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Sideline evaluation of concussion

Josh Bloom, MD, MPH
Jim G Blount, MD, CAQSM
Section Editor
Karl B Fields, MD
Deputy Editor
Jonathan Grayzel, MD, FAAEM


Concussions are common, but complex, traumatic brain injuries seen in athletes of all ages and skill levels in a wide variety of athletic settings. Given the variability of the clinical presentation associated with concussion, it is important that team physicians and other clinicians responsible for the care of athletes perform a systematic and comprehensive sideline evaluation of each athlete with a suspected concussion.  

This topic reviews the risk factors, clinical presentation, sideline evaluation, and initial management of adolescent and adult athletes with a concussion. More detailed discussions of mild traumatic brain injury and trauma assessment are provided separately. (See "Acute mild traumatic brain injury (concussion) in adults" and "Minor head trauma in infants and children: Evaluation" and "Postconcussion syndrome" and "Initial management of trauma in adults".)


A concussion is a complex, trauma-induced pathophysiological process affecting the brain. The biomechanical forces involved in the trauma (eg, acceleration, deceleration, rotation) can injure the brain via a direct blow to the head, face, or neck, or via a blow to the body that transmits force to the head (eg, whiplash). The ensuing brain disturbance is due to neurometabolic dysfunction, which manifests in a wide variety of symptoms and signs that may or may not include loss of consciousness [1,2]. No gross structural abnormalities are seen with conventional neuroimaging.

It is important to note that while a concussion typically manifests with rapid onset of short-lived neurologic dysfunction, in some cases, development of signs and symptoms of concussion can be delayed minutes to hours [1]. Detailed discussions of the definitions, pathophysiology, and epidemiology of concussion are provided separately. (See "Acute mild traumatic brain injury (concussion) in adults", section on 'Pathophysiology'.)


Evaluation and diagnosis of concussion remains a clinical exercise. At this point, there is no compelling evidence supporting one specific test, tool, biomarker, imaging study, or protocol to definitively diagnose or exclude a concussion. In the absence of such evidence, use of a consensus-derived, multimodal concussion assessment tool, such as the Sport Concussion Assessment Tool 5th Edition (SCAT5), is recommended as the framework for a sideline concussion evaluation [3].

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Literature review current through: Oct 2017. | This topic last updated: Aug 22, 2017.
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