Combined tDCS and Cognitive Training to Reduce Impulsivity in Patients With Traumatic Brain Injury

Minnesota Office of Higher Education, Center for Veterans Research and Education, The Defense and Veterans Brain Injury Center

Behavioral changes following a traumatic brain injury (TBI) are one of the biggest challenges for patients, as well as their family members and others involved in their recovery. One of the most common behavioral changes following TBI is the emergence of impulsive behavior, which has been associated with destructive, suicidal, and aggressive behavior, and is related to poor rehabilitation program adherence. The primary objective of this study is to investigate the effect of a novel neuroplasticity based intervention that combines cognitive training and transcranial direct current stimulation (tDCS) to reduce impulsivity and to improve outcomes and quality of life for those who have suffered a TBI.

Behavioral changes following a traumatic brain injury (TBI) are one of the biggest challenges for patients, as well as their family members and others involved in their recovery. One of the most common behavioral changes following TBI is the emergence of impulsive behavior, which has been associated with destructive, suicidal, and aggressive behavior, and is related to poor rehabilitation program adherence. The primary objective of this study is to investigate the effect of a novel neuroplasticity based intervention approach utilizing transcranial direct current stimulation (tDCS) to alter brain neuroplasticity combined with cognitive training tasks selected to functionally target cognition and brain circuits that are impaired in those TBI patients with impulsive behavior. This double-blind, randomized, placebo (sham) controlled study will recruit 30 Veterans with a history of mild, moderate or severe TBI, who exhibit a variety of impulsive behaviors. Participants will be randomly assigned to receive either active or sham tDCS, both paired with cognitive training tasks, once a day for five days. Additionally, participants will attend three follow up visits at 1, 2, and 3 months after the course of intervention visits is completed. Functional magnetic resonance imaging (fMRI) will be collected before and after intervention, to measure brain activity changes across time depending on intervention type.

Participants will receive 5 sessions of cognitive training concurrent with transcranial direct current stimulation (anode over left frontal cortex, cathode over right frontal cortex; 2 mAmps for 20 minutes).

Participants will receive 5 sessions of cognitive training concurrent with sham tDCS. For sham tDCS, electrodes are placed at the same locations as for active tDCS, but current is ramped up for the initial 30 secs, then immediately ramped back down. This method mimics the initial physical sensation of stimulation, but there is no active current for the remainder of the session.

Cognitive training concurrent with 2 mAmps of anodal stimulation applied to the left frontal cortex for 20 minutes.

Cognitive training concurrent with sham tDCS (30 secs ramp up/ramp down of current at beginning of session).

Differences in magnitude of change in BIS scores between active tDCS and sham groups from baseline to follow-up sessions. Higher total score on the BIS indicates higher levels of impulsivity.

Differences in magnitude of change in choice of higher risk option during the Risk Task between active tDCS and sham groups from baseline to follow-up sessions. Greater choice of higher risk options in the Risk Task indicates higher levels of risk-taking and impulsivity.

Compare magnitude of change in frontal-striatal functional connectivity between active tDCS and sham groups from baseline to following the 5 sessions of intervention.

Inclusion Criteria: Participants will be included in the study if they: have a clinical history of impulsive behavior, including substance abuse, gambling problems, legal issues such as DUI, violent acts, aggression, history of suicidality, or ADHD as assessed by the patient's clinical provider and/or screen of medical records are age 18 or older are receiving services from the Minneapolis VA Health Care System are stable on any medications for at least 1 week at the baseline visit have a diagnosis of mild, moderate, or severe TBI (as defined by VA/DoD Clinical Practice Guidelines criteria) Exclusion Criteria: Persons will be excluded from this study if they: have a significant neurological disorder based on the Principal Investigators judgment that would impact risk diagnosed with current active psychosis or mania have metallic cranial plates/screws or implanted devices have eczema on scalp or other scalp lesions or skin disorders that may become irritated by stimulation are pregnant