Parietal focal spikes evoked by contralateral tactile somatotopic stimulation in four non-epileptic subjects ☆

Abstract Tactile stimulation of the external border of the foot constantly evoked focal spikes in the contralateral paramedian parietal region in 4 young patients. The peak latency of these spikes was 50 msec. These patients were not epileptic and did not demonstrate clinical or radiological signs of a cerebral lesion. In one case a spontaneous irritative focus was observed 7 months after the initial observation. The authors briefly discuss the various interpretative possibilities of the exceptional facilitation of the focal reflex activity. They exclude a “startle effect” or a state of partial deafferentation of the somatosensory area.