Sleep and pain: The effects of sleep restriction on pain and evoked potentials

Abstract

Objective: This study investigates the 1) effect of sleep restriction on a) neurophysiological and b) psychophysiological pain responses. We also investigated the 2) effect of sleep on habituation by introducing stimulus repetition as a factor.

Methods: Twenty-two healthy volunteers were engaged in a within-subject cross-over design comparing two nights of 50% sleep restriction with habitual sleep. For activation of the nociceptive pathway, three blocks á thirty (total of 90) electrical stimulations of different intensity were directed to the forearm. Subjective pain responses were measured with numerical rating scale (NRS). Event related brain oscillations in somatosensory cortex (C3/C4) were recorded using 32 channel electroencephalography (EEG). Time-frequency presentation and point-by-point statistical analyses revealed stimulus induced changes in event related potentials (ERP), event related desyncronization (ERD) and gamma-band-oscillations.

Results: Two nights of 50% sleep restriction increased subjective pain scores (NRS) and event related potentials (ERP) to electrical stimulation. These results were not followed by changes in event related desynchronization (ERD) or gamma band oscillations (GBO). Habituation was unaffected by sleep restriction.