Concussion on the sports field is often undiagnosed because of bias in self-report, ambiguity in symptoms, and the lack of loss of consciousness (which does not always occur in a concussion). In the days that follow, however, the athlete that has sustained a head impact may develop delayed symptoms of a concussion, further confounding an accurate diagnosis.
A recent study looked at the types of impact that commonly occur to the head, as well as timing and frequency, and the relationship to concussion diagnosis. They found that an immediate diagnosis of concussion after head impact was highly associated with high kinematic metrics (peak linear and rotational acceleration, velocity, injury severity). Delayed concussion diagnosis was associated with higher numbers of head impacts on the day of injury. Impacts most associated with concussion diagnosis occurred to the front of the head (46%) followed by the top of the head (25%), side (16%), and back (13%).
These results suggest that different head impact measures can result in different clinical presentations, which should be considered during diagnosis.
Beckwith JG, Greenwald RM, Chu JJ, et al. Timing of concussion diagnosis is related to head impact exposure prior to injury. Sports & Exercise. (January 2012).