1. Department of Neurosurgery, CHU Bab El Oued, Algiers, Algeria
2. Department of Neurosurgery, Maradi Reference Hospital, Niger Republic
3. Department of General Surgery, Faculty of Health Sciences, University of Zinder, National Hospital, Zinder, Niger Republic
4. Department of Ophthalmology, Maradi Reference Hospital, Niger Republic
5. Department of Neurosurgery, Niamey National Hospital, Niger Republic