The aim is to characterize psychophysiological mechanisms in the autonomic control of muscle activity during sleep and to examine the hypothesis that autonomic dysregulation, manifest as a deviant muscle activity pattern during sleep, is associated with stress-induced muscle pain syndromes.
Stress-induced muscle pain is predominantly located to the shoulder, neck and head regions. It is therefore of interest that 24-hour ambulatory recordings show that subjects who are working, but report shoulder and neck pain the last 6 months, have significantly more muscle activity reflected in higher surface electromyographic (SEMG) activity levels in trapezius during sleep than subjects who report they are pain free.
30 female fibromyalgia patients and 30 age-matched female healthy controls will be monitored by ambulatory recording equipment for 24 hours. Bilateral recording of trapezius SEMG activity, sleep (EEG), heart rate and respiration will be made. Catecholamines will be measured in urine, cortisol in saliva.
This study is based on an international collaboration between researchers from Sweden, Norway and USA with complementary expertise in EMG signal analysis, motor control, and in muscle, sleep and stress physiology.
The proposed study has important implications for the study of physiological processes in sleep and potentially provides new insight in the etiology of very prevalent muscle pain syndromes. It is assumed that such insight is important for the prevention and/or treatment of these syndromes.