Brain
function disrupted. A concussion may result in neuropathological
changes but the acute clinical symptoms largely reflect a functional
disturbance in the brain rather than structural injury.
Loss
of consciousness not required. Concussions result in a graded set of
clinical symptoms that may or may not involved loss of consciousness
(LOC).
Resolution of clinical and cognitive symptoms typically follow a
sequential course, but in a small percentage of cases, post-concussive
symptoms may be prolonged.
Normal
MRI/CAT scans. Concussion is
typically associated with grossly normal structural neuroimaging
studies. In other words, unlike other injuries, concussions are usually
injuries no one sees and, contrary to popular belief, don't show up on
most magnetic resonance imaging (MRI) exams or CT scans. A brain CT -
or, where available, MR brain scan - should, however, be conducted if symptoms of a
more serious brain injury are present.