Pathways Relating Amnestic MCI to a Mild Traumatic Brain Injury History

Pathways Relating Amnestic MCI to a Mild Traumatic Brain Injury History

This study will probe if the biological changes in amnestic mild cognitive impairment (aMCI) are related to a history of mild traumatic brain injury (mTBI) using high definition transcranial direct current stimulation (HD-tDCS) and blood-derived biomarker tools. Participants who Do as well as those who Do Not have a history of mTBI will be enrolled in the study.

Ten study visits will be completed by each participant. The initial visit will include a blood draw and a baseline memory evaluation. Afterwards, participants will be randomized to begin with one of 3 conditions of HD-tDCS. The three conditions are sham-control, active stimulation to frontal region, and active stimulation to left temporal region. All participants will be expected to completed each HD-tDCS condition, which will be counterbalanced and separated by 14 days. Active HD-tDCS will be applied at 2 mA for 30 minutes over 3 consecutive daily sessions while sham stimulation will be applied for the same duration and timespan. All subjects will complete memory assessments again immediately following each HD-tDCS condition for a total of four test sessions.

Inclusion Criteria:

1. Active diagnosis of amnestic mild cognitive impairment
2. Presence of an mTBI history for the mTBI+ group; absence of an mTBI history for a control sample
3. Female and male subjects
4. All races/ethnicities
5. Age 55 years and older
6. Fluent in English

Exclusion Criteria:

1. Mild traumatic brain injury within past year
2. Lifetime history of moderate or severe brain injury
3. Lifetime major neurologic syndromes (e.g., stroke, epilepsy, brain tumor)
4. Lifetime major cardiovascular conditions (e.g., heart attack, heart failure)
5. Current substance use disorder
6. Current major psychiatric disorders (e.g., major depressive disorder, bipolar disorder)
7. Current vision or hearing impairment that interferes with testing
8. Any electronic and or metallic implants in the skull or brain
9. Current medication use known to alter HD-tDCS reactivity