Long-term treatment of chronic migraine with onabotulinumtoxinA: Efficacy, quality of life, and tolerability in a real-life setting. (25th December 2016) - Kollewe, Katja; Escher, Claus M.; Wulff, Dirk U.; Fathi, Davood; Paracka, Lejla; Mohammadi, Bahram; Karst, Matthias; Dressler, Dirk