1. Graduate Program in Medical Science, School of Medicine, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
2. Center for Clinical Research and Management Education, Division of Health Care Sciences, Dresden International University, Dresden, Germany
3. Laboratory of Pain and Neuromodulation, School of Medicine, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
4. Department of Neurology, University Hospital Carl Gustav Carus Technische Universitat, Dresden, Germany
5. Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
6. Pain and Palliative Care Service at Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil
7. Surgery Department, School of Medicine, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil