1. Gertrude H. Sergievsky Center; Columbia University; New York New York U.S.A.
2. IRCCS Institute of Neurological Sciences of Bologna; Bologna Italy
3. Department of Neurology; College of Physicians and Surgeons; Columbia University; New York New York U.S.A.
4. Department of Epidemiology; Mailman School of Public Health; Columbia University; New York New York U.S.A.