Pain-autonomic interaction after work-induced sleep restriction.
OBJECTIVE
Poor sleep is commonly associated with alterations in pain perception. However, there is a lack of studies that address work-associated sleep restriction (SR) and changes in non-nociceptive perception and autonomic responses after work-induced SR.


METHODS
This study was performed with 19 medical students after a normal-sleep night (NS phase) and after a night shift at the local emergency room (SR phase). We performed clinical assessment, quantitative sensory testing for electrical and temperature sensation, RR interval analysis, and recorded sudomotor skin responses (SSRs).


RESULTS
The total mean duration of sleep was 436 ± 18 min in the NS group and 120 ± 28 min in the SR group (P<0.001). The anxiety scores were higher following the SR phase compared with those after the NS phase (P<0.01). After SR, there was a decrease in heat-pain threshold, but neither warm nor electrical thresholds were affected. Following SR, subjects showed higher SSR amplitudes and an increased number of double responses at an interstimulus interval of 2 s. We also observed a moderate inverse correlation between heat-pain thresholds and SSR amplitude (r= -0.46; P<0.01). However, there was no correlation between anxiety scores and SSR parameters.


CONCLUSIONS
The effects of SR in the context of work stress on pain are specific and appear unrelated to general changes in sensory perception. Hyperalgesia was associated with abnormal autonomic responses, but not with increased anxiety, which suggests an association between the nociceptive and autonomic nervous systems that is independent of the emotional state.
Department of Neurology, EMG Unit from Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil. pedro.schestatsky@gmail.com
P
P
Schestatsky
L
L
Dall-Agnol
L
L
Gheller
L C
LC
Stefani
P R S
PR
Sanches
I C
IC
de Souza
I L
IL
Torres
W
W
Caumo
D000328:Adult; D001007:Anxiety / Q000523:psychology; D001342:Autonomic Nervous System Diseases / Q000150:complications / Q000209:etiology / Q000503:physiopathology*; D003627:Data Interpretation, Statistical; D004558:Electric Stimulation; D004576:Electromyography; D004636:Emergency Service, Hospital; D005712:Galvanic Skin Response; D006801:Humans; D016014:Linear Models; D008297:Male; D010146:Pain / Q000150:complications / Q000209:etiology / Q000503:physiopathology*; D010147:Pain Measurement; D058748:Pain Perception; D017288:Pain Threshold; D012892:Sleep Deprivation / Q000503:physiopathology*; D013337:Students, Medical; D013697:Thermosensing; D014937:Work; D055815:Young Adult