High-Definition Transcranial Direct Current Stimulation (HD-tDCS) for Sensory Deficits in Complex Traumatic Brain Injury

Inclusion Criteria

• are US Veteran or Active Duty Military personnel aged 18-59,
• have suffered a mild TBI (alteration in neurological functioning < 24 hours, loss of consciousness (LOC) less than 30 minutes, Glasgow coma scale (GCS) score (if available) of between 13 and 15 acutely, and less than 24 hours of post-traumatic amnesia (PTA));
• were injured between 3 months and 15 years ago;
• have post-traumatic sensory symptoms as evidenced by endorsing at least 2 out of 12 sensory symptoms on the Neurobehavioral Symptom Inventory (NSI), a measure of post-traumatic symptoms from the NIH Common Data Elements (CDE) to a severity of "3" or higher,
• are fluent in English,
• have been on stable doses of any psychotropic medications for the past 2 months.
• The imaging-only group will have the same inclusion and exclusion criteria except they will not have had a head injury.

Exclusion Criteria

• any history of moderate or severe TBI;
• a prior history of other neurological disease or any history of seizures beyond immediate post-traumatic seizure, to as to reduce risk of exacerbation of epilepsy or other neurological symptoms;
• history of psychosis, so as to reduce risk of psychiatric decompensation;
• history of current or recent (within two years) substance/alcohol dependence, to reduce confounding effects on cognition and plasticity;
• any discontinuity in skull electrical conductivity (i.e., unhealed burr holes in scalp) or artificially constructed (metal or plastic) craniotomy cover, to reduce risk of unimpeded electrical current;
• presence of any implanted electrical device (e.g. pacemaker), to reduce risk of device malfunction;
• recent medical hospitalization (within three weeks), to reduce risk of medical decompensation during the study;
• any condition that would prevent the subject from completing the protocol; 9) appointment of a legal representative, as assessed via direct inquiry of the subject and a designated trusted other, to avoid coercion of a vulnerable population;
• any significant blindness, to screen out peripheral sensory damage; 11) any significant deafness beyond mild hearing loss, to screen out peripheral sensory damage; 12) any ongoing litigation related to TBI, to prevent interference with legal proceedings; 13) any contraindication to MRI; 14) membership in an identified vulnerable population, including minors, pregnant women, and prisoners, so as to prevent coercion.