1 Department of Neurology, Hospital Clínico San Carlos, Health Research Institute "San Carlos" (IdISCC), Universidad Complutense de Madrid, 28040 Madrid, Spain.
2 Clinique Interdisciplinaire de Mémoire, Département des Sciences Neurologiques du CHU de Québec, Faculté de Médecine, Université Laval, Quebec City, QC G1V 0A6, Canada.
3 Department of Neurology, Mayo Clinic, Rochester, MN 55902, USA.