Manzano G M, De Navarro J M, Nóbrega J A, Novo N F, Juliano Y
Clinical Neurophysiology Laboratory, Escola Paulista de Medicina, São Paulo, Brazil.
Electroencephalogr Clin Neurophysiol. 1995 May;96(3):229-35. doi: 10.1016/0168-5597(94)00271-f.
Somatosensory evoked potentials were obtained by electrical stimulation of the median nerve in 10 normal subjects at 3 and 30 Hz. At the higher rate of stimulation, a reduction was observed in amplitudes and prolongation of latencies of the N9, N/P13 and N20 components as well as increase of the interpeak latency N9-N/P13. A significant increase between the onsets of the N11 and N20 components was also seen; however, no significant increase of the N/P13-N20 interpeak latency was observed. Analysis suggested that an important reason for this last finding was related to the fact that in some cases different fast frequency components (FFC) determined the N20 peak in the different situations. It was further observed that, in those cases in which at least 3 peaks in the fast frequency components were detected (7/10), a significantly different increase in latency between the first and the third peaks was noted. A possible thalamo-cortical generation of the FFC is discussed.
对10名正常受试者的正中神经进行电刺激，分别以3Hz和30Hz的频率记录体感诱发电位。在较高刺激频率下，观察到N9、N/P13和N20成分的波幅降低、潜伏期延长，以及N9-N/P13峰间潜伏期增加。N11和N20成分起始之间也有显著增加；然而，未观察到N/P13-N20峰间潜伏期有显著增加。分析表明，最后这一发现的一个重要原因与以下事实有关：在某些情况下，不同的快速频率成分（FFC）在不同情况下决定了N20峰。进一步观察到，在那些至少检测到快速频率成分中有3个峰的情况（7/10）中，第一个峰和第三个峰之间的潜伏期有显著不同的增加。文中讨论了FFC可能的丘脑-皮质起源。
