Absent median nerve P14 far-field somatosensory evoked potential with persistent tibial nerve P30 component in a patient with ischemic pontine lesion.

In a patient with an ischemic lesion of the right paramedian region of the pons, somatosensory evoked potential (SEP) recording to median nerve stimulation showed an absent P14 response with still preserved P13 and N18 potentials. The tibial nerve P30 and N33 SEP components were normal. Our results suggest that the median nerve P14 potential, absent in our patient, has a different origin from the tibial nerve P30 response, normal in the present case.