NCT04122001Active, not recruiting
Effects of Electrical Stimulation on Verbal Learning in Typical and Atypical Alzheimer's Disease
Transcranial Direct Current Stimulation in Typical and Atypical Alzheimer's Disease
Source: ClinicalTrials.gov · Last updated 15 Jul 2026
Brief summary (registry, in English)
Alzheimer's disease (AD) is the leading neurodegenerative disease of aging characterized by multiple cognitive impairments. Given the recent failures of disease-modifying drugs, the current focus is on preventing or mitigating synaptic damage that correlates with cognitive decline in AD patients. Transcranial Direct Current Stimulation (tDCS) is a safe, non-invasive, non-painful electrical stimulation of the brain that is shown to act as a primer at the synaptic level when administered along with behavioral therapy, mostly involving language, learning and memory. Previous studies have shown that tDCS over the left angular gyrus (AG) improves language associative learning in the elderly through changes in functional connectivity between the AG and the hippocampus. The investigators' previous clinical trial on the effects of tDCS in neurodegenerative disorders has also shown augmented effects of lexical retrieval for tDCS. In the present study the investigators will compare the effects of active vs. sham tDCS over the AG-an area that is part of the default mode network but also a language area, particularly important for semantic integration and event processing-in two predominant AD variants: probable AD with amnesic phenotype (amnesic/typical AD) and probable AD with non-amnesic (language deficit) phenotype also described as logopenic variant PPA with AD pathology (aphasic/atypical AD). The investigators aim to: (1) determine whether active high-definition tDCS (HD-tDCS) targeting the left AG combined with a Word-List Learning Intervention (WordLLI) will improve verbal learning; (2) identify the changes in functional connectivity between the stimulated area (AG) and other structurally and functionally connected areas using resting-state functional magnetic resonance imaging; (3) identify changes in the inhibitory neurotransmitter GABA at the stimulation site using magnetic resonance spectroscopy. Furthermore, the investigators need to determine the characteristics of the people that may benefit from the new neuromodulatory approaches. For this reason, the investigators will evaluate neural and cognitive functions as well as physiological characteristics such as sleep, and will analyze the moderating effects on verbal learning outcomes. Study results can help provide treatment alternatives as well as a better understanding of the therapeutic and neuromodulatory effects of tDCS in AD, thus improving patients' and caregivers' quality of life.
- Status (registry)
- Active, not recruiting
- Study type
- Interventional
- Enrollment
- 90 (actual)
- First submitted
- 8 Oct 2019
- Start date
- 17 Aug 2020
- Primary completion date
- 30 Nov 2026
- Lead sponsor
- Johns Hopkins University
- Diseases
- Alzheimer disease
- NCT number
- NCT04122001
What you commit to
- Study type: Interventional
- Participants enrolled: 90
- From 17 Aug 2020 to the primary completion date, 30 Nov 2026
- 1 site in 1 country
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Prior treatment
- People with previous neurological disease including vascular dementia (e.g., stroke, developmental dyslexia, dysgraphia or attentional deficit).
Other illness
- People with advanced dementia or severe language impairments (MMSE \< 15, or Montreal Cognitive Assessment \<10, or language Frontotemporal Dementia-specific Clinical Dementia Rating (FTD-CDR) = 3).
- People with pre-existing psychiatric disorders such as behavioral disturbances, severe depression, or schizophrenia that do not allow these people to comply or follow the study schedule and requirements such as repeated evaluation and therapy.
- People with cardiac pacemakers or ferromagnetic implants.
Other
- People with hearing loss (\> 25 decibel, using audiometric hearing screen).
- People with uncorrected visual acuity loss.
- Left handed individuals.
- People with severe claustrophobia.
- Pregnant women.
Who the study is looking for
- For the aphasic/atypical AD participants:
- Must be between 45-85 years of age.
- Must be right-handed.
- Must be proficient in English.
- Must have a minimum of high-school education.
- Must be diagnosed as logopenic variant Primary Progressive Aphasia (PPA) with Alzheimer's Disease (AD) biomarkers. Other possible diagnosis for the 'aphasic AD' variant would be Mild Cognitive Impairment (MCI) or 'possible AD' according to 2011 guidelines with AD biomarkers (CSF or positron emission tomography (PET) amyloid-beta or fluorodeoxyglucose (FDG)-positron emission tomography (PET) with unihemispheric atrophy).
- Participants will be diagnosed from PPA and early dementias clinics at Johns Hopkins University or other specialized centers in US using current consensus criteria. Diagnosis will be based on neuropsychological testing, language testing (most commonly the Western Aphasia Battery), MRI and clinical assessment. The investigators will also use two new variant classification tests the investigators have developed at the lab which discriminate PPA variants with great accuracy (above 80%): a spelling test and a speech production test (i.e.,Cookie Theft picture description task).
- For the amnesic/typical AD participants:
- Must be between 45-85 years of age.
- Must be right-handed.
- Must be proficient in English.
- Must have a minimum of high-school education.
- Must be diagnosed with 'probable AD' in specialized diagnostic centers with neuropsychological (e.g., RAVLT) and AD biomarkers according to 2011 guidelines.
- The investigators will also perform extensive testing in the investigators' test battery including the Mnemonic Similarity Test (MST) that discriminates and measures the most salient hippocampal deficit-pattern separation (PS).
Age in the registry: 45 years to 85 years · Sex: All · Accepts healthy volunteers
Sites (1)
Sites in registry order. Pick your city on the disease page to sort them by distance.
| Site | City | Country | Site status |
|---|---|---|---|
| Johns Hopkins Hospital Coordinator of this site? Confirm its status | Baltimore | United States | Unknown status |
This page is information, not medical advice. Discuss any trial with your doctor.