aProgram in Solid Tumors, Center for Applied Medical Research

bDepartment of Pediatrics, Clínica Universidad de Navarra

cCancer Center Clínica Universidad de Navarra

dHealth Research Institute of Navarra (IdiSNA)

eDepartment of Neurology, Clínica Universidad de Navarra, Pamplona, Navarra, Spain

Correspondence to Jaime Gállego Pérez-Larraya, Dpt. of Neurology. Clínica Universidad de Navarra, Avda. Pío XII 36, 31008 Pamplona. Spain. Tel: +34 948 25 54 00; e-mail: [email protected]