1. Hospital Clínico San Carlos, Neurology Department, C/ Prof Martín Lagos, 28040 Madrid, Spain
2. HEALTH VALUE, HE Department, C/ Virgen de Aránzazu, 21, 28034 Madrid, Spain
3. Merck, SLU, C/ María de Molina, 40, 28006 Madrid, Spain, an affiliate of Merck KGaA