An interventional study of HD-tDCS sessions and Sham HD-tDCS sessions in Posterior Cortical Atrophy, sponsored by University of Michigan. Recruiting at 1 site in United States. Open to participants aged 50 Years and older. Per ClinicalTrials.gov, last updated 2026-06-30.
Sponsored by University of Michigan · Not applicable, Interventional, and Treatment
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.
University of Michigan is the lead sponsor of 1,475 studies on the registry; 196 are open to participants now.
Of its 162 completed or terminated interventional studies of FDA-regulated products, 128 (79%) have results posted.
Counted across the registry records on this site, refreshed daily.
Exclusion Criteria:
Four consecutive days (2 sessions for 20 minutes each day for a total of 8 sessions) of this blinded stimulation.
Device: HD-tDCS sessions
Four consecutive days (2 sessions for 20 minutes each day for a total of 8 sessions) of this blinded stimulation.
Device: Sham HD-tDCS sessions
Participants that agree to this will have up to 26 weeks of additional HD-tDCS sessions at home or in-person.
Device: HD-tDCS sessions - Open-label (after randomized treatment)
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.
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.
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.
Change in network connectivity measured via fMRI
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).
Time frame: Baseline and Day 5 (after 4 days of HD-tDCS)
Measure of form coherence
This will evaluate dorsal and ventral visual stream functioning using a visual paradigm.
Time frame: Baseline and at end of study intervention (up to 6 months)
Long-term change in network connectivity via fMRI
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.
Time frame: Baseline and end of study intervention (up to 6 months)
Measures of motion tasks
This will evaluate dorsal and ventral visual stream function. Motion coherence is measured using a visual paradigm.
Time frame: Baseline and at end of study intervention (up to 6 months)
Measures of motion tasks
This will evaluate dorsal and ventral visual stream function. Motion coherence is measured using a visual paradigm.
Time frame: Baseline and day 5 (after 4 days of HD-tDCS)
Measure of form coherence tasks
Form coherence is measured using a visual paradigm.
Time frame: Baseline and day 5 (after 4 days of HD-tDCS)
Eye tracking - Number of fixations
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.
Time frame: Baseline and at end of study intervention (up to 6 months)
Eye tracking - Number of fixations
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.
Time frame: Baseline and day 5 (after 4 days of HD-tDCS)
Self-ratings of cognitive change using the Posterior Cortical Atrophy Questionnaire (PCA-Q)
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.
Time frame: Baseline and day 5 (after 4 days of HD-tDCS)
Self-ratings of cognitive change using the Posterior Cortical Atrophy Questionnaire (PCA-Q)
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
Time frame: Baseline and at end of study intervention (up to 6 months)
Immersive virtual reality (IVR) path length
Quotient of participants actual path length compared to the most efficient path length.
Time frame: Baseline and at end of study intervention (up to 6 months)
functional near infrared spectroscopy (fNIRS) - Activation magnitude of DAN (processed)
Measured using standard fNIRS analysis
Time frame: Baseline and at end of study intervention (up to 6 months)
Partner rating of cognitive change using the PCA-Q
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
Time frame: Baseline and day 5 (after 4 days of HD-tDCS)
Partner rating of cognitive change using the PCA-Q
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
Time frame: Baseline and at end of study intervention (up to 6 months)
Plan to share: Yes — Study data and documentation will be made available to the research community free of charge through the Deep Blue Data repository.
Supporting information: Study protocol, Icf
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