(The Editor’s Note: The following excerpt comes from an article written by Michael J. Perrotti, Ph.D., a concussion expert and frequent contributor to Concussion Litigation Reporter. The full article, as well as several other relevant articles (https://concussionpolicyandthelaw.com/2013/02/01/february-issue-of-concussion-litigation-reporter/), appears in the February issue of the Reporter.)
Recently the examination of the brain of Junior Seau revealed the diagnosis of chronic traumatic encephalopathy, or CTE. This diagnosis underlines the seriousness not only of repetitive brain trauma in professional sports and in military populations, but also raises continuing serious questions about the management and prevention of CTE in sports.
Introduction to Concepts: CTE, originally termed dementia pugilistica, is associated with memory disturbance, neurobehavioral disturbance, parkinsonism, and motor and speech abnormalities.
There has been increasing attention to neurological sequelae of concussive injuries in sports. While one has heard frequently of individuals having a “concussion” and then returning to play after the “concussion,” what is not realized is that players, as McKee et al. (2009) note, may experience thousands of subconcussive hits over the course of a single season. These are cumulative, and repetitive head trauma is applicable to athletes and military veterans.
Clinical Pathology: CTE was first introduced by Martland in 1928, who introduced the term “punch drunk” to a symptom complex related to repeated blows to the head. Symptoms of CTE are firstly deteriorations in functions of attention, concentration, and mnemic functions as well as disorientation and confusion occasionally accompanied by dizziness and headaches. Junior Seau frequently complained of headaches to peers. With progressive deterioration, additional symptoms, such as lack of insight, poor judgment, and dementia, become manifest. Severe cases are related to progressive slowing of muscular movements, gait disturbance, and speech disturbance. Corsellis et al. describe three stages of clinical deterioration. The first stage is characterized by affective disturbance and psychotic symptoms. Social instability, erratic behavior, memory loss, and initial symptoms of Parkinson’s appear during the second stage. The third stage consists of general cognitive dysfunction progressing to dementia and often accompanied by full-blown parkinsonism as well as speech and gait abnormalities.
Incidence: It is estimated that, in cases of repetitive concussion, there is mild traumatic brain injury (MTBI). At least 17% of these individuals develop CTE. Moreover, 1.6 to 3.8 million sports-related concussions occur annually in the U.S.
Prevention and Treatment: Of course, the most direct way to manage CTE and decrease incidents is to decrease the number of concussions or mild traumatic brain injuries by limiting exposure to trauma. The NFL is making some attempts at this, such as a second look at run backs after kickoffs as well as prescriptions against, or mandates against, helmet-to-helmet contact. However, from the players’ point of view, they are vocal in asking for independent medical personnel or independent health-care providers on the sidelines to make decisions about “concussions.”
Asymptomatic individuals have been shown to have persistent decreases in P300 amplitudes in response to an auditory stimulus at least five weeks after a concussion thereby casting doubt on the validity of the absence of symptoms as a guidepost. Neuropsychological tests have also helped provide estimates as to the appropriate time for athletes to return to play.
McKee et al. (2009) note that PET (positron emission tomography),,DTI (diffusion tensor imaging), and MRI (magnetic resonance imaging) studies have all shown abnormalities in concussed athletes or non-athletes with TBI lasting for two to four weeks. Thus, these studies indicate safe return-to-play guidelines might require at least four to six weeks to facilitate more complex recovery and protect from reinjury as a second concussion occurs much more frequently in the immediate period after a concussion. Animal studies note that there is expansion of brain injury and inhibition of functional recovery if the animal is subjected to overactivity within the first week.
(To read more, click https://concussionpolicyandthelaw.com/concussion-litigation-reporter/)