Funding for this research was provided by:
National Natural Science Foundation of China (81070963)
Natural Science Foundation of Shandong Province (ZR2010HM019)
Torbjørg Hauges’ Legacy
Text and Data Mining valid from 2017-03-31
Received: 14 February 2017
Revised: 27 March 2017
Accepted: 28 March 2017
First Online: 31 March 2017
Change Date: 11 April 2019
Change Type: Correction
Change Details: The Joint Editors-in-Chief have retracted this article  at the request of the University of Bergen and the Norwegian Board of Health Supervision.
Compliance with ethical standards
: Socrates J Tzartos has shares in the diagnostic laboratory Tzartos NeuroDiagnostics. All other authors declare no conflicts of interest.