An interventional study of Phoneme sequence learning and Cessation and re-enabling of stimulation of the STN in Parkinson's Disease (PD) and Essential Tremor, sponsored by Boston University Charles River Campus. Recruiting at 2 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-03-09.
Sponsored by Boston University Charles River Campus · Not applicable, Interventional, and Basic science
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.
4,573 studies on the registry are indexed under Parkinson Disease; 1,086 are open to participants now.
This study's planned enrollment of 80 is above the median of 40 across 3,353 interventional studies indexed under Parkinson Disease.
Browse Parkinson Disease studies →Boston University Charles River Campus is the lead sponsor of 159 studies on the registry; 33 are open to participants now.
Of its 14 completed or terminated interventional studies of FDA-regulated products, 9 (64%) have results posted.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Short tests of memory and thinking, each scored out of 30. Lower scores suggest more difficulty; criteria give a range, either to include people with memory problems or to leave them out.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
MMSE and MoCA
Short tests of memory and thinking, each scored out of 30. Lower scores suggest more difficulty; criteria give a range, either to include people with memory problems or to leave them out.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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
Behavioral: Phoneme sequence learning · Other: Cessation and re-enabling of stimulation of the STN
Arm 2: subjects with implanted STN deep brain stimulators will undergo learning tasks involving syllable sequences while their stimulators are turned on and off
Other: Cessation and re-enabling of stimulation of the STN · Behavioral: Multisyllabic sequence learning
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
Behavioral: Phoneme sequence learning · Other: Cessation and re-enabling of stimulation of the VIM thalamic nucleus
Arm 4: subjects with implanted VIM deep brain stimulators will undergo learning tasks involving syllable sequences while their stimulators are turned on and off
Other: Cessation and re-enabling of stimulation of the VIM thalamic nucleus · Behavioral: Multisyllabic 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.
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.
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.
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.
Change in speech sequencing accuracy
Investigators will evaluate recordings of speech productions to identify errors. This will be used to compare sequence accuracy before and after practice of novel sequences with DBS in the ON and OFF states.
Time frame: Day 1
Speech production duration
Investigators will inspect recordings of speech productions to identify production duration. This will be used to test hypotheses regarding differences in sequence duration before and after practice of novel sequences and with DBS in the ON and OFF states.
Time frame: Day 1
Beta power during speech production
Investigators will extract beta band (12-20 Hz) power from neural recordings taken while subjects practice and rehearse novel speech sequences. This will be used to test hypotheses regarding differences in beta power before and after practice of novel sequences and with DBS in the ON and OFF states.
Time frame: Day 1
Cognitive Assessment
The Montreal Cognitive Assessment (MoCa) test will be administered to all participants. Scores will be used to determine study eligibility and to identify correlations between cognitive capacity and other outcome measures. Score range: 0-30, higher score indicates higher cognitive performance.
Time frame: Baseline
Forward Digit Span
The forward digit span subtest of the Comprehensive Test of Phonological Awareness, 2nd Edition will be administered to all participants. Scores will be used to identify correlations between working memory capacity and other outcome measures.
Time frame: Baseline
Essential tremor severity
Participants with essential tremor will complete The Essential Tremor Rating and Assessment Scale (TETRAS) in both the DBS ON and OFF states to assess disease severity and to identify correlations between severity and other outcome measures. Score range: 0-64, lower score indicates less severe tremor.
Time frame: Day 1
Parkinson's disease severity
Part III (motor examination) of the Movement Disorder Society-sponsored revision of the Unified Parkinson's disease Ratings Scale (UPDRS part 3) will be administered to participants with Parkinson's disease in both the DBS ON and OFF states to assess disease severity and to identify correlations between severity and other outcome measures. Score range: 0-132, lower scores indicate lower motor symptom severity.
Time frame: Day 1
Plan to share: No — All planned analyses will be carried out by research staff who are already facilitating the study.
No publications or documents are linked to this record.
Started Feb 2026 (actual). Primary completion is estimated for Aug 2030, 54 months after the start.
Of 1,291 non-industry interventional studies with no phase under Parkinson Disease, half reached primary completion within 24 months of starting (the median), counting those still running; a quarter within 11 and three quarters within 44. This study's planned 54 months is above that.
Counting every sponsor, half of 1,367 studies reached it within 25 months; a quarter within 11 and three quarters within 44.
How these figures are worked out, and which studies are left out of them.
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