Prediction of post-traumatic complaints after mild traumatic brain injury: early symptoms and biochemical markers.

OBJECTIVES: To identify parameters at first presentation after mild traumatic brain injury (MTBI) that are predictive of the severity of post-traumatic complaints (PTC) after six months. Early recognition of patients with MTBI who are at risk of developing PTC would be useful because early follow up at the outpatient clinic may help to reduce the severity of these complaints in the long run.

METHODS: The presence of symptoms in the emergency room (ER) (headache, dizziness, nausea, vomiting, and neck pain) and biochemical markers (neurone specific enolase and S-100B) in serum were assessed as possible predictive variables for the severity of PTC. Outcome variables were the severity of 16 PTC six months after the trauma.

RESULT: After six months, the severity of most complaints had declined to pretrauma levels but medians for headache, dizziness, and drowsiness were still increased. In a series of 79 patients, 22 (28%) reported one or more PTC after six months. After adjustment for baseline variables, an at least twofold increased severity of all PTC subgroups was reported by those patients reporting headache, dizziness, or nausea in the ER. A twofold increased severity of "cognitive" and "vegetative" PTC was also found in those with increased concentrations of biochemical serum markers at first presentation. The prevalence of full recovery after six months increased from 50% in patients with three symptoms to 78% in those with no symptoms in the ER. Inclusion of biochemical markers showed that all 10 patients with no symptoms in the ER and normal markers recovered fully.

CONCLUSIONS: The presence of headache, dizziness, or nausea in the ER after MTBI is strongly associated with the severity of most PTC after six months. Identifying MTBI patients in the ER without headache, dizziness, nausea, or increased serum marker concentrations may be a promising strategy for predicting a good outcome.