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Introduction¹

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¹ The planning committee’s role was limited to planning the workshop, and the Proceedings of a Workshop has been prepared by the workshop rapporteurs as a factual summary of what occurred at the workshop. Statements, recommendations, and opinions expressed are those of individual presenters and participants, and are not necessarily endorsed or verified by the National Academies of Sciences, Engineering, and Medicine, and they should not be construed as reflecting any group consensus.

The National Academies of Sciences, Engineering, and Medicine hosted a virtual public workshop on March 11–12, 2025, to explore the state of knowledge regarding traumatic brain injury (TBI) as a chronic condition and discuss strategies to improve care and outcomes for people living with its longer-term consequences. This Proceedings of a Workshop highlights key points made by workshop participants during the presentations and panel discussions.² See Appendixes A and B for the workshop statement of task and agenda and Appendix C for biographies of planning committee members, video participants who shared their lived experience, and speakers.

Odette Harris, chair of the workshop planning committee and professor of neurosurgery at Stanford University and deputy chief of staff for rehabilitation at the Veterans Affairs Palo Alto Health Care System, opened the meeting. The workshop was motivated by recognition that some people experience long-term symptoms after a TBI, she said. Traumatic Brain Injury: A Roadmap for Accelerating Progress (NASEM, 2022), which helps guide the work of the National Academies ongoing Forum on Traumatic Brain Injury,³ described how multiple steps can be part of a care journey after TBI. Importantly, Harris said, care following TBI should not be static but needs to evolve with the patient’s condition, with the goal being recovery and reintegration into family, work, and community life to the greatest extent possible. However, as the TBI Roadmap report underscored, many individuals experience nonlinear and fragmented recovery paths after TBI, which can include delayed diagnoses, lapses in care, and barriers to accessing specialized services. Some individuals live with chronic symptoms and need long-term support, she said.

Another motivation for convening a workshop focused on the evidence and needs around chronic TBI was provided by the Traumatic Brain Injury Program Reauthorization Act of 2024, which had charged the Centers for Disease Control and Prevention (CDC) with evaluating whether brain injury should be designated as a chronic condition affecting individuals throughout their lives. This workshop was held at the request of CDC and other forum members to explore multiple dimensions of this complex topic and contribute to analyses and efforts to address the longer-term effects of TBI.⁴

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² ChatGPT was used to assist in drafting content summarizing speakers’ recorded presentations and remarks in this proceedings, drawing only from the workshop transcript. All material generated by an AI platform used in this document was fact checked to ensure accuracy of the presented information.

³ Harris noted that since its establishment in 2022, the Forum on Traumatic Brain Injury has worked to advance discussion and foster action on TBI prevention, care, and research and has held workshops on topics including TBI biomarkers, follow-up care systems, examples of technical innovations to address TBI needs, the importance of health data integration, and the issue of TBI among older adults. Information on the forum is available at www.nas.edu/TBIForum.

⁴ The TBI Act was not reauthorized during the 118th Congress (2023–2024).

The workshop’s first day focused on reviewing the evidence base for recognizing TBI as a chronic condition, drawing from sessions on epidemiology, neuropathophysiological mechanisms, and health outcomes and comorbidities. The workshop then explored rehabilitative care and specialized services for patients and families, including current service gaps and challenges. The second day centered on identifying examples of actionable strategies for improving care and advancing research, with sessions examining chronic care models, opportunities for care enhancements, and research priorities. A key element of the workshop, as emphasized by Harris, was the inclusion of video narratives from individuals living with chronic TBI symptoms. These voices anchor the technical and clinical discussions in the real world and ensure the workshop remains grounded in the needs of those most affected, she said. The first of these lived experience narratives opened the workshop (see Box 1-1); additional lived experience insights and perspectives are found in Chapters 2 and 3.

BRAIN INJURY AS A CHRONIC HEALTH CONDITION

John Corrigan, a professor of physical medicine and rehabilitation at the Ohio State University and director of the Ohio Valley Center for Brain Injury Prevention and Rehabilitation, provided an orientation to TBI as a chronic health condition, highlighting the dynamic nature of outcomes for many people and examples of next steps to improving TBI care—topics that were built on and expanded over the course of the workshop.

Defining Chronic Conditions and the Challenge of Classifying TBIs

Corrigan emphasized the lack of a universally accepted definition of chronic disease, highlighting differences among organizations such as the CDC, World Health Organization (WHO), and National Center for Health Statistics. He referenced Bernell and Howard (2016), who advocated for a common definition, proposing that chronic conditions be understood as those that “continue or occur again and again for a long time.” This framework distinguishes temporary injuries (e.g., a broken leg) from recurring or persistent ones (e.g., chronic back pain). Corrigan noted that TBI has historically been viewed as a time-limited condition, when in fact its long-term outcomes often defy this categorization because of patients’ ongoing changes in functioning.

Evidence for TBI as a Chronic Condition

Using longitudinal data from the TBI Model Systems National Database and studies like Transforming Research and Clinical Knowledge in TBI (TRACK-TBI), Corrigan presented data showing that people with both mild and moderate to severe TBIs show dynamic outcomes over many years. Successive assessments of a cohort of people diagnosed with moderate to severe TBI and followed through the TBI Model Systems program showed that although functional outcome scores between assessment periods (such as year 1 to year 2 or year 5 to year 10) remained the same for almost half of the people, the other half showed functional improvements or declines (Corrigan et al., 2025; see Figure 1-1).⁵ For instance, fewer than 10 percent of individuals initially experiencing upper severe disability at 1 year post-TBI remained in that category two decades later; even accounting for deaths, the stability rate was under 16 percent (Whiteneck et al., in press). Similarly, Braun (2023) and Brett and colleagues (2023) found that about half of individuals with mild TBI experienced changes—improvements or declines—over a 7-year period (see Figure 1-2). These trends suggest that TBI should be classified as a chronic condition because of its prolonged and variable effects, he said.

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⁵ For information about the TBI Model Systems program, see https://msktc.org/about-model-systems/TBI; for information about TRACK-TBI, see https://tracktbinet.ucsf.edu/ (both accessed August 31, 2025).

Implications of Chronic Condition Recognition

Corrigan outlined several advantages to designating TBI as a chronic health condition. First, it would prompt health care providers to consider a prior history of TBI when evaluating current symptoms, shifting their assumptions from stability to dynamism. Second, including TBI in chronic disease surveillance efforts, such as the CDC’s Behavioral Risk Factor Surveillance System (BRFSS),⁶ would enable better tracking and understanding of its public health burden, he noted. Currently, BRFSS excludes TBI despite evidence from the Brain Injury Association of America showing that 40 percent of adults have experienced a TBI and studies estimating that 18.2 percent of U.S. adults have had at least one TBI with loss of consciousness (Karamian et al., 2024), a rate that is similar to diabetes. Even using a more conservative metric of TBI with more than 30 minutes of unconsciousness, 2.9 percent of U.S. adults are affected, a rate higher than that of 6 of the 11 conditions currently surveyed by BRFSS.

Policy Implications

The recent inclusion of TBI in the Centers for Medicare & Medicaid Services’ (CMS) list of chronic conditions marks a significant policy development.⁷ While the CMS policy is narrow, addressing special needs plans, Corrigan emphasized the importance of including TBI on this federal list. With nearly 75 percent of Medicaid beneficiaries receiving care through managed care organizations (MCOs), which often provide expanded services for chronic conditions, this recognition opens the door for enhanced insurance coverage and care access for people with TBI, he emphasized. Corrigan noted that MCOs often add services for vulnerable populations, arguing that chronic brain injury merits inclusion on lists of chronic conditions to ensure that individuals receive comprehensive care tailored to their evolving needs.

Challenges and Caveats

Corrigan also addressed several potential concerns related to labeling TBI as a chronic condition. He cautioned against discounting unrelated long-term issues, for example preexisting substance use disorders, to TBI and emphasized the importance of holistic care that accommodates comorbidities. Furthermore, not all TBIs result in chronic impairment, he emphasized, and the absence of a clear “cut point” between transient and chronic

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⁶ https://www.cdc.gov/brfss/index.html (accessed July 22, 2025).

⁷ CFR 42 § 422.2(19)(iii).

outcomes after injury complicates classification. He also noted the potential risk of iatrogenic effects,⁸ referencing how increased awareness of chronic traumatic encephalopathy (CTE) among athletes has led some to conflate depression with CTE. Corrigan also pointed to emerging data linking TBI to an increased risk of mortality (Elser et al., 2023), comorbidities (Izzy et al., 2022), and dementia (Low et al., 2024), though the exact mechanisms—whether inflammatory, vascular, immune related, or otherwise—remain under investigation. A subsequent panel discussion among Corrigan and session speakers (see Chapter 2) provided an opportunity to further explore how long-term outcomes after TBI reflect an intersection with preexisting factors or comorbidities, the environmental and social context of injury, the aging process, an individual’s lifetime history of exposure, and other dimensions that affect how a person recovers—highlighting the importance of TBI studies that include preinjury health and social information.

Integrating Chronicity with Brain Health Promotion

Corrigan concluded by calling for a shift in perspective, advocating that TBI be recognized as a chronic condition and treated accordingly by health care professionals. He urged public health systems to reallocate resources to better track and address the lifelong effects of TBI and called for more systematic research into its underlying mechanisms. Additionally, Corrigan emphasized the importance of coupling recognition of chronic TBI with proactive promotion of brain health. Drawing on efforts by the Alzheimer’s Association, the American Academy of Neurology (Avitzur et al., 2022), and the World Economic Forum (Moose et al., 2024), he suggested that framing brain health as both a public and an economic good can support this dual message and help amplify impact and broaden engagement. Such a balanced approach would better serve individuals living with TBI and enhance society’s ability to respond to its long-term challenges, he said.

REFERENCES

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⁸ An iatrogenic effect is one that arises from the medical care or context of care rather than from the underlying condition itself.