Despite recent headlines proclaiming otherwise, we are still years away from a definitive test for concussions or traumatic brain injuries reaching the markets and the hands of healthcare professionals.
Without a reliable diagnostic test, we are forced to identify and treat mild traumatic brain injuries based on symptoms such as headache, nausea, memory problems, dizziness, and sensitivity to light. Doctors can also use tests of balance and reaction time to help gauge the seriousness of the injury, but there is very little else in their toolbox to assist in assessing concussions.
While this is already an alarming problem for people who suffer concussions as we understand them, new findings published in the journal Neurosurgery may paint an even grimmer picture. How do you diagnose a brain injury with no symptoms?
The idea that concussions or brain damage may be possible without symptoms is not new. Researchers have hinted at the possibility as several studies have suggested that soccer players who hit the ball with their head a lot may be accumulating brain damage without causing a diagnosable concussion.
Now, researchers have recreated the potential long-term brain trauma of these repeated “subconcussive” hits in mice, using a standard technique called the “impact-acceleration model”. The method produced “diffuse axonal injury” similar to concussions to the brain with visible evidence of damage on the cellular level. However, the mice showed no abnormalities in testing, despite an extensive pattern of brain injury.
“The lack of functional deficits is in sharp contrast to neuro-pathological findings indicating neural degeneration, astrocyte reactivity and microglial activation,” said Charles L. Rosen of West Virginia University.
The type of tests used were specifically chosen for their ability to isolate symptoms and functions used to diagnose concussion in humans sch as locomotor activity, coordination, cognitive function, and anxiety or depression-like behaviors.