Background: This report details the case histories of two women who suffer from chronic and debilitating episodes of excessive yawning in the absence of sleep problems.
Methods: Each woman independently provided information and answered questions about their excessive yawning symptoms and medical histories.
Results: Both women show signs of thermoregulatory dysfunction, and each reports symptom relief and/or the postponement of yawning attacks through means of behavioral cooling. One woman recorded her body temperature before and after bouts of yawning, revealing a significant drop in temperature following each episode (p < 0.05).
Conclusions: The trigger for yawning in these patients appears to be related to increases in body/brain temperature. These cases are consistent with growing evidence showing that recurrent episodes of excessive yawning are not necessarily associated with a sleep disorder, but rather may be indicative of thermoregulatory dysfunction.