Somatosensory evoked potentials are a valuable tool in functional test
ing of the lemniscal part of the somatosensory system. After adequate
stimulation, the ascending impulse volley may partly be recorded as ne
ar-field activity in the vicinity of different generators. Using far-f
ield recordings from the scalp with non cephalic leads, potentials gen
erated further away from the recording electrodes within different sit
es of the somatosensory system can be registrated. SEP recording both
can help to identify different types of pathological impulse conductio
n and to localize lesions within the somatosensory system.