The authors of this article state that there is no consistent concussion definition applied clinically or in research and through this systematic review attempt to describe the signs and symptoms of this condition.
We presented this article, entitled “Concussion Guidelines Step 1: systematic review of prevalent indicators”  using the following slides, available through Slideshare.
In summary, based on the authors’ premise that no definition exist for concussion they attempt to summary the literature on consistent indicators of this condition (“In the absence of physiological measure, evidence of concussion are signs, symptoms and objective measures of neurologic or cognitive dysfunction”). These indicators were best summarised by Sports Medicine Research:
“Prevalent and consistent indicators of a concussion include observing disorientation or confusion immediately after the injury, and slower reaction time, poor balance, and impaired verbal learning and memory within 2 days after the injury.”
Our only contention with the article, which is largely acknowledged by the authors, is the possibility of false positives and false negatives existing in the “concussion” cohorts they examined. In other words, some of the the “concussed” individuals may have not have an actual concussion, but more likely is that some of the “concussed” individuals may have been missed. These issues would obviously affect their outcome, but pragmatically speaking, this is not an issue that may never be eliminated in this very tricky field. As this is the first in a series of papers from this group to attempt to reduce the ambiguity of this condition, we can only hope more more clarity in future research.
We’d love to hear your thoughts on this highly contentious issue!
1. Carney N, Ghajar J, Jagoda A, et al. Concussion guidelines step 1: systematic review of prevalent indicators. Neurosurgery. 47, S3-S15. 2014