Newly proposed framework marks a major step forward and is expected to improve care for
the millions of people affected by a traumatic brain injury each year.
Milwaukee, Wis. – June 25, 2025 – Traumatic brain injury (TBI) has traditionally been categorized as “mild, moderate, or severe” based on relatively crude criteria. Clinicians, researchers, and patients alike all recognize that this over-simplified system is inadequate for a complex neurologic condition such as TBI. Researchers at the Medical College of Wisconsin (MCW) are playing a leading role in a global effort to create an improved framework for the characterization of TBI.
Several MCW faculty recently contributed to the National Institutes of Health-National Institute of Neurological Disorders and Stroke (NIH-NINDS) TBI Classification and Nomenclature Initiative. These included Drs. Michael McCrea, Lindsay Nelson, and Timothy Meier from the MCW Department of Neurosurgery and Dr. Danny Thomas, emergency medicine physician in the MCW Department of Pediatrics. All were selected based on their national recognition as experts in TBI care and research.
Dr. McCrea, co-director of MCW’s Center for Neurotrauma Research; head of MCW’s Brain Injury Research Program; and one of the world’s foremost researchers in TBI, served on the Steering Committee for the NIH Initiative and is co-senior author of “A new characterization of acute traumatic brain injury: the NIH-NINDS TBI Classification and Nomenclature Initiative,” published in the June issue of The Lancet Neurology.
The classification the group developed is a multidimensional framework with four main pillars: Clinical, Biomarkers, Imaging, and Modifiers (CBI-M). It moves beyond traditional categories by integrating multiple dimensions of injury assessment, including clinical assessments, blood-based biomarkers, advanced imaging techniques like CT and MRI, and modifiers such as pre-existing health conditions, socioeconomic status, and history of brain injury. Drs. McCrea, Nelson, and Meier all played a major role in the Working Groups that created the CBI-M framework; Dr. Nelson is also lead author on the report from the Modifiers Working group that was recently published in the Journal of Neurotrauma.
“While current categories for TBI can still be helpful in early clinical treatment, they were established in 1974, and don’t take into account the many advances our field has achieved over the last 50 years such as precise neuroimaging and biomarkers in your blood that can confirm TBI,” said Dr. Nelson.
The traditional classification system – the Glasgow Coma Scale – limits the ability to capture the complexity and variability of TBI. For example, some patients with “mild” TBI may experience persistent symptoms, while others with “severe” TBI may recover more fully than expected. Dr. Meier noted, “the CBI-M framework addresses these discrepancies by offering a more nuanced and comprehensive assessment, leading to improved patient stratification and potentially better outcomes.”
“Many people living with TBI feel like mild, moderate, and severe doesn’t really match their experience of recovery,” said Dr. Thomas. “Some have reported feeling like symptoms of mild cases weren’t taken as seriously, while some with severe TBIs have said the term suggests there’s no hope for recovery at all.”
Dr. McCrea is proud of the role MCW has played in this monumental movement, noting “adoption of the CBI-M framework is expected to enhance clinical decision-making, personalize treatment strategies, and improve the design and interpretation of clinical trials. While full integration into healthcare systems may take time, the framework represents a significant advancement in the field of neurotrauma care.”
PHOTO: Michael McCrea, PhD — Professor of Neurosurgery and Neurology; Vice Chair of Research; Co-director of the Center for Neurotrauma Research; and Director of Brain Injury Research at the Medical College of Wisconsin.
NOTE: Dr. McCrea and his MCW colleagues are available for media interviews. Please contact the MCW media relations team at media@mcw.edu for availability and to schedule.
