Facilitation of late somatosensory evoked potentials by electrical train stimuli

Facilitation dynamics of late somatosensory evoked potentials after sural nerve stimulation

“…3). This facilitatory effect is similar to previously reported data after stimulation of a sensory arm nerve (Zakharova and Kornhuber, 2013), and most certainly results from temporal summation of EPSPs at cortical somatosensory target neurons. The facilitation of the N1 response is presumably mediated primarily by fast conducting myelinated nerve fibres.…”

“…In agreement with such a view, amplitudes of the early EP responses displayed considerably lower amplitudes after sural nerve stimuli in this study as compared to radial superficial nerve stimuli (Zakharova and Kornhuber, 2013). By way of contrast to the early EP components, N1 has been shown to have a more widespread distribution (Allison et al, 1992).…”

“…2). This finding differs from the N20 facilitation by train stimuli over the radial nerve as reported previously (Zakharova and Kornhuber, 2013). At a first glance, this disagreement may be surprising.…”

“…Furthermore, in our previous investigation SSEP amplitudes were dependent on the stimulus frequency, indicating influences of refractoriness (Zakharova and Kornhuber, 2013). In the present study, recovery from refractoriness was addressed by way of a paired stimulus paradigm.…”

“…Thereby, the summation behaviour of SP arriving at cortical target neurones should become accessible in surface recordings. Previously, we have shown that SSEPs can be amplified compared to single stimuli by way of electrical train stimuli with very short within train interstimulus intervals (ISIs) in the range of few milliseconds (Zakharova and Kornhuber, 2013). This augmentation was similarly present for all SSEP components, i.e.…”