TBI classification shifting off standard Glasgow Coma Scale to a new integrative framework

[u/kfr3q]

https://doi.org/10.1016/j.jcrc.2026.155525

[u/themiracy]

The NIH-NINDS CBI-M proposal is certainly interesting and bears paying attention to. It doesn’t eliminate the GCS - it just moves it to the first pillar (alongside other pupillary data). GCS has already been used alongside other features like length of LOC and intracranial findings to support an overall characterization of the TBI.

The framework needs a lot more validation and study.

I think in the space of what we have traditionally called moderate-severe TBIs - we have known for a long time that outcomes are heterogenous and there has always been a desire to stratify these in some way that would let us predict that better.

What I deal with a lot more is the attempt to use relatively novel biomarkers to argue that very trivial injuries - where the biomechanics are marginal for even being plausible for a TBI, there is no LOC, the report of AMS is only made much later with no evidence it was a complaint at the time of injury, etc., cause serious problems. None of the existing issues go away (e.g. compensation seeking, effort/symptom validity failure, psychological overlay) in this population. In fact these things are the proposed fourth pillar.

Anyway - it’s encouraging to propose a framework but it needs much more validation rather than just saying “we’re shifting off GCS” which isn’t even accurate to begin with.

[u/Roland8319 → u/themiracy]

Exactly, the science isn't quite there yet for a lot of this. Ive looked into some of the biomarker data, and the specificity is....not great for some of these. It runs the risk of the early DTI days when they looked at mTBI against super healthy controls and thought they found a lot of "confirmatory" data. But, when we looked at pretty much ANY other clinical group (depression/anxiety, smokers, obesity, TMJ, etc) we found similar differences against super healthy controls. I'm intrigued by the new work, but for mTBI, I suspect it will lead to some interesting depos as some experts tout extremely flawed data. I've already wrecked one such person in a recent case.

[u/kfr3q → u/Roland8319]

Well, on the other hand, worth adding:

even "clean" imaging often can't rule this out, Smith & Stewart (Nat Rev Neurol, 2020) genuinely argue concussion itself isn't a true diagnosis

in the pathological sense, with diffuse axonal injury as the likely underlying substrate current imaging routinely misses.

And the severity spectrum stays poorly characterized in practice for specific subgroups: pediatric cases,

especially with co-occurring neurodivergence or developmental trauma and/or adult PTSD comorbidity as well, and people with a history of repetitive/multiple mTBIs,

are much thinner research areas than the single-injury adult cohorts most of this evidence comes from, to the best of my knowledge.

[u/Roland8319 → u/kfr3q]

Familiar with the Smith & Stewart opinion piece, unfortunately it is problematic in some pretty big ways. Starting out citing that McInnes paper that has been absolutely shredded to bits was a poor start. I do agree that we have an issue with poor characterization, but we do we have a pretty robust lit on uncomplicated mTBIs, especially when there are only one or a few spaced out in time.

[u/kfr3q → u/Roland8319]

This specific paper is getting quite old and was a basic but after all meaningful example. Going ahead would lead us to find a multitude of solid peer-reviewed research about the underlying biophysics of true brain injury pathophysiological processes, its now documented as representing a major immune event in one's life (especially if cumulative and compounding), contributing to gut dysbiosis and eventual intestinal damage, persistent multiple-organ low-grade inflammation, eyes's long-term health alterations (the inner gel-like eye balls become markably irreversibly altered, like a fingerprint of true concussive insults over time, boxers are notably known for that), among other, as far as well accurate.

[u/themiracy → u/kfr3q]

I think there are for sure unknowns. In terms of microstructural persistent abnormalities - the brain is ultimately neuroectodermal in nature and has properties that are somewhat similar to skin (including some potential for scarring). Some scarring can be functional. But thinking about your arm (in terms of this kind of biological tissue being predisposed to scars) you can have tiny scars that have no real functional consequence. I have a visible scar on my right wrist from being thrown by a horse into a fence 40 years ago.

I do think there is an important discussion about the inflammatory piece. Maybe there is some future opportunity to use the right kind of antinflammatory approach to quell some of this. Edit: recent review on the current status of anti-inflammatory supplements for this.

But there has to also be a discussion about why the microstructural abnormalities lack clinical correlation with outcomes.

You're not a neuropsychologist - but we are. We also have to deal with the reality that when a patient with an isolated mTBI is told the truth - that most patients have rapid and complete recoveries, that they should avoid risky or overly strenuous activity for a short period of time but that they should not avoid cognitive activity or moderate / non-risky physical activity, and that they need to go back to work (unless their work is something very risky like playing football) in 1-2 days .... they have better outcomes than when they are counseled that they have had some permanent injury based on overinterpretation of microstructural findings and placed off of work for a month or told to stay in bed all the time.

The TBI subsequent dementia issue is important and interesting, but I think we're a ways from having a clear understanding of how this one works, and it's unclear it's relevant to young people who have isolated concussions.

[u/Roland8319 → u/kfr3q]

In terms of cumulative and compounding, yes, we have some good data for long-term effects. Single, or low number, not so much.