Amnestic Mild Cognitive Impairment, Mild Traumatic Brain Injury, Traumatic Brain Injury
Conditions
Brief summary
The study will examine the efficacy of high definition transcranial direct current stimulation (HD-tDCS) and its influence on episodic memory in patients with amnestic mild cognitive impairment and a history of Traumatic brain injury. Ten sessions of HD-tDCS to the dorsal anterior cingulate region is expected to result in improvements in episodic memory measures immediately following the last session and at a 3-month follow-up.
Interventions
This wireless device delivers a very low electrical current to focused regions on the scalp in order to modulate underlying brain circuits to promote neuroplasticity. The device will be fitted onto a neoprene EEG cap, with 1 anode electrode placed and surrounded by 4 cathode electrodes in a ring pattern. Electrical stimulation will be applied using a constant voltage cortical stimulator (Model D185, Digitimer Ltd, UK, maximal output 1000 V/1.5 A) with single square-wave 50-μs pulses (0.1 A/μs rise time).
DEVICESham HD-tDCS
Sham HD-tDCS
Sponsors
Congressionally Directed Medical Research Programs
University of Texas Southwestern Medical Center
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
50 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Age 50 and older * Native English speakers * 12 years of education or higher * Active diagnosis of aMCI * History of TBI based on VA/DOD criteria
Exclusion criteria
* TBI within the past 2 years * Lifetime history of stroke, transient ischemic attack, heart attack, or congestive heart failure * Lifetime history of epilepsy * Major psychiatric disorders (i.e., posttraumatic stress disorder, bipolar disorder, schizophrenia) * Substance use disorder * Has metal fragments in head * 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 |
|---|---|---|
| Hopkins Verbal Learning Test-Revised Total Learning | Baseline, immediately following last HD-tDCS session, and again at 3-month follow-up | Episodic verbal memory will be assessed with the Hopkins Verbal Learning Test-Revised (HVLT-R). The HVLT-R is a verbal episodic memory task where a list of 12 words is read aloud for 3 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 0-36. 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 episodic memory performance. |
| Hopkins Verbal Learning Test-Revised Delayed Recall | Baseline, immediately following the last HD-tDCS session, and a 3-month follow-up | Episodic verbal memory will be assessed with the Hopkins Verbal Learning Test-Revised (HVLT-R). The HVLT-R is a verbal episodic memory task where a list of 12 words is read aloud for 3 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 0-36. 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 episodic memory performance. |
| Brief Visuospatial Memory Test-Revised (BVMT-R) Total Learning | Baseline, immediately post-treatment, and a 3 -month follow-up | Episodic verbal memory will be assessed with the Brief Visuospatial Memory Test-Revised (BVMT-R). The BVMT-R is a visual episodic memory task where where an array of 6 simple geometric visual designs are presented in a 2 x 3 matrix for 10 seconds for 3 trials. The number of items recalled immediately after each trial are summed for accuracy and placement 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 episodic memory performance. |
| Brief Visuospatial Memory Test-Revised Delayed Recall | Baseline, immediately post-treatment, and a 3-month follow-up | Episodic verbal memory will be assessed with the Brief Visuospatial Memory Test-Revised (BVMT-R). The BVMT-R is a visual episodic memory task where where an array of 6 simple geometric visual designs are presented in a 2 x 3 matrix for 10 seconds for 3 trials. The number of items recalled immediately after each trial are summed for accuracy and placement 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 episodic memory performance. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Phonemic Fluency | Baseline, immediately post-treatment, and a 3-month follow-up | The 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. |
| Digit Span Test | Baseline, immediate post-treatment, and a 3-month follow-up | The Wechsler Adult Intelligence Scale-4 Digit Span Test measures simple attention and working memory. The examiner reads aloud a series of numbers of increasing length, and individuals are required to repeat each series across 3 separate conditions, involving forwards, backwards, and in sequence. Each trial is scored as incorrect (0) or correct (1), and the total number of correct trials across the 3 conditions are summed, ranging from 0-48. Scores were converted to standardized scores (scaled-scores) using normative data, ranging from 1-19. Higher scores reflect better episodic memory performance |
| Semantic Fluency | Baseline, immediate post-treatment, and a 3-month follow-up | The semantic verbal fluency task is a measure of language and involves 3 conditions. The subject is required to name as many animals as possible within 1 minute. The outcome measure for this task is the total number of correct responses, ranging from 0-90. Scores were converted to standardized scores (T-scores) using normative data, ranging from 2-86. Higher scores reflect better performance. |
| Trail Making Test | Baseline, immediate post-treatment, and a 3-month follow-up | 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 |
| Stroop Color and Word Test | Baseline, immediate post-treatment, and a 3-month follow-up | The Stroop Color and Word Test is a measure of information processing speed and complex attention. The task requires the subject to as quickly as possible complete 3 conditions, involving word reading, color naming, and response inhibition. The outcome measure for this task was the response inhibition trial, which is scored as the total correct items completed in the administration time of 45 seconds, ranging from 0-100. Scores were converted to standardized scores (T-scores) using normative data, ranging from 2-86. Higher scores reflect better performance. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Active HD-tDCS Participants will receive 10 sessions of active stimulation (1 mA anodal HD-tDCS targeting dorsal anterior cingulate region for 20 minutes) across 2 weeks. | 16 |
| Sham HD-tDCS Participants will receive 10 sessions of sham stimulation across 2 weeks. | 8 |
| Total | 24 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Assigned to Treatment | Withdrawal by Subject | 2 | 0 |
| Follow-Up at 3 Months | Lost to Follow-up | 3 | 1 |
Baseline characteristics
| Characteristic | Active HD-tDCS | Sham HD-tDCS | Total |
|---|---|---|---|
| Age, Continuous | 70.3 years STANDARD_DEVIATION 5.6 | 72.5 years STANDARD_DEVIATION 8.1 | 71.0 years STANDARD_DEVIATION 6.4 |
| Education | 17.0 years STANDARD_DEVIATION 2.2 | 17.4 years STANDARD_DEVIATION 1.6 | 17.1 years STANDARD_DEVIATION 2 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 1 Participants | 0 Participants | 1 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 15 Participants | 8 Participants | 23 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 16 Participants | 8 Participants | 24 Participants |
| Region of Enrollment United States | 16 participants | 8 participants | 24 participants |
| Sex: Female, Male Female | 6 Participants | 2 Participants | 8 Participants |
| Sex: Female, Male Male | 10 Participants | 6 Participants | 16 Participants |
| Time since diagnosis | 2.2 years STANDARD_DEVIATION 1.8 | 1.5 years STANDARD_DEVIATION 1.4 | 2.0 years STANDARD_DEVIATION 1.7 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 16 | 0 / 8 |
| other Total, other adverse events | 0 / 16 | 1 / 8 |
| serious Total, serious adverse events | 0 / 16 | 0 / 8 |
Outcome results
Primary
Brief Visuospatial Memory Test-Revised (BVMT-R) Total Learning
Episodic verbal memory will be assessed with the Brief Visuospatial Memory Test-Revised (BVMT-R). The BVMT-R is a visual episodic memory task where where an array of 6 simple geometric visual designs are presented in a 2 x 3 matrix for 10 seconds for 3 trials. The number of items recalled immediately after each trial are summed for accuracy and placement 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 episodic memory performance.
Time frame: Baseline, immediately post-treatment, and a 3 -month follow-up
Population: 1 participant in active HD-tDCS group did not complete the BVMT-R immediately post-treatment. 4 participants were lost to follow-up.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Active HD-tDCS | Brief Visuospatial Memory Test-Revised (BVMT-R) Total Learning | Baseline | 33.0 T-score on a scale | Standard Deviation 10 |
| Active HD-tDCS | Brief Visuospatial Memory Test-Revised (BVMT-R) Total Learning | Immediate Post-treatment | 32.3 T-score on a scale | Standard Deviation 10.4 |
| Active HD-tDCS | Brief Visuospatial Memory Test-Revised (BVMT-R) Total Learning | 3-Month Follow-up | 33.8 T-score on a scale | Standard Deviation 8.1 |
| Sham HD-tDCS | Brief Visuospatial Memory Test-Revised (BVMT-R) Total Learning | Immediate Post-treatment | 33.3 T-score on a scale | Standard Deviation 7 |
| Sham HD-tDCS | Brief Visuospatial Memory Test-Revised (BVMT-R) Total Learning | Baseline | 29.1 T-score on a scale | Standard Deviation 8.9 |
| Sham HD-tDCS | Brief Visuospatial Memory Test-Revised (BVMT-R) Total Learning | 3-Month Follow-up | 34.1 T-score on a scale | Standard Deviation 12 |
Primary
Brief Visuospatial Memory Test-Revised Delayed Recall
Episodic verbal memory will be assessed with the Brief Visuospatial Memory Test-Revised (BVMT-R). The BVMT-R is a visual episodic memory task where where an array of 6 simple geometric visual designs are presented in a 2 x 3 matrix for 10 seconds for 3 trials. The number of items recalled immediately after each trial are summed for accuracy and placement 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 episodic memory performance.
Time frame: Baseline, immediately post-treatment, and a 3-month follow-up
Population: 1 participant in active HD-tDCS group did not complete the BVMT-R immediately post-treatment. 4 participants were lost to follow-up.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Active HD-tDCS | Brief Visuospatial Memory Test-Revised Delayed Recall | Baseline | 32.6 T-score on a scale | Standard Deviation 9.8 |
| Active HD-tDCS | Brief Visuospatial Memory Test-Revised Delayed Recall | Immediate Post-treatment | 32.4 T-score on a scale | Standard Deviation 11.9 |
| Active HD-tDCS | Brief Visuospatial Memory Test-Revised Delayed Recall | 3-Month Follow-up | 31.6 T-score on a scale | Standard Deviation 12.9 |
| Sham HD-tDCS | Brief Visuospatial Memory Test-Revised Delayed Recall | Baseline | 32.4 T-score on a scale | Standard Deviation 9.4 |
| Sham HD-tDCS | Brief Visuospatial Memory Test-Revised Delayed Recall | Immediate Post-treatment | 32.0 T-score on a scale | Standard Deviation 8.6 |
| Sham HD-tDCS | Brief Visuospatial Memory Test-Revised Delayed Recall | 3-Month Follow-up | 32.4 T-score on a scale | Standard Deviation 11.1 |
Primary
Hopkins Verbal Learning Test-Revised Delayed Recall
Episodic verbal memory will be assessed with the Hopkins Verbal Learning Test-Revised (HVLT-R). The HVLT-R is a verbal episodic memory task where a list of 12 words is read aloud for 3 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 0-36. 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 episodic memory performance.
Time frame: Baseline, immediately following the last HD-tDCS session, and a 3-month follow-up
Population: 4 participants lost to follow-up
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Active HD-tDCS | Hopkins Verbal Learning Test-Revised Delayed Recall | Baseline | 30.1 T-score on a scale | Standard Deviation 12.8 |
| Active HD-tDCS | Hopkins Verbal Learning Test-Revised Delayed Recall | Immediate Post-treatment | 27.7 T-score on a scale | Standard Deviation 11.4 |
| Active HD-tDCS | Hopkins Verbal Learning Test-Revised Delayed Recall | 3-Month Follow-up | 26.9 T-score on a scale | Standard Deviation 10.5 |
| Sham HD-tDCS | Hopkins Verbal Learning Test-Revised Delayed Recall | Baseline | 31.0 T-score on a scale | Standard Deviation 14.1 |
| Sham HD-tDCS | Hopkins Verbal Learning Test-Revised Delayed Recall | Immediate Post-treatment | 26.9 T-score on a scale | Standard Deviation 8.2 |
| Sham HD-tDCS | Hopkins Verbal Learning Test-Revised Delayed Recall | 3-Month Follow-up | 32.4 T-score on a scale | Standard Deviation 17.9 |
Primary
Hopkins Verbal Learning Test-Revised Total Learning
Episodic verbal memory will be assessed with the Hopkins Verbal Learning Test-Revised (HVLT-R). The HVLT-R is a verbal episodic memory task where a list of 12 words is read aloud for 3 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 0-36. 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 episodic memory performance.
Time frame: Baseline, immediately following last HD-tDCS session, and again at 3-month follow-up
Population: 4 participants were lost to follow-up
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Active HD-tDCS | Hopkins Verbal Learning Test-Revised Total Learning | Baseline | 35.8 T-score on a scale | Standard Deviation 10.4 |
| Active HD-tDCS | Hopkins Verbal Learning Test-Revised Total Learning | Immediate Post-treatment | 34.2 T-score on a scale | Standard Deviation 9.6 |
| Active HD-tDCS | Hopkins Verbal Learning Test-Revised Total Learning | 3 Month Follow-up | 32.7 T-score on a scale | Standard Deviation 8.8 |
| Sham HD-tDCS | Hopkins Verbal Learning Test-Revised Total Learning | Baseline | 35.9 T-score on a scale | Standard Deviation 8 |
| Sham HD-tDCS | Hopkins Verbal Learning Test-Revised Total Learning | Immediate Post-treatment | 31.6 T-score on a scale | Standard Deviation 4.4 |
| Sham HD-tDCS | Hopkins Verbal Learning Test-Revised Total Learning | 3 Month Follow-up | 37.1 T-score on a scale | Standard Deviation 17.2 |
Secondary
Digit Span Test
The Wechsler Adult Intelligence Scale-4 Digit Span Test measures simple attention and working memory. The examiner reads aloud a series of numbers of increasing length, and individuals are required to repeat each series across 3 separate conditions, involving forwards, backwards, and in sequence. Each trial is scored as incorrect (0) or correct (1), and the total number of correct trials across the 3 conditions are summed, ranging from 0-48. Scores were converted to standardized scores (scaled-scores) using normative data, ranging from 1-19. Higher scores reflect better episodic memory performance
Time frame: Baseline, immediate post-treatment, and a 3-month follow-up
Population: 1 participant did not complete the Digit Span Test in the active HD-tDCS group at the 3-month follow-up. 4 participants were lost to follow-up.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Active HD-tDCS | Digit Span Test | Baseline | 10.8 Scaled score on a scale | Standard Deviation 2 |
| Active HD-tDCS | Digit Span Test | Immediate Post-treatment | 10.6 Scaled score on a scale | Standard Deviation 1.7 |
| Active HD-tDCS | Digit Span Test | 3-Month Follow-up | 10.8 Scaled score on a scale | Standard Deviation 2 |
| Sham HD-tDCS | Digit Span Test | Baseline | 9.8 Scaled score on a scale | Standard Deviation 1.8 |
| Sham HD-tDCS | Digit Span Test | Immediate Post-treatment | 10.4 Scaled score on a scale | Standard Deviation 1.8 |
| Sham HD-tDCS | Digit Span Test | 3-Month Follow-up | 9.4 Scaled score on a scale | Standard Deviation 2.1 |
Secondary
Phonemic Fluency
The 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.
Time frame: Baseline, immediately post-treatment, and a 3-month follow-up
Population: 4 participants were lost to follow-up.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Active HD-tDCS | Phonemic Fluency | Baseline | 45.8 T-score on a scale | Standard Deviation 9.1 |
| Active HD-tDCS | Phonemic Fluency | Immediately Post-treatment | 46.3 T-score on a scale | Standard Deviation 5.8 |
| Active HD-tDCS | Phonemic Fluency | 3-Month Follow-up | 49.1 T-score on a scale | Standard Deviation 8.1 |
| Sham HD-tDCS | Phonemic Fluency | Immediately Post-treatment | 53.0 T-score on a scale | Standard Deviation 14.1 |
| Sham HD-tDCS | Phonemic Fluency | Baseline | 49.1 T-score on a scale | Standard Deviation 13.9 |
| Sham HD-tDCS | Phonemic Fluency | 3-Month Follow-up | 54.6 T-score on a scale | Standard Deviation 13.9 |
Secondary
Semantic Fluency
The semantic verbal fluency task is a measure of language and involves 3 conditions. The subject is required to name as many animals as possible within 1 minute. The outcome measure for this task is the total number of correct responses, ranging from 0-90. Scores were converted to standardized scores (T-scores) using normative data, ranging from 2-86. Higher scores reflect better performance.
Time frame: Baseline, immediate post-treatment, and a 3-month follow-up
Population: 4 participants were lost to follow-up.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Active HD-tDCS | Semantic Fluency | Baseline | 38.4 T-score on a scale | Standard Deviation 14.7 |
| Active HD-tDCS | Semantic Fluency | Immediate Post-treatment | 38.6 T-score on a scale | Standard Deviation 16.3 |
| Active HD-tDCS | Semantic Fluency | 3-Month Follow-up | 37.3 T-score on a scale | Standard Deviation 13.8 |
| Sham HD-tDCS | Semantic Fluency | Baseline | 37.4 T-score on a scale | Standard Deviation 15.4 |
| Sham HD-tDCS | Semantic Fluency | Immediate Post-treatment | 42.2 T-score on a scale | Standard Deviation 17.8 |
| Sham HD-tDCS | Semantic Fluency | 3-Month Follow-up | 38.4 T-score on a scale | Standard Deviation 18.2 |
Secondary
Stroop Color and Word Test
The Stroop Color and Word Test is a measure of information processing speed and complex attention. The task requires the subject to as quickly as possible complete 3 conditions, involving word reading, color naming, and response inhibition. The outcome measure for this task was the response inhibition trial, which is scored as the total correct items completed in the administration time of 45 seconds, ranging from 0-100. Scores were converted to standardized scores (T-scores) using normative data, ranging from 2-86. Higher scores reflect better performance.
Time frame: Baseline, immediate post-treatment, and a 3-month follow-up
Population: 4 participants were lost to follow-up
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Active HD-tDCS | Stroop Color and Word Test | Baseline | 38.8 T-score on a scale | Standard Deviation 6.9 |
| Active HD-tDCS | Stroop Color and Word Test | Immediate Post-treatment | 41.6 T-score on a scale | Standard Deviation 9.8 |
| Active HD-tDCS | Stroop Color and Word Test | 3-Month Follow-up | 39.9 T-score on a scale | Standard Deviation 12.4 |
| Sham HD-tDCS | Stroop Color and Word Test | Baseline | 39.1 T-score on a scale | Standard Deviation 10.3 |
| Sham HD-tDCS | Stroop Color and Word Test | Immediate Post-treatment | 40.0 T-score on a scale | Standard Deviation 9.6 |
| Sham HD-tDCS | Stroop Color and Word Test | 3-Month Follow-up | 37.9 T-score on a scale | Standard Deviation 11.8 |
Secondary
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
Time frame: Baseline, immediate post-treatment, and a 3-month follow-up
Population: 4 participants were lost to follow-up
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Active HD-tDCS | Trail Making Test | Baseline | 41.6 T-score on a scale | Standard Deviation 15.9 |
| Active HD-tDCS | Trail Making Test | Immediate Post-treatment | 45.7 T-score on a scale | Standard Deviation 10.2 |
| Active HD-tDCS | Trail Making Test | 3-Month Follow-up | 47.8 T-score on a scale | Standard Deviation 17.6 |
| Sham HD-tDCS | Trail Making Test | Baseline | 41.9 T-score on a scale | Standard Deviation 13.3 |
| Sham HD-tDCS | Trail Making Test | Immediate Post-treatment | 44.1 T-score on a scale | Standard Deviation 16.4 |
| Sham HD-tDCS | Trail Making Test | 3-Month Follow-up | 39.1 T-score on a scale | Standard Deviation 20.1 |