1. Charles Dent Metabolic Unit; National Hospital for Neurology and Neurosurgery; London United Kingdom
2. Sobell Department for Movement Disorders and Clinical Neuroscience; Institute of Neurology; National Hospital for Neurology and Neurosurgery; London United Kingdom
3. Movement Disorders Unit; Department of Neurology; Hospital Universtiari La Fe; Valencia Spain
4. Department of Neurology; Amedeo Avogadro University; Novara Italy
5. Department of Neurology; University of Ljubljana; Ljubljana Slovenia
6. Lysholm Department of Neuroradiology; National Hospital for Neurology and Neurosurgery; London United Kingdom
7. Clinical and Molecular Genetics Unit; UCL Institute of Child Health, Great Ormond Street Hospital; London United Kingdom