2 Division of Critical Care, Charlotte Maxeke Hospital and Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa.
3 Department of Neurology and Neurosurgery, Universidade Federal de São Paulo and Programa Integrado de Neurologia and Instituto de Ensino e Pesquisa, Hospital Israelita Albert Einstein, São Paulo, Brazil.
4 Bombay Hospital Institute of Medical Sciences, Mumbai, India. Electronic address: [email protected].