1. Department of Neurosurgery, Institut National de la Santé et de la Recherche Médicale, Unite 646, University Hospital, Angers, France
2. Department of Neurosurgery, University Hospital Pitié-Salpétrière, Paris, France
3. Department of Neurosurgery, University Hospital, Hospice de Lyon, Lyon, France
4. Department of Neurosurgery, University Hospital, Marseille, France
5. Department of Neurosurgery, University Hospital, Lille, France
6. Department of Neurosurgery, University Hospital, Poitiers, France
7. Department of Neurosurgery, University Hospital, Tours, France
8. Department of Neurosurgery, General Hospital, Orléans, France
9. Department of Neurosurgery, University Hospital, Nice, France
10. Department of Neurosurgery, University Hospital, Montpellier, France
11. Department of Neurosurgery, University Hospital, Kremlin Bicêtre, France
12. Department of Neurosurgery, University Hospital, Toulouse, France
13. Institut National de la Santé et de la Recherche Médicale, Unite 646, University of Angers, Angers France