1. University of Edinburgh; Division of Clinical Neurosciences; Bramwell Dott Building, Western General Hospital Crewe Road Edinburgh UK EH4 2XU
2. Ospedale di Città della Pieve; A USL 2 dell'Umbria; Via B. G. Villa, 1 Città della Pieve Italy 06062
3. Western General Hospital; Department of Radiology; Crewe Road Edinburgh UK EH4 2XU
4. University of Birmingham; Public Health, Epidemiology and Biostatistics; Edgbaston Birmingham UK B15 2TT