Review Concussion and the Autonomic, Immune, & Endocrine Systems: An Introduction to the Field and a Treatment Framework for Persisting Symptoms 2025 Pertab+

Abstract

A significant proportion of patients who sustain a concussion/mild traumatic brain injury endorse persisting, lingering symptoms. The symptoms associated with concussion are nonspecific, and many other medical conditions present with similar symptoms. Medical conditions that overlap symptomatically with concussion include anxiety, depression, insomnia, chronic pain, chronic fatigue, fibromyalgia, and cervical strain injuries. One of the factors that may account for these similarities is that these conditions all present with disturbances in the optimal functioning of the autonomic nervous system and its intricate interactions with the endocrine system and immune system—the three primary regulatory systems in the body. When clinicians are working with patients presenting with persisting symptoms after concussion, evidence-based treatment options drawn from the literature are limited.

We present a framework for the assessment and treatment of persisting symptoms following concussion based on the available evidence (treatment trials), neuroanatomical principles (research into the physiology of concussion), and clinical judgment.

We review the research supporting the premise that behavioral interventions designed to stabilize and optimize regulatory systems in the body following injury have the potential to reduce symptoms and improve functioning in patients. Foundational concussion rehabilitation strategies in the areas of sleep stabilization, fatigue management, physical exercise, nutrition, relaxation protocols, and behavioral activation are outlined along with practical strategies for implementing intervention modules with patients.

Open access

 

"Patients who overexert following concussion tend to present with a cyclic pattern of high levels of activity, which triggers exacerbation of symptoms, which in turn forces a period of low levels of activity until symptoms subside. This “roller coaster” of up and down levels of activity can occur within the day (for example, several hours of overexertion period followed by several hours of exacerbated symptoms forcing low activity) or between days (for example a “crash” of several days after a particularly demanding day of excessive activity that exacerbates symptoms). This “roller coaster” pattern has been described as a “boom-and-bust” pattern by other authors exploring interventions in the field of concussion [379], but we are not aware of any systematic explorations of this pattern in the research literature.

The practicalities of addressing fatigue and implementing a fatigue management program to avoid overexertion and underexertion patterns following concussion are relatively similar regardless of the pattern patients originally present with. Both patients who overexert and underexert will benefit from a structured approach that promotes (a) the individualized identification of a Goldilocks zone that establishes a maximum level of activity that does not significantly exacerbate symptoms and (b) gradual increases in activity over time as tolerance for activity improves. We acknowledge that this advice is remarkably similar to that proffered by John Hilton in the 1800s, as noted in the quote above—“in proportion to the severity and duration of the symptoms”."