Foramen magnum meningiomas: surgical treatment in a single public institution in a developing country - Colli, Benedicto Oscar; Carlotti Júnior, Carlos Gilberto; Assirati Júnior, João Alberto; Borba, Luis Alencar Biurrum; Coelho Júnior, Vicente de Paulo Martins; Neder, Luciano (Arquivos de Neuro-Psiquiatria, 2014)