[Exploration of traumatic brain-injury attention difficulty by event-related potentials]

To specify, in cognitive processing leading to an action, the localization of difficulties in attention following severe, traumatic brain injury.

Stimulus-locked and response-locked event-related potentials were recorded during a Stroop task in 25 patients with traumatic brain injury and 25 control subjects approximately 4 months after the accident. The latency and amplitude of the waves were compared between the two groups and correlated with clinical data.

The reaction times of brain-injured patients were significantly longer than those of the control group, but neither the number of errors nor the interference differed between the groups. Electrophysiological recordings showed early abnormalities between 100 and 200 ms after stimulus onset. The key area could be the medial occipitotemporal side connected with frontal regions. Recordings also showed disruptions in motor program monitoring, which implied frontomedial areas.

This protocol allows for precisely dating cognitive abnormalities. Future studies should relate cognitive with neuropsychological abnormalities and examine the possibilities of later regression.