Superior Parietal iTBS for PD-MCI

Accelerated Intermittent Theta Burst Stimulation for Mild Cognitive Impairment in Parkinson's Disease

The goal of this study is to determine the whether a short-term, high-dose form of non-invasive brain stimulation (intermittent theta burst stimulation; iTBS) is a promising and safe treatment for mild cognitive impairment in Parkinson's disease (PD-MCI).

Study Overview

• Status: Recruiting
• Conditions: Parkinson Disease; Mild Cognitive Impairment
• Intervention / Treatment: Device: Accelerated intermittent theta-burst stimulation (iTBS) rTMS to right superior parietal lobule (rSPL)

Detailed Description

Dementia occurs in 80% of people with Parkinson's disease (PD) within 20 years of diagnosis. Cognitive interventions in PD have centered on individuals with mild cognitive impairment (PD-MCI). A lack of efficacy of pharmacological interventions in PD-MCI has driven interest in nonpharmacological approaches. The most promising of these is intermittent theta burst stimulation (iTBS), a noninvasive brain stimulation method that is FDA-approved for several psychiatric conditions. Though iTBS has shown little to no benefit in PD-MCI thus far, there are modifiable issues with past interventions including exclusively targeting prefrontal cortex when cholinergic denervation in posterior cortex is strongly associated with cognitive decline in PD, and substantial underdosing compared to efficacious iTBS interventions (6,000 vs at least 18,000 pulses). Interventions will likely have better outcomes if they target the right superior parietal lobule (rSPL), a cortical region impacted by cholinergic denervation in PD that is essential to maintaining attention, and use accelerated iTBS (a-iTBS) to deliver a stimulation dose commensurate with FDA-approved protocols in a shorter timeframe. However, before the efficacy of such an intervention can be evaluated, it must be established as safe, tolerable and feasible in PD-MCI. This project therefore aims to evaluate the safety, tolerability and feasibility of a three-day a-iTBS intervention stimulating the rSPL with 18,000 total pulses.

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • South Carolina
    • Charleston, South Carolina, United States, 29425
      • Recruiting
      • Medical University of South Carolina
      • Contact: Sam Crowley, PhD; Phone Number: 843-792-7767; Email: crowleys@musc.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• 50-85 years of age
• Diagnosis of Parkinson's disease based on UK Brain Bank diagnostic criteria
• Parkinson's disease with mild cognitive impairment (PD-MCI) diagnosis per Movement Disorders Society Task Force Level II Diagnostic Criteria4 (i.e., scores ≥1.5 standard deviations below appropriate norms on 2 neuropsychological tests) as determined by a clinical neuropsychologist
• Stable on Parkinson's disease medications for 30 days (not expected to change through the course of the treatment)
• Has a caregiver willing and able to reliably complete a questionnaire focused on the participant's daily functioning

Exclusion Criteria:

• Claustrophobia or inability to lie supine in the scanner for an extended period of time
• Barriers to making contact between the TMS coil and the skin (e.g. braids that cannot be removed)
• Contraindications to MRI/TMS safety screening: This includes but is not limited to implanted medical devices (e.g., pacemakers), metallic objects or fragments, non-removable hair clips or piercings, and medications that reduce seizure threshold.
• Individuals with a diagnosis of bipolar disorder, schizophrenia, and/or active substance abuse disorder.
• History of significant or unstable condition/s or treatments for these condition/s that may impact cognition (as determined by the study investigators) such as significant cardiac (e.g. heart failure), infectious (e.g. HIV, urinary tract infection), or metabolic disease (e.g. labile diabetes), cancer (e.g. brain cancer, chemotherapy-induced cognitive impairment), developmental disorder (e.g. autism spectrum disorder, intellectual disability), or other neurologic disease (e.g. multiple sclerosis, moderate to severe brain injury, seizures).
• History of a seizure disorder.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Accelerated iTBS; Participants will undergo accelerated intermittent theta burst stimulation (iTBS) targeting the right superior parietal lobule (rSPL) using a MagVenture MagPro system with a cooled butterfly coil, with Brainsight neuronavigation identifying the stimulation site. Resting motor threshold (rMT) will be determined on the first stimulation visit using Parameter Estimation by Sequential Testing (PEST). Stimulation for the intervention will be delivered at 120% rMT. Stimulation sessions will occur over three consecutive days. Each day will include 10 sessions separated by 10-15 min. Each session delivers 600 pulses (50 Hz triplets; 2 s on/8 s off; ~190 seconds), totaling 6,000 pulses/day and 18,000 pulses overall. Coil position/angle and scalp-to-cortex distance are tracked; tolerability/acceptability (headache, pain, scalp irritation, facial twitching, fatigue, fear/anxiety) will be assessed before and after sessions.

Device: Accelerated intermittent theta-burst stimulation (iTBS) rTMS to right superior parietal lobule (rSPL); Participants in this single-arm study will receive a accelerated course of intermittent theta burst stimulation (iTBS) over superior parietal lobule, which is identified with MNI coordinates from past studies. The stimulation will be delivered using a MagVenture MagPro TMS System with a butterfly, active cooling coil at 120% of resting motor threshold. Each participant will complete 3 consecutive treatment days, undergoing10 rTMS sessions per day (600 pulses/session), totaling 18,000 pulses across the study. Safety, tolerability, adherence, and feasibility data will be collected for the intervention.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Serious Adverse Events	Number of serious adverse events experienced by study participants caused by the iTBS protocol	Week 4, 5 minutes before and 5 minutes after stimulation sessions on Days 1-3
Feasibility of the study protocol	Feasibility will be defined as the proportion of participants enrolled that complete all intervention procedures	Week 0 through completion of study (8 weeks)
Tolerability of TMS procedures	A questionnaire evaluating the presence and severity of commonly experienced side effects of TMS (i.e. headache, pain, scalp irritation, facial twitching, fatigue, fear/anxiety) within the past 24 hours and during stimulation. Ratings will be on a 6-point Likert scale from 0 (no symptoms) to 5 (severe symptoms).	Week 4, 5 minutes before and 5 minutes after stimulation sessions on Days 1-3
Test-retest reliability of the Continuous Temporal Expectancy Test (CTET)	The CTET is a tablet-administered measure designed to assess sustained attention and distractibility. Participants will be shown a grid with black and white squares on a tablet that rotate after either a longer duration (target stimulus; 1070ms) or a shorter duration (non-target stimulus; 800ms) and must press the screen when they identify a target stimulus. Participants will complete 10 one-minute trials. Half of the trials are performed without a distractor present, and the other half are performed with an audio-video distractor presented on an adjacent laptop screen. The primary outcome is the distractibility score, defined as the difference in latency (in ms) to identifying the target stimulus between distractor and non-distractor trials.	Week 0 (4 weeks pre-intervention) to Week 4, Day 1 (30 minutes prior to intervention)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Continuous Temporal Expectancy Task (CTET) Distractibility Score	Change in CTET Distractibility Score ([distraction trial latency in ms] - [non-distraction trial latency in ms]). Higher scores indicate worse performance.	Week 4, Day 1 (30 minutes prior to intervention) to Week 4, Day 3 (15 minutes after intervention) to Week 8 (4 weeks post-intervention)
Change in NIH Toolbox Cognitive Battery (NIHTB-CB) Composite Scores	The NIHTB-CB is a performance-based, iPad-administered suite of 7 tests that ascertain abilities in different cognitive domains (i.e. executive function, episodic memory, working memory, processing speed, language). It was developed using advanced psychometric techniques to minimize measurement error and produces normed subtest and composite scores. We will use the fully-corrected T-score (range T=0-100; Mean T=50, SD=10; higher scores indicating better cognition) of the Fluid Cognition Composite and Crystallized Cognition Composite, which are normed for age, sex, years of education, and race/ethnicity.	Week 4, Day 1 (30 minutes prior to intervention intervention) to Week 4, Day 3 (15 minutes after intervention) to Week 8 (4 weeks post-intervention)
Change in daily functioning	Change in caregiver ratings on the ECog-12, a questionnaire designed to measure the participant's everyday cognition and functional decline based on 12 Likert scale items ranging from 1 (no change compared to 10 years earlier) to 4 (consistently much worse).	Week 0 (1 month pre-intervention) to Week 8 (1 month post-intervention)
Change in Beck Depression Inventory II (BDI-II) Raw Score	The Beck Depression Inventory II (BDI-II) is a self-report measure of depressive symptoms comprised of 21 questions rated on a Likert scale from 0 (least severe) to 3 (most severe).	Week 4, Day 1 (pre-intervention) to Week 8 (1 month post-intervention)
Change in Beck Anxiety Inventory (BAI) Score	The Beck Anxiety Inventory (BAI) is a self-report measure of depressive symptoms comprised of 21 questions rated on a Likert scale from 0 (least severe) to 3 (most severe).	Week 1, Day 1 (pre-intervention) to Week 8 (one-month follow-up)
Change in Apathy Evaluation Scale (AES) Raw Score	The Apathy Evaluation Scale is a self-report measure of apathy symptoms comprised of 18 Likert scale items rated from 0 (least severe) to 3 (most severe).	Week 4, Day 1 (pre-intervention) to Week 8 (1-month post-intervention)

Collaborators and Investigators

• Sponsor: Medical University of South Carolina
• Collaborators: National Institutes of Health (NIH); National Center for Advancing Translational Sciences (NCATS)

Study record dates

Study Major Dates

• Study Start (Estimated): August 1, 2026
• Primary Completion (Estimated): February 1, 2028
• Study Completion (Estimated): April 30, 2028

Study Registration Dates

• First Submitted: June 29, 2026
• First Submitted That Met QC Criteria: July 8, 2026
• First Posted (Actual): July 14, 2026

Study Record Updates

• Last Update Posted (Actual): July 14, 2026
• Last Update Submitted That Met QC Criteria: July 8, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Neuromodulation; Parkinson's Disease; Cognitive Impairment; Transcranial Magnetic Stimulation; Theta Burst Stimulation
• Additional Relevant MeSH Terms: Synucleinopathies; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Mental Disorders; Neurocognitive Disorders; Cognition Disorders; Neurodegenerative Diseases; Movement Disorders; Parkinsonian Disorders; Basal Ganglia Diseases; Cognitive Dysfunction; Parkinson Disease
• Other Study ID Numbers: Pro00151225; K12TR005297 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Demographic information on trial participants and data acquired throughout the trial will be shared upon request to the principal investigator.
• IPD Sharing Time Frame: 6 months after publication
• IPD Sharing Access Criteria: 7/1/2027-7/1/2032
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes