Concussion Guidelines
Step 1: Systematic Review of Prevalent Indicators

Carney
N., Ghajar J., Jagoda A., Bedrick S., Davis-O’Reilly, C., Coudray Hd., Hack D.,
Helfand N., Huddleston A., Nettleton T., Riggio S. Neurology.2014;7(3):S3-S15.

Take Home Message: 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.

We
lack a widely accepted definition for a concussion. An evidence-based
development of a standardized concussion definition would enable medical
personnel to determine a concussion injury using specific diagnostic criteria
as well as prognostic indicators such as signs and symptoms. Therefore, the
purpose of the current systematic review is to provide evidence-based data on
indicators of a concussion injury. The authors performed an electronic
literature search, which included articles from 1980-2012 in Medline, Sports
Discus, PsychINFO, and Cochrane. For a study to be included in the review, the
authors required a study to include a broad definition of concussion and that
the presence of any particular signs and symptoms or deficit be reported at a
fixed time point. Twenty-six articles met the criteria and 11 articles were
included in the conclusion. The authors found that loss of consciousness
following a concussion injury was not very common (1 to 14% of injuries). The occurrence
of disorientation/confusion ranged from 18% to 45%, and the frequency of
headache, dizziness, blurred vision, and nausea exceeded 50% of injuries.
Thirty-one percent of individuals who were tested for balance deficits
immediately after the event demonstrated decrements in function. Balance
deficits remained affected 2 days after injury, and it was not until 7 days post
injury that there were no significant dysfunctions detected. Many injured
individuals (42 to 71%) had deficits with some measure of reaction time within
24 hours and this persisted through 2 days after injury. The occurrence of
deficits in attention/processing speeding/working memory ranged from 0-30% to
50-52.2% within 24 hours after injury. Measures of memory deficits within the
first 24 hours of injury occurred in 0% to 42% of injured individuals.

The
goal of this project was to establish an evidence-based foundation to derive a
definition of concussion as well as diagnostic criteria and prognostic
indicators of a concussion. This study found that the most common and
persistent indicators of a concussion are observing disorientation/confusion immediately
after the event, impaired balance within 1 day, slower reaction time within 2
days of injury, and/or impaired verbal learning and memory within 2 days after
injury. It should be noted that most of the participants included in this
review were athletes, and generalizing these findings to the general population
may not be applicable. In addition, without a definition for concussion the
common indicators the authors are reporting can only be attributed to a
concussion-like injury. Lastly, the authors excluded a considerable amount of
the concussion literature because of various methodological or reporting
issues. Medical professionals should be cognizant of these indicators when
assessing a potential sports-related concussion injury. Including a measure of
balance, reaction time, memory, and verbal learning could help identify
concussed athletes.

Questions for Discussion:
Do you think these indicators at these times points are helpful with diagnosing
a concussion? What time points are the most important to measure following a
concussion injury? 

Written
by: Jane McDevitt, PhD
Reviewed
by: Jeff Driban

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Carney N, Ghajar J, Jagoda A, Bedrick S, Davis-OʼReilly C, du Coudray H, Hack D, Helfand N, Huddleston A, Nettleton T, & Riggio S (2014). Concussion guidelines step 1: systematic review of prevalent indicators. Neurosurgery, 75 Suppl 1 PMID: 25006974