[1] Hosp Univ Marques de Valdecilla, Dept Neurol Surg, Santander 39008, Spain
[2] Hosp Univ Marques de Valdecilla, Spine Unit, Santander 39008, Spain
[3] Univ Cantabria, Fac Sci, Dept Appl Phys, Santander 39005, Spain
[4] Inst Invest Marques de Valdecilla IDIVAL, Santander 39012, Spain
[5] Hosp Univ Marques de Valdecilla, Serv Anat Patol, Santander 39008, Spain
[6] Univ Cantabria, Dept Anat & Cell Biol, Santander 39005, Spain
[7] Hosp Univ Marques de Valdecilla, Genet Unit, Santander 39008, Spain