[1] Hosp Crianca Brasilia, BR-70684831 Brasilia, Brazil
[2] Univ Hlth Network, Krembil Neurosci Ctr, Div Neurosurg, Toronto, ON M5T 2S8, Canada
[3] Univ Toronto, Inst Med Sci, Toronto, ON M5S 1A1, Canada
[4] Hosp Sick Children, Div Neurosurg, Toronto, ON M5G 1E8, Canada
[5] Univ Toronto, Dept Surg, Div Neurosurg, Toronto, ON M5S 1A1, Canada