title: Response to Shill and colleagues.
authors.affiliation: Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Thenganatt
authors.affiliation: Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, TX, USA. Electronic address: josephj@bcm.edu.
authors.forename: Joseph
authors.initials: J
authors.lastname: Jankovic