Specificity of postconcussion symptoms at 3 months after mild traumatic brain injury: results from a comparative cohort study.

OBJECTIVE: To assess the specificity of symptoms included in various symptom lists used to identify postconcussion syndrome (PCS), by using follow-up data comparing patients with mild traumatic brain injury (MTBI) and control patients during the month prior to injury and 3 months later. SETTING: The adult emergency department of a teaching hospital in Bordeaux, France. PARTICIPANTS: A cohort of patients with MTBI (n = 536) and a comparison group with nonhead injuries (n = 946). MAIN MEASURES: Postconcussion symptoms listed in the Rivermead Postconcussion Symptoms Questionnaire (RPQ), the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), and the 10th International Classification of Diseases (ICD-10). RESULTS: Analyses were performed comparing symptom occurrence in patients with MTBI and controls, before and 3 months after injury. Eight symptoms were identified as being specific to MTBI: headache, dizziness, intolerance of stress, forgetfulness, poor concentration, taking longer to think, blurred vision, and personality change. CONCLUSION: The relevance of symptoms proposed to constitute PCS should be reviewed. A more specific definition of PCS would make diagnosis easier and facilitate prevention as well as treatment of patients with MTBI.