Effects of Electrical Stimulation on Verbal Learning in Typical and Atypical Alzheimer's Disease

May 18, 2026 updated by: Johns Hopkins University

Transcranial Direct Current Stimulation in Typical and Atypical Alzheimer's Disease

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.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The investigation implements a double-blind, sham-controlled, within-subject, cross-over design that allows for the evaluation of the cognitive and neural effects of word-list learning as modulated by tDCS compared to sham stimulation. Participants in all groups will receive word-list learning intervention (WordLLI)+ High-Definition tDCS (HD-tDCS) or WordLLI+ sham in Period 1 or 2, randomized for the Period 1 stimulation condition. Each learning Period will last 2 weeks, with 5 learning sessions per week (for a total of 10 learning sessions per Period) with a 3-month (stimulation-free) wash-out period between the two Periods. The intensity, total number of learning sessions and number of learning items is consistent with most other tDCS studies in neurodegenerative disorders and the investigators have used this design successfully over the past 7 years in neurodegenerative disorders (PPA, mild AD). Stimulation is implemented every weekday to take advantage of the long-term potentiation induced by tDCS as found in early multi-session studies. A tDCS-only condition (without any intervention) is not implemented in this design because no study to date has shown improvement on motor, cognitive, or language performance after anodal tDCS-only for 2 or even more weeks. After each period the investigators will perform 1-month and 3-month follow-up sessions for evaluation purposes. For those participants who are long-distance, at the 1-month time point only the investigators may use a video conferencing tool such as GoToMeeting to administer the assessments. This is to mitigate the costs of travel for a short appointment.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
90

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • Maryland
      • Baltimore, Maryland, United States, 21287
        • Johns Hopkins Hospital

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

50 years to 75 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

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).

Exclusion Criteria:

  • People with previous neurological disease including vascular dementia (e.g., stroke, developmental dyslexia, dysgraphia or attentional deficit).
  • People with hearing loss (> 25 decibel, using audiometric hearing screen).
  • People with uncorrected visual acuity loss.
  • 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).
  • Left handed individuals.
  • 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.

Exclusion Criteria for MRI Participation:

  • People with severe claustrophobia.
  • People with cardiac pacemakers or ferromagnetic implants.
  • Pregnant women.

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: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Active HD-tDCS+word intervention then Sham+word intervention
Participants will receive active HD-tDCS + Word List Learning Intervention (WordLLI) and then receive Sham + WordLLI after a three-month washout period.
Device: Sham
Current will be administered in a ramp-like fashion but after the ramping the intensity will drop to 0 mA. Current under the Sham condition will last for a maximum of 30 seconds.
Other: Word List Learning Intervention (WordLLI)
Participants will receive a word list learning intervention (WordLLI) of semantically related and unrelated word lists. Word lists are presented across 10 trials, with an additional trial after a 10-minute delay to assess delayed recall. Immediately following verbal presentation of word lists during each trial, participants will be instructed to recall as many of the words from the list as possible. Participants may use the written modality as a strategy during recall. Word lists include 12 words matched based on psycholinguistics attributes (e.g., imageability, frequency). This task is designed to help participants improve memory via enhancing list learning capabilities.
Device: Active, in-person HD-tDCS or active remote tDCS
Stimulation will be delivered by a battery-driven constant current stimulator. The electrical current will be administered to a pre-specified region of the brain (angular gyrus). The stimulation will be delivered at an intensity of 2 milliamperes (mA) (estimated current density 0.04 mA/cm2; estimated total charge 0.048 Coulombs/cm2) in a ramp-like fashion for a maximum of 20 minutes. In the active, in-person HD-tDCS the current is delivered in a ring configuration. In the active remote tDCS current is delivered in one electrode patch.
Experimental: Sham+word intervention then active HD-tDCS+word intervention
Participants will receive Sham + Word List Learning Intervention (WordLLI) and then active HD-tDCS + WordLLI after a three-month washout period.
Device: Sham
Current will be administered in a ramp-like fashion but after the ramping the intensity will drop to 0 mA. Current under the Sham condition will last for a maximum of 30 seconds.
Other: Word List Learning Intervention (WordLLI)
Participants will receive a word list learning intervention (WordLLI) of semantically related and unrelated word lists. Word lists are presented across 10 trials, with an additional trial after a 10-minute delay to assess delayed recall. Immediately following verbal presentation of word lists during each trial, participants will be instructed to recall as many of the words from the list as possible. Participants may use the written modality as a strategy during recall. Word lists include 12 words matched based on psycholinguistics attributes (e.g., imageability, frequency). This task is designed to help participants improve memory via enhancing list learning capabilities.
Device: Active, in-person HD-tDCS or active remote tDCS
Stimulation will be delivered by a battery-driven constant current stimulator. The electrical current will be administered to a pre-specified region of the brain (angular gyrus). The stimulation will be delivered at an intensity of 2 milliamperes (mA) (estimated current density 0.04 mA/cm2; estimated total charge 0.048 Coulombs/cm2) in a ramp-like fashion for a maximum of 20 minutes. In the active, in-person HD-tDCS the current is delivered in a ring configuration. In the active remote tDCS current is delivered in one electrode patch.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in auditory recall accuracy based on the sum of words recalled in Trials 1-5 of semantically related - trained word-lists
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Each trained word-list (practiced during the intervention period) will consist of 12 semantically related words (e.g., birds). Word lists will be constructed using psycholinguistic databases. There will be 5 Trials to learn each list. The investigators will compute the raw score of items correctly recalled by summing all scores from Trial 1 to Trial 5 and transforming to percent correct (range: 0-100%) at each time point of the study. Increase in scores is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in auditory delayed recall accuracy of semantically related - trained word-lists
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Each trained word-list (practiced during the intervention period) will consist of 12 semantically related words (e.g., birds). Word lists will be constructed using psycholinguistic databases. There will be 5 Trials to recall each list, and then participants will be asked to recall that list 20 minutes later (delayed recall). The investigators will compute the raw score of items correctly recalled (delayed recall) and transform to percent correct (range: 0-100%) at each time point of the study. Increase in scores is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in auditory recall accuracy based on the sum of words recalled in Trials 1-5 of semantically unrelated - trained word-lists
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Each trained word-list (practiced during the intervention period) will consist of 12 semantically unrelated words (as in RAVLT). Word lists will be constructed using psycholinguistic databases. There will be 5 Trials to learn each list. The investigators will compute the raw score of items correctly recalled by summing all scores from Trial 1 to Trial 5 and transforming to percent correct (range: 0-100%) at each time point of the study. Increase in scores is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in auditory delayed recall accuracy of semantically unrelated - trained word-lists
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Each trained word-list (practiced during the intervention period) will consist of 12 semantically unrelated words (as in RAVLT). Word lists will be constructed using psycholinguistic databases. There will be 5 Trials to recall each list, and then participants will be asked to recall that list 20 minutes later (delayed recall). The investigators will compute the raw score of items correctly recalled (delayed recall) and transform to percent correct (range: 0-100%) at each time point of the study. Increase in scores is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in auditory recall accuracy based the sum of words recalled in Trials 1-5 of semantically related - untrained word-lists
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Each untrained word-list (not practiced during the intervention period) will consist of 12 semantically related words (e.g., birds). Word lists will be constructed using psycholinguistic databases. There will be 5 Trials to learn each list. The investigators will compute the raw score of items correctly recalled by summing all scores from Trial 1 to Trial 5 and transforming to percent correct (range: 0-100%) at each time point of the study. Increase in scores is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in auditory delayed recall accuracy of semantically related - untrained word-lists
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Each untrained word-list (not practiced during the intervention period) will consist of 12 semantically related words (e.g., birds). Word lists will be constructed using psycholinguistic databases. There will be 5 Trials to recall each list, and then participants will be asked to recall that list 20 minutes later (delayed recall). The investigators will compute the raw score of items correctly recalled (delayed recall) and transform to percent correct (range: 0-100%) at each time point of the study. Increase in scores is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in auditory recall accuracy based on the sum of words recalled in Trials 1-5 of semantically unrelated - untrained word-lists
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Each untrained word-list (not practiced during the intervention period) will consist of 12 semantically unrelated words (as in RVLT). Word lists will be constructed using psycholinguistic databases. There will be 5 Trials to learn each list. The investigators will compute the raw score of items correctly recalled by summing all scores from Trial 1 to Trial 5 and transforming to percent correct (range: 0-100%) at each time point of the study. Increase in scores is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in auditory delayed recall accuracy of semantically unrelated - untrained word-lists
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Each untrained word-list (not practiced during the intervention period) will consist of 12 semantically unrelated words (as in RVLT). Word lists will be constructed using psycholinguistic databases. There will be 5 Trials to recall each list, and then participants will be asked to recall that list 20 minutes later (delayed recall). The investigators will compute the raw score of items correctly recalled (delayed recall) and transform to percent correct (range: 0-100%) at each time point of the study. Increase in scores is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in Rey Auditory-Verbal Learning Test (RAVLT) score
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
RAVLT is a well-established verbal memory test. RAVLT includes a 5-trial presentation of a 15-word list (List A), a single presentation of an interference list (List B)(Trial 6), two post-interference recall trials (one immediate - Trial 7, one delayed - Trial 8) and recognition of the target words in the orthographic modality with distractors (Trial 9). Scoring includes the percent score of Trial 1, Trial 5, Trial 8 and Trial 9 as well as the sum of Trial 1 through 5, and the difference between Trial 5 and Trial 1 computed as the percent difference between the scores before intervention and each time point after. Increase in score is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in Mini Mental State Examination (MMSE)
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
MMSE is a well-established cognitive assessment test. It examines functions including registration (repeating named prompts), attention and calculation, recall, language, ability to follow simple commands and orientation. The total raw score is out of 30 points. The investigators will compute the raw score of items correct and transform to percent correct (range: 0-100%), computing change in outcome in percent difference between before intervention and each time point after. Increase in score is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in Mnemonic Similarity Task (MST) score
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
MST is a well-established test in order to assess high interference memory and general recognition memory via pattern separation. It involves differentiating between previously learned images and novel images. For the MST tasks, the Pattern Separation (PS) score will be calculated using two measures: a) the rate of similar items correctly identified minus the rate of similar items misidentified as new (S|S-S|N); b) the rate of similar items correctly identified minus the rate of similar items misidentified as old (S|S-O|S). The number of correct responses for each category of items (i.e., old, similar, new) and the type of errors (i.e., identifications of new items as similar; identification of similar items as old) will also be tracked. Change in outcome in percent difference will be computed between the scores before intervention and each time point after. Increase in scores is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in word repetition score
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Temple Assessment of Language and Short-Term Memory in Aphasia (TALSA) tasks include word repetition, with sets of 1-6 words. Scoring will be based on percent of words correctly repeated. The investigators will compute the raw score of items correct and transform to percent correct (range: 0-100%), computing change in outcome in percent difference between before intervention and each time point after. Increase in score is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in non-word repetition score
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
TALSA tasks include non-word repetition, with sets of 1-6 non-words. Scoring will be based on percent of non-words correctly repeated. The investigators will compute the raw score of items correct and transform to percent correct (range: 0-100%), computing change in outcome in percent difference between before intervention and each time point after. Increase in score is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in sentence repetition score
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Sentence repetition tasks come from the TALSA, with scoring based on percent of words in sentences correctly repeated. The investigators will compute the raw score of items correct and transform to percent correct (range: 0-100%), computing change in outcome in percent difference between before intervention and each time point after. Increase in score is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in oral naming Boston Naming Test score
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Accuracy in oral picture naming (30-item Boston Naming Test) will be compared for tDCS and sham conditions. The Boston Naming Test is a widely used picture naming test that detects lexical retrieval deficits in the oral modality. The investigators will compute the raw score of items correct and transform to percent correct (range: 0-100%), computing change in outcome in percent difference between before intervention and each time point after. Increase in score is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in oral naming Philadelphia Naming Test score
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Accuracy in oral picture naming (Philadelphia Naming Test) will be compared for tDCS and sham conditions. The Philadelphia Naming Test is an extensive picture naming test that comprises 275 items from a wide range of frequencies and other psycholinguistic characteristics. The investigators will compute the raw score of items correct and transform to percent correct (range: 0-100%), computing change in outcome in percent difference between before intervention and each time point after. Increase in score is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in written naming as assessed by Boston Naming Test
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Accuracy in written picture naming (30-item Boston Naming Test) will be compared for tDCS and sham conditions. The investigators will compute the raw score of items correct and transform to percent correct (range: 0-100%), computing change in outcome in percent difference between before intervention and each time point after. Increase in score is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in written naming as assessed by Philadelphia Naming Test
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Accuracy in written picture naming (Philadelphia Naming Test) will be compared for tDCS and sham conditions. The investigators will compute the raw score of items correct and transform to percent correct (range: 0-100%), computing change in outcome in percent difference between before intervention and each time point after. Increase in score is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in oral naming of action as assessed by Hopkins Assessment of Naming Actions (HANA)
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Accuracy in oral naming of actions will be compared for tDCS and sham conditions. The investigators will compute the raw score of items correct and transform to percent correct (range: 0-100%), computing change in outcome in percent difference between before intervention and each time point after. Increase in score is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in syntactic comprehension as assessed by Subject-relative, Object-relative, Active, Passive (S.O.A.P.) Syntactic Battery
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
The 40-item Subject-relative, Object-relative, Active, Passive (S.O.A.P.) Syntactic Battery of various sub-tests will be used to assess argument structure comprehension and production. The investigators will compute the raw score of items correct and transform to percent correct (range: 0-100%), computing change in outcome in percent difference between baseline and each time point. Increase in score is considered benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in verbal fluency task score
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Verbal fluency tasks (semantic and letter fluency) involve generating as many words as possible in one minute. Scoring will be based on number of words generated per minute. The investigators will compute the raw score of items correct and compute change in outcome between baseline and each time point. Increase in score is considered benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in spelling as assessed by the Johns Hopkins Dysgraphia battery
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Accuracy in spelling using the Johns Hopkins Dysgraphia battery will be compared for tDCS and sham conditions. The investigators will compute the raw score of items correct using a spelling scoring system accounting for additions, substitutions, and deletions, and transform to percent correct (range: 0-100%), computing change in outcome in percent difference before intervention and each time point after. Increase in score is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in digit span forward score
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Digit span forward involves the recall of a series of single digits (sets of 1-8 digits) in the same order the digits were presented. Scoring will be based on the number of consecutive digits correctly recalled. The investigators will compute the change in outcome between the time point before intervention and each time point after. Increase in score is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in digit span backward score
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Digit span backward involves the recall of a series of single digits (sets of 1-8 digits) in the reverse order than the digits were presented. Scoring will be based on the number of consecutive digits correctly recalled. The investigators will compute the change in outcome between the time point before intervention and each time point after. Increase in score is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in spatial span forward score
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Spatial span forward involves the recall of a series of positions on a board (sets of 1-9) in the same order the digits were presented. Scoring will be based on the number of consecutive positions correctly recalled. The investigators will compute the change in outcome between the time point before intervention and each time point after. Increase in score is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in spatial span backward score
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Spatial span backward involves the recall of a series of positions (sets of 1-8) in the reverse order than the digits were presented. Scoring will be based on the number of consecutive positions correctly recalled. The investigators will compute the change in outcome between the time point before intervention and each time point after. Increase in score is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in semantic content of connected speech
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Using the Cookie Theft image from the Boston Diagnostic Aphasia Examination (BDAE) and the Circus image from the Apraxia Battery for Adults (ABA) investigators will obtain representative language samples as participants describe the images. The investigators will compute the raw score of items (semantics) correct and transform to percent correct (range: 0-100%), computing change in outcome in percent difference between before intervention and each time point after. Increase in score is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in attention and manipulation of information scores
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Using the Trail Making Test (TMT) parts A and B, which include the sequential connection of letters/numbers in order to complete a trail, the investigators will obtain the time required by the participants to finish the tasks. Decrease in the time is considered a benefit.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in volumetric measurements of select brain regions
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Using Magnetization-Prepared Rapid Gradient-Echo (MPRAGE) Magnetic Resonance Imaging (MRI) investigators will perform volumetric measurements of select brain regions. Measurements will be collected in millimeters cubed (mm^3).
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in functional connectivity of select brain regions (z-correlations)
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Using resting stage functional MRI (rs-fMRI) investigators will detect activity of various brain regions under a resting/task-negative condition, which will help evaluate functional regional interactions as indicated by the z-correlations between the selected brain area.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in Gamma-Aminobutyric Acid (GABA) concentration
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Using Magnetic Resonance Spectroscopy (MRS) investigators will measure metabolite (GABA) concentrations from select brain regions in international units (IU).
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in location of white matter tracts of select brain regions
Time Frame: Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Using Diffusion Tensor Imaging (DTI) investigators will estimate the location of the brain's white matter tracts on the regions of concern.
Before intervention, immediately after intervention, 1 month and 3 months post intervention, up to 31 weeks
Change in anisotropy of white matter tracts of select brain regions
Time Frame: Before intervention, immediately after intervention and 3 months post intervention, up to 31 weeks
Using Diffusion Tensor Imaging (DTI) investigators will estimate the anisotropy of the brain's white matter tracts on the brain regions of concern.
Before intervention, immediately after intervention and 3 months post intervention, up to 31 weeks

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Correlation of primary and secondary outcomes with sleep efficiency
Time Frame: One week before intervention and one week post intervention, up to 8 weeks
Actigraphy for sleep is a method for observing sleep activity patterns. Actigraphy data is gathered via a wrist band with an accelerometer and a light detector. The investigators will compute the sleep efficiency (% of time in bed spent asleep) and assess whether it correlates with the performance on primary or secondary outcomes.
One week before intervention and one week post intervention, up to 8 weeks

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Johns Hopkins University

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Institute on Aging (NIA)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Kyrana Tsapkini, PhD, Johns Hopkins University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 17, 2020

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
October 30, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
October 30, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 8, 2019

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 8, 2019

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 10, 2019

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 19, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 18, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRB00229164
  • 5R01AG068881 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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Locations

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