OBJECTIVE: This study aimed to investigate scalp gamma-band oscillations (GBOs) induced by mechanical stimuli activating skin nociceptors before and after the induction of mechanical hypersensitivity using high-frequency electrical stimulation (HFS) of the skin. METHODS: In twenty healthy volunteers, we recorded the electroencephalogram during robot-controlled mechanical pinprick stimulation (512 mN) applied at the right ventral forearm before and after HFS. RESULTS: HFS induced a significant increase in mechanical pinprick sensitivity, but this increased pinprick sensitivity was, at the group level, not accompanied by a significant increase in GBOs. Visual inspection of the individual data revealed that possible GBOs were present in eight out of twenty participants (40%) and the frequency of these GBOs varied substantially across participants. CONCLUSIONS: Based on the low number of participants showing GBOs we question the (clinical) utility of mechanically-induced GBOs as an electrophysiological marker of pinprick hypersensitivity in humans. SIGNIFICANCE: Mechanical pinprick-induced scalp GBOs are not useful for evaluating mechanical pinprick hypersensitivity in humans.
Gousset, S., Torta, D. M., Mouraux, A., Lambert, J., & van den Broeke, E. (2023). Pinprick-induced gamma-band oscillations are not a useful electrophysiological marker of pinprick hypersensitivity in humans. Clinical Neurophysiology, 153, 102-110. https://doi.org/10.1016/j.clinph.2023.06.018 (Original work published 2023)