How Can Neurologists Diagnose and Manage Sport-Related Concussion?
What Should Be Done on the Field?
If a player at a sporting event sustains a head injury, he or she should be removed from play immediately and not allowed to return to the game. If he or she has not directly observed the injury, the neurologist should get information about it from witnesses. The neurologist should perform a focused physical examination, searching for evidence of decreased level of consciousness, confusion, focal weakness or incoordination, visual disturbance, cervical spine injury, or facial fractures. The Sport Concussion Assessment Tool (SCAT) can assist the clinician in concussion evaluation and treatment in a standardized and methodical way to determine whether and when a player can safely return to play.
A patient with an abnormal examination may need to be transferred to the local emergency department for further testing. CT imaging should not be performed automatically, because it may expose the patient to radiation unnecessarily. Two sets of criteria offer guidance about CT imaging. The New Orleans criteria state that a patient should undergo CT if he or she has a headache, has vomited, is older than 60, had been using alcohol or other drugs, had a seizure, has visible trauma above the clavicle, or has a short-term memory deficit. The Canadian CT Head Rule lists similar criteria, including a Glasgow Coma Scale score at two hours of less than 15, any sign of a basal skull fracture, and amnesia for events that took place 30 minutes before the injury.
Anticoagulants increase the risk of immediate or delayed hemorrhage after head injury. If a patient has intracranial hemorrhage on CT and has been using anticoagulants, the clinician should rapidly reverse the anticoagulant effect with the appropriate agent. A repeat head CT 24 hours later should be considered in those thought to be at high risk for intracranial hemorrhage and whose initial CT imaging is negative for bleed. “Err on the side of admitting these patients, at least for observation,” said Dr. Kosa. Before the patient is discharged from the emergency room, he or she should receive education about postconcussion symptoms that should prompt another visit to the emergency department. Educational materials are available on the CDC’s website.
When Can a Patient Return to Play?
The consensus statement on concussion in sport adopted at the Third International Conference on Concussion in Sport includes guidelines for graduated return to play. At first, the patient should undergo symptom-limited physical and cognitive rest until he or she recovers. Next, the patient may start light aerobic exercise such as walking, swimming, or cycling. The goal is to increase heart rate, but the patient should reduce activity if symptoms occur. Then, the patient may engage in sport-specific exercise. If recovery proceeds well, the patient may begin noncontact training drills and, later, full contact practice. Only when the patient has full confidence and coaching or training staff has assessed his or her functional skills can the athlete return to play.
What Concussion Research Is Under Way?
Investigations currently under way aim to improve understanding of concussion, as well as to aid diagnosis and treatment. Researchers are looking for a reliable biomarker of concussion that can be detected with an easy, cost-effective, and preferably noninvasive test. Saliva, tears, urine, blood, and CSF are among the candidate samples being studied. CSF is the most reliable fluid to test because of its proximity to the brain and its low susceptibility to extracerebral confounders, but it is the most invasive option. Groups are examining potential serum biomarkers such as S100b, neuron-specific enolase, myelin basic protein, glial fibrillary acidic protein, and cleaved tau.
In addition, McKee and colleagues are working to define clear pathologic criteria defining the various stages of CTE. They also are seeking a way of distinguishing CTE from Alzheimer’s disease, amyotrophic lateral sclerosis, and other neurodegenerative diseases in postmortem brain tissue. The group’s ultimate goal is to identify features that may assist in the diagnosis of CTE in living people using advanced neuroimaging.
—Erik Greb
Suggested Reading
Giza CC, Kutcher JS, Ashwal S, et al. Summary of evidence-based guideline update: evaluation and management of concussion in sports: report of the Guideline Development Subcommittee of the American Academy of Neurology. Neurology. 2013;80(24):2250-2257.
McCrory P, Meeuwisse W, Johnston K, et al. Consensus statement on concussion in sport--the 3rd International Conference on concussion in sport, held in Zurich, November 2008. J Clin Neurosci. 2009;16(6):755-763.
Omalu BI, Hamilton RL, Kamboh MI, et al. Chronic traumatic encephalopathy (CTE) in a National Football League Player: Case report and emerging medicolegal practice questions. J Forensic Nurs. 2010;6(1):40-46.
