title: The effect of levodopa on postural stability evaluated by wearable inertial measurement units for idiopathic and vascular Parkinson's disease.
abstract: BACKGROUND
  Postural stability analysis has shown that postural control is impaired in untreated idiopathic Parkinson's disease (IPD), even in the early stages of the disease. Vascular Parkinson's disease (VPD) lacks consensus clinical criteria or diagnostic tests. Moreover, the levodopa effect on postural balance remains undefined for IPD and even less so for VPD.
  
  
  OBJECTIVE
  To characterize postural stability, using kinematic analysis with wearable inertial measurement units, in IPD and VPD patients without clinical PI, and to subsequently analyze the response to levodopa.
  
  
  METHODS
  Ten patients with akinetic-rigid IPD and five patients with VPD were included. Clinical and postural stability kinematic analysis was performed before and after levodopa challenge, on different standing tasks: normal stance (NS), Romberg eyes open (REO) and Romberg eyes closed.
  
  
  RESULTS
  In the "off state", VPD patients had higher mean distances and higher maximal distance of p ostural sway on NS and REO tasks, respectively. VPD patients maintained a higher range of anterior-posterior (AP) postural sway after levodopa. In the absence of PI and non-significant differences in UPDRS-III, a higher mPIGD score in the VPD patients was mainly due to gait disturbance. Gait disturbance, and not UPDRS-III, influenced the degree of postural sway response to levodopa for VPD patients.
  
  
  CONCLUSIONS
  Quantitative postural sway evaluation is useful in the investigation of Parkinsonian syndromes. VPD patients have higher AP postural sway that is correlated with their gait disturbance burden and also not responsive to levodopa. These observations corroborate the interconnection of postural control and locomotor networks.
authors.affiliation: Neurology Department, Centro Hospitalar do Alto Ave (CHAA), EPE, Guimarães, Portugal; Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal; ICVS-3Bs PT Government Associate Laboratory, Braga, Guimarães, Portugal. Electronic address: miguelfgago@yahoo.com.
authors.forename: Miguel F
authors.initials: MF
authors.lastname: Gago
authors.affiliation: Algoritmi Center, Department of Industrial Electronics, School of Engineering, University of Minho, Braga, Portugal.
authors.forename: Vitor
authors.initials: V
authors.lastname: Fernandes
authors.affiliation: Algoritmi Center, Department of Industrial Electronics, School of Engineering, University of Minho, Braga, Portugal.
authors.forename: Jaime
authors.initials: J
authors.lastname: Ferreira
authors.affiliation: Algoritmi Center, Department of Industrial Electronics, School of Engineering, University of Minho, Braga, Portugal.
authors.forename: Hélder
authors.initials: H
authors.lastname: Silva
authors.affiliation: Neurology Department, Centro Hospitalar do Alto Ave (CHAA), EPE, Guimarães, Portugal; Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal.
authors.forename: Maria L
authors.initials: ML
authors.lastname: Rodrigues
authors.affiliation: Algoritmi Center, Department of Industrial Electronics, School of Engineering, University of Minho, Braga, Portugal.
authors.forename: Luís
authors.initials: L
authors.lastname: Rocha
authors.affiliation: Algoritmi Center, Department of Industrial Electronics, School of Engineering, University of Minho, Braga, Portugal.
authors.forename: Estela
authors.initials: E
authors.lastname: Bicho
authors.affiliation: Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, Braga, Portugal; ICVS-3Bs PT Government Associate Laboratory, Braga, Guimarães, Portugal.
authors.forename: Nuno
authors.initials: N
authors.lastname: Sousa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D005260:Female; D005684:Gait / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000188:drug therapy* / Q000503:physiopathology; D004856:Postural Balance / Q000187:drug effects*; D011187:Posture / Q000502:physiology*; D016896:Treatment Outcome
chemical_list: D007980:Levodopa
keywords: Idiopathic Parkinson's disease; Kinematic analysis; Postural stability; Vascular Parkinson's disease; Wearable inertial measurement units