Statistical Models of Parkinson’s Disease Progression: Predictive Validity in a 3-Year Follow-up

Rate of Progression in Activity and Participation Outcomes in Exercisers with Parkinson's Disease: A Five-Year Prospective Longitudinal Study

BACKGROUND

Rates of progression of motor symptoms and physical performance show declines between 2% and 7% annually in community samples with Parkinson's disease (PD). However, the effects of ongoing exercise behaviors on progression rates have not been considered.

OBJECTIVE

The primary purpose of this prospective, longitudinal study was to examine the annual rates of progression in activity and participation measures over five years in community-based exercisers with PD.

METHODS

A cohort of 55 regular exercisers with idiopathic PD was assessed at baseline and 1, 2, and 5 years. Regular exercise was defined as scores of 4-5 on the Stages for Readiness to Exercise Scale and a self-reported average of at least 60 minutes of exercise/week within six months of each testing session. Unadjusted and adjusted annual progression rates for activity and participation measures were calculated with a standardized equation of change from baseline. A linear mixed model with covariates of age at PD diagnosis and PD subtype was used to determine adjusted change scores.

RESULTS

Annual progression rates for unadjusted and adjusted variables were similar, and none exceeded 1.7% across time points for this group of exercisers with PD. Older age at PD diagnosis significantly contributed to faster progression of walking and balance functions. A nonlinear trajectory of the PD progression was demonstrated across most activity and participation outcomes.

CONCLUSIONS

Annual progression rates demonstrated by this sample of exercisers were lower than those previously reported for motor decline in general samples with PD. Assessing activity and participation outcomes longitudinally at interim time points was important for understanding the trajectory of change over time. The lower rates of progression in this study warrant further investigation into the long-term effects of exercise in PD.

Unveiling the relationship between central parkinsonian pain and motor symptoms in Parkinson's disease

BACKGROUND

Pain in Parkinson's disease (PD) is a common and heterogeneous non-motor symptom. Although the characteristics and predictors of pain in general and of central pain in particular are still largely unknown.

METHODS

A semi-structured interview, the Brief Pain Inventory and the Pain Disability Index were used to identify and characterize pain in a consecutive series of 292 PD patients. Unified PD Rating Scale-III, Hoehn & Yahr, Schwab and England Independence Scale and Freezing of Gait Questionnaire were applied to assess motor symptoms and functional independence in off and on conditions. Hospital Anxiety and Depression Scale and Questionnaire of Impulsive-Compulsive Control Disorders were used to screen for anxiety, depression and impulse control disorders.

RESULTS

Two hundred and twelve patients (73%) reported pain, which was classified as: musculoskeletal (63%), dystonia-related (27%), central parkinsonian (22%) and/or radicular or neuropathic (9%). Patients with pain had more comorbidities and more severe motor symptoms. Patients with central parkinsonian pain were significantly younger, had earlier disease onset, fewer comorbidities, greater non-axial motor symptom severity in on, more pain-related disability and more relief of pain with antiparkinsonian medication than patients with non-central parkinsonian pain.

CONCLUSIONS

PD patients with central parkinsonian pain have some distinctive demographic and clinical features, including lower levodopa responsiveness of motor appendicular/limb symptoms to levodopa, associated with greater responsiveness of pain symptoms to these same medications. These findings suggest the need for a more integrated approach to motor and non-motor symptoms in these patients' clinical care.

SIGNIFICANCE

In a consecutive series of 292 patients with PD, almost three quarters of patients with PD reported pain. The study results revealed that pain was related to more severe motor symptoms, anxiety symptoms and comorbidities. Among patients with pain, those with central parkinsonian subtype had distinct demographic and clinical features, including lower levodopa responsiveness for non-axial motor symptoms and greater responsiveness of pain to antiparkinsonian treatment.