Multiple functions of pain induced alpha event-related desynchronization

Abstract

INTRODUCTION: Painful stimulation using intra-epidermal electrical stimulation (IES) (Inui et al., 2002) provides an alternative method to activate nociceptors selectively (Mouraux et al., 2010), because electrical pulses delivered through needle electrode inserted in the epidermis could excite selectively Aδ and C fibre free nerve endings in the epidermis or in the superficial skin layers (i.e. without coactivating Aβ mechanoreceptors that located deeper than the epidermis). Such painful stimulation could elicit transient changes in the ongoing electroencephalographic (EEG) activity, reflected as phase-locked event-related potentials (ERPs) and non-phase-locked modulations of ongoing EEG oscillations (Pfurtscheller and Lopes da Silva, 1999). Among these non-phase-locked modulations, the effect of noxious stimuli on the suppression of α-band oscillations has been extensively investigated (Babiloni et al., 2003; Mouraux et al., 2003; Mouraux and Iannetti, 2008; Ohara et al., 2004; Ploner et al., 2006; Raij et al., 2004). However, a comprehensive understanding of the functional significance of pain induc…