Impact of delaying botulinum toxin treatment in patients with migraine during the COVID-19 pandemic

Background Due to coronavirus disease 2019 (COVID-19) pandemic response measures, the administration of botulinum toxin (BTX) was delayed for many patients during the first lockdown period in Portugal. Objectives To review the impact of postponing BTX treatment on migraine control. Methods This was a retrospective, single-center study. Patients with chronic migraine who had done at least three previous BTX cycles and were considered responders were included. The patients were divided into two groups, one that has had their treatment delayed (group P), and one that has not (controls). The Phase III Research Evaluating Migraine Prophylaxis Therapy (PREEMPT) protocol was used. Migraine-related data were obtained at baseline and at three subsequent visits. Results The present study included two groups, group P (n = 30; 47.0 ± 14.5 years; 27 females, interval baseline -1 (st) visit: 5.5 [4.1–5.8] months) and the control group (n = 6; 57.7 ± 13.2 years; 6 females; interval baseline–1 (st) visit 3.0 [3.0–3.2] months). No difference between the groups was present at baseline. When compared to baseline, the number of days/month with migraine (5 [3–6.2] vs. 8 [6–15] p < 0.001), days using triptans/month (2.5 [0–6] vs. 3 [0–8], p = 0.027) and intensity of pain (7 [5.8–10] vs. 9 [7–10], p = 0.012) were greater in the first visit for group P, while controls did not present a significant variation. The worsening of migraine-related indicators decreased in the following visits; however, even in the third visit, it had not returned to baseline. Correlations were significant between the delayed time to treatment and the increase in days/month with migraines at the first visit after lockdown (r = 0.507; p = 0.004). Conclusions There was a deterioration of migraine control after postponed treatments, with a direct correlation between the worsening of symptoms and the number of months that the treatment was delayed.