Brain response to one's own name in vegetative state, minimally conscious state, and locked-in syndrome

A major challenge in the management of severely brain-injured patients with altered states of consciousness is to estimate their residual perception of the environment.

To investigate the integrity of detection of one's own name in patients in a behaviorally well-documented vegetative state (VS), patients in a minimally conscious state (MCS), and patients with locked-in syndrome.

We recorded the auditory evoked potentials to the patient's own name and to 7 other equiprobable first names in 15 brain-damaged patients.

A P3 component was observed in response to the patient's name in all patients with locked-in syndrome, in all MCS patients, and in 3 of 5 patients in a VS. P3 latency was significantly (P<.05) delayed for MCS and VS patients compared with healthy volunteers.

These results suggest that partially preserved semantic processing could be observed in noncommunicative brain-damaged patients, notably for the detection of salient stimuli, such as the subject's own name. This function seems delayed in MCS and (if present) in VS patients. More important, a P3 response does not necessarily reflect conscious perception and cannot be used to differentiate VS from MCS patients.