[1] Univ Finis Terrae, Escuela Med, Santiago 7501015, Chile
[2] Univ Americas, Fac Hlth & Social Sci, Dept Morphol & Funct, Santiago 8370040, Chile
[3] Univ Andres Bello, Fac Med, Dept Morfol, Santiago 8370186, Chile
[4] Univ Bernardo OHiggins, Fac Ciencias Salud, Dept Ciencias Quim & Biol, Santiago 8370854, Chile
[5] Univ Santiago Chile, Fac Med Sci, Sch Med, Normal Human Anat Unit, Santiago 9170020, Chile
[6] Univ Andres Bello, Fac Med, Dept Morfol, Vina Del Mar 2531015, Chile
[7] Tulane Univ, Tulane Ctr Clin Neurosci, Dept Neurosurg, Sch Med, New Orleans, LA 70112 USA