Sideline Testing for Sports-Related Concussion: What is the Evidence?

Concussion is defined as a complex pathophysiological process affecting the brain from an impulsive force transmitted to the head or from a direct blow to the head, face, neck or elsewhere on the body that results in a new neurological sign or symptom.1 Increasing public awareness of the incidence of concussion, estimated at 4 million per year, and the possible long-term consequences on brain function are becoming a growing concern for participants in contact and collision sports.2 The development of a range of sideline screening tests has occurred in response to the concussion epidemic. The visual system is important in the diagnosis of concussion, particularly since ~50% of the brain's pathways are dedicated to vision.