Table 1

Concussion modifiers3

FactorModifier
SymptomsNumber
Duration (>10 days)
Severity
SignsProlonged loss of consciousness (>1 min), amnesia
SequelaeConcussive convulsions
TemporalFrequency—repeated concussions over time
Timing—injuries close together in time
‘Recency’—recent concussion or traumatic brain injury
ThresholdRepeated concussions occurring with progressively less impact or slower recovery after each successive concussion
AgeChild and adolescent (<18 years old)
Comorbidities and premorbiditiesMigraine, depression or other mental health disorders, attention deficit hyperactivity disorder, learning disabilities, sleep disorders
MedicationPsychoactive drugs, anticoagulants
BehaviourDangerous style of play
SportHigh-risk activity, contact and collision sport, high sporting level