Treating Mild Traumatic Brain Injury with High Definition Transcranial Direct Current Stimulation

The purpose of the study is to test whether low level electric stimulation, called transcranial Direct Current Stimulation (tDCS), on the part of the brain (i.e., presupplementary motor area) thought to aid in memory will improve verbal retrieval in military veteran participants with histories of traumatic brain injuries. The primary outcome measures are neuropsychological assessments of verbal retrieval, and the secondary measures are neuropsychological assessments of other cognitive abilities and electroencephalography (EEG) measures. Additionally, the study will examine the degree to which baseline assessments of cognition and concussion history predict responses to treatment over time, both on assessments administered within the intervention period and at follow-up.

Using two treatment arms, the study will examine improvement of verbal retrieval and other cognitive deficits associated with remote traumatic brain injury by comparing (1) 1 milliamp transcranial direct current stimulation (tDCS) active treatment applied to presupplementary motor area for 20 minutes over 15 sessions to (2) sham tDCS following the same schedule. Additionally, after completing the initial active or sham treatment and 3-month follow-up testing sessions, selected participants will be invited back for newly assigned treatment conditions, 20 minutes over 15 sessions and will be and re-evaluated at 2- and 3-months follow-up testing sessions.

Veterans with histories of traumatic brain injuries and observed cognitive deficits will be randomly assigned to one of the two treatment arms (and re-assigned for the second round of intervention, as described above). Primary outcome verbal retrieval measures, secondary neuropsychological and electroencephalography (EEG) measures, and prescreening assessments for study concussion history and contraindications for treatment will be collected prior to being assigned to a treatment arm (i.e., baseline).

Primary outcome verbal retrieval measures and secondary neuropsychological and electroencephalography (EEG) measures will be collected after treatment sessions 5, 10, and 15 and two times following treatment competition (i.e., 2-months and 3-months). For participants selected for the second round of intervention, primary outcome verbal memory measures and secondary neuropsychological and electroencephalography (EEG) measures will be collected again after treatment sessions 5, 10, and 15 and two times following competition of the second treatment (i.e., 2-months and 3-months).

Eligibility Criteria:
Inclusion Criteria: Participants are to be between the ages of 18-75, have previously served in the US armed services, and have had a traumatic brain injury that has led to a verbal retrieval deficit based on neuropsychological testing criteria. Traumatic brain injury must be in the mild to moderate range based on evaluation, including, the Ohio State TBI Identification Method (administered by our research group). You must be fluent in speaking and reading English.

Exclusion Criteria: Exclusion criteria include a history of a psychological or neurological disorder, including, dementia of any type, epilepsy or other seizure disorders, severe traumatic brain injury, post-traumatic stress disorder, brain tumor, present drug abuse, stroke, blood vessel abnormalities in the brain, Parkinson's disease, Huntington's disease, or multiple sclerosis. Additionally, exclusion criteria include inability to give informed consent; cranial implants or skull defects that affect tDCS administration; and use of medications that interact with or potentially interact with tDCS effects, including, anti-convulsants, amphetamines, L-dopa, carbamazepine, sulpiride, pergolide, lorazepam, rivastigmine, dextromethorphan, D-cycloserine, flunarizine, ropinirole, or citalopram.