title: Parkinson Disease: The Relationship Between Non-motor Symptoms and Motor Phenotype.
abstract: BACKGROUND
  Parkinson disease (PD) presents with motor and non-motor symptoms (NMS). The NMS often precede the onset of motor symptoms, but may progress throughout the disease course. Tremor dominant, postural instability gait difficulty (PIGD), and indeterminate phenotypes can be distinguished using Unified PD Rating scales (UPDRS-III). We hypothesized that the PIGD phenotype would be more likely to develop NMS, and that the non-dopamine-responsive axial signs would correlate with NMS severity.
  
  
  METHODS
  We conducted a retrospective cross-sectional chart review to assess the relationship between NMS and PD motor phenotypes. PD patients were administered the NMS Questionnaire, the UPDRS-III, and the Mini-Mental State Examination score. The relationship between NMS burden and PD subtypes was examined using linear regression models. The prevalence of each NMS among difference PD motor subtypes was analyzed using chi-square test.
  
  
  RESULTS
  PD patients with more advanced disease based on their UPDRS-III had higher NMS Questionnaire scores. The axial component of UPDRS-III correlated with higher NMS. There was no correlation between NMS and tremor scores. There was a significant correlation between PIGD score and higher NMS burden. PIGD group had higher prevalence in most NMS domains when compared with tremor dominant and indeterminate groups independent of disease duration and severity.
  
  
  CONCLUSIONS
  NMS profile and severity vary according to motor phenotype. We conclude that in the PD population, patients with a PIGD phenotype who have more axial involvement, associated with advanced disease and poor motor response, have a higher risk for a higher NMS burden.
authors.affiliation: 1Movement Disorder Program,Division of Neurology,University of Alberta,Kaye Edmonton Clinic,Edmonton,Alberta,Canada.
authors.forename: Fang
authors.initials: F
authors.lastname: Ba
authors.affiliation: 1Movement Disorder Program,Division of Neurology,University of Alberta,Kaye Edmonton Clinic,Edmonton,Alberta,Canada.
authors.forename: Mona
authors.initials: M
authors.lastname: Obaid
authors.affiliation: 1Movement Disorder Program,Division of Neurology,University of Alberta,Kaye Edmonton Clinic,Edmonton,Alberta,Canada.
authors.forename: Marguerite
authors.initials: M
authors.lastname: Wieler
authors.affiliation: 1Movement Disorder Program,Division of Neurology,University of Alberta,Kaye Edmonton Clinic,Edmonton,Alberta,Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Camicioli
authors.affiliation: 1Movement Disorder Program,Division of Neurology,University of Alberta,Kaye Edmonton Clinic,Edmonton,Alberta,Canada.
authors.forename: W R Wayne
authors.initials: WR
authors.lastname: Martin
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D020233:Gait Disorders, Neurologic / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications*; D010641:Phenotype; D004856:Postural Balance; D012189:Retrospective Studies; D014202:Tremor / Q000209:etiology
keywords: Parkinson’s disease; motor subtype; non-motor symptoms