Background: Mild traumatic brain injury is associated with persistent cognitive difficulties. However, these symptoms may not be specific to the head injury itself. We sought to evaluate the prevalence of these symptoms in patients following trauma.
Methods: A prospective analysis of patients who were seen in the outpatient trauma clinic during a 20-month period and completed self-administered Rivermead Post-Concussion Symptoms Questionnaire was conducted. "Significant" difficulty with cognition was defined by two or more symptoms reported as severe or four or more symptoms reported as moderate. Head injury was defined as head Abbreviated Injury Scale (AIS) score greater than 0, including the diagnosis of concussion. Multivariable logistic regression was used to test associations between head injury, injury severity, sex, and age with significant cognitive difficulties, loss of work/school, and unmet physical, occupational, or psychological therapy needs.
Results: A total of 587 completed questionnaires were matched to trauma registry admissions (382 early, 111 mid, 86 late). The incidence of significant cognitive difficulties was 37% at less than 1 month, 40% at 1 month to 3 months, and 45% of patients at more than 3 months following injury. Head injury was not associated with increased odds for significant cognitive difficulties (adjusted odds ratio, 1.21; 95% confidence interval, 0.82-1.77; p = 0.3) There was no significant difference in symptoms in patients who carried a head injury diagnosis and those who did not.
Conclusion: Cognitive problems occur frequently following injury even in the absence of a head injury diagnosis. Either mild traumatic brain injury is grossly underdiagnosed or these symptoms are not specific to postconcussive states and simply are the cognitive sequelae of traumatic injury. The reporting of moderate-to-severe symptoms suggests a need to better understand the effects of trauma on cognitive function and strongly suggests that services for these patients are badly needed to maximize cognitive function and return to preinjury quality of life.
Level of evidence: Prognostic/epidemiologic study, level II.