Randomized Controlled Trial of Treatment to Optimize Heart Rate Variability for Persistent Post-Concussion Symptoms

Many combat veterans (c-Vs), service members (SMs) and civilians with mild traumatic brain injury (mTBI, also termed concussion) suffer from persistent post-concussion symptoms (PPCS) that degrade physical and cognitive well-being and have been linked with early neurodegeneration. PPCS include somatosensory (e.g., headache, disturbed vision), vestibular (e.g., dizzy, clumsy), cognitive (e.g., executive function, memory) and affective symptoms (e.g., sleep disturbance, irritability, depression). A key pathological process that provokes and perpetuates PPCS is autonomic nervous system (ANS) dysfunction such as unremitting sympathetic nervous system activation that also exacerbates other pathology such as inflammation. ANS activity can be readily quantified by measuring heart rate variability (HRV), or the variation in heart rate over time, which serves as a valid index of both physiological and psychological health

Inclusion Criteria: * age 18 or older * History of military service * Self-Reported hx of 1 or more mild TBI * Most recent TBI more than 1 year ago * Significant Persistent Post-Concussion Symptom burden (Neurobehavioral Symptom Inventory \[NSI\] total score greater than or equal to 20). * Current Sleep Difficulties * Fluent English * Able to provide Informed Consent Exclusion Criteria: * Any TBI with severity greater than mild (i.e., Moderate or Severe TBI defined as initial injury loss of consciousness (LOC) duration \>30 minutes, posttraumatic amnesia (PTA) duration \>24 hours, or traumatic hemorrhage on head computerized tomography (CT) and determined by the study investigator based on information gathered during administration of the study's validated TBI structured interview instrument. * Conditions or medications that can affect HRV measurement (pacemaker or an implant that stimulates your heart (e.g., cardioverter-defibrillator or ICD); heart transplant or heart surgery within the last year, including bypass or other surgery, but not including a stent) * Hx of stroke * Mental conditions that may impede adherence (e.g., dementia, psychotic disorder, panic disorder)