Bulletin

20 | Bulletin vol. 32 no. 1 Nyaz Didehbani, Ph.D. Marsha Siebenmorgen, Ph.D. Concussion 101: Keeping your head in the Game What is a Concussion? A concussion is a mild traumatic brain injury (mTBI) defined as a disruption in the function of the brain due to a biomechanical force (Menon et al., 2010). It is largely differentiated from more moderate or severe TBI's by loss of consciousness less than 30 minutes, post-traumatic amnesia lasting less than one day, and a Glasgow Coma Scale (GCS) score greater than 12. While this commonly includes a direct injury to the head by an external force, it can also stem from a sudden rotation or force exerted on the head and/or body, such as whiplash. A concussion can cause a range of pathophysiological changes in the brain, including a disruption in blood flow, change in glucose (blood sugar), neurotransmitter dysregulation (chemicals released by brain nerves), and neuroinflammation (Giza and Hovda, 2001). Mechanism of Injury The most common cause for mTBI is falls, which disproportionately affect the youngest and oldest age groups. The most common causes among children are non-accidental trauma in infants, falls in toddlers, pedestrian versus motor vehicle accidents (MVA) in school-age children, and MVA in adolescents 16 years and older (Tayler, Bell, & Breiding, 2017). According to the Centers for Disease Control (CDC), it is estimated that the overall reported incidence of sports-related concussion (SRC) and recreational activity in the United States is between 1.6 to 3.8 million a year (CDC, 2018). Of those, approximately 10% represent SRC and the incidence rate is on the rise (CDC, 2018). The rate for SRC has increased steadily – largely due to an increase in public awareness (Taylor et al, 2017) and better surveillance by coaches and trainers (Buckley, Burdette, & Kelly, 2015). Signs and Symptoms of Concussion Signs of a concussion are observable indications of an injury and may include disorientation, incoherent speech, vacant stare, confusion, or loss of consciousness. Signs requiring immediate attention and hospitalization include loss of consciousness, seizure, vomiting, severe headache, pupillary asymmetry, or painful cervical range of motion. Symptoms of a concussion are self-reported indicators of an injury and are often categorized into physical, emotional, or cognitive symptoms, which typically resolve within a few weeks (Crowe et al., 2016). Common physical symptoms may include blurry and/or double vision, headache, sensitivity to light or sound, ringing in the ears, dizziness, nausea, and poor balance. Cognitive symptoms may include fogginess, difficulty concentrating, forgetfulness, and slowness to respond. Emotional symptoms may include feeling irritable, frustrated, sad, emotionally labile, or nervous. More recently, sleep disturbances have been proposed as a fourth category of post concussive symptoms that can also be a result of physiological brain changes or reciprocal interaction between cognitive, emotional, and physical symptoms. In general, post-concussive symptoms may impact school or work performance, self-regulation, social interaction, and every day adaptive functioning (CDC, 2018; Treble-Barna et al., 2017). Sports Related Concussion Evaluation As with any type of injury, symptoms and the events preceding and following the injury are assessed after a suspected SRC. Screening tools like the SCAT5 (Sideline Concussion Assessment Tool-5th edition) or ACE (Acute Concussion Evaluation) may also be administered immediately after the injury to assess symptoms. The SCAT5 is a sideline assessment for an acute injury and includes orientation questions related to the current game, Glasgow Coma Scale, a cervical spinal screen, symptom checklist, neurologic screen, a balance test, and a cognitive screen. During the recovery period, a range of health care providers may repeatedly assess post-concussion symptoms using neurological examinations, balance tests, and cognitive measures including standard neuropsychological tests or computerized tests like the ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing). ImPACT is often used with student athletes to compare baseline to post-injury functioning (Covassin et al., 2009). While these types of evaluations make use of randomized stimuli to reduce practice effects and make efforts to consider pre- injury differences (ADHD, learning problems, culture/linguistics, psychiatric history), computerized tests can be less sensitive in assessing post-injury cognitive changes than evaluations completed by a neuropsychologist (Meyer & Arnett, 2015). More thorough evaluations by concussion specialists are often needed for athletes who continue to exhibit symptoms beyond the typical 1-4-week recovery period.

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