Research Report
Population: Adult
Ryan P Duncan, PT, DPT, Assistant Professor of Physical Therapy & Neurology, Washington University School of Medicine – Program in Physical Therapy duncanr@wusm.wustl.edu
Marie McNeely, PhD, Instructor in Physical Therapy & Neurology, Washington University School of Medicine – Program in Physical Therapy mcneelym@wusm.wustl.edu
James Cavanaugh, PT, PhD, NCS, Associate Professor of Physical Therapy, University of New England – Department of Physical Therapy jcavanaugh@une.edu
Lee Dibble, PT, PhD, Associate Professor of Physical Therapy, University of Utah – Department of Physical Therapy lee.dibble@hsc.utah.edu
Terry Ellis, PT, PhD, NCS, Assistant Professor of Physical Therapy, Boston University – Department of Physical Therapy & Athletic Training tellis@bu.edu
Keywords: Prediction, Parkinson’s Disease, Motor Performance, Quality of Life
Purpose/Hypothesis: To determine if longitudinal changes in motor sign severity, quality of life, upper extremity function, and stability in gait differ between motor phenotypes in Parkinson disease (PD). We hypothesized that those with the postural instability gait difficulty (PIGD) phenotype would decline at a faster rate than those with tremor dominant (TD) PD.
Subjects: Two-hundred sixty subjects (mean age: 67.5 ± 9.3; 43% female) with idiopathic PD.
Materials/Methods: Subjects completed laboratory evaluations at baseline and 1 and 2 years from baseline. Measures collected at each time point included the Movement Disorder Society-Unified Parkinson Disease Rating Scale III (MDS-UPDRS III – motor sign severity), Parkinson Disease Questionnaire-39 (PDQ-39 – quality of life), 9 Hole Peg Test (9HPT – upper extremity function), and the Functional Gait Assessment (FGA – stability in gait). Subjects were classified as PIGD (n=160), TD (n=79), or Indeterminate (n=21) using the MDS-UPDRS III based on previously established methods. A repeated measures analysis of variance was used to determine main effects of group and time as well as group x time interactions (α=0.05). Post-hoc tests were used as appropriate to determine specific differences.
Results: There were no significant group x time interactions for any of the dependent variables. There was a significant effect of time on MDS-UPDRS III (F(1.32, 337.94) = 38.24, p<0.001), PDQ-39 (F(1.03, 263.57) = 13.38, p<0.001), and FGA (F(2, 514) =325.90, p<0.001). In post-hoc pairwise comparisons, MDS-UPDRS III increased between baseline and two years, as well as between one year and two years (p<0.001). PDQ-39 decreased between baseline and one year (p<0.001) and increased between one year and two years (p<0.001). FGA decreased significantly between each time point (p<0.001). There was a significant effect of group on PDQ-39 (F(2, 257) = 11.298, p<0.001, 9HPT (F(2, 257) = 4.193, p=0.016), and FGA (F(2, 257) = 18.263, p<0.001). Post-hoc pairwise comparisons revealed that PDQ-39 (p<0.001) and 9HPT (p=0.029) were higher for PIGD than TD, while FGA (p<0.001) was higher for TD than PIGD.
Conclusions: Motor sign severity, quality of life, and stability in gait worsened over two years regardless of motor phenotype in a cohort of individuals with PD. Individuals with TD PD had better quality of life, upper extremity function, and stability in gait than PIGD PD.
Clinical Relevance: Although individuals with TD PD had better quality of life, upper extremity function, and stability in gait, the rate of decline in these constructs was not different between the different motor phenotypes. This suggests that, regardless of motor phenotype, all people with PD would benefit from optimized pharmacologic and exercise interventions in an attempt to modify the trajectory of decline in motor function and quality of life in PD.
Citation:
Duncan, Ryan P, PT, DPT; McNeely, Marie E, PhD; Cavanaugh, James T, PT, PhD, NCS; Dibble, Lee E, PT, PhD; Ellis, Terry D, PT, PhD, NCS. Tracking Progression of Motor Signs and Quality of Life Based on Motor Phenotype in Parkinson Disease.. Poster Presentation. IV STEP Conference, American Physical Therapy Association, Columbus, OH, July 17, 2016. Online. https://u.osu.edu/ivstep/poster/abstracts/081_duncan-et-al/