Alzheimer Disease, Dementia, Mild Cognitive Impairment
Conditions
Keywords
Transcranial direct current stimulation, Alzheimer Disease, Mild Cognitive Impairment, Dementia, MCI, Mild neurocognitive disorder, Amnestic, Pre- alzheimer
Brief summary
The research objective of this study is to examine the efficacy of HD-tDCS to the preSMA/DACC region and its influence on verbal episodic memory in patients with MCI or dementia after 10 sessions of HD-tDCS. There will be three treatment arms: two active HD-tDCS (1 mA or 2 mA) and a sham group. A verbal episodic memory task will be completed at baseline, immediately following the last HD-tDCS session, and a 2-month follow-up.
Detailed description
This is a pilot study being done to attempt to improve verbal episodic memory in persons with mild cognitive impairment (MCI) and dementia. Although the hippocampus is a brain structure most often associated with early deficits in MCI and dementia, the pre-supplemental motor area (preSMA) and dorsal anterior cingulate cortex (DACC) have been shown to play a role in verbal episodic memory for such patients. The purpose of this study is to examine the efficacy of high-definition transcranial direct current stimulation (HD-tDCS) to the preSMA/DACC region and its influence on verbal episodic memory in patients with MCI and dementia. Entraining the preSMA/DACC circuit with 10 sessions at one of two levels of HD-tDCS will allow the researchers to investigate whether neuromodulation may be used to improve verbal episodic memory. Participants will receive 10 sessions at one of two levels of active stimulation (1 mA or 2 mA anodal HD-tDCS targeting preSMA/DACC for 20 min) or sham across 2 weeks. The device is used to deliver high definition transcranial direct current stimulation to targeted regions. A verbal episodic memory task will be completed at baseline, immediately following the last HD-tDCS session, and a 2-month follow-up. The investigators plan to recruit English-speaking participants aged 50 years and older with MCI and dementia. Participants will be randomized into HD-tDCS conditions.
Interventions
DEVICEActive Transcranial direct current stimulation (STARStim 8)
Participants wear a neoprene cap on their head and electrodes filled with gel are attached and will deliver 1mA to the scalp.
DEVICESham Transcranial direct current stimulation (STARStim 8)
Participants wear a neoprene cap on their head and electrodes filled with gel are attached and will deliver no current to the scalp.
Sponsors
University of Texas Southwestern Medical Center
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
50 Years to No maximum
Healthy volunteers
No
Inclusion criteria
1. Age 50 and older 2. Fluent in English 3. Active diagnosis of MCI or dementia
Exclusion criteria
1. Substance use disorder 2. Has metal fragments in head 3. Taking medications that may interact with the HD-tDCS effect (i.e., amphetamines, L-dopa, carbamazepine, sulpiride, pergolide, lorazepam, dextromethorphan, D-cycloserine, flunarizine, or ropinirole)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Score on the Rey Auditory Verbal Learning Test (RAVLT) | Baseline, immediately following last treatment session, and 2-months post treatment | The RAVLT is a verbal episodic memory task where a list of 15 words is read aloud for 5 consecutive trials followed by a 20 minute delayed recall trial. The number of items recalled immediately after each trial are summed to create a total learning score, ranging from 0-75. Also, the number of items recalled for the delayed trial are recorded as a delayed recall score, ranging from 0-15. Scores were converted to standardized scores (T-scores) using normative data, ranging from 2-86. Higher scores reflect better episodic memory performance. Changes from baseline for the total learning and delayed recall scores at the last HD-tDCS session and the 2-month follow-up will be measured as the primary outcomes. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Score on the Boston Naming Test Short Form | Baseline, immediately following last treatment session, and 2-months post treatment | The Boston Naming Test Short Form is a 30 item version of the task (odd and even item versions of the full test) and a measure of language. The subject is shown pictures of objects and is required to correctly name them as quickly as possible. The outcome measure for this task is the total number of correct responses, ranging from 0-30. Scores were converted to standardized scores (T-scores) using normative data, ranging from 2-86. Higher scores reflect better performance. Changes from baseline to the last HD-tDCS session and the 2-month follow-up will be measured. |
| Change in Score on the Delis Kaplan Executive Function System (DKEFS) Phonemic Fluency | Baseline, immediately following last treatment session, and 2-months post treatment | The DKEFS phonemic verbal fluency task is a measure of language. The subject is required to name as many words as possible that begin with specified letters within 1 minute. Three different letter trials are completed. The outcome measure for this task is the total number of correct responses across the trials, ranging from 0-90. Scores were converted to standardized scores (T-scores) using normative data, ranging from 2-86. Higher scores reflect better performance. Changes from baseline to the last HD-tDCS session and the 2-month follow-up will be measured. |
| Change in Score on the Delis Kaplan Executive Function System (DKEFS) Semantic Fluency | Baseline, immediately following last treatment session, and 2-months post treatment | The DKEFS semantic verbal fluency task is a measure of language and involves 3 conditions. The subject is required to name as many animals and people names as possible within 1 minute. The outcome measure for this task is the total number of correct responses for both conditions combined, ranging from 0-90. Scores were converted to standardized scores (T-scores) using normative data, ranging from 2-86. Higher scores reflect better performance. Changes from baseline to the last HD-tDCS session and the 2-month follow-up will be measured. |
| Change in Score on the Brief Visuospatial Memory Test-Revised (BVMT-R) | Baseline, immediately following last treatment session, and 2-months post treatment | The BVMT-R is a visual episodic memory task where 6 simple designs are shown for 10 seconds in a 2 x 3 matrix for 3 learning trials followed by a 25-minute delayed recall trial. The number of items recalled immediately after each trial are summed to create a total learning score, ranging from 0-36. Also, the number of items recalled for the delayed trial are recorded as a delayed recall score, ranging from 0-12. Scores were converted to standardized scores (T-scores) using normative data, ranging from 2-86. Higher scores reflect better visual episodic memory performance. Changes from baseline for the total learning and delayed recall scores at the last HD-tDCS session and the 2-month follow-up will be measured. |
| Change in Score on the Southwestern Assessment of Processing Speed | Baseline, immediately following last treatment session, and 2-months post treatment | The Southwestern Assessment of Processing Speed is a measure of psychomotor processing speed. The subject is required to transcribe numbers to their corresponding written symbol as quickly as possible within 60 seconds. The outcome measure for this task is the total number of correct responses, ranging from 0-75. Scores were converted to standardized scores (T-scores) using normative data, ranging from 2-86. Higher scores reflect better performance. Changes from baseline to the last HD-tDCS session and the 2-month follow-up will be measured. |
| Change in Score on the DKEFS Color-Word Interference Test | Baseline, immediately following last treatment session, and 2-months post treatment | The DKEFS Color-Word Interference test is a measure of information processing speed and complex attention. The task requires the subject to as quickly as possible complete four conditions, involving color naming, word reading, response inhibition, and then switching back-and-forth between two response patterns. The outcome measures for this task was the response inhibition trial and the switching trial, which are scored as the time in seconds to complete the conditions, ranging from 20-180. Scores were converted to standardized scores (T-scores) using normative data, ranging from 2-86. Higher scores reflect better performance. Changes from baseline to the last HD-tDCS session and the 2-month follow-up will be measured. |
| Change in Score on the Trail Making Test | Baseline, immediately following last treatment session, and 2-months post treatment | The Trail Making Test is a measure of cognitive flexibility and executive functions. The task requires the subject to as quickly as possible complete two conditions, involving number sequencing and then number-letter switching. The outcome measure for this task is the time in seconds to complete the number-letter switching condition, ranging from 15-300. Scores were converted to standardized scores (T-scores) using normative data, ranging from 2-86. Higher scores reflect better performance. Changes from baseline to the last HD-tDCS session and the 2-month follow-up will be measured. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Sham Group sham HD-tDCS for 20 minutes, meaning no stimulation. | 5 |
| Active Stimulation at 1mA 1 mA active HD-tDCS for 20 minutes. | 9 |
| Active Stimulation at 2mA 2 mA active HD-tDCS for 20 minutes. | 9 |
| Total | 23 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 |
|---|---|---|---|---|
| Follow-Up at 2 Months | Lost to Follow-up | 1 | 0 | 0 |
| Started Treatment | Adverse Event | 0 | 0 | 1 |
| Started Treatment | Withdrawal by Subject | 0 | 0 | 3 |
Baseline characteristics
| Characteristic | Sham Group | Total | Active Stimulation at 2mA | Active Stimulation at 1mA |
|---|---|---|---|---|
| Age, Continuous | 69.4 years STANDARD_DEVIATION 9 | 70.8 years STANDARD_DEVIATION 8.8 | 68.4 years STANDARD_DEVIATION 7.8 | 74.0 years STANDARD_DEVIATION 9.5 |
| Education | 16.0 years STANDARD_DEVIATION 3.2 | 14.7 years STANDARD_DEVIATION 2.3 | 14.4 years STANDARD_DEVIATION 2.4 | 14.3 years STANDARD_DEVIATION 1.7 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants | 1 Participants | 0 Participants | 1 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 5 Participants | 22 Participants | 9 Participants | 8 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 1 Participants | 1 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants | 1 Participants | 1 Participants | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 5 Participants | 21 Participants | 7 Participants | 9 Participants |
| Region of Enrollment United States | 5 participants | 23 participants | 9 participants | 9 participants |
| Sex: Female, Male Female | 2 Participants | 11 Participants | 5 Participants | 4 Participants |
| Sex: Female, Male Male | 3 Participants | 12 Participants | 4 Participants | 5 Participants |
| Time since diagnosis | 2.3 years STANDARD_DEVIATION 1 | 2.3 years STANDARD_DEVIATION 2.4 | 1.1 years STANDARD_DEVIATION 1 | 3.4 years STANDARD_DEVIATION 3.3 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 5 | 0 / 12 | 0 / 13 |
| other Total, other adverse events | 0 / 5 | 0 / 12 | 0 / 13 |
| serious Total, serious adverse events | 0 / 5 | 0 / 12 | 1 / 13 |
Outcome results
Primary
Change in Score on the Rey Auditory Verbal Learning Test (RAVLT)
The RAVLT is a verbal episodic memory task where a list of 15 words is read aloud for 5 consecutive trials followed by a 20 minute delayed recall trial. The number of items recalled immediately after each trial are summed to create a total learning score, ranging from 0-75. Also, the number of items recalled for the delayed trial are recorded as a delayed recall score, ranging from 0-15. Scores were converted to standardized scores (T-scores) using normative data, ranging from 2-86. Higher scores reflect better episodic memory performance. Changes from baseline for the total learning and delayed recall scores at the last HD-tDCS session and the 2-month follow-up will be measured as the primary outcomes.
Time frame: Baseline, immediately following last treatment session, and 2-months post treatment
Population: One participant lost to follow-up
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Sham Group | Change in Score on the Rey Auditory Verbal Learning Test (RAVLT) | RAVLT total learning Baseline | 13.8 T-score on a scale | Standard Deviation 10.4 |
| Sham Group | Change in Score on the Rey Auditory Verbal Learning Test (RAVLT) | RAVLT Total Learning Immediate post-treatment | 13.4 T-score on a scale | Standard Deviation 11.7 |
| Sham Group | Change in Score on the Rey Auditory Verbal Learning Test (RAVLT) | RAVLT Total Learning 2 months | 16.3 T-score on a scale | Standard Deviation 5.6 |
| Sham Group | Change in Score on the Rey Auditory Verbal Learning Test (RAVLT) | RAVLT Delayed Baseline | 20.6 T-score on a scale | Standard Deviation 0.9 |
| Sham Group | Change in Score on the Rey Auditory Verbal Learning Test (RAVLT) | RAVLT Delayed Immediate Post-treatment | 21.2 T-score on a scale | Standard Deviation 1.8 |
| Sham Group | Change in Score on the Rey Auditory Verbal Learning Test (RAVLT) | RAVLT Delayed 2 Months | 21.8 T-score on a scale | Standard Deviation 1.5 |
| Active Stimulation at 1mA | Change in Score on the Rey Auditory Verbal Learning Test (RAVLT) | RAVLT Delayed 2 Months | 25.7 T-score on a scale | Standard Deviation 10.1 |
| Active Stimulation at 1mA | Change in Score on the Rey Auditory Verbal Learning Test (RAVLT) | RAVLT total learning Baseline | 17.8 T-score on a scale | Standard Deviation 11.2 |
| Active Stimulation at 1mA | Change in Score on the Rey Auditory Verbal Learning Test (RAVLT) | RAVLT Delayed Baseline | 24.4 T-score on a scale | Standard Deviation 6.1 |
| Active Stimulation at 1mA | Change in Score on the Rey Auditory Verbal Learning Test (RAVLT) | RAVLT Delayed Immediate Post-treatment | 24.0 T-score on a scale | Standard Deviation 6.2 |
| Active Stimulation at 1mA | Change in Score on the Rey Auditory Verbal Learning Test (RAVLT) | RAVLT Total Learning Immediate post-treatment | 21.0 T-score on a scale | Standard Deviation 9.7 |
| Active Stimulation at 1mA | Change in Score on the Rey Auditory Verbal Learning Test (RAVLT) | RAVLT Total Learning 2 months | 23.3 T-score on a scale | Standard Deviation 13.8 |
| Active Stimulation at 2mA | Change in Score on the Rey Auditory Verbal Learning Test (RAVLT) | RAVLT Total Learning Immediate post-treatment | 21.9 T-score on a scale | Standard Deviation 12.8 |
| Active Stimulation at 2mA | Change in Score on the Rey Auditory Verbal Learning Test (RAVLT) | RAVLT Total Learning 2 months | 17.2 T-score on a scale | Standard Deviation 11 |
| Active Stimulation at 2mA | Change in Score on the Rey Auditory Verbal Learning Test (RAVLT) | RAVLT Delayed 2 Months | 21.1 T-score on a scale | Standard Deviation 1.3 |
| Active Stimulation at 2mA | Change in Score on the Rey Auditory Verbal Learning Test (RAVLT) | RAVLT Delayed Baseline | 22.3 T-score on a scale | Standard Deviation 2.7 |
| Active Stimulation at 2mA | Change in Score on the Rey Auditory Verbal Learning Test (RAVLT) | RAVLT total learning Baseline | 18.0 T-score on a scale | Standard Deviation 10.3 |
| Active Stimulation at 2mA | Change in Score on the Rey Auditory Verbal Learning Test (RAVLT) | RAVLT Delayed Immediate Post-treatment | 22.3 T-score on a scale | Standard Deviation 1.8 |
Comparison: RAVLT Total Learningp-value: 0.25ANCOVA
Comparison: RAVLT Total Learningp-value: 0.18ANCOVA
Comparison: RAVLT Delayedp-value: 0.48ANCOVA
Comparison: RAVLT Delayedp-value: 0.64ANCOVA
Secondary
Change in Score on the Boston Naming Test Short Form
The Boston Naming Test Short Form is a 30 item version of the task (odd and even item versions of the full test) and a measure of language. The subject is shown pictures of objects and is required to correctly name them as quickly as possible. The outcome measure for this task is the total number of correct responses, ranging from 0-30. Scores were converted to standardized scores (T-scores) using normative data, ranging from 2-86. Higher scores reflect better performance. Changes from baseline to the last HD-tDCS session and the 2-month follow-up will be measured.
Time frame: Baseline, immediately following last treatment session, and 2-months post treatment
Population: One participant lost to follow-up
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Sham Group | Change in Score on the Boston Naming Test Short Form | 2 Months | 39.5 T-score on a scale | Standard Deviation 27.7 |
| Sham Group | Change in Score on the Boston Naming Test Short Form | Immediate Posttreatment | 30.4 T-score on a scale | Standard Deviation 14.9 |
| Sham Group | Change in Score on the Boston Naming Test Short Form | Baseline | 30.6 T-score on a scale | Standard Deviation 16.2 |
| Active Stimulation at 1mA | Change in Score on the Boston Naming Test Short Form | 2 Months | 32.1 T-score on a scale | Standard Deviation 8.5 |
| Active Stimulation at 1mA | Change in Score on the Boston Naming Test Short Form | Baseline | 31.6 T-score on a scale | Standard Deviation 8.1 |
| Active Stimulation at 1mA | Change in Score on the Boston Naming Test Short Form | Immediate Posttreatment | 31.5 T-score on a scale | Standard Deviation 9 |
| Active Stimulation at 2mA | Change in Score on the Boston Naming Test Short Form | 2 Months | 27.6 T-score on a scale | Standard Deviation 8.4 |
| Active Stimulation at 2mA | Change in Score on the Boston Naming Test Short Form | Immediate Posttreatment | 31.9 T-score on a scale | Standard Deviation 8.1 |
| Active Stimulation at 2mA | Change in Score on the Boston Naming Test Short Form | Baseline | 30.1 T-score on a scale | Standard Deviation 9 |
p-value: 0.94ANCOVA
p-value: 0.47ANCOVA
Secondary
Change in Score on the Brief Visuospatial Memory Test-Revised (BVMT-R)
The BVMT-R is a visual episodic memory task where 6 simple designs are shown for 10 seconds in a 2 x 3 matrix for 3 learning trials followed by a 25-minute delayed recall trial. The number of items recalled immediately after each trial are summed to create a total learning score, ranging from 0-36. Also, the number of items recalled for the delayed trial are recorded as a delayed recall score, ranging from 0-12. Scores were converted to standardized scores (T-scores) using normative data, ranging from 2-86. Higher scores reflect better visual episodic memory performance. Changes from baseline for the total learning and delayed recall scores at the last HD-tDCS session and the 2-month follow-up will be measured.
Time frame: Baseline, immediately following last treatment session, and 2-months post treatment
Population: One participant lost to follow-up
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Sham Group | Change in Score on the Brief Visuospatial Memory Test-Revised (BVMT-R) | BVMT Total Learning Immediate Post-treatment | 22.8 T-score on a scale | Standard Deviation 2.6 |
| Sham Group | Change in Score on the Brief Visuospatial Memory Test-Revised (BVMT-R) | BVMT Delayed Immediate Posttreatment | 20.6 T-score on a scale | Standard Deviation 1.3 |
| Sham Group | Change in Score on the Brief Visuospatial Memory Test-Revised (BVMT-R) | BVMT Delayed Baseline | 21.4 T-score on a scale | Standard Deviation 3.1 |
| Sham Group | Change in Score on the Brief Visuospatial Memory Test-Revised (BVMT-R) | BVMT Total Learning Baseline | 20.8 T-score on a scale | Standard Deviation 1.1 |
| Sham Group | Change in Score on the Brief Visuospatial Memory Test-Revised (BVMT-R) | BVMT Delayed 2 Months | 20.3 T-score on a scale | Standard Deviation 0.5 |
| Sham Group | Change in Score on the Brief Visuospatial Memory Test-Revised (BVMT-R) | BVMT Total Learning 2 Months | 20.0 T-score on a scale | Standard Deviation 0 |
| Active Stimulation at 1mA | Change in Score on the Brief Visuospatial Memory Test-Revised (BVMT-R) | BVMT Delayed Baseline | 26.9 T-score on a scale | Standard Deviation 12.7 |
| Active Stimulation at 1mA | Change in Score on the Brief Visuospatial Memory Test-Revised (BVMT-R) | BVMT Total Learning Baseline | 24.2 T-score on a scale | Standard Deviation 8.9 |
| Active Stimulation at 1mA | Change in Score on the Brief Visuospatial Memory Test-Revised (BVMT-R) | BVMT Total Learning Immediate Post-treatment | 24.2 T-score on a scale | Standard Deviation 5.2 |
| Active Stimulation at 1mA | Change in Score on the Brief Visuospatial Memory Test-Revised (BVMT-R) | BVMT Total Learning 2 Months | 24.6 T-score on a scale | Standard Deviation 9.9 |
| Active Stimulation at 1mA | Change in Score on the Brief Visuospatial Memory Test-Revised (BVMT-R) | BVMT Delayed Immediate Posttreatment | 24.7 T-score on a scale | Standard Deviation 10.1 |
| Active Stimulation at 1mA | Change in Score on the Brief Visuospatial Memory Test-Revised (BVMT-R) | BVMT Delayed 2 Months | 25.4 T-score on a scale | Standard Deviation 11.5 |
| Active Stimulation at 2mA | Change in Score on the Brief Visuospatial Memory Test-Revised (BVMT-R) | BVMT Delayed 2 Months | 21.1 T-score on a scale | Standard Deviation 2.4 |
| Active Stimulation at 2mA | Change in Score on the Brief Visuospatial Memory Test-Revised (BVMT-R) | BVMT Delayed Immediate Posttreatment | 22.8 T-score on a scale | Standard Deviation 5.2 |
| Active Stimulation at 2mA | Change in Score on the Brief Visuospatial Memory Test-Revised (BVMT-R) | BVMT Total Learning Immediate Post-treatment | 21.1 T-score on a scale | Standard Deviation 2 |
| Active Stimulation at 2mA | Change in Score on the Brief Visuospatial Memory Test-Revised (BVMT-R) | BVMT Total Learning Baseline | 21.7 T-score on a scale | Standard Deviation 3.1 |
| Active Stimulation at 2mA | Change in Score on the Brief Visuospatial Memory Test-Revised (BVMT-R) | BVMT Delayed Baseline | 20.3 T-score on a scale | Standard Deviation 1 |
| Active Stimulation at 2mA | Change in Score on the Brief Visuospatial Memory Test-Revised (BVMT-R) | BVMT Total Learning 2 Months | 20.7 T-score on a scale | Standard Deviation 1 |
Comparison: BVMT total learningp-value: 0.98ANCOVA
Comparison: BVMT total learningp-value: 0.22ANCOVA
Comparison: BVMT delayedp-value: 0.97ANCOVA
Comparison: BVMT delayedp-value: 0.23ANCOVA
Secondary
Change in Score on the Delis Kaplan Executive Function System (DKEFS) Phonemic Fluency
The DKEFS phonemic verbal fluency task is a measure of language. The subject is required to name as many words as possible that begin with specified letters within 1 minute. Three different letter trials are completed. The outcome measure for this task is the total number of correct responses across the trials, ranging from 0-90. Scores were converted to standardized scores (T-scores) using normative data, ranging from 2-86. Higher scores reflect better performance. Changes from baseline to the last HD-tDCS session and the 2-month follow-up will be measured.
Time frame: Baseline, immediately following last treatment session, and 2-months post treatment
Population: One participant lost to follow-up
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Sham Group | Change in Score on the Delis Kaplan Executive Function System (DKEFS) Phonemic Fluency | Immediate Posttreatment | 33.6 T-score on a scale | Standard Deviation 14.9 |
| Sham Group | Change in Score on the Delis Kaplan Executive Function System (DKEFS) Phonemic Fluency | Baseline | 39.0 T-score on a scale | Standard Deviation 13.7 |
| Sham Group | Change in Score on the Delis Kaplan Executive Function System (DKEFS) Phonemic Fluency | 2 Months | 35.3 T-score on a scale | Standard Deviation 11 |
| Active Stimulation at 1mA | Change in Score on the Delis Kaplan Executive Function System (DKEFS) Phonemic Fluency | Immediate Posttreatment | 40.4 T-score on a scale | Standard Deviation 9.7 |
| Active Stimulation at 1mA | Change in Score on the Delis Kaplan Executive Function System (DKEFS) Phonemic Fluency | Baseline | 37.5 T-score on a scale | Standard Deviation 8.7 |
| Active Stimulation at 1mA | Change in Score on the Delis Kaplan Executive Function System (DKEFS) Phonemic Fluency | 2 Months | 41.7 T-score on a scale | Standard Deviation 9.9 |
| Active Stimulation at 2mA | Change in Score on the Delis Kaplan Executive Function System (DKEFS) Phonemic Fluency | Baseline | 32.7 T-score on a scale | Standard Deviation 14.5 |
| Active Stimulation at 2mA | Change in Score on the Delis Kaplan Executive Function System (DKEFS) Phonemic Fluency | 2 Months | 32.1 T-score on a scale | Standard Deviation 12.3 |
| Active Stimulation at 2mA | Change in Score on the Delis Kaplan Executive Function System (DKEFS) Phonemic Fluency | Immediate Posttreatment | 35.9 T-score on a scale | Standard Deviation 14.2 |
p-value: 0.06ANCOVA
p-value: 0.07ANCOVA
Secondary
Change in Score on the Delis Kaplan Executive Function System (DKEFS) Semantic Fluency
The DKEFS semantic verbal fluency task is a measure of language and involves 3 conditions. The subject is required to name as many animals and people names as possible within 1 minute. The outcome measure for this task is the total number of correct responses for both conditions combined, ranging from 0-90. Scores were converted to standardized scores (T-scores) using normative data, ranging from 2-86. Higher scores reflect better performance. Changes from baseline to the last HD-tDCS session and the 2-month follow-up will be measured.
Time frame: Baseline, immediately following last treatment session, and 2-months post treatment
Population: One participant lost to follow-up
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Sham Group | Change in Score on the Delis Kaplan Executive Function System (DKEFS) Semantic Fluency | Immediate Posttreatment | 25.0 T-score on a scale | Standard Deviation 15.7 |
| Sham Group | Change in Score on the Delis Kaplan Executive Function System (DKEFS) Semantic Fluency | Baseline | 24.2 T-score on a scale | Standard Deviation 10.6 |
| Sham Group | Change in Score on the Delis Kaplan Executive Function System (DKEFS) Semantic Fluency | 2 Months | 24.5 T-score on a scale | Standard Deviation 9 |
| Active Stimulation at 1mA | Change in Score on the Delis Kaplan Executive Function System (DKEFS) Semantic Fluency | Immediate Posttreatment | 30.9 T-score on a scale | Standard Deviation 8.7 |
| Active Stimulation at 1mA | Change in Score on the Delis Kaplan Executive Function System (DKEFS) Semantic Fluency | Baseline | 28.1 T-score on a scale | Standard Deviation 6.4 |
| Active Stimulation at 1mA | Change in Score on the Delis Kaplan Executive Function System (DKEFS) Semantic Fluency | 2 Months | 30.2 T-score on a scale | Standard Deviation 13.1 |
| Active Stimulation at 2mA | Change in Score on the Delis Kaplan Executive Function System (DKEFS) Semantic Fluency | Baseline | 24.9 T-score on a scale | Standard Deviation 6 |
| Active Stimulation at 2mA | Change in Score on the Delis Kaplan Executive Function System (DKEFS) Semantic Fluency | 2 Months | 23.9 T-score on a scale | Standard Deviation 4.6 |
| Active Stimulation at 2mA | Change in Score on the Delis Kaplan Executive Function System (DKEFS) Semantic Fluency | Immediate Posttreatment | 22.8 T-score on a scale | Standard Deviation 5.6 |
p-value: 0.61ANCOVA
p-value: 0.38ANCOVA
Secondary
Change in Score on the DKEFS Color-Word Interference Test
The DKEFS Color-Word Interference test is a measure of information processing speed and complex attention. The task requires the subject to as quickly as possible complete four conditions, involving color naming, word reading, response inhibition, and then switching back-and-forth between two response patterns. The outcome measures for this task was the response inhibition trial and the switching trial, which are scored as the time in seconds to complete the conditions, ranging from 20-180. Scores were converted to standardized scores (T-scores) using normative data, ranging from 2-86. Higher scores reflect better performance. Changes from baseline to the last HD-tDCS session and the 2-month follow-up will be measured.
Time frame: Baseline, immediately following last treatment session, and 2-months post treatment
Population: Several participants were unable to complete the test in the administration time due to the level of cognitive impairment. Thus, the test was discontinued for many participants, prohibiting scores to be derived for several in data analysis. Scores are therefore missing for these, and the number that was able to complete the test varied across conditions and time points.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Sham Group | Change in Score on the DKEFS Color-Word Interference Test | Immediate Posttreatment | 29.7 T-score on a scale | Standard Deviation 20.2 |
| Sham Group | Change in Score on the DKEFS Color-Word Interference Test | Baseline | 35.5 T-score on a scale | Standard Deviation 21.8 |
| Sham Group | Change in Score on the DKEFS Color-Word Interference Test | 2 Months | 25.0 T-score on a scale | Standard Deviation 14 |
| Active Stimulation at 1mA | Change in Score on the DKEFS Color-Word Interference Test | Immediate Posttreatment | 30.3 T-score on a scale | Standard Deviation 12.9 |
| Active Stimulation at 1mA | Change in Score on the DKEFS Color-Word Interference Test | Baseline | 25.1 T-score on a scale | Standard Deviation 10.6 |
| Active Stimulation at 1mA | Change in Score on the DKEFS Color-Word Interference Test | 2 Months | 28.3 T-score on a scale | Standard Deviation 14.3 |
| Active Stimulation at 2mA | Change in Score on the DKEFS Color-Word Interference Test | Baseline | 35.0 T-score on a scale | Standard Deviation 14.4 |
| Active Stimulation at 2mA | Change in Score on the DKEFS Color-Word Interference Test | 2 Months | 36.4 T-score on a scale | Standard Deviation 14 |
| Active Stimulation at 2mA | Change in Score on the DKEFS Color-Word Interference Test | Immediate Posttreatment | 34.2 T-score on a scale | Standard Deviation 13.8 |
Secondary
Change in Score on the Southwestern Assessment of Processing Speed
The Southwestern Assessment of Processing Speed is a measure of psychomotor processing speed. The subject is required to transcribe numbers to their corresponding written symbol as quickly as possible within 60 seconds. The outcome measure for this task is the total number of correct responses, ranging from 0-75. Scores were converted to standardized scores (T-scores) using normative data, ranging from 2-86. Higher scores reflect better performance. Changes from baseline to the last HD-tDCS session and the 2-month follow-up will be measured.
Time frame: Baseline, immediately following last treatment session, and 2-months post treatment
Population: One participant lost to follow-up. Data missing for this measure on one participant in active 2 mA group.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Sham Group | Change in Score on the Southwestern Assessment of Processing Speed | Immediate Posttreatment | 30.2 T-score on a scale | Standard Deviation 10.1 |
| Sham Group | Change in Score on the Southwestern Assessment of Processing Speed | Baseline | 27.6 T-score on a scale | Standard Deviation 7.7 |
| Sham Group | Change in Score on the Southwestern Assessment of Processing Speed | 2 Months | 27.8 T-score on a scale | Standard Deviation 6.8 |
| Active Stimulation at 1mA | Change in Score on the Southwestern Assessment of Processing Speed | Immediate Posttreatment | 31.0 T-score on a scale | Standard Deviation 10 |
| Active Stimulation at 1mA | Change in Score on the Southwestern Assessment of Processing Speed | Baseline | 34.0 T-score on a scale | Standard Deviation 14 |
| Active Stimulation at 1mA | Change in Score on the Southwestern Assessment of Processing Speed | 2 Months | 30.8 T-score on a scale | Standard Deviation 9.3 |
| Active Stimulation at 2mA | Change in Score on the Southwestern Assessment of Processing Speed | Baseline | 26.1 T-score on a scale | Standard Deviation 5.5 |
| Active Stimulation at 2mA | Change in Score on the Southwestern Assessment of Processing Speed | 2 Months | 29.1 T-score on a scale | Standard Deviation 10.6 |
| Active Stimulation at 2mA | Change in Score on the Southwestern Assessment of Processing Speed | Immediate Posttreatment | 27.9 T-score on a scale | Standard Deviation 8.8 |
p-value: 0.11ANCOVA
p-value: 0.68ANCOVA
Secondary
Change in Score on the Trail Making Test
The Trail Making Test is a measure of cognitive flexibility and executive functions. The task requires the subject to as quickly as possible complete two conditions, involving number sequencing and then number-letter switching. The outcome measure for this task is the time in seconds to complete the number-letter switching condition, ranging from 15-300. Scores were converted to standardized scores (T-scores) using normative data, ranging from 2-86. Higher scores reflect better performance. Changes from baseline to the last HD-tDCS session and the 2-month follow-up will be measured.
Time frame: Baseline, immediately following last treatment session, and 2-months post treatment
Population: Several participants were unable to complete the test in the administration time due to the level of cognitive impairment. Thus, the test was discontinued for many participants, prohibiting scores to be derived for several in data analysis. Scores are therefore missing for these, and the number that was able to complete the test varied across conditions and time points.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Sham Group | Change in Score on the Trail Making Test | Immediate Posttreatment | 28.0 T-score on a scale | Standard Deviation 27.4 |
| Sham Group | Change in Score on the Trail Making Test | Baseline | 22.3 T-score on a scale | Standard Deviation 19.1 |
| Sham Group | Change in Score on the Trail Making Test | 2 Months | 24.5 T-score on a scale | Standard Deviation 20.4 |
| Active Stimulation at 1mA | Change in Score on the Trail Making Test | Immediate Posttreatment | 24.4 T-score on a scale | Standard Deviation 14.8 |
| Active Stimulation at 1mA | Change in Score on the Trail Making Test | Baseline | 31.3 T-score on a scale | Standard Deviation 17.4 |
| Active Stimulation at 1mA | Change in Score on the Trail Making Test | 2 Months | 28.5 T-score on a scale | Standard Deviation 15.8 |
| Active Stimulation at 2mA | Change in Score on the Trail Making Test | Baseline | 22.8 T-score on a scale | Standard Deviation 9.9 |
| Active Stimulation at 2mA | Change in Score on the Trail Making Test | 2 Months | 19.7 T-score on a scale | Standard Deviation 10.5 |
| Active Stimulation at 2mA | Change in Score on the Trail Making Test | Immediate Posttreatment | 20.6 T-score on a scale | Standard Deviation 13.2 |