Correlation between cognitive P300 changes and the grade of closed head injury

OBJECTIVE: To investigate the use of auditory oddball cognitive P300 changes in an attempt to find out the correlation between the grade and consequences of closed head injury. MATERIALS AND METHODS: Twenty patients with cerebral concussion (mean age 38.5 +/- 10.5 years) and twenty patients with cerebral contusion (mean age 35.5 +/- 9.8 years) underwent auditory oddball P300 investigation within 0.5 - 28 months after the incident. CT was performed in all of patients before P300 testing. The control group consisted of 30 healthy persons, age and sex matched to the study cohort. RESULTS: All of the patients with concussion showed normal results in P300. Sixteen cases with contusion (80%, CI 62.5-97.3%, p < 0.05) revealed abnormal P300 (latency more than 360 msec and absent P300 response in 4 cases). CONCLUSION: Years after the head injury, cognitive P300 changes make cerebral contusion objective.