What is a Concussion? An In-Depth Q&A with US Lacrosse Experts
Dr. Margot Putukian and Dr. Ruben Echemendia of the US Lacrosse Sports Science and Safety Committee were among presenters at the International Consensus Conference on Concussions in Zurich, Switzerland.
Concussions are a type of traumatic brain injury (TBI), caused by a blow or jolt to the head or body that produces shaking of the brain inside the skull, resulting in mild to severe disruption in the way the brain normally works. Since there are no clear biomarkers in the diagnosis of the injury, care providers look for symptoms — immediate or delayed. Symptoms include headache, nausea, dizziness, confusion, amnesia, loss of consciousness or unresponsiveness.
To get a better understanding of concussions, we turned to two members of the US Lacrosse Sports Science and Safety Committee. Dr. Margot Putukian and Dr. Ruben Echemendia are world-renowned experts on concussions and were among the invited presenters at the 2012 International Consensus Conference on Concussions in Zurich, Switzerland.
What is the biology of a concussion? What actually happens to the brain?
RE: A concussion creates changes in the chemistry of the brain that produces a "neuro-metabolic cascade" that renders cells temporarily inoperative and vulnerable to further injury. This metabolic cascade is accompanied by a disruption of the blood supply to the brain, thereby reducing the amount of glucose (fuel) available to the brain for healing. These changes affect the entire brain, not just one region.
What are the risks of playing with a concussion? What is second-impact syndrome?
MP: It is difficult to know the exact risks of continuing to play while concussed, but in the younger athlete, there has been a concern that a second insult can occur while the athlete is still recovering from a first injury, and that a dysregulation in the blood flow to the brain can then result, causing a significant increase in the pressure in the brain. Though considered controversial by some researchers, second-impact syndrome has been reported in youth athletes and associated with significant complications, including death.
RE: Continuing to play while having symptoms places the vulnerable brain at risk for additional injury that may lead to more severe, prolonged or even life-long problems with cognitive and psychological functioning. Second-impact syndrome is rare and thought to occur when an individual sustains a blow to the brain during a time when the brain has not fully recovered from a previous concussion. The blow can often be a relatively mild one.
Are there long-term health implications from concussions?
MP: The majority of concussions resolve in 10-14 days without any known long-term consequences. However, in a very small percentage, there are persistent symptoms and ongoing difficulties with cognitive function or balance.
RE: Some studies suggest there can be long-term changes in neurocognitive functioning; others do not. There is no consensus among experts in the field. The key appears to be appropriate evaluation and management of the injury.
What impact, if any, does age play in concussions?
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MP: Younger athletes appear to take longer to recover and therefore should be treated with caution. Other modifiers that are associated with a prolonged recovery include an increased number and duration of symptoms and a history of prior concussion. Other modifiers that may play a role in prolonged recovery include a history of migraine headaches, attention deficit hyperactivity disorder (or other learning disorders) and history of depression, anxiety or other mental health disorders.
Besides rest (physical and mental), what else can help recovery?
MP: An initial period of rest is important, and avoiding cognitive activity, such as texting, video games and extended computer work, also is important. After a few days, light exercise can be initiated assuming it doesn't worsen symptoms. It's unclear if other interventions are helpful in assisting recovery, but alcohol, aspirin, narcotics and other medications that impair cognitive function or increase bleeding are typically avoided in the first few days.
RE: It is very important that athletes with concussions remain well hydrated, maintain good nutritional habits and get plenty of sleep. Keep in mind that physical and cognitive rest does not mean placing the child in a cocoon. Typical activities of daily living, including school, should be added as soon as they are tolerated without producing an increase in symptoms.
What misperceptions about concussions do you encounter?
MP: One myth is that helmets prevent concussion. Though they are effective in preventing skull fracture and bleeds, and may lessen impact forces, they do not prevent concussion. Sometimes the assumption is that putting a helmet on an athlete will protect them, when it might not. In fact, if they have a false sense of security, they may play more aggressively and therefore be at a greater risk for injury. Another myth is that the greater the impact force, the more likely that a concussion will occur or the more severe the concussion. There is not enough research to support this, and what limited data we have actually suggests that concussive injury can occur with different levels of impact.
RE: Some people still believe that you need to lose consciousness or have serious memory impairment to have a concussion. Neither is true. Some believe that a concussion is a bruise to the brain; it is not. Many believe that you have to be hit hard or be hit on the head to have a concussion. Neither is true.
Can you comment on the effectiveness of neurocognitive (baseline) testing?
RE: Baseline testing can be very useful in establishing the pre-injury functioning of the athlete. If available, athletes should take advantage of baseline testing. However, baseline testing sometimes creates significant complexity in the evaluation of an athlete's cognitive functioning. Because of this complexity, a qualified neuropsychologist should interpret any neuropsychological testing.
MP: The utility of baseline computerized neuropsychological testing has recently been questioned. Although it appears to promising, there are several factors to consider in NP testing including the effects of fatigue, injury and motivation.
What are your opinions on the return-to-play laws that have been passed in 49 states and D.C.?
MP: The Zack Lystedt Law passed in Washington State was the first of many that have raised the awareness of the importance of this injury as well as the importance of removing athletes from play when signs and symptoms of concussion are present.
RE: These laws are a good first step towards raising awareness and providing basic guidelines for the management of concussion. The laws are not uniform across states, and hence some are better than others.
US Lacrosse contends there yet no scientific evidence to suggest helmets prevent concussions. Do you adhere to this position?
RE: Yes, this is accurate. Helmets are designed to prevent catastrophic head injury, and they are very good at doing that. They just were not designed to, and do not, prevent concussion.
MP: We need to explore the effects of various headgear options and continue to investigate the mechanisms of injury in lacrosse for both the men's and women's game, and evaluate interventions that can decrease injury — including rule changes, rule enforcement, coaches and player education. Whether future equipment modifications can prevent or lessen the severity of injury remains unanswered at this time.
Do you have other recommendations from the conference in Zurich?
MP: There has been a lot of research regarding the assessment and management of concussion that has led to a more cautious approach to this important injury. There are advanced neuroimaging techniques which show promise in demonstrating functional and structural injury with concussion. There also has been a significant amount of information regarding the acceleration forces that occur in different sports that quantify the number, extent and location of forces to the head with sport.
RE: Thus far we have focused a great deal of
attention, effort and money on baseline testing but have not
focused much on the post-injury evaluation, which is in many ways
far more crucial. It is imperative that any athlete with a
concussion be evaluated by a qualified medical professional who is
specifically trained in the evaluation and management of this
injury. The use of a multidisciplinary team of professionals
— physicians, neuropsychologists and athletic trainers
— is ideal.