[1] Sureste Univ Hosp, Dept Endocrinol, C Ronda Sur 10, Madrid 28500, Spain
[2] Ramon & Cajal Univ Hosp, Dept Neurosurg, Madrid, Spain
[3] Puerta Hierro Univ Hosp, Dept Neurosurg, Madrid, Spain
[4] CSIC, Comp Ctr, Stat Dept, Madrid, Spain
[5] La Princesa Univ Hosp, Dept Neurosurg, Madrid, Spain