NCT07455760 · Boston University Charles River Campus
Investigating Subcortical Contributions to Speech Sequencing in Deep Brain Stimulator Recipients
What this study is about
This study will examine how two important brain circuits - one involving the subthalamic nucleus (STN) and one involving the ventral intermediate nucleus of the thalamus (VIM) - contribute to learning and producing speech sequences. Participants will include two groups: 1. individuals with Parkinson's disease who have deep brain stimulation (DBS) devices targeting the STN and 2.
View original scientific description
This study will examine how two important brain circuits - one involving the subthalamic nucleus (STN) and one involving the ventral intermediate nucleus of the thalamus (VIM) - contribute to learning and producing speech sequences. Participants will include two groups: 1. individuals with Parkinson's disease who have deep brain stimulation (DBS) devices targeting the STN and 2. individuals with essential tremor who have DBS devices targeting the VIM. Participants will complete speech tasks involving the learning and repetition of novel sound sequences. During some parts of the study, DBS stimulation will be temporarily turned on or off in a controlled research setting. This will allow researchers to examine how stimulation affects both the learning of new speech sequences and the production of previously learned sequences. All STN participants and most VIM participants will also be equipped with a cutting-edge DBS system, the Percept PC, which will enable the recording of deep brain activity during the tasks. The results of this study will improve our understanding of how different brain circuits support speech learning and production. In particular, this study will help to differentiate the roles of the STN and VIM in learning the ordering of speech sounds within a syllable from learning of speech sequences containing multiple syllables. This knowledge may help guide future approaches to optimizing DBS settings to improve both movement and speech outcomes in individuals with neurological disorders, as well as provide greater general insight into how these brain structures contribute to speech production and learning.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Native speakers of American English
- Adults at least 18 years of age
- A clinically established diagnosis of Parkinson's disease or essential tremor
- Able to provide informed consent in the judgment of the investigator
- Treated with deep brain stimulation of the subthalamic nucleus (Parkinson's disease) or ventral intermediate nucleus of the thalamus (essential tremor)
- Stable Parkinson's disease or essential tremor medication regimen for at least one month
- Stable DBS program settings for at least one month
- Nominal DBS system function, including normal impedances at therapeutic DBS contacts, and adequate battery life or adequate IPG charging status for therapy
- For DBS sensing, implanted with Medtronic Percept PC or Percept RC implantable pulse generator
- Corrected vision adequate to easily read text presented during speech motor task
Exclusion criteria
- Cognitive impairment (Montreal Cognitive Assessment (MoCA; Nesreddine et al., 2005) score \< 25) or active psychotic or behavioral symptoms that would, in the judgment of the investigator, preclude proper participation in the study
- Hearing impairment that interferes with accurate perception of the speech motor learning stimulus (25dB hearing level threshold at 500, 1k, 2k, and 4kHz frequencies)
- Language impairment (aphasia) or speech articulation impairment (dysarthria) that precludes performance of the speech motor learning task
- Neurological disorder that interferes with speech motor learning
- Inability to tolerate symptoms when DBS is off
- Orthodontia or atypical oral structure (e.g., cleft palate) that interferes with speech
- For participants in the sub-syllabic sequence learning study (Study C.2.1), experience with the following languages: Hebrew, Polish, Lithuanian, Romanian, Georgian, Tepehua, Hungarian, and Pima
Where
- Boston, Massachusetts
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Mar 9, 2026 · Source of record for eligibility and locations