Nicolaas I Bohnen1,2,3,4, Jacob Haugen1, Andrew Ridder2,3, Vikas Kotagal2,3, Roger L Albin2,3,4, Kirk A Frey1,2, Martijn L T M Müller1,4. 1. Radiology, University of Michigan, Ann Arbor, MI, United States, 48104. 2. Neurology, University of Michigan, Ann Arbor, MI, United States, 48104. 3. Neurology Service and GRECC, VAAAHS, Ann Arbor, MI, United States, 48104. 4. Morris K. Udall Center of Excellence for Parkinson's Disease Research, University of Michigan, Ann Arbor, MI, United States.
Abstract
BACKGROUND: Visual function deficits are more common in imbalance-predominant compared to tremor-predominant PD suggesting a pathophysiological role of impaired visual functions in axial motor impairments. OBJECTIVE: To investigate the relationship between changes in color discrimination and motor impairments in PD while accounting for cognitive or other confounder factors. METHODS: PD subjects (n=49, age 66.7±8.3 years; Hoehn & Yahr stage 2.6±0.6) completed color discrimination assessment using the Farnsworth-Munsell 100 Hue Color Vision Test, neuropsychological, motor assessments and [11C]dihydrotetrabenazine vesicular monoamine transporter type 2 PET imaging. MDS-UPDRS sub-scores for cardinal motor features were computed. Timed up and go mobility and walking tests were assessed in 48 subjects. RESULTS: Bivariate correlation coefficients between color discrimination and motor variables were significant only for the Timed up and go (RS=0.44, P=0.0018) and the MDS-UPDRS axial motor scores (RS=0.38, P=0.0068). Multiple regression confounder analysis using the Timed up and go as outcome parameter showed a significant total model (F(5,43)= 7.3, P<0.0001) with significant regressor effects for color discrimination (standardized β=0.32, t=2.6, P=0.012), global cognitive Z-score (β=-0.33, t=-2.5, P=0.018), duration of disease (β=0.26, t=1.8, P=0.038), but not for age or striatal dopaminergic binding. The color discrimination test was also a significant independent regressor in the MDS-UPDRS axial motor model (standardized β=0.29, t=2.4, P=0.022; total model t(5,43)= 6.4, P=0.0002). CONCLUSIONS: Color discrimination errors associate with axial motor features in PD independent of cognitive deficits, nigrostriatal dopaminergic denervation, and other confounder variables. These findings may reflect shared pathophysiology between color discrimination visual impairments and axial motor burden in PD.
BACKGROUND: Visual function deficits are more common in imbalance-predominant compared to tremor-predominant PD suggesting a pathophysiological role of impaired visual functions in axial motor impairments. OBJECTIVE: To investigate the relationship between changes in color discrimination and motor impairments in PD while accounting for cognitive or other confounder factors. METHODS: PD subjects (n=49, age 66.7±8.3 years; Hoehn & Yahr stage 2.6±0.6) completed color discrimination assessment using the Farnsworth-Munsell 100 Hue Color Vision Test, neuropsychological, motor assessments and [11C]dihydrotetrabenazine vesicular monoamine transporter type 2 PET imaging. MDS-UPDRS sub-scores for cardinal motor features were computed. Timed up and go mobility and walking tests were assessed in 48 subjects. RESULTS: Bivariate correlation coefficients between color discrimination and motor variables were significant only for the Timed up and go (RS=0.44, P=0.0018) and the MDS-UPDRS axial motor scores (RS=0.38, P=0.0068). Multiple regression confounder analysis using the Timed up and go as outcome parameter showed a significant total model (F(5,43)= 7.3, P<0.0001) with significant regressor effects for color discrimination (standardized β=0.32, t=2.6, P=0.012), global cognitive Z-score (β=-0.33, t=-2.5, P=0.018), duration of disease (β=0.26, t=1.8, P=0.038), but not for age or striatal dopaminergic binding. The color discrimination test was also a significant independent regressor in the MDS-UPDRS axial motor model (standardized β=0.29, t=2.4, P=0.022; total model t(5,43)= 6.4, P=0.0002). CONCLUSIONS: Color discrimination errors associate with axial motor features in PD independent of cognitive deficits, nigrostriatal dopaminergic denervation, and other confounder variables. These findings may reflect shared pathophysiology between color discrimination visual impairments and axial motor burden in PD.
Authors: V E Kelly; C O Johnson; E L McGough; A Shumway-Cook; F B Horak; K A Chung; A J Espay; F J Revilla; J Devoto; C Wood-Siverio; S A Factor; B Cholerton; K L Edwards; A L Peterson; J F Quinn; T J Montine; C P Zabetian; J B Leverenz Journal: Parkinsonism Relat Disord Date: 2015-04-14 Impact factor: 4.891
Authors: Nicolaas I Bohnen; Martijn L T M Müller; Vikas Kotagal; Robert A Koeppe; Michael R Kilbourn; Sid Gilman; Roger L Albin; Kirk A Frey Journal: J Cereb Blood Flow Metab Date: 2012-05-09 Impact factor: 6.200
Authors: Marie Y Davis; Catherine O Johnson; James B Leverenz; Daniel Weintraub; John Q Trojanowski; Alice Chen-Plotkin; Vivianna M Van Deerlin; Joseph F Quinn; Kathryn A Chung; Amie L Peterson-Hiller; Liana S Rosenthal; Ted M Dawson; Marilyn S Albert; Jennifer G Goldman; Glenn T Stebbins; Bryan Bernard; Zbigniew K Wszolek; Owen A Ross; Dennis W Dickson; David Eidelberg; Paul J Mattis; Martin Niethammer; Dora Yearout; Shu-Ching Hu; Brenna A Cholerton; Megan Smith; Ignacio F Mata; Thomas J Montine; Karen L Edwards; Cyrus P Zabetian Journal: JAMA Neurol Date: 2016-10-01 Impact factor: 18.302