Pharmacopsychiatry 2003; 36 - 224
DOI: 10.1055/s-2003-825467

Sex-specific differences in pain-induced facial muscle activation

T Raedler 1, K Wolf 1, K Wiedemann 1
  • 1University Hospital Hamburg-Eppendorf, Dept. of Psychiatry, Hamburg, Germany

The perception of pain underlies intra- and interindividual differences. So far, only little is known about pain-induced facial muscle activation, in particular with regards to sex-specific differences. In a small pilot-study we combined Thulium-YAG-laser-induced painful stimuli with a highly sensitive facial EMG-device to study sex-specific effects of painful stimuli on facial expression.

Methods: 10 healthy male and 12 healthy female subjects underwent a series of laser-induced painful stimulations of varying intensity (200–800J). Following standardized electrode placement, facial muscle activity was continuously measured using nine bipolar electrodes placed over nine facial muscles.

Results: While male subjects showed a uniform pattern of activation (mentalis and orbicularis oculi muscles), we found a diffuse activation of different facial muscles without distinct pattern in females.

Conclusions: The results of pilot-study make it seem possible that sex-specific differences may exist in pain-induced facial muscle activation.