Received: 1 May 2018
Accepted: 26 June 2018
First Online: 13 July 2018
Ethics approval and consent to participate
: Ethical approval was obtained from each study side with Duesseldorf (Ethic Committee of Medical Faculty of Heinrich-Heine University Duesseldorf, Germany; Head: Prof. Dr. T. Hohlfeld; study-number: 5644R and registration-ID: 2016075289 approved on 16th September 2016) being the national headquarter for all german ethic committees (Additional file InternalRef removed: ethics committees). Written informed consent was obtained from all patients.
: Not applicable.
: The authors declare that they have no competing interests.
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