Kringel, D
Ultsch, A
Zimmermann, M
Jansen, J-P
Ilias, W
Freynhagen, R
Griessinger, N
Kopf, A
Stein, C http://orcid.org/0000-0001-5240-6836
Doehring, A
Resch, E
Lötsch, J
Article History
Received: 26 September 2015
Revised: 5 November 2015
Accepted: 13 November 2015
First Online: 3 May 2016
Competing interests
: The authors declare no conflict of interest.