Background: OnabotulinumtoxinA (OnabotA) is considered effective in in patients with chronic migraine (CM) who failed on traditional therapies. This study was designed to evaluate the effect of OnabotA injection series on migraine outcome, negative emotional states and sleep quality in patients with CM. Methods: A total of 190 patients with CM (mean (SD) age: 39.3 (10.2) years
