1 Brain and Spine Associates, Monroe, Louisiana, USA; Department of Neurosurgery, University of Mississippi, Jackson, Mississippi, USA.
2 Autonomous University of Central America School of Medicine, San Jose, Costa Rica.
3 Department of Neurological Surgery, University of Washington, Seattle, Washington, USA.
4 Department of Neurosurgery, Hospices Civils de Lyon, Pierre Wertheimer Neurological Hospital, Bron, France; France and Laboratory of Anatomy, Faculty of Medicine Lyon Est, Claude Bernard University Lyon 1, Lyon, France.
5 Department of Neurosurgery, University of Mississippi, Jackson, Mississippi, USA.