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NCT Number: NCT07191327

Testing Personalized High-Definition Transcranial Direct Current Stimulation (HD-tDCS) as a Treatment of Posterior Cortical Atrophy

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.

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Key information

Conditions

Posterior Cortical Atrophy

Age range

50 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

HD-tDCS sessions

Device

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.

Sham HD-tDCS sessions

Device

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.

HD-tDCS sessions - Open-label (after randomized treatment)

Device

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 outcomes

  1. 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).

  2. 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.

  3. 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.

  4. 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.

Secondary outcomes

  1. Measures of motion tasks

    Time frame: Baseline and day 5 (after 4 days of HD-tDCS)

    This will evaluate dorsal and ventral visual stream function. Motion coherence is measured using a visual paradigm.

  2. Measure of form coherence tasks

    Time frame: Baseline and day 5 (after 4 days of HD-tDCS)

    Form coherence is measured using a visual paradigm.

  3. Eye tracking - Number of fixations

    Time frame: Baseline and at end of study intervention (up to 6 months)

    The study team will quantify the number and duration of fixations, while the participants perform visual search, reading, or other visual tasks affected by PCA.

  4. Eye tracking - Number of fixations

    Time frame: Baseline and day 5 (after 4 days of HD-tDCS)

    The study team will quantify the number and duration of fixations, while the participants perform visual search, reading, or other visual tasks affected by PCA.

  5. Self-ratings of cognitive change using the Posterior Cortical Atrophy Questionnaire (PCA-Q)

    Time frame: Baseline and day 5 (after 4 days of HD-tDCS)

    The PCA-Q has 32 items and measures cognitive difficulty in 12 domains. It is reported as a composite score, with a lower overall score demonstrating less cognitive impairment.

  6. Self-ratings of cognitive change using the Posterior Cortical Atrophy Questionnaire (PCA-Q)

    Time frame: Baseline and at end of study intervention (up to 6 months)

    The PCA-Q has 32 items and measures cognitive difficulty in 12 domains. It is reported as a composite score, with a lower overall score demonstrating less cognitive impairment

  7. Immersive virtual reality (IVR) path length

    Time frame: Baseline and at end of study intervention (up to 6 months)

    Quotient of participants actual path length compared to the most efficient path length.

  8. functional near infrared spectroscopy (fNIRS) - Activation magnitude of DAN (processed)

    Time frame: Baseline and at end of study intervention (up to 6 months)

    Measured using standard fNIRS analysis

  9. Partner rating of cognitive change using the PCA-Q

    Time frame: Baseline and day 5 (after 4 days of HD-tDCS)

    The PCA-Q has 32 items and measures cognitive difficulty in 12 domains. It is reported as a composite score, with a lower overall score demonstrating less cognitive impairment

  10. Partner rating of cognitive change using the PCA-Q

    Time frame: Baseline and at end of study intervention (up to 6 months)

    The PCA-Q has 32 items and measures cognitive difficulty in 12 domains. It is reported as a composite score, with a lower overall score demonstrating less cognitive impairment

Study contacts

Contact information is provided by the study sponsor or research team.

Eileen Robinson, RN-BC

CONTACT

[email protected]

734-763-1356

Stephen Schlaefflin, BS

CONTACT

[email protected]

734-936-7360

Sponsors and collaborators

Lead sponsor

University of Michigan

Other

Registry information

Official study title

Testing Personalized High Definition Transcranial Direct Current Stimulation (HD-tDCS) as a Treatment of Posterior Cortical Atrophy

Acronym: PCA

Important dates

Study start
2026
Primary completion
2029
Study completion
2029
First posted
Sep 24, 2025
Registry last updated
Jun 30, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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