The 2017 Concussion in Sport Group (CISG) consensus statement is designed to build on the principles outlined in the previous statements1–4 and to develop further conceptual understanding of sport-related concussion (SRC) using an expert consensus-based approach. This document is developed for physicians and healthcare providers who are involved in athlete care, whether at a recreational, elite or professional level. While agreement exists on the principal messages conveyed by this document, the authors acknowledge that the science of SRC is evolving and therefore individual management and return-to-play decisions remain in the realm of clinical judgement.

This consensus document reflects the current state of knowledge and will need to be modified as new knowledge develops. It provides an overview of issues that may be of importance to healthcare providers involved in the management of SRC. This paper should be read in conjunction with the systematic reviews and methodology paper that accompany it. First and foremost, this document is intended to guide clinical practice; however, the authors feel that it can also help form the agenda for future research relevant to SRC by identifying knowledge gaps.

A series of specific clinical questions were developed as part of the consensus process for the Berlin 2016 meeting. Each consensus question was the subject of a specific formal systematic review, which is published concurrently with this summary statement. Readers are directed to these background papers in conjunction with this summary statement as they provide the context for the issues and include the scope of published research, search strategy and citations reviewed for each question. This 2017 consensus statement also summarises each topic and recommendations in the context of all five CISG meetings (that is, 2001, 2004, 2008, 2012 as well as 2016). Approximately 60 000 published articles were screened by the expert panels for the Berlin …

https://bjsm.bmj.com/content/bjsports/51/11/838.full.pdf

Consensus statement on concussion in sport—the 5th international conference on concussion in sport held in Berlin, October 2016

Consensus statement on Concussion in Sport - The 4th International Conference on Concussion in Sport held in Zurich, November 2012

The new 2012 Zurich Consensus statement is designed to build on the principles outlined in the previous documents and to develop further conceptual understanding of this problem using a formal consensus-based approach. A detailed description of the consensus process is outlined at the end of this document under the Background section. This document is developed primarily for use by physicians and healthcare professionals who are involved in the care of injured athletes, whether at the recreational, elite or professional level.

/pdf/consensus-statement-on-concussion-in-sport-1b9nytxe0j.pdf

Consensus statement on concussion in sport

ContextLack of empirical data on recovery time following sport-related concussion
hampers clinical decision making about return to play after injury.ObjectiveTo prospectively measure immediate effects and natural recovery course
relating to symptoms, cognitive functioning, and postural stability following
sport-related concussion.Design, Setting, and ParticipantsProspective cohort study of 1631 football players from 15 US colleges.
All players underwent preseason baseline testing on concussion assessment
measures in 1999, 2000, and 2001. Ninety-four players with concussion (based
on American Academy of Neurology criteria) and 56 noninjured controls underwent
assessment of symptoms, cognitive functioning, and postural stability immediately,
3 hours, and 1, 2, 3, 5, 7, and 90 days after injury.Main Outcome MeasuresScores on the Graded Symptom Checklist (GSC), Standardized Assessment
of Concussion (SAC), Balance Error Scoring System (BESS), and a neuropsychological
test battery.ResultsNo player with concussion was excluded from participation; 79 players
with concussion (84%) completed the protocol through day 90. Players with
concussion exhibited more severe symptoms (mean GSC score 20.93 [95% confidence
interval {CI}, 15.65-26.21] points higher than that of controls), cognitive
impairment (mean SAC score 2.94 [95% CI, 1.50-4.38] points lower than that
of controls), and balance problems (mean BESS score 5.81 [95% CI, –0.67
to 12.30] points higher than that of controls) immediately after concussion.
On average, symptoms gradually resolved by day 7 (GSC mean difference, 0.33;
95% CI, −1.41 to 2.06), cognitive functioning improved to baseline levels
within 5 to 7 days (day 7 SAC mean difference, −0.03; 95% CI, −1.33
to 1.26), and balance deficits dissipated within 3 to 5 days after injury
(day 5 BESS mean difference, −0.31; 95% CI, −3.02 to 2.40). Mild
impairments in cognitive processing and verbal memory evident on neuropsychological
testing 2 days after concussion resolved by day 7. There were no significant
differences in symptoms or functional impairments in the concussion and control
groups 90 days after concussion.ConclusionsCollegiate football players may require several days for recovery of
symptoms, cognitive dysfunction, and postural instability after concussion.
Further research is required to determine factors that predict variability
in recovery time after concussion. Standardized measurement of postconcussive
symptoms, cognitive functioning, and postural stability may enhance clinical
management of athletes recovering from concussion.

https://jamanetwork.com/journals/jama/articlepdf/197668/JOC30118.pdf

Acute Effects and Recovery Time Following Concussion in Collegiate Football Players: The NCAA Concussion Study

ContextApproximately 300 000 sport-related concussions occur annually
in the United States, and the likelihood of serious sequelae may increase
with repeated head injury.ObjectiveTo estimate the incidence of concussion and time to recovery after concussion
in collegiate football players.Design, Setting, and ParticipantsProspective cohort study of 2905 football players from 25 US colleges
were tested at preseason baseline in 1999, 2000, and 2001 on a variety of
measures and followed up prospectively to ascertain concussion occurrence.
Players injured with a concussion were monitored until their concussion symptoms
resolved and were followed up for repeat concussions until completion of their
collegiate football career or until the end of the 2001 football season.Main Outcome MeasuresIncidence of concussion and repeat concusion; type and duration of symptoms
and course of recovery among players who were injured with a concussion during
the seasons.ResultsDuring follow-up of 4251 player-seasons, 184 players (6.3%) had a concussion,
and 12 (6.5%) of these players had a repeat concussion within the same season.
There was an association between reported number of previous concussions and
likelihood of incident concussion. Players reporting a history of 3 or more
previous concussions were 3.0 (95% confidence interval, 1.6-5.6) times more
likely to have an incident concussion than players with no concussion history.
Headache was the most commonly reported symptom at the time of injury (85.2%),
and mean overall symptom duration was 82 hours. Slowed recovery was associated
with a history of multiple previous concussions (30.0% of those with ≥3
previous concussions had symptoms lasting >1 week compared with 14.6% of those
with 1 previous concussion). Of the 12 incident within-season repeat concussions,
11 (91.7%) occurred within 10 days of the first injury, and 9 (75.0%) occurred
within 7 days of the first injury.ConclusionsOur study suggests that players with a history of previous concussions
are more likely to have future concussive injuries than those with no history;
1 in 15 players with a concussion may have additional concussions in the same
playing season; and previous concussions may be associated with slower recovery
of neurological function.

https://jamanetwork.com/journals/jama/articlepdf/197667/JOC30117.pdf

Cumulative Effects Associated With Recurrent Concussion in Collegiate Football Players: The NCAA Concussion Study

ContextDespite the high prevalence and potentially serious outcomes associated
with concussion in athletes, there is little systematic research examining
risk factors and short- and long-term outcomes.ObjectivesTo assess the relationship between concussion history and learning disability
(LD) and the association of these variables with neuropsychological performance
and to evaluate postconcussion recovery in a sample of college football players.Design, Setting, and ParticipantsA total of 393 athletes from 4 university football programs across the
United States received preseason baseline evaluations between May 1997 and
February 1999. Subjects who had subsequent football-related acute concussions
(n=16) underwent neuropsychological comparison with matched control athletes
from within the sample (n=10).Main Outcome MeasuresClinical interview, 8 neuropsychological measures, and concussion symptom
scale ratings at baseline and after concussion.ResultsOf the 393 players, 129 (34%) had experienced 1 previous concussion
and 79 (20%) had experienced 2 or more concussions. Multivariate analysis
of variance yielded significant main effects for both LD (P<.001) and concussion history (P=.009),
resulting in lowered baseline neuropsychological performance. A significant
interaction was found between LD and history of multiple concussions and LD
on 2 neuropsychological measures (Trail-Making Test, Form B [P=.007] and Symbol Digit Modalities Test [P=.009]),
indicating poorer performance for the group with LD and multiple concussions
compared with other groups. A discriminant function analysis using neuropsychological
testing of athletes 24 hours after acute in-season concussion compared with
controls resulted in an overall 89.5% correct classification rate.ConclusionsOur study suggests that neuropsychological assessment is a useful indicator
of cognitive functioning in athletes and that both history of multiple concussions
and LD are associated with reduced cognitive performance. These variables
may be detrimentally synergistic and should receive further study.

https://jamanetwork.com/journals/jama/articlepdf/191533/JOC80880.pdf

David Cordry

Papers

Relationship between concussion and neuropsychological performance in college football players.