1. Medical Education Promotion Center, Tokyo Medical University, Tokyo 160-0023, Japan
2. Unité des Ataxies Cérébelleuses, Service de Neurologie, CHU-Charleroi, 6000 Charleroi, Belgium
3. Service des Neurosciences, University of Mons, 7000 Mons, Belgium
4. Louis Stokes Cleveland VA Medical Center, University Hospitals Cleveland Medical Center, Cleveland, OH 44106, USA