Guidelines for assessment and management of sport-related concussion. Canadian Academy of Sport Medicine Concussion Committee.

Concussion is defined by the Congress of Neurological Surgeons as “a clinical syndrome characterized by immediate and transient post traumatic impairment of neural function, such as alteration of consciousness, disturbance of vision and/or equilibrium due to brain stem involvement. ” Sports-related concussions are a significant problem. Between 1931 and 1986, there were over 800 deaths from North American football alone and currently there are estimated to be 300,000 concussions per year in contact sport in the United States. A concussion may be sustained through a variety of mechanisms. A direct blow to the head, blow to the jaw, sudden twisting or shearing force and a sudden deceleration of the head [similar to a “whiplash”-type injury] can all produce concussive signs and symptoms. In severe trauma, there may be bleeding or obvious damage to brain structures. In the more typical sport-related concussion, no obvious damage is found on tests such as X-rays, CT scans, and MRIs. It is unclear as to what happens to the brain but, after injury, it may not function normally and is vulnerable to further damage for a period of time. The exact length of this period of vulnerability is not known. Concussion can cause a variety of symptoms. It is of critical importance to be aware of the fact that one does not have to lose conciousness to have had a concussion! Typical postconcussive symptoms can include feeling dazed, “having your bell rung,” memory problems, confusion, poor coordination, headache, and/or nausea. Return to play in a contact activity while still symptomatic is very dangerous. The most severe consequence is the “second impact syndrome”; this is a rare but usually fatal condition whereby even a seemingly mild blow to a previously concussed brain leads to massive brain swelling. Return to play while symptomatic has also been shown to increase the risk of further concussion, persistence of postconcussive symptoms, and other injury. Postconcussive symptoms may also increase with any type of exercise following injury, so a gradual increase in exercise and return to play protocol should be used. It has also been shown that multiple concussions can lead to permanent, irreversible changes, such as memory loss, concentration problems, headaches, etc. While much has been learned about concussion, considerable controversy still exists in several areas. Numerous concussion grading systems have been proposed, but are not based on scientific evidence. There is controversy related to the relative importance of loss of consciousness, posttraumatic amnesia, and postconcussive symptoms in grading injury severity. It is therefore difficult to endorse any specific guideline. Return to play guidelines are similarly based on experience rather than evidence; it is still not known how long the brain is vulnerable following the concussive injury. Therefore, it is prudent to err on the side of caution in returning an athlete to play. Protective equipment has been shown to reduce the risk and severity of head injury in sports. Approved helmets should be worn in all collision sports or activities with a risk of head trauma (e.g., cycling, in-line skating). Helmets should be kept in good condition and worn properly. Currently, there is considerable interest in the medical and public sectors, as well as amateur and professional sport groups, in learning more about concussion, its safe management, and prevention. Important questions still exist, and there is an urgent need for answers. With this mandate, the Canadian Academy of Sport Medicine [CASM] Committee on Concussion has brought together a national group of interested and qualified CASM members to undertake the task of addressing these issues in the scientific, practical manner in order for CASM to authoritatively develop a guideline on this topic. CASM is attempting to provide leadership in this controversial field. Following a meeting of the committee at our annual conference, the following guidelines were agreed on by the membership. The literature as pertains to each members’ area of expertise was reviewed, presented, and discussed. While the guideline is by no means a comprehensive accumulation of all available data, it is agreed that it represents a practical, usable consensus for use in the management of sport-related concussion. As such, we have made a first step in the development of an ongoing critical update on this important injury. Address correspondence to Karen M. Johnston, MD, PhD, Division of Neurosurgery, Montreal General Hospital, 1650 Cedar Ave., Montreal, Quebec, Canada H3G 1A4. Reprinted with permission of the Canadian Academy of Sport Medicine. Clinical Journal of Sport Medicine, 10:209–211 © 2000 Lippincott Williams & Wilkins, Inc., Philadelphia