1. Department of Neurology, Inst. Investigacions Biomèdiques-Hospital Sant Pau, Universitat Autónoma de Barcelona, Barcelona, Spain
2. Centro de Investigación Biomédica en Red en Enfermedades Neurodegenerativas, CIBERNED, Spain
3. Department of Neurology, Center for Research and Advanced Therapies, Fundación CITA-Alzheimer Fundazioa, San Sebastián, Spain
4. Department of Neurology, Alzheimer's Disease and other Cognitive Disorders Unit, Hospital Clínic, Barcelona, Spain
5. Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, University of Göteborg, Göteborg, Sweden