CTE and Domestic Violence: Reason Is Conspicuously Absent

Today’s headline was stark: Boston University researchers have found a link between traumatic brain injury and domestic violence. Temporal lobe lesions were reported in retired football players, which researchers speculated explains players’ aggressive behavior towards family members.  This perfect storm of NFL crises has been labeled “the dream meme,” referring to the explosive and headline-making nature of the problems.

The anterior temporal lobe is the suspect region, according to advance press from the HBO “Real Sports” segment airing tonight.  The anterior temporal lobe is a pretty complex area of the brain, important for memory, social behavior and semantic processing.

See this link for more: http://www.jneurosci.org/content/33/10/4213.full

And this one: http://braincoretherapy.com/wp-content/uploads/2014/01/Wong.pdf

These are both great articles on temporal/anterior temporal functions and anatomy.

But there is more to the story.

What's missing? Discussion of non-CTE factors and other correlates of tau...
What’s missing? Discussion of non-CTE factors and other correlates of tau…

 

First, tau deposition is not specific to traumatic brain injury or concussion.  It can be seen in neurodegenerative disease, psychiatric illness, substance abuse, and even normal aging.  There are people with reported CTE-like findings who never sustained concussion,  persons with multiple concussions who do not exhibit the pathology or symptoms of CTE, and the majority of retired NFL players do not show evidence of brain damage (see the Casson et al article below for a recent study).

The definition of the CTE disease entity itself is evolving and not entirely clear.   The symptoms listed under “CTE” are so broad and nonspecific that any number of unrelated neurologic and psychiatric  conditions would meet the criteria.

And perhaps most importantly from a neuropsychological perspective, there is no dearth of factors that can explain the behavior noted by CTE researchers, such as mental illness, drug use (including steroids),alcohol use and dementia.  Paul Oliver, the former San Diego Chargers player who tragically committed suicide at such a young age, was described by family at the time of his death as depressed over his release from the team, but today’s new story quotes as leading researcher as saying, “These guys used to be fine. They were entirely reasonable at all times of day,” presumably until CTE led to behavior changes.  There is a conspicuous absence of potential non-CTE contributing factors in the media coverage–and even in the BU research.

Finally, traumatic brain injury is not a progressive condition.  The endlessly variable combination of biomechanical forces, insult to brain tissue, neurotransmitter changes and cellular response are sometimes followed by secondary  processes like increased brain pressure, fluid collection, infection or ischemia, but these all generally take place at the time of injury or soon afterward–not months and years later.  The idea that CTE is the progressive expression of discrete events goes against what we know about the course of recovery from traumatic brain injury.

So for now, take the media hype with a grain of salt.  In my opinion, more deserving of media attention are the patients who have sustained documented severe TBI with profound permanent consequences.  They have invisible wounds that effectively destroy their lives and the lives of their loved ones, with little social understanding of their disabilities.  And in many cases, the resources available to them are woefully inadequate.

References:

http://www.nydailynews.com/sports/football/study-cte-linked-domestic-violence-article-1.1978936

Casson, I, Viano, D., Haacke, E., Kou, Z, LeStrange, D Is there chronic brain damage in retired NFL players? Sports Health, 2014 Sept 6(5).

Karantzoulis, S, Randolph, C Modern CTE in retired athletes: What is the evidence? Neuropsychol Rev 2013, Dec 23(4).

Solomon, G, Zuckerman, S CTE in professional sports: Retrospective and prospective views.  Brain Injury 2014 Oct 14: 1-7.