Understandably CTE is more prevalent among athletes who participate in collision, combat, and contact sports as well as military personnel but it’s important to consider the population bias of most CTE research. Although most individuals affected by CTE become symptomatic in the fifth to sixth decade of life and die shortly after there’s been cases of athletes as young as 17-years-old with confirmed CTE on autopsy. Information extrapolated from retroactive studies lists cognitive deficits, headaches, hostility, impulsivity, irritability, depression, and suicidal as the most common CTE related symptoms.
Over the past decade concussions have received substantial attention worldwide with chronic traumatic encephalopathy, better known as CTE, following close behind. While science strives to understand the best diagnostic, treatment, and prevention strategies for concussions & CTE numerous misconceptions have emerged.
Terminology:
Though a developing term, concussion is described as an external force to the head or body that alters brain metabolism, cerebrovascular function, & network connectivity. CTE is a neurodegenerative condition associated with repetitive head injuries (RHI) and less likely a single head injury. The lingo can be confusing since the term head injury & concussion are often used interchangeably.
CTE is a progressive condition that is commonly divided into four stages based on laboratory and imaging factors rather than signs or symptoms. There is a corresponding decline in psychological and cognitive functioning as the brains normal tissue is replaced with a substance called p-tau begins. During the fourth stage the persistent transformation of normal brain tissue into p-tau depositions causes the brain to decreases in size & weight.
Demographics:
Understandably CTE is more prevalent among athletes who participate in collision, combat, and contact sports as well as military personnel but it’s important to consider the population bias of most CTE research. Although most individuals affected by CTE become symptomatic in the fifth to sixth decade of life and die shortly after there’s been cases of athletes as young as 17-years-old with confirmed CTE on autopsy. Information extrapolated from retroactive studies lists cognitive deficits, headaches, hostility, impulsivity, irritability, depression, and suicidality as the most common CTE related symptoms.
CTE can affect anyone with a history of RHI but given the high-risk environment amateur and professional athletes participating in boxing, wrestling, football, rugby, soccer, hockey and bull riding have been most commonly documented. The first case reports describing CTE was by Corsellis, Bruton, and Freeman-Browne around 1950. In 2009 there were only 48 verified cases of CTE in the literature and no mention of CTE in American National Football League (NFL) players until 2011 by Omalu et al. a NFL study including over 3,000 football athletes.
Diagnosis:
Before successful treatment and prevention is achievable science must understand how to detect and diagnosis CTE. Since diagnoses is only possible after someone has died the actual occurrence of CTE is unknown. Although brain magnetic resonance imaging (MRI) is superior to computed tomography (CT) in evaluating structural brain changes these findings are not specific to concussions or CTE. Similarly, functional MRI, diffuse tensor imaging (DTI), susceptibility-weighted imaging (SWI), and positron emission tomography (PET) imaging tools have similar limitations. Given the p-tau deposition in brain tissue with CTE, fluid biomarkers have focused on detecting p-tau from blood and CSF. However, high p-tau levels are not specific to CTE making it impossible to differentiate between CTE and other medical conditions that increase tau levels. As such fluid biomarkers become more widely available perhaps a biomarker panel of some sort could be used to identify similar conditions including CTE.
Protective Gear:
The consumer market is being bombarded with gadgets and software claiming to detect and prevent concussions as well as CTE. The bottom line is concussion-protection gear is not effective in preventing concussions or CTE. Some technology may actually encourage more aggressive play due to false confidence that the device will protect the athlete from a head injury. Published in 2000, Hedlund suggests the theory of risk compensation which can be applied to the thought that protective gear encourages more dangerous behavior during sport participation. In theory if an athlete feels more safeguarded by gear, their acceptable level of risk decreases and their actions change. Whether or not changes in behavior increase an athlete’s risk of concussion is yet to be determined but is theoretically reasonable.
In theory, helmets protect against head-to-head or head-to-surface (e.g. ground, ball, etc.) with some able to withstand single or multiple- head impacts. Helmets used in hockey and football are made from compressible, durable material capable of withstanding multiple impacts whereas helmets used in motor sport, bicycling, and alpine skiing, must be replaced following a single impact. While helmets prove to decrease facial injuries and skull fractures, technology does not reduce rotational or linear acceleration nor do they protect injury sustained through high velocity whiplash-like movements absent of direct contact. Because of this, technology has recently focused on reducing both acceleration and velocity of the head during injury to lessen the risk of concussion and CTE.
Ice hockey face shields are attached to a player’s helmet, sometimes covering the entire face or limited to the upper portion of the face (e.g. visors). Most face shields are made from strong plastic that is resistant to impact whereas cages, also a full-face shield, are made of metal. Cages helmets offer the athlete complete protection and will prevent any potential injuries to the face. However, the drawback of a cage is the limited visibility that many players find distracting during games. A study by the National Hockey League (NHL) found that athletes wearing half face-shields had the same risk of sustaining a concussion as those not wearing facial protection. half-F ace protection versus those who wear full-face protection use among collegiate and armature ice hockey players also does not appear to alter the incidence of concussion.
Rules:
The risk of concussion can be reduced through enforcement of the rules by sporting organizations, coaches and officials. Reducing the number of injuries through changing rules, reducing the number of games, and shortening games while also reducing the strength of hits by increasing penalty consequences have shown to be effective. Officials involved in sporting events must be knowledgeable, willing to implement rules in addition to their other responsibilities during competition. Research through the NFL, NHL, and other sporting organizations have demonstrated a direct relationship between certain rules and concussion risk. Requiring teams to employ highly-specialized clinicians such as primary care sports medicine doctors, to be present during and following sporting events to manage head injuries has been a prevailing and effective change in concussion and CTE monitoring and management. As an Unaffiliated Neurotrauma Consultant (UNC) for the NFL I see firsthand the generous and effective effort to minimize concussions and CTE through the creation of unbiased concussion protocols. Indeed, changing rules when necessary and educating athlete’s and others involved may help to reduce the incidence and severity of sports-related concussions it does not necessarily translate into changes in behavior.
The Future:
Although diagnostic imaging, neurocognitive, balance, and visual, testing to predict pre and post-concussion functioning has proven useful, diagnosing concussions and CTE is a subjective undertaking. Imaging such as CT and MRI have limited use as do blood tests for the diagnosis of concussions and CTE given nonspecific findings. I look forward to the new discoveries as research continues to push for more objective diagnostic testing for concussions and CTE.
Enhancement in concussion management through return to play protocols, comparing pre and post-injury testing results, active recovery, and other individualized treatment modalities have shown to be beneficial. Given the serious physical and psychological consequences of concussions and CTE I encourage researchers and clinicians to place more emphasis on post-impact treatment in addition to diagnosis and prevention. Although fixing the problem is ideal, sport participation will continue to be a part of human existence as will non-sport related injuries. An advocate for the mental health of athletes and all, I implement modalities such as EMDR, ART, and more homeopathic methods in my management of concussions. To learn more, check out my blog written with the outstanding Lauran Hahn, an EMDR therapist, educator, and mentor of mine.
For more information check out the CTE Prevention Protocol from The Concussion Legacy Foundation: https://concussionfoundation.org/