Patient-reported outcome parameters and disability worsening in progressive multiple sclerosis

Ahmed Abdelhak, Kai Antweiler, Markus C. Kowarik, Makbule Şenel, Joachim Havla, Uwe K. Zettl, Ingo Kleiter, Muna‐Miriam Hoshi, Thomas Skripuletz, Axel Haarmann, Alexander Stahmann, André Huss, Stefan Gingele, Markus Krumbholz, Charlotte Selge, Tim Friede, Albert C. Ludolph, James Overell, Harold Koendgen, Susanne Clinch, Qing Wang, Ulf Ziemann, Stephen L. Hauser, Tania Kümpfel, Ari Green, Hayrettin Tumani