A recent study published in JAMA Network Open finds that patients with a history of traumatic brain injury (TBI), including mild TBI (mTBI), are at significantly greater risk of developing chronic cardiovascular, endocrine, neurological and psychiatric disorders. This proved to be true in all age groups, including younger adults (18-40).
This study is important because, as the authors note, “the risks of incident comorbidities in previously healthy patients who sustained mTBI and msTBI (moderate-severe TBI) has not previously been reported.” The most important takeaway of the study is that “patients with TBI in all age groups may benefit from a proactive targeted screening program for chronic multisystem diseases, particularly cardiometabolic diseases.”
Dr. Saef Izzy, a neurologist at Brigham and Women’s Hospital, and his colleagues conducted a longitudinal cohort study using hospital-based patient registry data to examine the incidence of cardiovascular, endocrine, neurological and psychiatric comorbidities in TBI patients from 2000 to 2015. Patients were matched to an unexposed group without head injuries. The analysis included 4,351 patients with mTBI, 4351 patients with msTBI and 4,371 unexposed individuals. The conditions where increased risk was found include diabetes and other endocrine diseases, coronary artery disease, hyperlipidemia, obesity, dementia, psychotic disorders, anxiety disorders, ischemic stroke, hypertension, and seizure disorders. In discussing the possible cause of this data the authors reference “recent clinical and experimental studies [that] suggest TBI may alter systemic metabolomic, gut and immune pathways” and also observe that TBI may lead to contributing behavioral and lifestyle changes. It concludes that “the high risk of comorbidities after TBI likely represents a combination of direct (hormonal and inflammatory changes caused by injury) and indirect factors (psychosocial factors.)”
In an interview discussing his findings, Dr. Izzy observed that “we are finding that TBI is not just an acute injury, but a chronic disease and multisystem condition that affects far more than just the brain. Comorbidities linked to TBI can complicate the course of recovery, increase mortality and add to overall healthcare costs.”
Dr. Izzy’s observations are supported by other literature previously discussed in this blog. One analogous way of thinking about this is to compare the brain to the hard drive in a computer. If it becomes corrupted it may impact the function of all the software dependent on the hard drive (the various systems of the body.) The key, as Dr. Izzy notes, is to recognize this risk and appropriately monitor patients following injury, so comorbidities can be identified and appropriately treated.