gaps. We will document speech performance of
both groups through functional communication ability (i.e. objective measures of intelligibility and a
validated survey tool for quantifying communication participation) and instrumental speech (i.e. acoustic)
measures pre-surgery, 6- and 12-months post-surgery with all subjects off PD medications and with the
STN-DBS subjects evaluated with stimulation ON & OFF at both post-operative timepoints. Direct
neuronal recordings will be obtained during DBS implantation surgery during both speech and limb motor
tasks to define speech-specific STN neurophysiology. In addition, we will perform regression analyses
using baseline patient factors and intraoperative physiology findings to identify factors leading to the
speech outcomes we will document, and test the feasibility of low frequency DBS in reversing DBS-
induced speech declines.
 To our knowledge, this data will be the first of its kind to evaluate patients before, during, and after
surgery with the goals of both directly defining the role of STN in speech and predicting speech outcome
after STN-DBS. Such knowledge will provide mechanistic insights that cannot be obtained using other
techniques and will guide development of new treatments of impaired speech in PD.

## Key facts

- **NIH application ID:** 10075899
- **Project number:** 5R01DC017718-02
- **Recipient organization:** UNIVERSITY OF IOWA
- **Principal Investigator:** Jeremy Greenlee
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $611,099
- **Award type:** 5
- **Project period:** 2020-07-01 → 2025-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10075899

## Citation

> US National Institutes of Health, RePORTER application 10075899, Role of Subthalamic nucleus in Speech and Movement among people with Parkinson’s as Revealed by Intraoperative Recordings and Deep Brain Stimulation (5R01DC017718-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10075899. Licensed CC0.

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