OnabotulinumtoxinA Improves Sleep Quality in Patients with Chronic Migraine: A Prospective Real-World Study

Sleep disturbances are highly prevalent in patients with chronic migraine (CM) and are increasingly recognized as major contributors to disease burden and headache chronification. Growing evidence suggests that dysregulation of calcitonin gene-related peptide (CGRP) signaling and central sensitization may represent common biological mechanisms linking migraine and sleep impairment. OnabotulinumtoxinA (OBT-A), an established preventive treatment for CM, inhibits the release of CGRP and other nociceptive mediators from trigeminal sensory neurons, thereby reducing peripheral and central sensitization. However, its effects on sleep quality remain incompletely characterized. The aim of this prospective real-world observational pilot study was to evaluate the impact of OBT-A treatment on sleep quality in patients with CM. Consecutive patients initiating OBT-A therapy at a tertiary headache center were enrolled and assessed at baseline (before the first OBT-A treatment cycle) and after three months, immediately before the second scheduled administration, using the Pittsburgh Sleep Quality Index (PSQI), alongside measures of migraine frequency, acute medication use, migraine-related disability, and headache impact. Fifteen patients completed follow-up evaluations. OBT-A treatment was associated with significant improvements across all clinical outcomes. Median monthly migraine days decreased from 18 to 10 (adjusted p = 0.006), while acute medication use, MIDAS scores, and HIT-6 scores were significantly reduced. Sleep quality improved markedly, with median PSQI scores decreasing from 10 to 6 (adjusted p = 0.006). Eleven of 15 patients (73.3%) achieved a ≥3-point reduction in PSQI, and the proportion of participants with pathological sleep quality (PSQI > 5) decreased from 86.7% to 53.3%. Although this categorical improvement did not reach statistical significance (exact p = 0.063), likely due to the limited sample size, it may nonetheless suggest a beneficial effect on sleep quality, although the lack of statistical significance warrants cautious interpretation. These findings provide preliminary real-world evidence that OBT-A treatment is associated with improved subjective sleep quality in patients with chronic migraine. Improvements in sleep quality occurred alongside reductions in migraine frequency, acute medication use, disability, and headache impact. Given the observational and uncontrolled design of the study, it remains unclear whether sleep improvement reflects a direct effect of OBT-A or occurs secondarily to improvements in migraine-related outcomes. Larger prospective controlled studies are needed to clarify the mechanisms underlying sleep improvement and its relationship with treatment response.