title: Is Dominant-Side Onset Associated With a Better Motor Compensation in Parkinson's Disease?
abstract: BACKGROUND
  Unilateral onset and persistent asymmetry of motor signs are unique features of PD. The dominant hemisphere may have more efficient motor networks with greater neural reserve to cope with pathological changes. Therefore, this study compared dominant-side onset and non-dominant-side onset PD to evaluate whether dominant-side onset patients have greater neural reserve and fewer motor deficits despite similar pathological changes.
  
  
  METHODS
  We included the data of 157 consecutive, de novo PD patients with documented right-handedness who underwent dopamine transporter PET scans for an initial diagnostic workup. Among them, 118 patients with significant asymmetric motor deficits were selected for the analyses.
  
  
  RESULTS
  Dominant-side patients (i.e., the majority of motor deficits on the right side) showed significantly fewer motor deficits (i.e., the part III score of the UPDRS) than non-dominant-side patients (18.0 ± 8.1 and 22.9 ± 10.1, respectively; P = 0.005). Other variables, including symptom duration and striatal dopaminergic activities, were similar between the two groups. A general linear model showed that this difference in motor deficits remained statistically significant after controlling for patient age, sex, symptom duration, and striatal dopaminergic activity in the posterior putamen (P = 0.013).
  
  
  CONCLUSIONS
  These results suggest that dominant-side patients have greater neural reserve, allowing them to better cope with PD-related pathological changes (i.e., fewer motor deficits despite similar dopamine reduction) compared to non-dominant-side patients.
authors.affiliation: Department of Neurology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jee H
authors.initials: JH
authors.lastname: Ham
authors.affiliation: Department of Neurology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jae J
authors.initials: JJ
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jae S
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Neurology, Yonsei University College of Medicine, Seoul, Korea.|Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Phil H
authors.initials: PH
authors.lastname: Lee
authors.affiliation: Department of Neurology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Young H
authors.initials: YH
authors.lastname: Sohn
mesh_terms: D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins
keywords: PET; Parkinson's disease; dopamine transporter; hand dominance; neural reserve