The Concussion Blog

Biomarkers are the next frontier in the concussion realm, really any specific and reliable objective measure to confirm a concussion.  Currently we can view concussion a “diagnosis in absence”; meaning if you have head trauma and there is no remarkable imaging the default diagnosis would be concussion.  This can be effective if there were enough signs that warranted the exam or the individual was truthful about symptoms; but what about the population that either does not respect/believe concussions or refuses to accept that they are a brain injury?

That is why the race is on to find either a biomarker or imaging technique that someone can say; “look, see these numbers/images, it means you have a concussion.”  This is great if the process of evidence based practices (EBP) was swift and widely accepted; the sub-issue is that there is ALWAYS “more research to be done”.  The first study deals with not a blood drawn biomarker, rather an imaging measured biomarker.

Dr. Michael Lipton of the Albert Einstein College of Medicine in New York presented this information recently;

In a single-center, case-control study, patients with mild traumatic brain injury (TBI) who had more abnormally high fractional anisotropy (FA) had fewer concussive symptoms and better quality of life a year after their injury than those who had less of the biomarker, […]

“If abnormally high FA represents neuroplastic effects, and if that’s how people recover from brain injury, it would be possible to use this in translational studies to identify the underlying mechanisms of pathology and to identify therapies that don’t look at how we fix the damage, but how we enhance the brain’s ability to compensate for that damage,” Lipton said during the briefing.

[…]
Overall, all patients had detectable areas of abnormally high FA: some had more, others had less, Lipton said.

But those who had higher levels of abnormally high FA had fewer post-concussive symptoms and better health-related quality of life a year after their injury, he reported.

Higher levels significantly predicted improvements in concussive symptoms (P=0.01), as well as better outcomes in terms of the quality-of-life outcomes of mobility control (P=0.024) and psychological functioning (P=0.007).

This suggests that the “brain is compensating for its injuries,” Lipton said, and that high FA “may be a manifestation of neuroplasticity.” Because the brain does not form new axons, he said, it could be that the connections between existing axons are changing or strengthening.

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At the same time  a group led by Dr. Yulin Ge found and published in Radiology that functional magnetic resonance imaging (fMRI) may have a potential “baseline” role in concussions;

Compared with normal controls, patients with posttraumatic symptoms soon after mild TBI showed reduced connectivity in some regions, and increased connectivity in others within the network that the brain uses during inactivity for information processing and maintenance.

These abnormalities were associated with cognitive dysfunction, depression, anxiety, fatigue, and post-concussion syndrome […]

The study findings “suggest that resting-state functional MR imaging can be used as an additional clinical tool for detecting subtle brain injury that is not apparent with conventional MR imaging,” Ge’s group wrote.

If longitudinal studies confirm these results, functional MRI monitoring of the default-mode network could track progression and recovery in mild TBI, they suggested.

This study also took note about how the specific areas of the brain that showed the discrepancies are the same areas of the brain that get much attention from Alzheimer’s, autism and schizophrenia.

The mild brain injury group showed significantly decreased connectivity in the posterior portion, but increased connectivity in the anterior portion of the default-mode network compared with the controls (P<0.01).

The increased connectivity was seen primarily in the anterior medial prefrontal cortex region, while the decreased connectivity was primarily in the posterior medial cingulate cortex and parietal regions.

These opposite impacts were significantly correlated (P=0.03), “suggesting that these opposite within-network changes are essentially associated.”

Cognition and symptoms appeared tied to these brain connectivity abnormalities.

It certainly would be nice to have something to show the injured athlete, their caregivers and coaches (I know about HIPAA) to show that they are not lying and that there is a problem.  It would also be nice to find a reliable measure that can give us a more definitive return to activity time.

The only caveat is; “more research needs to be done”…  Duh, like always…