NCT07191327 · University of Michigan
Testing Personalized High-Definition Transcranial Direct Current Stimulation (HD-tDCS) as a Treatment of Posterior Cortical Atrophy
(PCA)
What this study is about
This study is being completed to learn if high-definition transcranial direct current stimulation (HD-tDCS) has an effect on visual and thinking abilities in persons with posterior cortical atrophy (PCA). Participants will be randomly assigned to receive real or sham HD-tDCS (8 sessions over 4 days).
View original scientific description
This study is being completed to learn if high-definition transcranial direct current stimulation (HD-tDCS) has an effect on visual and thinking abilities in persons with posterior cortical atrophy (PCA). Participants will be randomized to receive real or sham HD-tDCS (8 sessions over 4 days). Following the randomized treatment, participants will have optional open-label phase with real HD-tDCS up to 26 weeks and other possible testing.
Interventions
DEVICE
HD-tDCS sessions
This project translates decades of observational neuroimaging research into a biologically plausible stimulation target (i.e., DAN) and uses functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) to plan personalized brain stimulation and to ensure target engagement. When available; those not MRI compatible will receive a standard montage with per channel amplitudes of up to 5 milliamperes (mA) or a montage derived from other imaging methods. Participants will receive 4 days of HD-tDCS sessions in person. During these sessions participants will have electrodes placed on different areas of the head and held in place with headgear. Participants may also have memory and thinking tests during and after the sessions as well as questionnaires about the experience. Additionally, on the fourth day participants may have repeat immersive virtual reality (iVR) as well as other study activities.
DEVICE
Sham HD-tDCS sessions
Participants will receive 4 days of sham HD-tDCS sessions in person. During these sessions participants will have electrodes placed on different areas of the head and held in place with headgear. Participants may also have memory and thinking tests during and after the sessions as well as questionnaires about the experience. Additionally, on the fourth day participants may have repeat immersive virtual reality (iVR) as well as other study activities.
DEVICE
HD-tDCS sessions - Open-label (after randomized treatment)
Optional 26 weeks of additional HD-tDCS sessions. Participants can complete up to 5 days per week, but most people will complete about 3 days per week. The study team may also collect audio recordings of these sessions. Participants can complete this in person or at-home via using a secure, HIPAA-compliant videoconferencing with the supervision of a research staff member. Participant's that decide to complete the additional sessions at home, a research staff member will train a study partner during the first 4 HD-tDCS sessions in the office. This option may not be available or appropriate for all participants and the study team member will discuss this with participant's and study partners.
Primary outcome measures
Change in network connectivity measured via fMRI
Time frame: Baseline and Day 5 (after 4 days of HD-tDCS)
Functional connectivity measures whether activity in different brain regions show similar patterns of change over time. Graph theory metrics of resting-state fMRI can characterize functional connectivity within the Dorsal Attention Network (DAN).
Measure of form coherence
Time frame: Baseline and at end of study intervention (up to 6 months)
This will evaluate dorsal and ventral visual stream functioning using a visual paradigm.
Long-term change in network connectivity via fMRI
Time frame: Baseline and end of study intervention (up to 6 months)
Functional connectivity measures whether activity in different brain regions show similar patterns of change over time. Graph theory metrics of resting-state fMRI can characterize functional connectivity within the Dorsal Attention Network.
Measures of motion tasks
Time frame: Baseline and at end of study intervention (up to 6 months)
This will evaluate dorsal and ventral visual stream function. Motion coherence is measured using a visual paradigm.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Diagnosis or symptoms consistent with PCA
- Fluent in English
- HD-tDCS compatible
- Stable on relevant medications for at least approximately 4 weeks prior to study enrollment
- If completing any additional, optional, long-term study visits in a remote location (i.e., not our office), a study partner is required in order to administer HD-tDCS. Those choosing to return to our office may have, but are not required to have, a study partner.
Exclusion criteria
- Other relevant neurological disease (e.g., epilepsy) or injuries (e.g., large vessel stroke, moderate-severe traumatic brain injury) viewed as primary to deficits since these could interfere with etiologic considerations and confound study results
- Active, relevant psychiatric conditions (e.g., bipolar disorder, schizophrenia) since the symptoms of these conditions may confound study participation.
- A recent (e.g., within the past 2 years) significant history of, or current, alcohol or drug abuse/dependence. Remote history of abuse/dependence is not exclusionary as long as it is not considered to be the primary etiology for visuospatial deficits.
- Women that are lactating/breastfeeding, pregnant, or may potentially be pregnant will be excluded from the study.
Where
- Ann Arbor, Michigan
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 30, 2026 · Source of record for eligibility and locations