Let live or let die after traumatic coma: Scrutinizing somatosensory evoked potentials.

It is now firmly established that bilateral abolition of somatosensory evoked potentials (SEPs) after a nontraumatic coma has 100% specificity for nonawakening. In traumatic coma, a bilateral absence of the N20 components of SEPs does not implicate nonawareness. Comatose brain-injured patients should be systematically explored with auditory evoked potentials to check the functional integrity of another sensory pathway and the mesencephalic tegmento-tectal region on cerebral MRI should be carefully examined. Repeated evaluations during follow-up are also mandatory.