A topic frequently addressed in this blog is the building body of evidence showing that the minority of patients who have long term, sometimes permanent, symptoms following concussion typically experience those symptoms because of injury to the brain, not to achieve some “secondary gain.” Although scientists do not have a clear understanding about why some people are more vulnerable to these injuries, we know as discussed in prior posts, that certain factors can play a role, such as genetics, prior head injuries and a history of migraines. Two recently published studies contribute to our understanding that real pathology likely underlies most persistent symptoms and that this pathology can be identified with advanced neuroimaging techniques. Read More
In recent years a great deal of research has been done to identify an objective “biomarker” of concussion. As reported in this blog, some promise has been found in blood biomarkers (measuring plasma tau protein levels) and neuroimaging, such as the DTI MRI sequence. Unfortunately, these approaches are invasive and/or expensive and are not always a reliable indicator of concussion and concussion recovery. As reported in our November 27, 2016 blog post, until now, one of the most promising concussion screening tools was a series of vision tests endorsed by the Department of Defense.
Scientists at Northwestern University have now found a related, and what appears to be an even more precise and accurate tool, a measure of the brain’s electrophysiological response to sound. Read More
The University of Pennsylvania Perelman School of Medicine issued a press release on November 23, 2015 declaring “mild brain injury an oxymoron” based on newly released research. The research, performed in collaboration with the University of Glasgow, demonstrates how brain wiring can be damaged after a concussion–damage that in some cases never repairs.
The research, published online in November in Acta Neuropathologica, builds on prior studies showing that nerve fiber damage in the brain can be demonstrated by the presence of a brain protein called SNTF. Read More
The weight of scientific evidence demonstrates that “diffusion tensor imaging” is an effective tool for demonstrating damage to the white matter of the brain associated with mild traumatic brain injury.
The damage typically associated with mild traumatic brain injury (mTBI) is in the axons, the microscopic fiber tracts in the white matter of the brain too small to be seen by conventional tools such as MRI and CT. In fact an individual with a perfectly normal MRI and CT could even be in a coma due to a brain injury. Treatment providers have been left to infer injury from clinical symptoms. However, even the most commonly used clinical tools, such as neuropsychological assessment, are generally seen as insensitive to the subtle, but sometimes life altering, effects of mTBIs. Read More
In August, 2013, the NFL announced that it had reached a $765 million dollar settlement of claims by more than 4,500 players alleging that they were suffering from long-term consequences of concussions that the NFL had known about for years, hid from players, and failed to minimize by establishing appropriate protocols for return to play. The alleged cover-up by the NFL, with co-conspirators in the medical community, was recently the subject of an extensively researched PBS Frontline special titled “League of Denial.”
By settling the players’ claims early in the litigation it appeared that the league would avoid further examination of what the league knew and when it knew about the long-term effects of concussion. However, several recent developments indicate that these issues will likely be examined further. The judge overseeing the litigation has appointed a “special master” to make recommendations concerning the settlement and the Brain Injury Association of America has petitioned to intervene in the litigation to make sure that the settlement takes proper account of the
“progressive physical, psychiatric and cognitive disease processes that are caused and/or accelerated by brain injury, but may not manifest in clinically significant symptoms on initial presentation.”
In a study published November 18, 2013 in Frontiers in Neurology, researchers from Penn and Baylor report that they have identified a blood biomarker – SNTF – that if found on the day of injury predicts with substantial accuracy both cognitive impairment persisting more than 3 months and the existence of abnormal brain imaging finding in the corpus callosum and uncinate fasciculus of the brain (using diffusion tensor imaging (DTI). Read More
One of the causes of the failure of clinical trials to successfully treat TBI, the authors contend, is the common classification of TBIs as “mild, moderate or severe.” These classifications do not incorporate newer insights and findings from diagnostic tools such as imaging and biomarkers and therefore do not promote “mechanistic targeting” for clinical trials. The authors support the transition to a more nuanced approach, a precise disease classification model that is based on the precise pathoanatomical and molecular features of the injury. Read More
Defense attorneys often cite “meta-analytic” reviews of neurological studies to make the argument that “mild” traumatic brain injuries (mTBIs) cause no lasting effect beyond three months post-injury. A “meta-analysis” involves a statistical study of multiple studies published in the literature.
Meta-analyses in mTBI are often used to show that persistent symptoms are “neurotic” rather than “organic”
Fortunately, it is generally agreed that the majority of people who suffer mTBIs, sometimes referred to as “concussions”, report full recovery from symptoms within three months of the injury – in fact many recover much faster. A great deal of research over the past few years has focused on the minority of people who do not fully recover within three months, described as having a “persistent post-concussion symptoms (PCS).” These patients are sometimes referred to as the “miserable minority.” The “meta-analyses” are often cited as demonstrating that changes in performance after three months have “limited statistical and clinical significance;” in other words, that persistent symptoms must be psychological or “neurotic” rather than “organic” or neurologic. Read More