Different symptom patterns of concussion depend on the precise nature of the damage to the brain
Medical research is increasingly identifying the various ways a concussion can impact the brain and is providing explanations for why different symptoms persist in a subset of people diagnosed with concussion, based on the anatomy and physiology of the brain.
Much of this recent research has benefited from new techniques to “image” the brain, including various MRI techniques such as “diffusion tensor imaging” (“DTI”). In a prior post, I discussed research concerning the subset of concussed patients who experience persistent ocular (vision) and vestibular (balance) problems. A paper published online on April 15, 2014 in the journal Radiology reported that DTI imaging of patients with these symptoms revealed damage in the parts of the brain know to be associated with vision and balance. Read More
Recent research has shown that traumatic brain injury, (TBI) including mild traumatic brain injury (mTBI), can damage and cause dysfunction in the pituitary gland, a pea-sized gland located in the center of the skull that releases several essential hormones affecting such functions as growth and metabolism (part of the neuroendocrine system). Researchers have found that a surprisingly high percentage of patients with persistent symptoms following a TBI show evidence of neuroendocrine dysfunction.
It turns out that the anatomy of this gland makes it particularly susceptible to the sheering injuries seen in TBI. The most common dysfunction found after TBI is deficiency in the Growth Hormone (GH), one of the key hormones released by the pituitary gland. The symptoms of GH deficiency overlap with many persistent TBI symptoms including fatigue, poor memory, depression, emotional lability, lack of concentration and attention difficulties. Read More
Most current guidelines recommend “cognitive rest” during the initial stages of recovery from concussion. “Cognitive rest” involves limiting activities that require attention and concentration such as reading, doing homework, text messaging, playing video games, working online, watching movies and television and listening to music. Cognitive rest has been recommended in the past based on somewhat limited evidence suggesting that failing to minimize these activities in the early stages following a concussion could delay recovery. Read More
Recent literature has highlighted the prevalence of dysfunctions in vision following traumatic brain injuries of all levels of severity (including concussion.) Research published by the Veterans Administration (VA) in 2012 indicates that the percentage of TBI victims with vision problems could be as high as 60%. They explain that this prevalence is not surprising, since over 50% of the brain is involved in visual processing. Alvarez et. al. explain how visual and other symptoms occur when the brain is subjected to “acceleration/deceleration” forces: Read More
On January 23, 2014 the Defense and Veterans Brain Injury Center released new clinical recommendations with a standardized approach for concussion recovery. Included in the recommendations for managing concussion symptoms is a first of its kind five-stage approach for return to activity following a concussion. Detailed “do”s and “do not”s are specified for each stage. Movement from stage to stage is determined by scores on a simple twenty-two item “neurobehavioral symptom inventory” included in the recommendations. 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
There has been much debate over what happens to the brain following a concussion, much of it recently focused on concussions in sports. One side of the debate maintains that concussions, also referred to as “mild traumatic brain injuries,” involve only a very short term disruption of brain function with no damage to the brain. As discussed in previous posts, this view has been discounted by a growing body of research involving advanced imaging technologies as well as post-mortem pathological studies showing that in a minority of cases concussions can cause lasting damage to the brain as well as persistent symptoms.
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
Medical research is increasingly identifying the various ways a concussion can impact the brain and is providing explanations for why different symptoms persist in a subset of people diagnosed with concussion, based on the anatomy and physiology of the brain.