OnabotulinumtoxinA to Prevent Chronic Migraine with Comorbid Bruxism: Real-World Data from the GRASP Study Group

This study, designed by the Greek Research Alliance for the Study of Headache and Pain (GRASP), sought to prospectively examine whether the treatment with two consecutive OnabotulinumtoxinA (BoNTA) cycles might improve the frequency and severity of chronic migraine (CM) with comorbid bruxism. We also explored whether the potential BoNTA-related alleviation of bruxism can directly influence the improvements in migraine efficacy outcomes.

A total of 58 CM patients with comorbid bruxism at baseline, attaining two consecutive (quarterly given) BoNTA cycles, were studied. The changes in bruxism-related pain were assessed with the 0-10 numeric scale PI-NRS. Bruxism was clinically diagnosed using the self-report Bruxscreen-Q questionnaire. Any phenotypic changes in bruxism, according to Bruxscreen-Q, from baseline (T0) to the last efficacy evaluation follow-up (T1), were analyzed and then compared. Migraine-related efficacy and disability outcomes, mostly mean headache days (MHD), were also compared between T0 and T1.

BoNTA exerted significant improvements in bruxism-related pain, with PI-NRS median scores being significantly reduced from 7 at T0 to 3 at T1 (p < 0.001). The rates of masseter hypertrophy at T1 significantly dropped, compared to T0 (chi-square: 16; p < 0.001). Patients also self-reported significant improvements in the Bruxscreen-Q items at T1, compared to T0. At T1, 41/58 (70.7%) patients responded to BoNTA. The significant decrease in MHD frequency at T1 was positively correlated with improvements in bruxism-related pain severity (Pearson's correlation: 0.710; p < 0.001).

BoNTA exerts dual beneficial effects towards both the reduction of migraine frequency and the alleviation of bruxism-related pain and disability. Both of these effects seem closely interrelated in our study.