Head Pain as a Result of Experimental Ischemic Exercise of the Temporalis Muscle

Abstract
SYNOPSISReports indicate that ischemia relative to cranial muscle activity accompanies muscle contraction headache and jaw claudication. The purpose of this study was to experimentally create ischemia in exercising temporalis muscle in order to determine if this combination would produce head pain. Ten subjects were studied during each of three experimental conditions: temporalis muscle ischemia, rhythmic temporalis muscle exercise, and both ischemia and temporalis muscle exercise combined. Ischemia was produced by a scalp sphygmomanometer and verified by Doppler ultrasonic flowmetry of the superficial temporal artery. Temporalis muscle exercise was produced by gum chewing at 60 strokes/min using 30% of maximum electromyographic (EMG) activity. The time to onset of pain and the time to reach pain tolerance were measured. Pain, using either exercise or ischemia alone developed in a median time of 27 minutes and was seldom located in the temporal area. Pain, using both exercise and ischemia, developed in a median time of three minutes and was predominantly located in the temporal area. Both onset and tolerance times were shorter in the combined protocol when compared to ischemia or exercise alone (r<.001). Tenderness to palpation was observed in the temporal muscle following the combined procedure but not following the individual procedures. The results support the view that ischemic temporal muscle activity can produce head pain.