The neuropsychology of blunt head injury in the early postacute stage: effects of focal lesions and diffuse axonal injury.

This investigation evaluated the neuropsychological symptoms in the early posttraumatic period following blunt head injury and their correlation to routine imaging data in a consecutive series of TBI patients (Magdeburg Neurotrauma Databank). Of 135 consecutive patients, 68 could be assessed neuropsychologically 8-21 days after trauma. In 61 patients, routine clinical CT data were sufficient for neuroradiological analysis focusing on the presence or absence of CT signs of diffuse axonal injury (DAI) or focal traumatic injury. In these patients, the initial GCS score was significantly correlated with the presence of DAI but not with focal pathology. The presence of DAI was correlated with behavioral and cognitive symptoms of frontal lobe dysfunction, especially in interference tasks (Go/NoGO and Stroop reaction times) and semantic fluency. The presence of local frontal or temporal traumatic lesions was associated with deficits in concept formation, fluency tasks and behavioral symptoms, but not with increased interference. Patients with frontal contusions were impaired in a task of visuomotor planning and performance (Block design). Our data indicate that both traumatic DAI and focal lesions result in frontal lobe symptoms. We conclude that, even in clinically "mild" TBI, brain imaging should be used to identify patients with substantial brain damage. These should be assessed neuropsychologically for possible posttraumatic cognitive or behavioral impairment. In consideration of its easy accessibility, the refined use of the CT is considered a promising and valid tool for patient stratification. The application of MRI and biochemical markers may further improve prognostic predictions.