Six children with tactile-evoked spikes in the EEG, also defined as extreme somatosensory evoked potentials (ESEPs), underwent an SEPs study in order to define the characteristics of such evoked potentials. Short-latency SEPs showed normal mean latency and amplitude values. Mid- or long-latency SEPs of abnormally high amplitude were recorded after stimulation of one or more extremities. Such extreme responses which showed the same reactivity proper to normal long-latency SEPs could be considered to correspond to the evoked spikes in the EEG.