tDCS and Cognitive Training in Active Duty Service Members With Mild TBI: A Pilot Study

The proposed study will evaluate a new approach to cognitive rehabilitation of mild traumatic brain injury (mTBI) using a brain stimulation technique called transcranial direct current stimulation (tDCS). Specifically, we will investigate how tDCS combined with cognitive training improves deficits to attention and working memory in Active Duty Service Members with a history of mild traumatic brain injury (TBI). Measures of attention-related brain activity, neurocognitive assessments, and self-reported clinical outcomes will be used to determine effects of tDCS vs. sham tDCS when paired with a cognitive training intervention. By doing this study, we hope to find a reliable, noninvasive, and efficient method of treating mild TBI cognitive symptoms.

Objectives: The proposed study will evaluate a new approach to cognitive rehabilitation of mild traumatic brain injury (mTBI) using a brain stimulation technique called transcranial direct current stimulation (tDCS). Specifically, we will investigate how tDCS combined with cognitive training improves deficits to attention and working memory in Active Duty Service Members with a history of mTBI. Measures of attention-related brain activity, neurocognitive assessments, and self-reported clinical outcomes will be used to determine effects of tDCS vs. sham tDCS when paired with a cognitive training intervention. By doing this study, we hope to find a reliable, noninvasive, and efficient method of treating mild TBI cognitive symptoms.

Research Plan and Methods: This is a double-blind, randomized, placebo (sham) controlled pilot study. We will recruit 60 Active Duty Service Members who are receiving outpatient services at Naval Medical Center San Diego, with a history of mTBI and reported neurocognitive symptoms related to attention, working memory, and related cognitive processes. Intake will involve a full pre-assessment of symptoms, neurocognitive performance, and an optional MRI scan. Participants will be randomized to either active or sham tDCS. Training/tDCS sessions will occur daily over five consecutive days. Random permuted blocks will be used to ensure exactly equal treatment numbers at certain equally spaced points in the sequence of patient assignment. Post-intervention assessment will include another assessment of symptoms, neurocognitive performance, and an optional MRI scan. Participants will complete assessments of symptoms and neurocognitive performance six-weeks following the post-intervention assessment.

Clinical Relevance to TBICoE/Navy Medicine: Aspects of this study will provide insight into a major research gap highlighted in the mission of the Defense and Veterans Brain Injury Center, specifically in identifying/ developing innovative treatments/interventions which promote patient recovery and/or mitigate symptoms after mTBI. Novel, well-tolerated, neuroplasticity-based interventions that can improve attention, concentration, and working memory by targeting the underlying neural dysfunction are needed to improve outcomes and quality of life for Active Duty Service Members affected by neurocognitive weakness and dysfunction following mTBI. If tDCS proves successful in reducing TBI-related symptoms, improving cognition, or enhancing functional recovery, this non-invasive intervention could be implemented within various DoD and VA settings, enhancing recovery, improving quality of life, and bolstering occupational performance.

Eligibility Criteria:
Inclusion Criteria:

* (1) Have a remote history mild traumatic brain injury as defined by the VA/DoD clinical practice guidelines(The Management of Concussion/mTBI Working Group, 2016) that is \>/= 6 months, and report moderate severity neurocognitive symptoms related to attention, concentration, working memory, or memory based on NSI scores and self-report.
* (2) Are between the ages of 18-55.
* (3) Are stable on any medications for at least 2 weeks at the baseline visit (Visit #1).

Exclusion Criteria:

* (1) Have a history of seizures or epilepsy.
* (2) Have a history of ECT or cortical energy exposure within the past 12 months, including participation in any other neuromodulation studies.
* (3) Have current stimulant dependence.
* (4) Have a diagnosis of intellectual disability or pervasive developmental disorder (i.e. premorbid IQ less than or equal to 70).
* (5) Have any medical condition or treatment other than mild TBI (e.g. stroke, tumor, HIV, moderate-severe TBI), with significant neurological disorder or insults that, based on the Principal Investigator's judgement, would impact risk.
* (6) Diagnosed with current active psychosis or mania.
* (7) Have metallic cranial plates/screws or implanted device,
* (8) Have eczema on scalp or other scalp lesions or skin disorders that may become irritated by stimulation.
* (9) Pregnant individuals and individuals with ferromagnetic metal in their body that would prohibit them from being safe in the MRI will not be excluded from the overall study, but will be excluded from the optional MRI.