Contributions of functional magnetic resonance imaging (fMRI) to sport concussion evaluation.

Mild traumatic brain injury (mTBI) in contact sport is a problem of such magnitude that improved approaches to diagnosis, investigation and management are urgent. Concussion has traditionally been described as a transient, fully reversible, cerebral dysfunction. However, this seemingly 'mild' injury sometimes results in long-lasting and disabling post-concussion symptoms (PCS) and abnormal neuropsychological profiles characteristic of frontal and/or temporal lobe dysfunction. At present, the pathological changes following concussion remain unclear, but it is now widely accepted that concussion results mainly in functional disturbance rather than structural damage. Therefore, functional imaging techniques can help in demonstrating brain abnormalities undetectable by structural imaging methods. This paper will review the use of functional magnetic resonance imaging (fMRI) in studies of concussion. Our existing and ongoing fMRI studies will be described as examples to highlight the potential and contribution of this non-invasive functional neuroimaging technique in the assessment of sports-related concussion and its management.