[Somatosensory evoked potentials following tactile skin stimulation]

Somatosensory evoked potentials were recorded for tactile stimuli applied to the fingers II and V as well as paravertebrally. The advantage of the painless mechanical stimuli is their specificity and the well defined stimulus localization. The question was therefore if the evoked responses are clearly demarcated. Nack potentials (N22: 22.5 and 22.3 ms) as well as cortical SEP's (P1: 33.2 and 32.8 ms) were easily to derive. It was also possible to get SEP's for segmental paravertebral tactile stimuli. For the finger stimulation an Erb's potential could not be recorded reliably.