Accelerated rTMS for Apathy in Parkinson's Disease

November 2, 2026 updated by: Medical University of South Carolina

This single-site, open-label pilot study will evaluate the feasibility, tolerability, and preliminary efficacy of accelerated intermittent theta-burst stimulation (iTBS) targeting the dorsomedial prefrontal cortex (dmPFC) for apathy in individuals with Parkinson's Disease (PD). Fifteen participants with PD and clinically significant apathy will undergo imaging (EEG and MRI) and one day of TMS including twelve iTBS sessions across two visits. Outcomes include adherence, tolerability, changes in apathy (Lille Apathy Rating Scale), functional engagement, and neural target engagement assessed via resting-state fMRI and EEG. Follow-up assessments will occur at one week, two weeks, and four weeks post-treatment. Fifteen participants with PD without clinically significant apathy will act as a comparison group and will undergo imaging (EEG and MRI), assessments, and questionnaires at baseline. Caregivers for each participant will complete questionnaires regarding their co-participant's symptoms as well as answer questions about their experience as a caregiver.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This study is designed to explore a new treatment option for people with Parkinson's disease who experience apathy, which means loss of motivation or interest in daily activities. Apathy is common in Parkinson's disease and can lower quality of life, but current treatments are limited. Investigators are testing whether a non-invasive brain stimulation technique called repetitive transcranial magnetic stimulation (rTMS) is tolerable, acceptable and can be used to improve apathy in patients with Parkinson's disease. TMS delivers brief magnetic pulses to specific areas of the brain that are linked to motivation and decision-making. In this study, Investigators will use an "accelerated" version of TMS, which gives several short sessions in a single day, reducing the number of visits required. The purpose of this research is to see whether this treatment approach is feasible, tolerable and and potentially effective at treating apathy in people with Parkinson's disease. If successful, this research study will hopefully lead to a larger study in the future where the efficacy of the treatments can be studied.

Study Type

Interventional

Enrollment (Estimated)

30

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • South Carolina
      • Charleston, South Carolina, United States, 29425
        • Recruiting
        • Medical University of South Carolina
        • Principal Investigator:
          • Daniel Lench, PhD
        • Contact:
          • Emily Laramie Study Coordinator
          • Phone Number: 843-792-3873
          • Email: laramie@musc.edu

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

45 years to 85 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

PD Apathy Participant

Inclusion criteria:

  1. 45-85 years of age
  2. Diagnosis of PD based on UK Brain Bank diagnostic criteria
  3. Symptomatic apathy as confirmed by a total score on the Apathy Evaluation Scale by the participant or the caregiver/co-participant (AES) of ≥37
  4. Stable on Parkinsons medications (not expected to change through the course of the treatment)
  5. Ability to have a co-participant/caregiver who meets criteria below.

Exclusion Criteria:

  1. Claustrophobia or inability to lie supine in the scanner for an extended period of time
  2. barriers to making contact between the TMS coil and the skin (e.g. braids that cannot be removed)
  3. Contraindications to MRI/TMS safety screening: This includes but is not limited to implanted medical devices (e.g., pacemakers), metallic objects or fragments, and non-removable hair clips or piercings.
  4. Individuals with a diagnosis of bipolar disorder, schizophrenia, and/or active substance abuse disorder.
  5. Pregnancy
  6. Individuals with a history of seizure(s).
  7. Presence of cognitive impairment or dementia that would impact participant's capacity to give informed consent or ability to participate in study procedures as indicated by chart review and/or measured by the MoCA (<21)
  8. Acute suicidality as assessed by the Columbia Suicide Severity Rating Scale (C-SSRS) or suicide attempt in the previous year

Co-participant/Caregiver

Inclusion Criteria:

  1. 18 years of age or older
  2. Is a reliable informant who has at least weekly contact with the participant and can speak to the participant's apathy and everyday functioning.

Exclusion criteria:

1) Unable to engage with study procedures in which co-participant input is needed.

PD Control Group

Inclusion Criteria:

  1. Age matched to participants in the PD Apathy group (45 to 85 years of age)
  2. Diagnosis of PD based on UK Brain Bank diagnostic criteria [17]
  3. Stable on Parkinsons medications (not expected to change through the course of the study)

Exclusion Criteria:

  1. Symptomatic apathy as confirmed by a total score on the Apathy Evaluation Scale by the participant or the caregiver/co-participant (AES) of ≥37
  2. Claustrophobia or inability to lie supine in the scanner for an extended period of time
  3. Contraindications to MRI safety screening: This includes but is not limited to implanted medical devices (e.g., pacemakers), metallic objects or fragments, and non-removable hair clips or piercings
  4. Neuropsychiatric disorder diagnosis
  5. Uncorrected visual or hearing impairments, as indicated by self-report
  6. Pregnancy
  7. Presence of cognitive impairment or dementia that would impact participant's capacity to give informed consent or ability to participate in study procedures as indicated by chart review and/or measured by the MoCA (<21)

Co-participant/Caregiver

Inclusion Criteria:

3) 18 years of age or older 4) Is a reliable informant who has at least weekly contact with the participant and can speak to the participant's mood and everyday functioning.

Exclusion criteria:

2) Unable to engage with study procedures in which co-participant input is needed.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: PD Apathetic group

Participants with Parkinson's disease and clinically significant apathy receive accelerated iTBS rTMS targeting the left dorsomedial prefrontal cortex (dmPFC) using a MagVenture MagPro system with a cooled figure-of-eight coil and Brainsight neuronavigation (slightly off midline). Resting motor threshold (rMT) is determined on the first stimulation visit (PEST) and stimulation is delivered at 120% rMT. Treatment occurs on one day, with 12 sessions separated by 10-15 min. Each session delivers 600 pulses (50 Hz triplets; 2 s on/8 s off; ~190 s), totaling 7,200 pulses overall. Coil position/angle and scalp-to-cortex distance are tracked; tolerability/acceptability (headache, pain, scalp irritation, facial twitching, fatigue, fear/anxiety) is assessed before/after sessions.

Accelerated intermittent theta-burst stimulation (iTBS) rTMS to left dorsomedial prefrontal cortex (dmPFC) (MagVenture MagPro with cooled figure-of-eight coil; Brainsight neuronavigation; 120% rMT; 1 treatment day; 12 sessions; 600 pulses/session; 10-15 min inter-session interval).

No Intervention: Non-Apathetic PD Control Group

Participants with Parkinson's Disease without clinically significant apathy will not undergo TMS but will act as a comparison group at baseline. This group will undergo imaging (EEG and MRI), assessments, and answer questionnaires with their caregiver.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
TMS adherence
Time Frame: Day 1 through Day 14 (6 treatment days over approximately 2 weeks)

Proportion of planned accelerated iTBS sessions completed. Adherence is calculated as number of iTBS sessions completed out of 48 scheduled sessions (6 treatment days × 8 sessions/day).

Day 1 through Day 14 (6 treatment days over approximately 2 weeks)
Frequency and Severity of TMS-Induced Side effects (TMS tolerability and acceptability)
Time Frame: Measured during each treatment day (6 days within a 2-week period)

Participant-reported tolerability/acceptability assessed with a standardized questionnaire capturing frequency and severity of common TMS side effects (e.g., headache, pain, scalp irritation, facial twitching, fatigue, fear/anxiety), collected during treatment days (pre/post sessions).

Measured during each treatment day (6 days within a 2-week period)
Apathy severity as measured by the Lille Apathy Rating Scale
Time Frame: Baseline (Day 0), immediately post-treatment (Day 14), 2 weeks post-treatment, and 4 weeks post-treatment

Change in apathy measured by the Lille Apathy Rating Scale (LARS) patient and caregiver/informant versions; analyzed as change from baseline to post-treatment and follow-up timepoints. Possible scores range from -36 to 36 with higher scores indicating greater apathy.

Baseline (Day 0), immediately post-treatment (Day 14), 2 weeks post-treatment, and 4 weeks post-treatment
Target engagement (dmPFC network modulation)
Time Frame: Baseline MRI/EEG assessments (Days 0-1) and post-treatment MRI/EEG assessments (Days 14-15)

Change in dmPFC target engagement measured by (1) resting-state fMRI functional connectivity of dmPFC to motivation/effort-related nodes and (2) EEG waveform/response metrics during motivation/effort tasks, comparing pre- vs post-intervention.

Baseline MRI/EEG assessments (Days 0-1) and post-treatment MRI/EEG assessments (Days 14-15)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Goal attainment
Time Frame: Baseline (Day 0), immediately post-treatment (Day 14), 2 weeks post-treatment, and 4 weeks post-treatment

Change in goal-directed behavior measured by Bangor Goal-Setting Interview outcomes, including proportion/percent attainment of individualized goals across assessment timepoints.

Baseline (Day 0), immediately post-treatment (Day 14), 2 weeks post-treatment, and 4 weeks post-treatment
Change in apathy as measured by the Dimensional Apathy Scale
Time Frame: Baseline (Day 0), immediately post-treatment (Day 14), 2 weeks post-treatment, and 4 weeks post-treatment"

Change in apathy-related symptoms measured using the Dimensional Apathy Scale (DAS), including patient/informant reports where applicable. Scores range from 0-24 on each of the three subscales (executive, emotional, and behavior/ cognitive initiation) with higher scores indicating greater apathy.

Baseline (Day 0), immediately post-treatment (Day 14), 2 weeks post-treatment, and 4 weeks post-treatment"
Change in apathy-related behavior as measured by the Frontal Systems Behavior Scale
Time Frame: Baseline (Day 0), immediately post-treatment (Day 14), 2 weeks post-treatment, and 4 weeks post-treatment"

Change in apathy-related symptoms measured using the Frontal Systems Behavior Scale (FRSBE), including patient/informant reports where applicable. Apathy components include 14 questions scored 0-4 for a range of scores 0-56 with higher scores indicating greater apathy.

Baseline (Day 0), immediately post-treatment (Day 14), 2 weeks post-treatment, and 4 weeks post-treatment"

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Investigators

  • Principal Investigator: Daniel Lench, Medical University of South Carolina

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 9, 2026

Primary Completion (Estimated)

September 9, 2027

Study Completion (Estimated)

September 9, 2027

Study Registration Dates

First Submitted

January 7, 2026

First Submitted That Met QC Criteria

February 2, 2026

First Posted (Actual)

February 10, 2026

Study Record Updates

Last Update Posted (Actual)

November 5, 2026

Last Update Submitted That Met QC Criteria

November 2, 2026

Last Verified

November 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • Pro00147039

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.

No

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