Introduction: Nocturnal bruxism has been known to result in bi-temporal morning headaches. However, treatments directed toward controlling nocturnal bruxism such as intraoral splints do not always reduce the pain of these headaches. Other factors such as caffeine withdrawal and analgesic rebound are known to result in chronic daily headaches and are implicated in causing morning headaches. The purpose of this study was to attribute the etiology of morning headaches to nocturnal bruxism, caffeine/analgesic withdrawal or other factors.
Methods: Forty-four female patients who presented to a TMJ and orofacial pain clinic participated in the study. To be included, patients had to awaken with a headache after having gone to sleep headache-free. A diagnosis of nocturnal bruxism or caffeine/analgesic rebound was made based on a thorough medical history and exam. The diagnosis of rebound headache was confirmed only with complete elimination of the morning headaches after withdrawal of the suspected substance. A diagnosis of bruxism as a contributing factor was confirmed if the patient reported complete cessation of the morning headache following initiation of intraoral splint therapy. In the instance of caffeine or analgesic overuse in conjunction with suspected bruxism, reduction of the suspected rebound agents was initiated first. If relief was not obtained within two weeks of withdrawal, then intraoral splint therapy was implemented.
Results: Forty patients completed the study. Nocturnal bruxism accounted for 16/40 (45%) of the study group's morning headaches, while 21/40 (52.5%) were attributed to rebound, and for 3/20 (7.5%) a diagnosis could not be determined. From the rebound group 16 (40%) of all the headaches were from caffeine overuse, 3/40 (7.5%) from analgesic rebound and 2/40 (5%) from both (i.e. ASA + caffeine).
Conclusions: Morning headaches can result not only from nocturnal
bruxism, but also from the effects of caffeine and analgesic withdrawal.