Assessment and exercise for Freezing of Gait in Parkinson’s Disease

Parkinson's disease (PD) is a neurodegenerative disorder characterized through multiple motor- and non-motor symptoms. Gait disorders and balance deficits are very common in people with PD and often cannot be fully alleviated by standard therapy. The mentioned deficits not only lower the quality of life but also increase the risk for falls. Especially people with PD who experience Freezing of Gait (FOG), an episodic gait disturbance, are at risk and need individualized therapy options. Therefore, exercise and physical therapy have become increasingly important in the rehabilitation of PD. This work aims to investigate the validity and reliability for assessment methods for FOG and check their potential as outcome measures for clinical trials. Furthermore, it explores feasibility and treatment options of the Split-belt treadmill (SBT) as a tool modulate gait asymmetry in people with PD as well as the short-term effects on gait. Study 1 focused on the validity of the German version of the New Freezing of Gait-Questionnaire. It found that the translated version was a valid instrument to assess the severity of FOG in the German-speaking PD population. Study 2 investigated the within-session reliability of the assessment of anticipatory postural adjustment in PD+FOG and found a high variability in the reliability scores, depending on the outcome of interest. Study 3 summarized the current literature on SBT walking in people with PD and showed that people with PD can successfully adapt their gait to the split belts. The final study investigated the short-term effects of one SBT training session and found that SBT with changing conditions was most useful to improve gait adaptation in PD+FOG. This thesis provides some important findings regarding the assessment of FOG and highlights opportunities for suitable outcome measures for clinical studies in this field. Furthermore, it highlights the potential of SBT training for the rehabilitation of PD by showing that it is feasible, safe and above all has positive effects on gait adaptation in people with PD. Those findings give important implications for the selection of outcome measure and the design of training interventions for PD+FOG in future studies

Moderate Frequency Resistance and Balance Training Do Not Improve Freezing of Gait in Parkinson's Disease: A Pilot Study

Background and Aim: Individuals with Parkinson's disease (PD) and Freezing of Gait (FOG) have impaired postural control, which relate to the severity of FOG. The aim of this study was to analyze whether a moderate frequency resistance (RT) and balance training (BT), respectively, are effective to diminish FOG.Methods: This post-hoc sub-analysis of a randomized controlled training intervention study of PD patients with and without FOG reports about results from FOG patients. Twelve FOG patients performed RT and 8 BT (training 2x/week, 7 weeks). Testing was performed prior and post intervention. FOG was assessed with the FOG Questionnaire (FOGQ) and with the FOG score of a FOG provoking walking course. Balance performance was evaluated with the Fullerton Advanced Balance (FAB) scale. Tests were conducted by raters blinded to group allocation and assessment time point (only FOG score and FAB scale).Results: For the FOGQ and FOG score, no significant differences were found within and between the two training groups (p > 0.05) and effect sizes for the improvements were small (r < 0.1). Groups did not significantly improve in the FAB scale. FOG score changes and FAB scale changes within the RT group showed a trend toward significant negative correlation (Rho = −0.553, p = 0.098).Conclusions: Moderate frequency RT and BT was not effective in reducing FOG in this pilot study. The trend toward negative correlation between changes in FOG score and FAB scale suggests an interaction between balance (improvement) and FOG (improvement). Future studies should include larger samples and high frequency interventions to investigate the role of training balance performance to reduce the severity of FOG

Multidifferential study of identified charged hadron distributions in ZZ-tagged jets in proton-proton collisions at s=\sqrt{s}=13 TeV

Jet fragmentation functions are measured for the first time in proton-proton collisions for charged pions, kaons, and protons within jets recoiling against a $Z$ boson. The charged-hadron distributions are studied longitudinally and transversely to the jet direction for jets with transverse momentum 20 $< p_{\textrm{T}} < 100$ GeV and in the pseudorapidity range $2.5 < \eta < 4$. The data sample was collected with the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.64 fb$^{-1}$. Triple differential distributions as a function of the hadron longitudinal momentum fraction, hadron transverse momentum, and jet transverse momentum are also measured for the first time. This helps constrain transverse-momentum-dependent fragmentation functions. Differences in the shapes and magnitudes of the measured distributions for the different hadron species provide insights into the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb public pages

Can split-belt treadmill training improve dual-task turning performance in patients with Parkinson’s disease with Freezing of gait

BACKGROUND AND AIM: Motor-cognitive dual tasks (DT) pose several difficulties for patients with Parkinson’s disease with Freezing of gait (PD+FOG) as it requires continuous adaptation and switching of attention. Targeted motor-cognitive DT training has been shown to improve DT performance in PD+FOG with limited retention and transfer effects. Split-belt treadmill training (SBT) implicitly requires online monitoring and adaptation of gait, however the potential to induce learning and influence DT performance is unknown. Therefore in this study, we investigated whether motor adaptation training by means of SBT could improve motor-cognitive DT performance in PD+FOG. METHODS: To date, thirty-nine PD patients with FOG and twenty-seven age-matched healthy controls (HC) participated in a single training session at two centers (KU Leuven, Belgium and CAU of Kiel, Germany). They were randomized to four 30-minutes (6x5min) intervention groups: A) SBT belts’ speed ratio 1:2; B) SBT belts’ speed ratio 3:4; C) SBT changing belts’ speed ratios; D) Tied-Belt. For the SBT conditions (A-C) the belt's speed was reduced of the leg with the longer step length measured during overground gait analysis. A one-minute 360° turning at the spot test with alternating directions and while simultaneously performing an auditory stroop task was performed pre- and post-training as well as at 24h retention. A linear mixed models analysis was applied to investigate the effect of training condition over time. RESULTS: Preliminary analysis showed that PD+FOG and HC both improved in DT Turning from Pre-training to 24h Retention (DT Peak Turning Speed: Main effect of Time F=6.07; p>0.01; Relative change from baseline to Retention: PD+FOG 6.1%; HC 7.9%). Although PD+FOG showed deterioration from Pre- to Post-training, likely due to fatigue and dopamine exhaustion, offline consolidation was preserved (DT Peak Turning Speed: Post-training to Retention – relative change: PD+FOG 8.1% vs HC 2.6%). Performance on the auditory Stroop task also showed improvements from Pre-training to retention, trending towards greater improvements for SBT vs Tied Belt training in the whole group (Faster Response Time – Training*Time effect F=1.59; p=0.22; relative change from Baseline to retention 3.3%) and for PD+FOG subgroup (Lower Response Time variability – Training*Time effect F=2.09; p=0.16 ; relative change from Baseline to retention 7.6%) CONCLUSIONS: A single SBT session was seen to induce learning in HC as well as PD+FOG, with motor adaptation effects showing trends of transfer and automaticity to DT turning situation. This improved automaticity possibly frees up attentional resources as improvements were found in the cognitive task as well. Future work should investigate these mechanisms as well as the longer term effects of SBT on motor-cognitive DT performance.status: publishe

Short-Term Effects of Single-Session Split-Belt Treadmill Training on Dual-Task Performance in Parkinson's Disease and Healthy Elderly

Background: Dual-tasking is challenging for people with Parkinson's disease and freezing of gait (PD+FOG) and can exacerbate freezing episodes and falls. Split-belt treadmill training (SBT) is a novel tool to train complex gait and may improve dual-task (DT) walking and turning. Objective: To investigate the single-session effects of SBT on DT walking and DT turning performance in PD+FOG and older adults (OA), compared to regular treadmill training. Methods: Forty-five PD+FOG and 36 OA participated in a single training session (30 min). They were randomized into one of four training groups: (A) SB75—steady belt speed ratio 0.75:1; (B) SB50—steady belt speed ratio 0.5:1; (C) SBCR—changing belt speed ratios between 0.75:1 and 0.5:1; and (D) Tied-Belt (TBT). Over-ground straight-line gait and an alternating turning in place task combined with a cognitive dual-task (DT) (auditory Stroop) were assessed pre- and post-training, and the following day (retention). Constrained longitudinal data analysis was used to investigate the training effects for all participants and for PD+FOG alone. Results: DT gait speed improved at post-training for all groups (p < 0.001). However, SBT (SB50 and SBCR) led to larger post-training improvements compared to TBT, which were still visible at retention (SB50). For mean DT turning speed and Stroop response time while walking, only SBT groups showed significant improvements at post-training or retention. DT stride length, peak DT turning speed, and Stroop performance index while walking also showed larger gains in SBT compared to TBT. Results for PD+FOG alone showed similar effects although with smaller effect sizes. Conclusions: A single session of SBT in PD+FOG and OA showed larger short-term effects on DT walking and turning compared to TBT. Cognitive DT performance was also improved in SBT, likely due to reduced cortical control of gait. These results illustrate the potential for SBT to improve DT during complex gait and possibly reduce fall risk in clinical and healthy populations.status: Published onlin

Validation of the German Version of the New Freezing of Gait Questionnaire for People with Parkinson‘s Disease

Freezing of gait (FOG) in Parkinson’s disease (PD) is a highly disabling symptom which impacts quality of life. The New FOG Questionnaire (NFOG-Q) is the most commonly used tool worldwide to characterize FOG severity in PD. This study aims to provide a German translation of the NFOG-Q and to assess its validity in people with PD. The questionnaire was translated using forward-backward translation. Validity was tested in 57 PD patients with FOG via Cronbach’s alpha for internal consistency and Spearman correlations with several clinical measures to quantify disease severity, mobility, fall risk, and cognitive state for convergent and divergent validity. The German version of the NFOG-Q shows good internal consistency (Cα = 0.84). Furthermore, the NFOG-Q score was significantly correlated with the MDS-UPDRS III, H&Y stage, Timed Up and Go test, and the subjective fear of falling (FES-I). The lack of correlation with cognition (MoCA) points towards good divergent validity. This study provides a German version of the NFOG-Q which proved to be valid for the assessment of FOG severity in individuals with PD

The Effect of One Session Split-Belt Treadmill Training on Gait Adaptation in People With Parkinson's Disease and Freezing of Gait

BACKGROUND: Freezing of gait (FOG) in Parkinson's disease (PD) is associated with gait asymmetry and switching difficulty. A split-belt treadmill may potentially address those deficits. OBJECTIVE: To investigate the immediate and retention effects of one-session split-belt treadmill training (SBT) in contrast to regular tied-belt treadmill training (TBT) on gait asymmetry and adaptation in people with PD and FOG (PD + FOG) and healthy controls (HC). Additionally, to investigate differential effects of 3 SBT protocols and compare different gait adaptation outcomes. METHODS: PD + FOG (n = 45) and HC (n = 36) were randomized to 1 of 3 SBT groups (belt speeds' ratio 0.75:1; 0.5:1 or changing ratios) or TBT group. Participants were tested at Pre, Post, and Retention after one treadmill training session. Gait asymmetry was measured during a standardized adaptation test on the split-belt treadmill. RESULTS: SBT proved beneficial for gait adaptation in PD + FOG and HC (P < .0001); however, HC improved more. SBT with changing ratios demonstrated significant effects on gait adaptation from Pre to Post in PD + FOG, supported by strong effect sizes (d = 1.14) and improvements being retained for 24 hours. Mean step length asymmetry during initial exposure was lower in HC compared with PD + FOG (P = .035) and differentiated best between the groups. CONCLUSIONS: PD + FOG improved gait adaptation after a single SBT session although effects were smaller than in HC. SBT with changing ratios was the most effective to ameliorate gait adaptation in PD + FOG. These promising results warrant future study on whether long-term SBT strengthens adaptation in PD + FOG and has potential to induce a better resilience to FOG. Clinical trial ID: NCT03725215.status: publishe

Split-belt treadmill walking in patients with Parkinson’s disease: a systematic review

Background: Walking on a split-belt treadmill (SBT) can help to modulate an asymmetric gait, particularly for people with neurological conditions, such as Parkinson’s disease (PD), where asymmetry plays a role due to the laterality of the disease. Research question: This systematic review critically evaluates the literature on SBT in PD. First, different SBT paradigms and methodological approaches were evaluated. Second, the review explored how people with PD adapt their gait to different SBT conditions compared to healthy controls (HC). Methods: We conducted a systematic search of the PubMED, PsychINFO, and Web of Knowledge databases. Original research articles, published in English and investigating SBT walking in people with PD, were included. Results: From the 925 studies originally identified, seven met the inclusion criteria and were selected for evaluation (n = 118 individuals with PD of whom 44 had freezing of gait (FOG)). The SBT paradigms varied across studies regarding the SBT settings, definitions of gait variables, and criteria for determining dominance of body side. Gait variability and bilateral coordination were found to adapt to the SBT condition similarly in people with PD and healthy controls (HC). Inconsistent results were found with respect to the adaptation of gait asymmetry, for the differences between PD and HC participants. The subgroup of people with PD and FOG showed reduced accuracy in detecting belt speed differences and slower adaptation to SBT conditions. Conclusion: Individuals with mild to moderately severe PD adapted similarly to HCs to SBT walking for gait variability and bilateral gait coordination. However, those with FOG had impaired perception of belt speed differences and did not adapt their gait so readily. Although SBT can be useful for modulating gait asymmetry in some people with PD, it was not beneficial for all. We recommend standardization of SBT protocols for clinical practice in future studies.status: Published onlin

Towards a better understanding of anticipatory postural adjustments in people with Parkinson's disease.

IntroductionPrevious studies have shown that anticipatory postural adjustments (APAs) are altered in people with Parkinson's disease but its meaning for locomotion is less understood. This study aims to investigate the association between APAs and gait initiation, gait and freezing of gait and how a dynamic postural control challenging training may induce changes in these features.MethodsGait initiation was quantified using wearable sensors and subsequent straight walking was assessed via marker-based motion capture. Additionally, turning and FOG-related outcomes were measured with wearable sensors. Assessments were conducted one week before (Pre), one week after (Post) and 4 weeks after (Follow-up) completion of a training intervention (split-belt treadmill training or regular treadmill training), under single task and dual task (DT) conditions. Statistical analysis included a linear mixed model for training effects and correlation analysis between APAs and the other outcomes for Pre and Post-Pre delta.Results52 participants with Parkinson's disease (22 freezers) were assessed. We found that APA size in the medio-lateral direction during DT was positively associated with gait speed (pConclusionsThe findings of this work revealed new insights into how APAs were not associated with first step characteristics and freezing and only baseline APAs during DT were related with DT gait characteristics. Training-induced changes in the size of APAs were related to training benefits in the first step ROM only in non-freezers. Based on the presented results increasing APA size through interventions might not be the ideal target for overall improvement of locomotion