TABLE 4

Risk factors for persisting post-concussional symptoms

Predisposing factorsPrecipitating factorsPerpetuating factors
Organic influences Prior head injury
 Female
 Age >40
 Low IQ, dementia
 Poor education
 APOE-4 alleleSeverity of head injury:
 - GCS 13–14
 - PTA >1 hour
 - intracranial abnormality on imaging
 - acute headache, dizziness, nausea
 - anosmia
 - “double”“double”double” trauma (intoxication, re-injury prior to recovery)
 -serum S-100BPsychotropic medication
 Analgesic use
 Alcohol use
 Cannabis use
Psychiatric influences Anxiety
 Major depressionTraumatic memories of the event (traumatic memory)Anxiety state
 Post-traumatic stress disorder
 Major depression
Psychological influences Expectation of disability
 “Stress”
 Inadequate information
 Iatrogenic secondary to failed interventions (eg, return to work)Deactivation
 “Fear” avoidance
 Secondary gain (personal, social, or financial gain from the impairments)
 Litigation