Do somatosensory evoked potentials in traumatic brain injury patients indicate brainstem generators for frontally recorded N18, P20 and cervical N13?

To examine the generator of frontal somatosensory evoked potentials by studying patients with traumatic brain injury in the chronic phase. A prospective, non-comparative case series. Median nerve somatosensory evoked potentials were performed in 26 survivors of severe traumatic brain injury, which had taken place at a mean of 7 months before. Potentials of short latency somatosensory evoked potentials were recorded simultaneously over the frontal and parietal scalp. Frontally recorded latencies N18, P20 and N13 recorded from C2 correlated highly significantly with the duration of coma (p