title: Arm swing as a potential new prodromal marker of Parkinson's disease.
abstract: Reduced arm swing is a well-known clinical feature of Parkinson's disease (PD), often observed early in the course of the disease. We hypothesized that subtle changes in arm swing and axial rotation may also be detectable in the prodromal phase.
  
  
  
  The purpose of this study was to evaluate the relationship between the LRRK2-G2019S mutation, arm swing, and axial rotation in healthy nonmanifesting carriers and noncarriers of the G2019S mutation and in patients with PD.
  
  
  
  A total of 380 participants (186 healthy nonmanifesting controls and 194 PD patients) from 6 clinical sites underwent gait analysis while wearing synchronized 3-axis body-fixed sensors on the lower back and bilateral wrists. Participants walked for 1 minute under the following 2 conditions: (1) usual walking and (2) dual-task walking. Arm swing amplitudes, asymmetry, variability, and smoothness were calculated for both arms along with measures of axial rotation.
  
  
  
  A total of 122 nonmanifesting participants and 67 PD patients were carriers of the G2019S mutation. Nonmanifesting mutation carriers walked with greater arm swing asymmetry and variability and lower axial rotation smoothness under the dual task condition when compared with noncarriers (P < .04). In the nonmanifesting mutation carriers, arm swing asymmetry was associated with gait variability under dual task (P = .003). PD carriers showed greater asymmetry and variability of movement than PD noncarriers, even after controlling for disease severity (P < .009).
  
  
  
  The G2019S mutation is associated with increased asymmetry and variability among nonmanifesting participants and patients with PD. Prospective studies should determine if arm swing asymmetry and axial rotation smoothness may be used as motor markers of prodromal PD. © 2016 International Parkinson and Movement Disorder Society.
authors.affiliation: Laboratory for Early Markers of Neurodegeneration, Tel Aviv Medical Center, Tel Aviv, Israel. anatmi@tlvmc.gov.il.|Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel. anatmi@tlvmc.gov.il.|Neurology Institute, Tel Aviv Medical Center, Tel Aviv, Israel. anatmi@tlvmc.gov.il.|Center for the Study of Movement, Cognition and Mobility, Tel Aviv Medical Center, Tel Aviv, Israel. anatmi@tlvmc.gov.il.
authors.forename: Anat
authors.initials: A
authors.lastname: Mirelman
authors.affiliation: Laboratory for Early Markers of Neurodegeneration, Tel Aviv Medical Center, Tel Aviv, Israel.|Center for the Study of Movement, Cognition and Mobility, Tel Aviv Medical Center, Tel Aviv, Israel.
authors.forename: Hagar
authors.initials: H
authors.lastname: Bernad-Elazari
authors.affiliation: Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.|Neurology Institute, Tel Aviv Medical Center, Tel Aviv, Israel.
authors.forename: Avner
authors.initials: A
authors.lastname: Thaler
authors.affiliation: Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Eytan
authors.initials: E
authors.lastname: Giladi-Yacobi
authors.affiliation: Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.|Neurology Institute, Tel Aviv Medical Center, Tel Aviv, Israel.
authors.forename: Tanya
authors.initials: T
authors.lastname: Gurevich
authors.affiliation: Genetic Institute, Tel Aviv Medical Center, Tel Aviv, Israel.
authors.forename: Mali
authors.initials: M
authors.lastname: Gana-Weisz
authors.affiliation: Departments of Neurology, Mount Sinai Beth Israel Medical Center, New York, New York, USA.|Icahn School of Medicine at Mount Sinai, New York, New York, USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Saunders-Pullman
authors.affiliation: Departments of Neurology, Mount Sinai Beth Israel Medical Center, New York, New York, USA.|Icahn School of Medicine at Mount Sinai, New York, New York, USA.
authors.forename: Deborah
authors.initials: D
authors.lastname: Raymond
authors.affiliation: Departments of Neurology, Mount Sinai Beth Israel Medical Center, New York, New York, USA.|Icahn School of Medicine at Mount Sinai, New York, New York, USA.
authors.forename: Nancy
authors.initials: N
authors.lastname: Doan
authors.affiliation: Departments of Neurology, Mount Sinai Beth Israel Medical Center, New York, New York, USA.|Icahn School of Medicine at Mount Sinai, New York, New York, USA.
authors.forename: Susan B
authors.initials: SB
authors.lastname: Bressman
authors.affiliation: Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, New York, USA.|G. H. Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, New York, USA.
authors.forename: Karen S
authors.initials: KS
authors.lastname: Marder
authors.affiliation: Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, New York, USA.
authors.forename: Roy N
authors.initials: RN
authors.lastname: Alcalay
authors.affiliation: G. H. Sergievsky Center, College of Physicians and Surgeons, Columbia University, New York, New York, USA.|Department of Rehabilitation & Regenerative Medicine (Physical Therapy), New York, New York, USA.
authors.forename: Ashwini K
authors.initials: AK
authors.lastname: Rao
authors.affiliation: Hertie-Institut für klinische Hirnforschung, Tubingen, Germany.
authors.forename: Daniela
authors.initials: D
authors.lastname: Berg
authors.affiliation: Hertie-Institut für klinische Hirnforschung, Tubingen, Germany.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Brockmann
authors.affiliation: Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Jan
authors.initials: J
authors.lastname: Aasly
authors.affiliation: Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Bjørg Johanne
authors.initials: BJ
authors.lastname: Waro
authors.affiliation: Institut de Neurociències Hospital Clìnic, Barcelona, Spain.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Tolosa
authors.affiliation: Institut de Neurociències Hospital Clìnic, Barcelona, Spain.
authors.forename: Dolores
authors.initials: D
authors.lastname: Vilas
authors.affiliation: Institut de Neurociències Hospital Clìnic, Barcelona, Spain.
authors.forename: Claustre
authors.initials: C
authors.lastname: Pont-Sunyer
authors.affiliation: Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.|Genetic Institute, Tel Aviv Medical Center, Tel Aviv, Israel.
authors.forename: Avi
authors.initials: A
authors.lastname: Orr-Urtreger
authors.affiliation: Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.|Neurology Institute, Tel Aviv Medical Center, Tel Aviv, Israel.|Center for the Study of Movement, Cognition and Mobility, Tel Aviv Medical Center, Tel Aviv, Israel.|Department of Physical Therapy, Tel Aviv University, Tel Aviv, Israel.|Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Hausdorff
authors.affiliation: Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.|Neurology Institute, Tel Aviv Medical Center, Tel Aviv, Israel.|Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Nir
authors.initials: N
authors.lastname: Giladi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001132:Arm / Q000503:physiopathology*; D005260:Female; D020233:Gait Disorders, Neurologic / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D000071158:Leucine-Rich Repeat Serine-Threonine Protein Kinase-2 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000175:diagnosis* / Q000235:genetics* / Q000503:physiopathology; D062706:Prodromal Symptoms
chemical_list: C495280:LRRK2 protein, human; D000071158:Leucine-Rich Repeat Serine-Threonine Protein Kinase-2
keywords: G2019S; LRRK2; Parkinson's disease; arm swing; gait