Interindividual variations in peak alpha frequency do not predict the magnitude or extent of secondary hyperalgesia induced by high-frequency stimulation

Abstract

Previous studies have shown an association between interindividual variations in the frequency of a-band EEG oscillations such as estimates of peak alpha frequency (PAF) and pain sensitivity. Whether differences in PAF also influence the susceptibility to develop central sensitization (CS) is unknown. This study aimed to determine whether the PAF of vision- and sensorimotor-related alpha-band activity is associated with the magnitude and extent of secondary mechanical hyperalgesia induced by high-frequency stimulation (HFS) of the skin, a surrogate marker of CS. The EEG was recorded in 32 healthy participants at rest during eyes open and eyes closed conditions, and during bilateral finger movements. Then, HFS was applied to the right forearm. Pinprick sensitivity was assessed at both forearms, before and 40 min after HFS, to assess the magnitude and extent of HFS-induced secondary hyperalgesia. Two methods were used to isolate vision- and sensorimotor-related alpha-band activity basedon sensitivity to eye closure and movement: one based on an independent component analysis, the other on spectral subtraction. PAF was characterized using a center-of-gravity approach and also using Gaussian fitting after removal of the aperiodic EEG component. Neither sensorimotor- nor vision-related PAF were significantly correlated with the magnitude or extent of HFS-induced secondary hyperalgesia. However, exploratory analyses revealed that participants with higher vision-related PAF showed greater pinprick habituation at the nonsensitized forearm, indicating a possible link between PAF and perceptual habituation. Interindividual variations of PAF at baseline were not significantly associated with the susceptibility to develop HFS-induced secondary hyperalgesia.

NEW & NOTEWORTHY Using several methods to estimate vision- and sensorimotor-related peak alpha frequency (PAF) in the EEG frequency spectrum, we found no significant association between interindividual variations in PAF at baseline and the susceptibility to develop secondary hyperalgesia following high-frequency stimulation (HFS) of the skin in healthy participants.

alpha-band; central sensitization; high-frequency stimulation (HFS); peak alpha frequency; secondary hyperalgesia

Authors

Lebrun, L., Ricci, G., Courtin, A. S., van den Broeke, E. N., Lenoir, C., & Mouraux, A.