Parkinson’s Disease Motor Subtypes Change with the Progression of the Disease: Results from the COPPADIS Cohort at 2-Year Follow-Up

Background: Motor phenotype (MP) can be associated with a different prognosis in Parkinson’s disease (PD), but it is not fixed and can change over time. Objective: Our aim was to analyze how the MP changed over time and to identify factors associated with the changes in PD patients from a multicenter Spanish PD cohort. Methods: PD patients who were recruited from January-2016 to November-2017 (baseline visit; V0) and evaluated again at a 2-year±30 days follow-up (V2) from 35 centers of Spain from the COPPADIS cohort, were included in this study.MP was calculated at both visits based on Jankovic classification in TD (tremor dominant), IND (indeterminate), or PIGD (postural instability and gait difficulty). Sociodemographic and clinical data were collected, including serum biomarkers. Results: Five hundred eleven patients (62.57±8.59 years old; 59.2%males) were included in the study. At V0, MP was: 47.4%(242/511) TD; 36.6%(187/511) PIGD; 16%(82/511) IND. Up to 38%(194/511) of the patients changed their phenotype from V0 to V2, being the most frequent from TD to IND (8.4%) and from TD to PIGD (6.7%). A worse cognitive status (OR = 0.966) and less autonomy for activities of daily living (OR = 0.937) at V0 and a greater increase in the globalNMS burden (OR = 1.011) from V0 to V2 were associated with changing from TD to another phenotype after 2-year follow-up. Conclusion: The MP in PD can change over time. With disease progression, the percentage of cases with non-tremoric MP increases. PD patients who changed from TD to postural instability and gait difficulty increased NMS burden significantly.

Motor and Non-motor Symptoms Associated With Exercise Behavior in Parkinson's Disease Patients: Factors Differ Between Patients With and Without Postural Instability

Background: Exercise is an important treatment for Parkinson's disease (PD). Therefore, recognizing determinants of exercise behavior for PD based on disease stage is essential. We sought to find whether the determinants differ based on presence of postural instability (PI), which is indicative of disease stage in PD.Methods: We enrolled patients at Samsung Medical Center from September 2019 to November 2020, who had the ability to perform exercise [modified Hoehn and Yahr (HY) stage ≤ 3]. All the motor and non-motor symptoms were investigated. The exercise of the PD patients was evaluated using the Physical Activity Scale of the Elderly (PASE)-leisure score. We classified patients into PD without PI (HY stage 1 – 2) and PD with PI (HY stage 2.5 – 3) groups. Multivariate linear regression was performed using backward elimination in each group to determine factors associated with PASE-leisure score.Results: A total of 233 patients were enrolled. In the PD without PI group (n = 177), the positive determinant of exercise was Activities-Specific Balance Confidence (ABC) score (β = 0.142, p = 0.032), and the negative determinants were fatigue score (β = −0.228, p = 0.018), female (β = −6.900, p = 0.016) and currently employed status (β = −6.072, p = 0.046). In the PD with PI group (n = 56), the positive determinant was non-motor symptom scale (NMSS) score (β = 0.221, p = 0.017) and disease duration (β = 1.001, p = 0.036), while the negative determinants were UPDRS part 3 score (β = −0.974, p < 0.001), UPDRS part 4 score (β = −2.192, p = 0.002), and age (β = −1.052, p < 0.001).Conclusion: Different motor and non-motor symptoms were associated with the exercise in PD patients with and without PI. When encouraging PD patients to exercise, personalized and different strategies should be applied based on the presence of PI.

Cortical and Cerebellar Oscillatory Responses to Postural Instability in Parkinson's Disease

Introduction: Posture and balance dysfunctions critically impair activities of daily living of patients with progressing Parkinson's disease (PD). However, the neural mechanisms underlying postural instability in PD are poorly understood, and specific therapies are lacking. Previous electrophysiological studies have shown distinct cortical oscillations with a significant contribution of the cerebellum during postural control tasks in healthy individuals.Methods: We investigated cortical and mid-cerebellar oscillatory activity via electroencephalography (EEG) during a postural control task in 10 PD patients with postural instability (PDPI+), 11 PD patients without postural instability (PDPI–), and 15 age-matched healthy control participants. Relative spectral power was analyzed in the theta (4–7 Hz) and beta (13–30 Hz) frequency bands.Results: Time-dependent postural measurements computed by accelerometer signals showed poor performance in PDPI+ participants. EEG results revealed that theta power was profoundly lower in mid-frontal and mid-cerebellar regions during the postural control task in PDPI+, compared to PDPI– and control participants. In addition, theta power was correlated with postural control performance in PD subjects. No significant changes in beta power were observed. Additionally, oscillatory changes during the postural control task differed from the resting state.Conclusion: This study underlines the involvement of mid-frontal and mid-cerebellar regions in postural stability during a balance task and emphasizes the important role of theta oscillations therein for postural control in PD.

The Impact of Parkinson’s Disease on Postural Control in Older People and How Sex can Mediate These Results: A Systematic Review

Introduction: Parkinson’s disease is most prevalent among elderly people, 65 years and over, and leads to an alteration in motor control associated with postural instability. Current evidence shows that postural control decreases with the aging process. In addition, postural control is more altered in healthy aged men than in women. Until today, few studies have evaluated the combined impact of Parkinson’s disease and sex on postural control. This review has allowed to evaluate the impact of Parkinson’s disease and sex on postural control measurements in elderly people. Methodology: Studies have been selected from two main databases: PubMed and EBSCO using the keywords “Parkinson”, “postural control OR balance” and “sex”. Articles related to the evaluation of postural control, including men and women with Parkinson’s aged over 65 years old, regardless of stage, were included (n = 179). Articles were excluded if not written in French or English or not presenting original content. Results: Ten (10) studies out of 179 that fulfilled inclusion and exclusion criteria were reported in the final analysis, which cumulates a total of 944 individuals with Parkinson’s (410 women). In general, results show greater postural instability among people with Parkinson’s compared to healthy subjects, and this according to different objective measurements using stabilographic parameters from force platforms. Only two studies out of ten evaluated postural control while briefly considering distinctions between sex, but without showing a significant difference between men and women with Parkinson’s. Parkinson’s severity, length of time of Parkinson’s disease and cognitive state of the person are the three variables with a negative impact on postural control. Conclusion: Older people with Parkinson’s disease have greater postural instability. Sex does not seem to influence the postural control of elderly people with Parkinson’s, although more studies are necessary.