Alcohol use disorder (AUD) and mild traumatic brain injury (mTBI) impact functional
abilities. AUD occurs in up to 35% of Veterans with mTBI. Evidence suggests that
co-occurrence of AUD and mTBI (AUD+mTBI) leads to an exacerbation of brain dysfunction,
symptom manifestation, and ultimately, functional disability. Alcohol-related
characteristics are operationally defined per AUD symptoms and outcomes including, but
not limited to, alcohol consumption, alcohol craving, and AUD severity. Repetitive
transcranial magnetic stimulation (rTMS) is a non-invasive neuromodulatory treatment that
will soon be a treatment option at 30 VAs nationwide. Preliminary rTMS efficacy is
demonstrated for AUD alone and mTBI alone using a variety of neural targets. rTMS is,
thus, a promising treatment for AUD+mTBI. The objectives of this study are to 1) identify
neural targets (i.e. site of stimulation) associated with both alcohol-related
characteristics and self-reported functional disability, and 2) assess preliminary
efficacy and sustainability of a high frequency rTMS protocol applied to these customized
neural targets relative to the commonly used left dorsolateral prefrontal cortex (DLPFC)
site. Addressing these objectives are essential steps towards the long-term research goal
[to customize and clinically implement a rTMS treatment] that can improve brain function
resulting in optimal recovery for Veterans with AUD+mTBI. To address the first study
objective, Veterans will be recruited and classified into one of two groups based on
structured-interviews, self-report measures, and neuropsychological assessments: 1)
AUD+mTBI, and 2) [Veteran controls] without a history or symptoms of mTBI or AUD.
Alcohol-related characteristics will be assessed through objective measures of alcohol
use, self-report measures, and structured interviews. Self-reported functional disability
will be assessed using the World Health Organization Disability Assessment Schedule 2.0
(WHODAS). Neuroimaging metrics will be assessed through a multi-modal, functional and
structural Magnetic Resonance Imaging (MRI) scan. Participants will complete a functional
MRI (fMRI) protocol where brain activation will be measured in response to viewing images
related to alcohol, compared to neutral images. Advanced neuroimaging procedures to
determine the structural integrity of white matter fibers in the brain and spontaneous
activity in brain networks, a process called resting state functional connectivity
(rsFC), will also be conducted. To address the second study objective, AUD+mTBI Veterans
will receive rTMS at one site randomly assigned from a set of 4 sites: 3 customized
neural targets identified in this study, and the commonly used left DLPFC. AUD+mTBI
Veterans will complete 10 PLACEBO, then 10 ACTIVE rTMS sessions in a within-subjects
design. Follow-up WHODAS assessments will occur at 2-weeks, 1-month and 6-months
post-ACTIVE rTMS. Aim 1 will identify unique neural targets for rTMS to treat AUD+mTBI by
determining which multi-modal neuroimaging metrics are most strongly associated with both
alcohol-related characteristics and functional disability. Aim 2 will [test preliminary
efficacy of high-frequency rTMS administered over the customized neural targets] to treat
functional disability among Veterans with AUD+mTBI. Aim 3 will assess sustainability of
rTMS effects on functional disability for Veterans with AUD+mTBI. The investigators
hypothesize that for Veterans with AUD+mTBI, there are neural substrates of AUD related
to functional disability, and that neuromodulation of these substrates will be related to
gains in functional disability. The investigators' innovative approach represents an
advancement in the field of neurorehabilitation because a neural target will be
systematically defined, using multi-modal neuroimaging, prior to preliminary rTMS
efficacy and sustainability testing. These steps are necessary to customize rTMS
treatment for a population of Veterans with co-occurring conditions and unique health
care needs. Thus, the outcomes of this research will optimize function for Veterans with
AUD+mTBI.