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Investigating Subcortical Contributions to Speech Sequencing in Deep Brain Stimulator Recipients

Who can join

As published by the study on ClinicalTrials.gov. "Not stated" means the study hasn't said — ask the study team.

Age
18 Years and older
Sex
All sexes
Healthy volunteers
Not accepted
Compensation
Not stated

Other requirements are listed under Eligibility below. Only the study team can confirm whether you can join.

What to expect

No one can promise a trial will help you personally — that is what the research is trying to find out.

What participation involves

Not stated in the study description — ask the study team about visits and procedures.

Compensation
Not stated
  • Study-related exams and procedures are typically provided at no cost. This is how many trials work in general — confirm the details for this study with the study team.
  • Participants are monitored closely by the research team throughout the study.
  • Some participants may receive access to an investigational treatment, which is still being studied.
  • Your participation helps researchers learn whether this approach could help future patients.

About this study

In plain language

This study looks at how two brain areas help people learn and repeat new speech sounds. It is for adults with Parkinson’s disease or essential tremor who have deep brain stimulation (DBS) devices that send electrical signals to specific brain areas. Participants will do speech tasks while their DBS is briefly turned on or off in a controlled research setting.

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.

Compensation is read from the study's own description and may be missing — always confirm with the study team.

Eligibility

Who can join

  • Age 18 or older, with American English as your native language.
  • Have a confirmed diagnosis of Parkinson’s disease or essential tremor.
  • Have DBS targeting the subthalamic nucleus (STN) for Parkinson’s disease or the ventral intermediate nucleus (VIM) for essential tremor.
  • Can understand and agree to join the study, as judged by the researcher.
  • Have had no changes to your condition’s medicines or DBS settings for at least one month.
  • Have a DBS system that works normally and has enough battery power or charge.
  • For brain activity recording, have a Medtronic Percept PC or Percept RC implanted device.
  • Can easily read the text used in speech tasks, with glasses or contacts if needed.

Who can't join

  • Have a score below 25 on the MoCA thinking and memory test, or current mental health or behavior symptoms that the researcher thinks would prevent proper participation.
  • Have hearing loss that makes it hard to hear the speech task sounds accurately.
  • Have trouble with language or forming speech sounds that prevents you from doing the tasks.
  • Have a brain or nerve disorder that interferes with learning speech movements.
  • Cannot tolerate your symptoms when DBS is turned off.
  • Have braces or an unusual mouth structure, such as a split in the roof of the mouth, that interferes with speech.
  • Are pregnant.
  • For Study C.2.1, which tests learning sound order within a syllable: have experience with Hebrew, Polish, Lithuanian, Romanian, Georgian, Tepehua, Hungarian, or Pima.

Simplified for readability. The official criteria below are what the study team uses.

Official eligibility criteria

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 sites (2)

MA