Recruiting

STN & VIMInvestigating Subcortical Contributions to Speech Sequencing in Deep Brain Stimulator Recipients

Sponsor:

Boston University Charles River Campus

Code:

NCT07455760

Conditions

Parkinson's Disease (PD)

Essential Tremor

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Phoneme sequence learning

Cessation and re-enabling of stimulation of the STN

Cessation and re-enabling of stimulation of the VIM thalamic nucleus

Multisyllabic sequence learning

Study Details

Brief summary:

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.

Conditions

Parkinson's Disease (PD)

Essential Tremor

Study ID

NCT07455760

Start date

Feb 18, 2026

Status verified date

Mar, 2026

Completion date

Aug, 2030

Anticipated

Primary completion date

Aug, 2030

Anticipated

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

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
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

Study Design

Enrollment

80 participants

Anticipated

Allocation

Non randomized

Intervention Model

Parallel Assignment

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: Subthalamic nucleus with subsyllabic learning arm

Arm 1: subjects with implanted STN deep brain stimulators will undergo learning tasks involving non-English sound sequences while their stimulators are turned on and off

experimental: Subthalamic nucleus with multisyllabic learning arm

Arm 2: subjects with implanted STN deep brain stimulators will undergo learning tasks involving syllable sequences while their stimulators are turned on and off

experimental: Ventral intermediate thalamus with subsyllabic learning arm

Arm 3: subjects with implanted VIM deep brain stimulators will undergo learning tasks involving non-English sound sequences while their stimulators are turned on and off

experimental: Ventral intermediate thalamus with multisyllabic learning arm

Arm 4: subjects with implanted VIM deep brain stimulators will undergo learning tasks involving syllable sequences while their stimulators are turned on and off

Interventions

Phoneme sequence learning

Approximately half of subjects enrolled in the study will participate in this intervention.

Subjects will read aloud monosyllabic sequences that are presented orthographically on a screen. Each sequence is formed by a non-native consonant cluster followed by a vowel and final consonant (CCVC). Speech trials will be grouped into blocks. After a Familiarization block, subjects will produce a set of twelve CCVCs in a Pretest block. Subjects will then repeatedly produce two of those CCVCs in one Training block, and two other CCVCs in a subsequent Training block. Following training, subjects will produce all four trained CCVCs and four additional novel CCVCs in each of two Test blocks. Washout blocks, during which no speech task trials are completed, will follow the Pretest, Training, and first Test block to allow subjects to rest and to complete standardized testing.

Cessation and re-enabling of stimulation of the STN

20 adults with Parkinson's disease (PD) who have deep brain stimulator (DBS) implants in the subthalamic nucleus (STN). Stimulation of the STN will be intermittently turned off while subjects complete speech sequence learning tasks. After no more than 35 minutes, stimulation will be re-enabled with normal clinical parameters for each participant.

Cessation and re-enabling of stimulation of the VIM thalamic nucleus

20 adults with essential tremor who have deep brain stimulator (DBS) implants in the ventral intermediate nucleus (VIM) of the thalamus will participate in this intervention. Stimulation of the VIM will be intermittently turned off (DBS OFF state) while subjects complete speech sequence learning tasks. After no more than 35 minutes, stimulation will be re-enabled with normal clinical parameters for each participant.

Multisyllabic sequence learning

Approximately half of subjects enrolled in the study will participate in this intervention.

Subjects will read aloud sequences that are presented orthographically on a screen. Speech trials will be grouped into blocks. After a Familiarization block, subjects will produce 2- and 7-syllable sequences in an Assessment block to determine the appropriate length sequence for the remainder of the intervention. Subjects will produce a set of eight sequences in a Pretest block. Subjects will then repeatedly produce two of those sequences in one Training block and two other sequences in a subsequent Training block. Following training, subjects will produce all four trained sequences and two additional novel sequences in each of two Test blocks. Washout blocks, during which no speech task trials are completed, will follow the Pretest, Training, and first Test Block to allow subjects to rest and to complete standardized testing.

Primary outcome measure

Change in speech sequencing accuracy [ Time Frame: Day 1 ]
Speech production duration [ Time Frame: Day 1 ]
Beta power during speech production [ Time Frame: Day 1 ]

Central Contacts and Locations

Central contacts

Frank H Guenther, Ph.D.

617-353-5765 guenther@bu.edu

Barbara G Holland, MA

617-353-6181 bobbieh@bu.edu

Locations

Boston University

Recruiting

Boston, Massachusetts, United States, 02215

Contacts

Frank H Guenther, Ph.D.

617-353-5765 guenther@bu.edu

Barbara G Holland, MA

bobbieh@bu.edu

Principal Investigator:

Frank H Guenther, Ph.D.

Massachusetts General Hospital

Recruiting

Boston, Massachusetts, United States, 02215

Contacts

Todd Herrington, MD, PHD

6177265532 therrington@mgh.harvard.edu

Principal Investigator:

Todd Herrington, MD, PHD

More Information

Sponsor

Boston University Charles River Campus

Last update posted

Mar 9, 2026

Last verified

Mar, 2026

Keywords

Deep Brain Stimulation
Parkinson's Disease
Essential Tremor
Speech Disorders
Neurocomputational Modeling
Stuttering

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Boston University Charles River Campus on 2026-03-09.