title: Motor symptoms in Parkinson's disease: A unified framework.
abstract: Parkinson's disease (PD) is characterized by a range of motor symptoms. Besides the cardinal symptoms (akinesia and bradykinesia, tremor and rigidity), PD patients show additional motor deficits, including: gait disturbance, impaired handwriting, grip force and speech deficits, among others. Some of these motor symptoms (e.g., deficits of gait, speech, and handwriting) have similar clinical profiles, neural substrates, and respond similarly to dopaminergic medication and deep brain stimulation (DBS). Here, we provide an extensive review of the clinical characteristics and neural substrates of each of these motor symptoms, to highlight precisely how PD and its medical and surgical treatments impact motor symptoms. In conclusion, we offer a unified framework for understanding the range of motor symptoms in PD. We argue that various motor symptoms in PD reflect dysfunction of neural structures responsible for action selection, motor sequencing, and coordination and execution of movement.
authors.affiliation: Department of Veterans Affairs, New Jersey Health Care System, East Orange, NJ, United States; School of Social Sciences and Psychology & Marcs Institute for Brain and Behaviour, Western Sydney University, Sydney, New South Wales, Australia; Marcs Institute for Brain and Behaviour, Western Sydney University, Sydney, New South Wales, Australia. Electronic address: a.moustafa@westernsydney.edu.au.
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: Moustafa
authors.affiliation: Department of Biotechnology, Indian Institute of Technology, Madras, Chennai, India.
authors.forename: Srinivasa
authors.initials: S
authors.lastname: Chakravarthy
authors.affiliation: School of Social Sciences and Psychology & Marcs Institute for Brain and Behaviour, Western Sydney University, Sydney, New South Wales, Australia.
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Phillips
authors.affiliation: Department of Biotechnology, Indian Institute of Technology, Madras, Chennai, India.
authors.forename: Ankur
authors.initials: A
authors.lastname: Gupta
authors.affiliation: Nyírő Gyula Hospital, National Institute of Psychiatry and Addictions, Budapest, Hungary; Department of Cognitive Science, Budapest University of Technology and Economics, Budapest, Hungary; Department of Physiology, Faculty of Medicine, University of Szeged, Hungary.
authors.forename: Szabolcs
authors.initials: S
authors.lastname: Keri
authors.affiliation: Nyírő Gyula Hospital, National Institute of Psychiatry and Addictions, Budapest, Hungary; Department of Cognitive Science, Budapest University of Technology and Economics, Budapest, Hungary.
authors.forename: Bertalan
authors.initials: B
authors.lastname: Polner
authors.affiliation: Department of Cognitive, Linguistic Sciences and Psychological Sciences, Brown Institute for Brain Science, Brown University, Providence RI 02912, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Frank
authors.affiliation: Cognitive Motor Neuroscience Group and Unit of Functional Neurosurgery, Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, The National Hospital for Neurology and Neurosurgery London, UK.
authors.forename: Marjan
authors.initials: M
authors.lastname: Jahanshahi
mesh_terms: D046690:Deep Brain Stimulation; D015259:Dopamine Agents; D005684:Gait; D006801:Humans; D009043:Motor Activity; D010300:Parkinson Disease; D013060:Speech
chemical_list: D015259:Dopamine Agents
keywords: Akinesia; Bradykinesia; Freezing of gait; Grip force; Handwriting; Parkinson’s disease; Rigidly; Speech; Tremor