Footnotes

• Collaborators Angelo Antonini, Clive Ballard, Claudio Babiloni, Alexandra Bernadotte, Roberta Biundo, Bradly Boeve, Jan Booij, Sevasti Bostantjopoulou, Carlo De Lena, Richard Dodel, Cristian Falup-Pecurariu,Tormod Fladby, Sara Garcia- Pacek, Josep Garre, Gert J. Geurtsen, Martha Therese Gjestsen, Oskar Hansson, Frank Jan de Jong, Vesna Jelic, Zoe Katsarou, Milica Kramberger, Elisabet Londos, Ian McKeith, Brit Mollenhauer, Flavio Nobili, John O’Brien, Alessandro Padovani, Maria Petrova, Andrea Pilotto, Irena Rektorova, Arvid Rongve, Jon Snaedal, Elka Stefanova, Per Svenningsson, John Paul Taylor, Pietro Tiraboschi, Latchezar Traykov, Rik Vandenberghe, Zuzana Walker, Eric Westman, Bengt Winblad, Henrik Zetterberg.

• Contributors RDC analysed the data, performed statistical analyses and wrote the manuscript. CA, FB, OB, AWL, IvS provided CSF data and critically revised the paper; MO critically revised the paper, DA and LB supervised RDC work and critically revised the manuscript.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests None declared.

• Patient consent for publication Not required.

• Provenance and peer review Not commissioned; externally peer reviewed.