Investigating Subcortical Contributions to Speech Sequencing in Deep Brain Stimulator Recipients

Recruiting now · Not applicable

Conditions studied: Parkinson's Disease (PD), Essential Tremor

In brief

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.

Key facts

Study ID: NCT07455760
Run by: Boston University Charles River Campus
People needed: 80
Starts: 2026-02-18
Expected to finish: 2030-08-01
Last updated by the study team: 2026-03-09

Who can join

Age: 18 and older. Sex: any. Healthy volunteers: not accepted.

You may qualify if…

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

You may not qualify if…

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
Pregnancy
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 it is running

Boston University — Boston, Massachusetts, United States (enrolling)
Massachusetts General Hospital — Boston, Massachusetts, United States (enrolling)

Full record on ClinicalTrials.gov

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