Beyond “Mild” - A new framework for brain injury classification
If you’ve ever had a client diagnosed with “mild TBI” but whose symptoms didn’t seem so mild—you’re not alone.
In a previous post, I shared why over-reliance on the Glasgow Coma Scale (GCS) can be misleading. While GCS has its place, it’s too crude a tool to capture the true complexity of brain injuries. People labelled “mild” can have life-altering symptoms; others labelled “severe” may make excellent recoveries.
Now, there's an important shift.
The NIH–NINDS TBI Classification and Nomenclature Initiative has proposed a new, more nuanced system: the CBI-M framework, which characterises injury across four pillars:
🔹 Clinical: Beyond the GCS total, clinicians document all components (eye, verbal, motor) and symptoms like amnesia, dizziness, or headaches.
🔹 Biomarkers: Blood-based tests for brain proteins (e.g., GFAP, UCH-L1) help to evaluate brain injury even when imaging is normal.
🔹 Imaging: CT and MRI findings are systematically incorporated into the injury profile.
🔹 Modifiers: Contextual factors such as mental health history, prior TBIs, medications, social disadvantage, or injury circumstances.
💼 Implications for the legal context:
🔸 “Mild” isn’t always mild. A client with a GCS of 15, no CT abnormalities—but elevated biomarkers—might still be flagged for serious follow-up. This matters for claims involving care needs and long-term impairment.
🔸 Better prognostic tools. With more data (labs, imaging, modifiers), clinicians can give more refined recovery predictions—crucial in personal injury litigation.
🔸 Contextualising outcomes. Modifiers aren’t excuses; they help explain divergent recovery trajectories. These can influence both damages claims and assessments of causation.
📈 Outlook
CBI-M is currently being piloted in the US and internationally. While it’s not yet standard practice, it’s likely to shape expert reports and testimony in the coming years. Lawyers should be alert to the shift—especially in cases where traditional severity labels don’t match the lived impact.
At Neuroinsight, we are already integrating the CBI-M framework into our clinical formulations and medicolegal assessments.
For more detail, see:
Manley, G. T., et al. (2025). The Lancet Neurology, 24(6), 512–523.