Prospective Comparison of Longer Needle Lengths to Assess the Risk of OnabotulinumtoxinA-Associated Neck Pain in Patients with Chronic Migraine.

We were not able to identify significant differences or correlations in the incidence, characteristics and location of neck pain with the use of different needle length to inject BoNTA, although the use of the longer 1-inch needles likely increased the risk of this adverse event.