OBJECTIVE: To verify the possibility of selective activation of C-fibers by a 5-Hz transcutaneous electrical stimulus. METHODS: Because Aβ-, Aδ- and C-fibers have different conduction velocities, we verified the selective activation of A- and C-fibers on the basis of evoked potential latencies. We tested whether a 5-Hz sinusoidal electric stimulus could selectively activate C-fibers and consequently generate ultra-late N2/P2 components in the 750-1200 ms range. RESULTS: We found that a 5-Hz sine wave stimulus, whether of high or low intensity, elicited N2/P2 complexes only in the late latencies (160-390 ms), suggesting that A-fibers were concomitantly activated along with C-fibers. CONCLUSIONS: These findings are in agreement with those of previous simulation studies suggesting that activation of fibers of diameter less than 2.5 μm (i.e., C-fibers) at the 5-Hz frequency requires accompanying activity from Aβ- and Aδ-fibers. SIGNIFICANCE: Transcutaneous electrical stimulation with sine wave currents of different frequencies does not seem to be a reliable method for the selective assessment of somatosensory pathways.
OBJECTIVE: To verify the possibility of selective activation of C-fibers by a 5-Hz transcutaneous electrical stimulus. METHODS: Because Aβ-, Aδ- and C-fibers have different conduction velocities, we verified the selective activation of A- and C-fibers on the basis of evoked potential latencies. We tested whether a 5-Hz sinusoidal electric stimulus could selectively activate C-fibers and consequently generate ultra-late N2/P2 components in the 750-1200 ms range. RESULTS: We found that a 5-Hz sine wave stimulus, whether of high or low intensity, elicited N2/P2 complexes only in the late latencies (160-390 ms), suggesting that A-fibers were concomitantly activated along with C-fibers. CONCLUSIONS: These findings are in agreement with those of previous simulation studies suggesting that activation of fibers of diameter less than 2.5 μm (i.e., C-fibers) at the 5-Hz frequency requires accompanying activity from Aβ- and Aδ-fibers. SIGNIFICANCE: Transcutaneous electrical stimulation with sine wave currents of different frequencies does not seem to be a reliable method for the selective assessment of somatosensory pathways.
Authors: Stéphanie van der Lely; Melanie R Schmidhalter; Stephanie C Knüpfer; Andrea M Sartori; Marc P Schneider; Stephanie A Stalder; Thomas M Kessler; Martina D Liechti; Ulrich Mehnert Journal: BJU Int Date: 2021-10-28 Impact factor: 5.969
Authors: Céline Z Duval; Yannick Goumon; Véronique Kemmel; Jürgen Kornmeier; André Dufour; Olivier Andlauer; Pierre Vidailhet; Pierrick Poisbeau; Eric Salvat; André Muller; Ayikoé G Mensah-Nyagan; Catherine Schmidt-Mutter; Anne Giersch Journal: Sci Rep Date: 2016-03-03 Impact factor: 4.379