Burstein R, Blumenfeld AM, Silberstein SD, et al. - This study was intended to examine the literature on the mechanism of action of onabotulinumtoxinA in chronic migraine. This study's findings indicated that the following injection into tissues, onabotulinumtoxinA inhibits soluble N‐ethylmaleimide‐sensitive fusion attachment protein receptor‐mediated vesicle trafficking by cleaving one of its essential proteins, soluble N‐ethylmaleimide‐sensitive fusion attachment protein, which happens in both motor and sensory nerves. It was shown that via sensory mechanisms, onabotulinumtoxinA likely acts to treat chronic migraines. OnabotulinumtoxinA likely acts via sensory mechanisms to treat chronic migraines.