aPain Center, Department of Neurology, School of Medicine, University of São Paulo, São Paulo, Brazil
bNeurosurgery Division, Department of Neurology, School of Medicine, University of São Paulo, São Paulo, Brazil
cPhysical Medicine, Department of Orthopedics, School of Medicine, University of São Paulo, São Paulo, Brazil
dInstituto do Câncer do Estado de São Paulo Octávio Frias de Oliveira, University of São Paulo, São Paulo, Brazil
*Corresponding author. Address: Divisão de Clínica Neurocirúrgica do Hospital das Clínicas da FMUSP, Secretaria da Neurologia, Instituto Central, Av. Dr. Enéas de Carvalho Aguiar, 255, 5° andar, sala 5084 – Cerqueira César, São Paulo, SP 05403-900, Brazil. Tel./fax: +55 11 26 61 71 52.
Submitted March 18, 2014; revised August 12, 2014; accepted August 13, 2014.
