1. Department of Neurology and MRI Institute; Medical University of Graz; Graz; Austria
2. Department of Radiology and Neurology; VU University Medical Center; Amsterdam; the Netherlands
3. Neurology Service; Egas Moniz Study Center; Saint Mary Hospital; Lisbon; Portugal
4. Institute of Neuroscience and Physiology; the Sahlgrenska Academy at University of Gothenburg; Gothenburg; Sweden
5. Department of Neurological and Psychiatric Sciences; University of Florence; Florence; Italy
6. Department of Neurology; Helsinki University Central Hospital and Department of Neurological Sciences; University of Helsinki; Finland