Technically speaking, a concussion is defined as “a loss of consciousness of less than 30 minutes or amnesia lasting less than 24 hours, or any period of altered mental status at the time of injury.” This same experience is also often referred to as a “mild traumatic brain injury” ( mTBI), which is can be further defined by a Glasgow Coma Scale (GCS) score of 13-15. Although, the word “mild” in this context is a bit of a misnomer, because there is nothing mild about a traumatic brain injury (TBI) that registers no reduction in the GCS. Nonetheless, a traumatic brain injury that registers a score of 3-8 can appropriately be defined as a severe TBI. GCS testing is administered to detect the presence of an active brain bleed, as a perfect score of 15 is achieved when the patient’s eyes are open and reactive (+4), verbally responsive and oriented (+5), and can obey simple commands/is motor responsive (+6).
A “mild” traumatic brain injury is the most common type of traumatic brain injury. Mild TBIs can cause impaired cognitive function and other debilitating symptoms including, but not limited to, headaches, fatigue, depression, anxiety, and irritability; which is collectively referred to as “post-concussion syndrome” (PCS), among other symptoms. Where mTBIs used to be thought of as a relatively inconsequential mild injury, it is now more closely associated with the latter three letters of its acronym – traumatic brain injury. Researchers say he term mild also “misrepresents the immediate and long-term burden of TBI and other cooccurring factors.”
Practically speaking, it can sometimes be difficult to prove PCS and the effects from TBIs in personal injury litigation. Researchers say that conventional CT and MRI scans in a concussion are normal. Neuroimaging is not typically indicated for mild TBI, but many researchers are exploring more advanced techniques because the majority of TBIs are “mild” in severity.
One such neuroimaging technique that has gained prominence and recent recognition is called diffusion tensor imaging (DTI), which shows the asymmetry and amount of water diffusion in the brain to assess damage to white matter following a TBI. In the setting of a TBI, diffuse axonal injury (DAI) is understood to be the compression, tension, shearing, bending and torsion forces upon the white matter in the brain, creating microstructural changes that DTI can both detect and quantify. Alterations to the diffusion of water through “voxels” in the brain is quantified using a measure known as fractional anisotropy (FA), a marker of microstructural integrity ranging from 0 to 1, which is reduced by DAI.
Through expert testing, analysis and reporting, DTI measures the flow of water through 130,000 plus voxels in the brain and provides scores between 0 and 1. The scores are then compared to a normal database and highlight those voxels that are at least two (or sometimes three) standard deviations below the mean. The computer then looks for clusters of voxels, which can then be highlighted and superimposed on an MRI of the brain.
The FA score is objective evidence of white matter abnormalities that are consistent with TBI. The clinician or expert can opine that these abnormalities are caused by the DAI. Without this imaging, this individual was destined for trial and all the uncertainties that come with it. This person was the subject of an unwitnessed head strike in which the individual could not recall whether they lost consciousness (but had a visible two-inch gash). The person incurred more than $30,000 in medical bills and had little to no time off work and no lost wages. Of all the PCS symptoms this person endured, emotional lability and altered relationship with the person’s partner were among the greatest complaints. Notwithstanding the special damages, due in large part to DTI, this case settled for seven figures.
The case study above is but one example of how great a tool DTI can be in helping brain-injured people get justice, “mild” or otherwise.