[1] Angers Univ Hosp, UNAM, Dept Neurosci, Div Geriatr Med,UPRES EA 4638, F-49933 Angers 9, France
[2] Univ Hosp Geneva, Dept Neurol, Geneva, Switzerland
[3] Univ Geneva, Geneva, Switzerland
[4] Univ Western Ontario, Dept Med Biophys, Robarts Res Inst, Schulich Sch Med & Dent, London, ON, Canada