Original Research ARTICLE
Tooth clenching induces abnormal cerebrovascular responses in migraineurs.
- 1University of Eastern Finland, Finland
- 2Kuopio University Hospital, Finland
- 3University of Helsinki, Finland
- 4Turku University Hospital, Finland
Prevalence of masticatory parafunctions, such as tooth clenching and grinding, is higher among migraineurs than non-migraineurs, and masticatory dysfunctions may aggravate migraine. Migraine predisposes to cerebrovascular disturbances, possibly due to impaired autonomic vasoregulation and sensitization of the trigeminovascular system. The relationships between clenching, migraine and cerebral circulation are poorly understood.
We used Near-Infrared Spectroscopy to investigate bilateral relative oxy- (%Δ[O2Hb]), deoxy- (%Δ[HHb]), and total (%Δ[tHb]) haemoglobin concentration changes in prefrontal cortex induced by maximal tooth clenching in twelve headache-free migraineurs and fourteen control subjects.
From the start of the test, migraineurs showed a greater relative increase in right-side %Δ[HHb] than controls, who showed varying reactions, and right-side increase in %∆[tHb] was also greater in migraineurs (p < 0.001 and p<0.05, respectively, time-group interactions, Linear mixed models). With multivariate regression model, migraine predicted the magnitude of maximal blood pressure increases, associated in migraineurs with mood scores and an intensity of both headache and painful signs of temporomandibular disorders (pTMD). Although changes in circulatory parameters predicted maximal NIRS responses, the between-group differences in the right-side NIRS findings remained significant after adjusting them for systolic blood pressure and heart rate. A family history of migraine, reported by all migraineurs and four controls, also predicted maximal increases in both %∆[HHb] and %∆[tHb]. Presence of pTMD, revealed in clinical oral examination in eight migraineurs and eight controls, was related to maximal %∆[HHb] increase only in controls.
To conclude, the greater prefrontal right-side increase in cerebral %∆[HHb] and %∆[tHb] may reflect disturbance of the tooth clenching-related cerebral (de)oxygenation based on impaired reactivity and abnormal microcirculation processes in migraineurs. This finding may have an impact in migraine pathophysiology and help to explain the deleterious effect of masticatory dysfunctions in migraine patients. However, the role of tooth clenching as a migraine trigger calls for further studies.
Keywords: cerebral blood flow, Headache, imaging, near-infrared spectroscopy, Trigeminovascular system
Received: 11 Oct 2018;
Accepted: 05 Dec 2018.
Edited by:Anna Andreou, King's College London, United Kingdom
Reviewed by:Ali SAZCI, Kocaeli University, Turkey
Anders Hougaard, Danish Headache Center, Rigshospitalet, Denmark
Copyright: © 2018 Zaproudina, Rissanen, Lipponen, Vierola, Rissanen, Karjalainen, Soinila and Närhi. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Nina Zaproudina, University of Eastern Finland, Kuopio, Northern Savonia, Finland, email@example.com