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

INTRODUCTION

Previous 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.

METHODS

Gait 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.

RESULTS

52 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 (p<0.001) and stride length (p<0.001) under DT conditions at Pre. The training effect was largest for first step range of motion and was similar for both training modes. For the associations between changes after the training (pooled sample) medio-lateral APA size showed a significant positive correlation with first step range of motion (p = 0.033) only in the DT condition and for the non-freezers only.

CONCLUSIONS

The 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.

Differential Implications of Cerebral Hypoperfusion and Hyperperfusion in Parkinson's Disease

BACKGROUND

Patients with Parkinson's disease (PD) exhibit widespread brain perfusion changes.

OBJECTIVE

This study investigated whether cerebral regions with hypoperfusion and hyperperfusion have differential effects on motor and cognitive symptoms in PD using early-phase 18 F-N-(3-fluoropropyl)-2β-carboxymethoxy-3β-(4-iodophenyl) nortropane (18 F-FP-CIT) positron emission tomography (PET) scans.

METHODS

We enrolled 394 patients with newly diagnosed PD who underwent dual-phase 18 F-FP-CIT PET scans. Indices reflecting associated changes in regional cerebral hypoperfusion and hyperperfusion on early-phase 18 F-FP-CIT PET scans were calculated as PD[hypo] and PD[hyper] , respectively. The associations of PD[hypo] and PD[hyper] on motor and cognitive symptoms at baseline were assessed using multivariate linear regression. Also, Cox regression and linear mixed models were performed to investigate the effects of baseline PD[hypo] and PD[hyper] on longitudinal outcomes.

RESULTS

There was a weak correlation between PD[hypo] and PD[hyper] (γ = -0.19, P < 0.001). PD[hypo] was associated with baseline Unified Parkinson's Disease Rating Scale Part III scores (β = -1.02, P = 0.045), rapid increases in dopaminergic medications (β = -18.02, P < 0.001), and a higher risk for developing freezing of gait (hazard ratio [HR] = 0.67, P = 0.019), whereas PD[hyper] was not associated. Regarding cognitive function, PD[hypo] was more relevant to the baseline cognitive performance levels of visuospatial, memory, and frontal/executive function than PD[hyper] . However, greater PD[hyper] was associated with future dementia conversion (HR = 1.43, P = 0.004), whereas PD[hypo] was not associated.

CONCLUSIONS

These findings suggest that PD[hypo] and PD[hyper] may differentially affect motor and cognitive functions in patients with PD. © 2023 International Parkinson and Movement Disorder Society.

Influence of Crouch Angle on Postural Stability in Quiet Stance and Functional Tasks Among Children with Cerebral Palsy

The aim of this study is to investigate postural stability and function (functional tasks) in younger (<12 yr) and older (>12 yr) children with lesser (<25°) and greater crouch (>25°) during stance. Postural stability and functional tasks were assessed in 53 ambulatory children with spastic cerebral palsy (CP). Younger and older children with greater crouch angle demonstrated higher displacement of center of pressure compared to children with lesser crouch angle during gait (p < .01). All (younger and older) children with severe crouch angle demonstrated strong association of postural control with stair climb (r = 0.732; p < .05) and timed-up-and-go test (r = 0.84; p < .01). Greater crouch angle demonstrates a moderate association with postural stability (r = 0.528; p < .01) in quiet stance and a strong association with functional tasks in children with CP (r = 0.7-0.84; p < .05).

Topological reorganization of functional hubs in patients with Parkinson's disease with freezing of gait

BACKGROUND AND PURPOSE

Resting-state functional MRI (rs-fMRI) studies in Parkinson's disease (PD) patients with freezing of gait (FOG) have implicated dysfunctional connectivity over multiple resting-state networks (RSNs). While these findings provided network-specific insights and information related to the aberrant or altered regional functional connectivity (FC), whether these alterations have any effect on topological reorganization in PD-FOG patients is incompletely understood. Understanding the higher order functional organization, which could be derived from the "hub" and the "rich-club" organization of the functional networks, could be crucial to identifying the distinct and unique pattern of the network connectivity associated with PD-FOG.

METHODS

In this study, we use rs-fMRI data and graph theoretical approaches to explore the reorganization of RSN topology in PD-FOG when compared to those without FOG. We also compared the higher order functional organization derived using the hub and rich-club measures in the FC networks of these PD-FOG patients to understand whether there is a topological reorganization of these hubs in PD-FOG.

RESULTS

We found that the PD-FOG patients showed a noticeable reorganization of hub regions. Regions that are part of the prefrontal cortex, primary somatosensory, motor, and visuomotor coordination areas were some of the regions exhibiting altered hub measures in PD-FOG patients. We also found a significantly altered feeder and local connectivity in PD-FOG.

CONCLUSIONS

Overall, our findings demonstrate a widespread topological reorganization and disrupted higher order functional network topology in PD-FOG that may further assist in improving our understanding of functional network disturbances associated with PD-FOG.

Traditional Chinese medicine Pingchan granule for motor symptoms and functions in Parkinson's disease: A multicenter, randomized, double-blind, placebo-controlled study

BACKGROUND

Pingchan granule (PCG) is a traditional Chinese medicine for Parkinson's disease (PD).

HYPOTHESIS/PURPOSE

This was the first study aiming to evaluate the efficacy and safety of PCG for motor symptoms, gait impairments and quality of life in PD.

STUDY DESIGN AND METHODS

In this multicenter, randomized, double-blind, placebo-controlled trial, 292 participants were included and followed for 9 months, randomly assigned at a 1:1 ratio to receive PCG or placebo. The primary outcome was the severity of motor symptoms assessed by Movement Disorder Society Unified Parkinson's Rating Scale III (MDS-UPDRS-III) motor score. Secondary outcomes included timed up and go test (TUG), functional gait assessment (FGA), freezing of gait (FOG), and quality of life assessed by Parkinson's disease questionnaire (PDQ-39). Assessments were done at baseline (T0), 3 months (T1), 6 months (T2) and 9 months (T3).

TRIAL REGISTRATION

Chinese Clinical Trial Register, ChiCTR-INR-1,701,194.

RESULTS

Generalized estimating equation analyses revealed that PCG group had significantly better improvement in MDS-UPDRS-III motor score than placebo group, as well as its domain scores of axial symptoms, bradykinesia, rigidity, and tremor. Improvements of TUG time, FGA, FOG questionnaire (FOGQ), and PDQ39 scores were also observed.

CONCLUSION

PCG had a long-lasting efficacy for motor symptoms and function in PD with good tolerance, supporting that PCG might be a viable alternative in the management of PD.

Freezing of Gait in Parkinson's Disease: Implications for Dual-Task Walking

BACKGROUND

The simultaneous completion of multiple tasks (dual-tasking, DT) often leads to poorer task performance (DT cost, DTC). People with Parkinson's disease (PwPD) exhibit difficulty with DT, and DTC may be particularly pronounced in PwPD with freezing of gait (FOG).

OBJECTIVE

This study assessed the relationship between FOG status and DTC during gait.

METHODS

Gait parameters were collected using inertial sensors in 106 PwPD (off-medication), including definite-freezers (dFOG; n = 25), possible-freezers (pFOG; n = 16), and non-freezers (nFOG; n = 65) during single (ST)-and DT walking.

RESULTS

PwPD with dFOG had larger (worse) DTC than nFOG for foot-strike angle, stride length, toe-off angle, variability of foot-strike angle, and arm range of motion (ROM). After accounting for covariates, DTC for toe-off angle and stride length remained worse in PwPD who freeze. Worse cognition predicted larger DTC for stride length, gait cycle duration, gait speed, and step duration across groups. Men had larger DTC compared to women for gait speed, variability in foot-strike angle, stride length, and arm ROM. Increased variability in gait speed DTC was associated with increased disease severity.

CONCLUSION

These findings provide additional support that PwPD who freeze may rely on greater cortical control for the execution of specific gait metrics. The results also underscore the importance of considering cognition when assessing DT ability in PwPD.

The 'Pants-Sign': A Predictor for Falling in People with Parkinson's Disease?

BACKGROUND

A history of falls is the most established predictor of future falls in people with Parkinson's disease (PD). However, predicting a first fall remains challenging.

OBJECTIVE

To assess whether experiencing difficulties putting on pants while standing is a viable predictor of future falling, and specifically a first fall, in persons with PD. We define this 'Pants-sign' as people who resort to putting on their pants only while seated.

METHODS

264 persons with PD were included. Information on the Pants-sign, history of falls, disease severity (MDS-UPDRS part III), freezing of gait (N-FOGQ > 0), cognitive function (MoCA), self-reported disability (Schwab & England scale), health-related quality of life (SF-12), Timed-Up-and-Go, and one-legged stance were determined at baseline and after one-year follow-up. The association between the Pants-sign and future falling was examined by univariate logistic regression analysis. A multivariate step-wise logistic regression with forward selection was employed to identify the strongest associations in the entire cohort and a sub-cohort of people without falls in the year prior to baseline.

RESULTS

The Pants-sign was univariably associated with a future fall (OR = 2.406, 95% CI [1.313-4.409], p = 0.004]), but was not an independent predictor in the multivariate logistic regression; predictors were higher MDS-UPDRS part III scores (OR = 1.088, 95% CI [1.056-1.121], p < 0.001] and history of falls (OR = 5.696, 95% CI [2.650-12.243], p≤0.001]. For the sub-cohort of people without falls in the previous year (n = 189), the Pants-sign was not associated with future falls.

CONCLUSIONS

The Pants-sign is simple to assess and is associated with future falling in PD but is not an independent predictor.

Effects of a Cognitively Challenging Agility Boot Camp Program on Balance and Gait in People With Parkinson's Disease: Does Freezing of Gait Status Matter?

BACKGROUND AND AIM

Individuals with Parkinson's disease (PD) with and without freezing of Gait (FoG) may respond differently to exercise interventions for several reasons, including disease duration. This study aimed to determine whether both people with and without FoG benefit from the Agility Boot Camp with Cognitive Challenges (ABC-C) program.

METHODS

This secondary analysis of our ABC-C trial included 86 PD subjects: 44 without FoG (PD-FoG) and 42 with FoG (PD + FoG). We collected measures of standing sway balance, anticipatory postural adjustments, postural responses, and a 2-minute walk with and without a cognitive task. Two-way repeated analysis of variance, with disease duration as covariate, was used to investigate the effects of ABC-C program. Effect sizes were calculated using standardized response mean (SRM) for PD-FoG and PD + FoG, separately.

RESULTS

The ABC-C program was effective in improving gait performance in both PD-FoG and PD + FoG, even after controlling for disease duration. Specifically, dual-task gait speed (P < .0001), dual-cost stride length (P = .012), and these single-task measures: arm range of motion (P < .0001), toe-off angle (P = .005), gait cycle duration variability (P = .019), trunk coronal range of motion (P = .042), and stance time (P = .046) improved in both PD-FoG and PD + FoG. There was no interaction effect between time (before and after exercise) and group (PD-FoG/PD + FoG) in all 24 objective measures of balance and gait. Dual-task gait speed improved the most in PD + FoG (SRM = 1.01), whereas single-task arm range of motion improved the most in PD-FoG (SRM = 1.01).

CONCLUSION

The ABC-C program was similarly effective in improving gait (and not balance) performance in both PD-FoG and PD + FoG.

Associated factors and abnormal dorsal raphe nucleus connectivity patterns of freezing of gait in Parkinson's disease

BACKGROUND

Freezing of gait (FOG) is a common, disabling symptom of Parkinson's disease (PD), and its exact pathophysiological mechanism is still poorly understood. The control of gait is a complex process that may be influenced by emotions modulated by serotonergic networks. Therefore, this study aimed to determine factors associated with FOG in PD patients and to evaluate the importance of the dorsal raphe nucleus (DRN; central node in the serotoninergic system) in FOG pathophysiology.

METHODS

We combined cross-sectional survey data from 453 PD patients. According to the Freezing of Gait Questionnaire (FOGQ), patients were divided into two groups: the "PD with frozen gait (PD-FOG)" and "PD without frozen gait (PD-nFOG)" groups. Demographic characteristics, clinical features, and motor and nonmotor symptoms (NMS) assessments of PD patients were recorded. Univariate statistical analysis was performed between the two groups, and then regression analysis was performed on related factors. We also acquired resting-state functional MRI (rs-fMRI) data from 20 PD-FOG, 21 PD-nFOG, and 22 healthy controls (HCs) who were randomly chosen. We defined seeds in the DRN to evaluate functional connectivity (FC) patterns.

RESULTS

The overall frequency of FOG was 11.9% patients in the PD-FOG group were older, had a longer disease duration, had a higher levodopa equivalent daily dose, had more severe motor symptoms and worse quality of life, had a higher proportion of dyskinesia, wearing-off and postural instability/gait difficulty (PIGD) clinical phenotype, and experienced more depression and impaired sleep function than those in the PD-nFOG group. Logistic regression analysis showed that H&Ystage ≥ 3, UPDRS-III scores, PIGD clinical phenotype and excessive daytime sleepiness were associated with FOG. In addition, there was significantly lower FC between the DRN and some cortical structures, including the supplementary motor area (SMA), left superior frontal gyrus (SFG), and left median cingulated cortex (MCC) in PD-FOG patients than HCs and PD-nFOG patients.

CONCLUSIONS

These results demonstrate that the severity of PD and PIGD clinical phenotype are associated factors for freezing and that DRN dysfunction may play a key role in PD-related NMS and FOG. An abnormal cortical and brainstem networks may contribute to the mechanisms underlying FOG.

Predicting the onset of freezing of gait in Parkinson's disease

BACKGROUND

Freezing of gait is a debilitating symptom of Parkinson's disease associated with high risks of falls and poor quality of life. While productive therapy for FoG is still underway, early prediction of FoG could help high-risk PD patients to take preventive measures. In this study, we predicted the onset of FoG in de novo PD patients using a battery of risk factors from patients enrolled in PPMI cohort.

METHODS

Baseline characteristics were compared between subjects who developed FoG (68 patients, 37.2%, pre-FoG group) during the five-year follow up and subjects who did not (115 patients, 62.8%, non-FoG group). A multivariate logistic regression model was built based on backward stepwise selection of factors that were associated with FoG onset in the univariate analysis. ROC curves were used to assess sensitivity and specificity of the predictive model.

RESULTS

At baseline, age, PIGD score, cognitive functions, autonomic functions, sleep behavior, fatigue and striatal DAT uptake were significantly different in the pre-FoG group relative to the non-FoG group. However, there was no difference in genetic characteristics between the two patient sets. Univariate analysis showed several motor and non-motor factors that correlated with FoG, including PIGD score, MDS-UPDRS part II score, SDMT score, HVLT Immediate/Total Recall, MOCA, Epworth Sleepiness Scale, fatigue, SCOPA-AUT gastrointestinal score, SCOPA-AUT urinary score and CSF biomarker Abeta42. Multivariate logistic analysis stressed that high PIGD score, fatigue, worse SDMT performance and low levels of Abeta42 were independent risk factors for FoG onset in PD patients.

CONCLUSIONS

Combining motor and non-motor features including PIGD score, poor cognitive functions and CSF Abeta can identify PD patients with high risk of FoG onset.

Long-Term Changes in Sarcopenia and Body Composition in Diabetes Patients with and without Charcot Osteoarthropathy

BACKGROUND

Charcot osteoarthropathy of the foot (COA) can currently only be treated using prolonged periods of immobilization of the affected extremity. Therefore, the hypothesis is that COA leads to altered body composition and increased sarcopenia.

OBJECTIVE

To investigate the changes over several years in sarcopenia, body composition, and fat distribution in diabetes patients with previous COA compared to diabetes patients without previous COA.

METHODS

Prospective observational clinical study. Twenty-one subjects were included and had two DXA scans done with mean 8.6-year intervals to compare changes in lean mass and fat distribution. The lean mass of limbs was used as an estimate of appendicular lean mass (aLM). Fat mass and aLM were then used to detect sarcopenic individuals using different methods. Results and Conclusions. As compared to baseline, both groups had significant loss of lean mass, and diabetics without COA had significant gain of total fat percentage. No statistically different prevalence of sarcopenia between the groups could be established. Likewise, no difference was found in total lean and fat mass changes. None of the groups had statistically significant changes of android fat distribution. As compared with published data on sarcopenia, people with diabetes might be more prone to sarcopenia than healthy individuals.

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.

Structural Connectivity of Subthalamic Nucleus Stimulation for Improving Freezing of Gait

BACKGROUND

Freezing of gait (FOG) is among the most common and disabling symptoms of Parkinson's disease (PD). Studies show that deep brain stimulation (DBS) of the subthalamic nucleus (STN) can reduce FOG severity. However, there is uncertainty about pathways that need to be modulated to improve FOG.

OBJECTIVE

To investigate whether STN-DBS effectively reduces FOG postoperatively and whether structural connectivity of the stimulated tissue explains variance of outcomes.

METHODS

We investigated 47 patients with PD and preoperative FOG. Freezing prevalence and severity was primarily assessed using the Freezing of Gait Questionnaire (FOG-Q). In a subset of 18 patients, provoked FOG during a standardized walking course was assessed. Using a publicly available model of basal-ganglia pathways we determined stimulation-dependent connectivity associated with postoperative changes in FOG. A region-of-interest analysis to a priori defined mesencephalic regions was performed using a disease-specific normative connectome.

RESULTS

Freezing of gait significantly improved six months postoperatively, marked by reduced frequency and duration of freezing episodes. Optimal stimulation volumes for improving FOG structurally connected to motor areas, the prefrontal cortex and to the globus pallidus. Stimulation of the lenticular fasciculus was associated with worsening of FOG. This connectivity profile was robust in a leave-one-out cross-validation. Subcortically, stimulation of fibers crossing the pedunculopontine nucleus and the substantia nigra correlated with postoperative improvement.

CONCLUSION

STN-DBS can alleviate FOG severity by modulating specific pathways structurally connected to prefrontal and motor cortices. More differentiated FOG assessments may allow to differentiate pathways for specific FOG subtypes in the future.

Grouping successive freezing of gait episodes has neutral to detrimental effect on freeze detection and prediction in Parkinson's disease

Freezing of gait (FOG) is an intermittent walking disturbance experienced by people with Parkinson's disease (PD). Wearable FOG identification systems can improve gait and reduce the risk of falling due to FOG by detecting FOG in real-time and providing a cue to reduce freeze duration. However, FOG prediction and prevention is desirable. Datasets used to train machine learning models often generate ground truth FOG labels based on visual observation of specific lower limb movements (event-based definition) or an overall inability to walk effectively (period of gait disruption based definition). FOG definition ambiguity may affect model performance, especially with respect to multiple FOG in rapid succession. This research examined whether merging multiple freezes that occurred in rapid succession could improve FOG detection and prediction model performance. Plantar pressure and lower limb acceleration data were used to extract a feature set and train decision tree ensembles. FOG was labeled using an event-based definition. Additional datasets were then produced by merging FOG that occurred in rapid succession. A merging threshold was introduced where FOG that were separated by less than the merging threshold were merged into one episode. FOG detection and prediction models were trained for merging thresholds of 0, 1, 2, and 3 s. Merging slightly improved FOG detection model performance; however, for the prediction model, merging resulted in slightly later FOG identification and lower precision. FOG prediction models may benefit from using event-based FOG definitions and avoiding merging multiple FOG in rapid succession.

Transcutaneous magnetic spinal cord stimulation for freezing of gait in Parkinson's disease

Dopaminergic drugs partially alleviate gait problems in Parkinson's disease, but the effects are not sustained in the long-term. Particularly, the freezing of gait directly impacts patients' quality of life. Experimental epidural spinal cord stimulation (SCS) studies have suggested positive effects on locomotion among PD patients, but the effects of non-invasive stimulation have never been explored. Here, we investigated in a prospective, open-label, pilot study the efficacy and safety of non-invasive magnetic stimulation of the spinal cord in five patients with PD who experienced gait problems, including freezing of gait. A trial of transcutaneous magnetic SCS was performed at the level of the fifth thoracic vertebra. The primary outcome was the change in freezing of gait 7 days after stimulation. Secondary outcome measures included changes in gait speed and UPDRS part III. After non-invasive spinal cord stimulation, patients experienced a 22% improvement in freezing of gait (p = 0.040) and 17.4% improvement in the UPDRS part III (p = 0.042). Timed up and go times improved by 48.2%, although this did not reach statistical significance (p = 0.06). Patients' global impression of change was 'much improved' for four patients. Improvement in gait after stimulation was reversible, since it returned to baseline scores 4 weeks after stimulation. No severe side effects were recorded. This pilot study suggests that transcutaneous magnetic spinal cord stimulation is feasible and can potentially improve gait problems in PD, without severe adverse effects. Large scale phase II trials are needed to test this hypothesis.

Muscle weakness has a limited effect on motor control of gait in Duchenne muscular dystrophy

Aim

Our aim was to determine if synergy weights and activations are altered in Duchenne muscular dystrophy (DMD) and if these alterations could be linked to muscle weakness.

Methods

In 22 children with DMD and 22 typical developing (TD) children of a similar age, surface electromyography (sEMG) of the gluteus medius, rectus femoris (REF), medial hamstrings, tibialis anterior, and medial gastrocnemius (GAS) were recorded during gait. Muscle weakness was assessed with maximal voluntary isometric contractions (MVIC). Synergies were calculated with non-negative matrix factorization. The number of synergies explaining ≥90% of the variance in the sEMG signals (N90), were extracted and grouped with k-means cluster analysis. We verified differences in weights with a Mann-Whitney U test. Statistical non-parametric mapping (Hotelling's T² test and two-tailed t-test) was used to assess group differences in synergy activations. We used Spearman’s rank correlation coefficients and canonical correlation analysis to assess if weakness was related to modifications in weights and activations, respectively.

Results

For both groups, average N90 was three. In synergy one, characterized by activity at the beginning of stance, the DMDs showed an increased REF weight (p = 0.001) and decreased GAS weight (p = 0.007). Synergy activations were similar, with only a small difference detected in mid-swing in the combined activations (p<0.001). Weakness was not associated with these differences.

Conclusion

Despite the apparent weakness in DMD, synergy weights and activations were similar between the two groups. Our findings are in line with previous research suggesting non-neural alterations have limited influence on muscle synergies.

Apomorphine subcutaneous infusion in patients with Parkinson's disease with persistent motor fluctuations (TOLEDO): a multicentre, double-blind, randomised, placebo-controlled trial

BACKGROUND

Subcutaneous apomorphine infusion is a clinically established therapy for patients with Parkinson's disease with motor fluctuations not optimally controlled by oral medication. Open-label studies have shown that apomorphine infusion is effective in reducing off time (periods when antiparkinsonian drugs have no effect), dyskinesias, and levodopa dose, but confirmatory evidence from double-blind, controlled studies is lacking. We aimed to investigate the efficacy and safety of apomorphine infusion compared with placebo in patients with Parkinson's disease with persistent motor fluctuations despite optimised oral or transdermal treatment.

METHODS

In this randomised, placebo-controlled, double-blind, multicentre trial, we enrolled patients at 23 European hospitals who had been diagnosed with Parkinson's disease more than 3 years previously and had motor fluctuations not adequately controlled by medical treatment. Patients were randomly assigned (1:1) with a computer-generated randomisation code, stratified by site, to receive 3-8 mg/h apomorphine or placebo saline infusion during waking hours (16 h a day [range 14-18 was acceptable]) for 12 weeks. The flow rate of the study drug and other oral medications could be adjusted during the first 4 weeks on the basis of individual efficacy and tolerability, after which patients entered an 8-week maintenance period. The primary endpoint was the absolute change in daily off time based on patient's diaries, and was assessed in the full analysis set, which was defined as all patients who received at least one dose of allocated study drug and had efficacy data available at any timepoint post-baseline. Safety was assessed in all patients who received at least one dose of apomorphine or placebo. All study participants and investigators were masked to treatment assignment. Both the 12-week double-blind phase and the 52-week open-label phase of this study are now complete; this paper reports results for the double-blind phase only. This study is registered with ClinicalTrials.gov (NCT02006121).

FINDINGS

Between March 3, 2014, and March 1, 2016, 128 patients were screened for eligibility and 107 were randomly assigned, of whom 106 were included in the full analysis set (n=53 in both groups). Apomorphine infusion (mean final dose 4·68 mg/h [SD 1·50]) significantly reduced off time compared with placebo (-2·47 h per day [SD 3·70] in the apomorphine group vs -0·58 h per day [2·80] in the placebo group; difference -1·89 h per day, 95% CI -3·16 to -0·62; p=0·0025). Apomorphine was well tolerated without any unexpected safety signals. Six patients in the apomorphine group withdrew from the study because of treatment-related adverse events.

INTERPRETATION

Apomorphine infusion results in a clinically meaningful reduction in off time in patients with Parkinson's disease with persistent motor fluctuations despite optimised oral or transdermal therapy.

FUNDING

Britannia Pharmaceuticals.

The association between gait and physical fitness in adults with intellectual disabilities

BACKGROUND

Gait deviations are often seen in adults with intellectual disabilities (ID). Their low physical fitness levels may be associated with these deviations. Understanding the impact of fitness on gait in this population is important for developing interventions to improve gait. In a cross-sectional study, we assessed the association between multiple physical fitness components and spatiotemporal gait parameters in adults with ID.

METHOD

Gait characteristics of 31 adults (42.77 ± 16.70 years) with ID without Down syndrome were assessed with the GAITRite at comfortable (CS) and fast speed (FS), along with fitness assessments (body composition, muscular endurance, strength, balance, Short Physical Performance Battery).

RESULTS

At CS, adults with ID with higher BMI and/or waist circumference spent more time in double support. At FS, those with better muscular endurance took steps faster, those with better balance took bigger steps and strides and those with better Short Physical Performance Battery scores took bigger steps and strides at higher velocity.

CONCLUSIONS

Body composition was mostly associated with gait at CS, while the other physical fitness components were mostly associated with gait at FS. Better fitness may therefore be more important in more challenging conditions. These insights are useful for developing interventions to improve gait in adults with ID.

Lycra splinting garments for adults with intellectual disabilities who fall due to gait or balance issues: a feasibility study

BACKGROUND

Adults with intellectual disabilities (IDs) experience high rates of falls and have high rates of gait or balance issues which contribute to falls. Lycra splinting garments (LSGs) have potential to improve gait or balance, but they have never before been tested with adults with IDs who fall due to gait or balance issues. The aim of this study was to test in adults with IDs, the feasibility of using LSGs to improve movement and function and reduce falls, whilst also exploring usability and likely compliance.

METHOD

A convenience sample of nine adults with IDs wore tailored LSGs over a 6-week assessment period. Laboratory-based foot clearance, balance, and gait measures were collected pre- and post-LSG-wear. Falls charts and questionnaires on usability and likely compliance were also completed.

RESULTS

Seven participants experienced a reduction in falls during their six weeks of LSG wear; most notably in the group of five participants who wore lycra splinting socks, compared with only two in the group of four who wore lycra splinting shorts or leggings only.

CONCLUSION

Lycra splinting socks are likely to bring about positive outcomes for adults with IDs who fall due to gait/balance issues on an individual case by case basis over time, but further research is required to test this hypothesis under randomised controlled trial conditions. Potential benefits of more intrusive LSGs are outweighed by reported problems with usability and compliance.

Altered resting-state brain activity in Parkinson's disease patients with freezing of gait

Freezing of gait (FOG) is a common and debilitating symptom in Parkinson's disease (PD). The current study investigated alterations of resting-state spontaneous brain activity in PD patients with FOG. A total of 29 patients with FOG, 28 patients without FOG and 31 controls were included. All subjects underwent resting-state functional MRI, and the amplitude of low-frequency fluctuation (ALFF) was calculated to measure the spontaneous brain activity. Between-group differences and correlations with FOG severity (both subjective and objective measures) were analyzed. Compared to those without FOG, patients with FOG showed increased ALFF in right anterior cingulate cortex (ACC) and left inferior parietal lobule (IPL), as well as decreased ALFF in right superior frontal gyrus (SFG), bilateral cerebellum and left thalamus. Correlation analyses demonstrated that ALFF within the right SFG, right ACC and bilateral pallidum were positively correlated with FOG; while ALFF within the thalamus, putamen, cerebellum and sensorimotor regions were negatively correlated. Our results indicate that FOG is associated with dysfunction within frontal-parietal regions, along with increased inhibitory outputs from basal ganglia. Additionally, altered activity of cerebellum implicates its role in the pathophysiology of FOG. These findings provide further insight into the underlying neural mechanisms of FOG in PD patients.

Dual task interference on postural sway, postural transitions and gait in people with Parkinson's disease and freezing of gait

Freezing of gait (FoG) is associated with less automatic gait and more impaired cognition, balance and postural transitions compared to people with PD who do not have FoG. However, it is unknown whether dual-task cost during postural sway, postural transitions (such as gait initiation and turning), and gait are more in subjects with Parkinson's disease (PD) who have freezing of gait (FoG+) compared to those who do not have FoG (FoG-). Here, we hypothesized that the effects of a cognitive dual task on postural sway, postural transitions and gait would be larger in FoG+ than FoG-. Thirty FoG- and 24 FoG+ performed an Instrumented Stand and Walk test in OFF medication state, with and without a secondary cognitive task (serial subtraction by 3s). Measures of postural sway, gait initiation, turning, and walking were extracted using body-worn inertial sensors. FoG+ showed significantly larger dual task cost than FoG- for several gait metrics, but not during postural sway or postural transitions. During walking, FoG+ exhibited a larger dual task cost than FoG- resulting in shorter stride length and slower stride velocity. During standing, FoG+ showed a larger postural sway compared to FoG- and during gait initiation, FoG+, but not FoG-, showed a longer first step duration during the dual-task condition compared to single-task condition (interaction effect, p=0.04). During turning, both groups showed a slower turn peak speed in the dual-task condition compared to single task condition. These findings partly support our hypothesis that dual task cost on walking is greater in FoG+ than FoG-.

The coefficient of friction in Parkinson's disease gait

This study aimed to characterize the coefficient of friction (COF) curves of patients with Parkinson's disease (PD) during barefoot gait and to evaluate the relationships between this variable and functional scales. Twenty-two subjects with PD (ON phase of levodopa) and 22 healthy subjects participated in this study. The participants walked barefoot along a pathway that went over two force plates embedded in the floor of the data collection room. The instantaneous COF was calculated as the ratio between the horizontal and vertical components of the ground reaction forces. Two-sample t-tests applied to every 1% of the support phase of the COF curve were used to compare the groups and to identify the phases in which the two groups were different. Specifically, three COF areas were computed: Area 1 (for the loading response phase), Area 2 (for the midstance phase) and Area 3 (for the terminal stance phase). Pearson's tests were applied to assess the associations between the COF curve areas and the clinical scales. The subjects with PD exhibited lower COF values during the loading response and terminal stance phases and higher COF values during the mid-stance phase compared with the control group. A strong positive correlation was observed between Area 1 and the Timed Up and Go Test (90.3%). In conclusion, the patients' COFs exhibited patterns that were different from those of the control group. Moreover, during the loading response phase, these differences were well-correlated with the Timed Up and Go Test scale data; Timed Up and Go Test data can be used to identify the risk of falls among PD patients.

Exercise interventions for the improvement of falls-related outcomes among older adults with diabetes mellitus: A systematic review and meta-analyses

INTRODUCTION

Falls as a complication of diabetes mellitus (DM) can have a major impact on the health of older adults. Previous reviews have demonstrated that certain exercise interventions are effective at reducing falls in older people; however, no studies have quantified the effectiveness of exercise interventions on falls-related outcomes among older adults with DM.

METHODS

A systematic search for all years to September 2015 identified available literature. Eligibility criteria included: appropriate exercise intervention/s; assessed falls-related outcomes; older adults with DM. Effect sizes were pooled using a random effects model. Positive effect sizes favoured the intervention.

RESULTS

Ten RCTs were eligible for the meta-analyses. Exercise interventions were more effective than the control condition for static balance (0.53, 95% CI: 0.13 to 0.93), lower-limb strength (0.63, 95% CI: 0.09 to 1.18), and gait (0.59, 95% CI: 0.22 to 0.96). No RCTs assessed falls-risk; one RCT reported 12month falls-rate, with no differential treatment effect observed.

CONCLUSION

Exercise interventions can improve certain falls-related outcomes among older adults with DM. Substantial heterogeneity and limited numbers of studies should be considered when interpreting results. Among older adults, where DM burden is increasing, exercise interventions may provide promising approaches to assist the improvement of falls-related outcomes.

[Osteoporosis Liaison Service and exercise regimens, based on Locomotive Syndrome.]

The purpose of Osteoporosis Liaison Service(OLS)is primary and secondary prevention of osteoporosis and fragility fracture by multiple medical occupations. Exercise instruction and exercise intervention are important factors in OLS. Exercise has effects of increasing bone density and preventing falls. In OLS, it is also necessary to disseminate knowledge on osteoporosis and fractures to the public. Main measures against locomotive syndrome(LS), meaning weakening of ambulatory ability, are exercise and nutrition, and the LS prevention campaign is thought to lead to prevention of falls. In addition, LS is in common with OLS because it aims to spread such preventive measures widely. Exercise for LS prevention can be used safely and effectively at hospitals and workshops, as well as regional comprehensive care system.

[Gait disturbances and falls in various types of dementias]

Dementia is a group of symptoms of damage of higher cortical functions. The causes of dementia include brain diseases, most often chronic and progressive, leading to cognitive impairment typical of these disorders. Apart from progressive cognitive deficits, dementias may coexist with mental disorders, sleep disorders, epileptic seizures, parkinsonism and other motor disorders. Motor disorders, including gait disturbances and falls, represent a serious challenge to the health of older adults and contribute to loss of mobility and independence. Analysis of motor disturbances in the population of healthy older adults and those with progressive cognitive impairment is likely to support effective planning of pharmacological therapies and rehabilitation for this group of patients.

[Bone and Joint Diseases in Present and Future]

With the increase of elderly population, orthopaedic surgeons need to deal with the diseases related to aging, such as joint disorders and fragility fractures. The number of total joint replacements, for example, is two times more than it was 10 years ago. With these backgrounds, the Japanese Orthopaedic Association (JOA) has proposed the concept of locomotive syndrome; conditions under which the elderly have been receiving care services due to problems of the locomotive organs. To prevent geriatric or disuse syndrome, JOA is currently providing the care‒prevention programs such as the loco-check and loco-training. Recent advances in the orthopaedic fields were cited in this review article, including the topics of new biomaterials, regenerative medicine of cartilage, spinal cord injury and computer assisted orthopaedic surgery. These new technologies and knowledge are changing or have potential to change the future orthopedic medical care.

Clinical motion analyses over eight consecutive years in a child with crouch gait: a case report

BACKGROUND

This case report provides a unique look at the progression of crouch gait in a child with cerebral palsy over an 8-year time period, through annual physical examinations, three-dimensional gait analyses, and evaluation of postural balance. Our patient received regular botulinum toxin-A injections, casting, and physical therapy but no surgical interventions.

CASE PRESENTATION

A white American boy with spastic diplegic cerebral palsy was evaluated annually by clinical motion analyses, including physical examination, joint kinematics, electromyography, energy expenditure, and standing postural balance tests, from 6 to 13 years of age. These analyses revealed that the biomechanical factors contributing to our patient's crouch gait were weak plantar flexors, short and spastic hamstrings, moderately short hip flexors, and external rotation of the tibiae. Despite annual recommendations for surgical lengthening of the hamstrings, the family opted for non-surgical treatment through botulinum toxin-A injections, casting, and exercise. Our patient's crouch gait improved between ages 6 and 9, then worsened at age 10, concurrent with his greatest body mass index, increased plantar flexor weakness, increased standing postural sway, slowest normalized walking speed, and greatest walking energy expenditure. Although our patient's maximum knee extension in stance improved by 14 degrees at 13 years of age compared to 6 years of age, peak knee flexion in swing declined, his ankles became more dorsiflexed, his hips became more internally rotated, and his tibiae became more externally rotated. From 6 to 9 years of age, our patient's minimum stance-phase knee flexion varied in an inverse relationship with his body mass index; from 10 to 13 years of age, changes in his minimum stance-phase knee flexion paralleled changes in his body mass index.

CONCLUSIONS

The motor deficits of weakness, spasticity, shortened muscle-tendon lengths, and impaired selective motor control were highlighted by our patient's clinical motion analyses. Overall, our patient's crouch gait improved mildly with aggressive non-operative management and a supportive family dedicated to regular home exercise. The annual clinical motion analyses identified changes in motor deficits that were associated with changes in the child's walking pattern, suggesting that these analyses can serve to track the progression of children with spastic cerebral palsy.

[Safety and efficacy of surgical closure of the larynx for recurrent aspiration pneumonia in persons with severe motor and intellectual disabilities: a comparative study with tracheoesophageal diversion]

OBJECTIVE

We retrospectively investigated the efficacy and complications of surgical closure of the larynx (SCL) for recurrent aspiration pneumonia in comparison with tracheoesophageal diversion.

METHODS

The subjects were persons with severe motor and intellectual disabilities (SMID) who had undergone surgery for recurrent aspiration pneumonia between 1994 and 2011: A 8 SCL patients group and a 16 tracheoesophageal diversion patients group. We investigated two groups the lower respiratory infection incidence, length of hospital stay for the surgery, postoperative complications, and rate of cannula withdrawal, by reviewing medical records.

RESULTS

Both the SCL and the tracheoesophageal diversion group showed a reduction in the incidence of infection after surgery, indicating that the efficacy of SCL was equivalent to that of tracheoesophageal diversion in preventing aspiration pneumonea. The SCL group showed a reduction in the length of hospital stay and an increased rate of cannula withdrawal as compared with the tracheoesophageal diversion group.

CONCLUSION

The efficacy of SCL was equivalent to that of tracheoesophageal diversion in preventing aspiration for SMID. We consider SLC to have potential for reducing the burden on patients.

Gait characteristics in older adults with diabetes and impaired fasting glucose: The Rotterdam Study

AIMS

To investigate the association of diabetes mellitus and impaired fasting glucose with gait in the general middle-aged and elderly population.

METHODS

We performed a cross-sectional study on 3019 participants from the population-based Rotterdam Study (aged >45years, 54% women). The presence of diabetes mellitus and impaired fasting glucose was evaluated by measuring serum glucose levels and by documenting anti-diabetic treatment. Participants underwent gait analysis using an electronic walkway. Thirty gait variables were summarized into five independent gait domains for normal walking (Rhythm, Variability, Phases, Pace and Base of Support), one for turning (Turning) and one for walking heel to toe (Tandem), which were averaged into Global Gait. Linear regression analyses were performed to determine the association of diabetes, impaired fasting glucose and continuous glucose levels within the normal range with gait.

RESULTS

Diabetes mellitus was associated with worse Global Gait (Z-score difference -0.19, 95% confidence interval (CI) -0.30; -0.07), worse Pace (-0.20, 95% CI -0.30; -0.10) and worse Tandem (-0.21, 95% CI -0.33; -0.09), after adjusting for age, sex, height and weight. The association with Tandem remained significant after additional adjustment for cardiovascular risk factors. Impaired fasting glucose and continuous glucose levels within the normal range were not associated with any of the gait domains.

CONCLUSION

In our population-based study diabetes mellitus was associated with worse Global Gait, which was mostly reflected in Pace and Tandem. These associations were partly driven by other cardiovascular risk factors, emphasizing the importance of optimal control of cardiovascular risk factor profiles in patients with diabetes.

Amplitude Manipulation Evokes Upper Limb Freezing during Handwriting in Patients with Parkinson's Disease with Freezing of Gait

Background

Recent studies show that besides freezing of gait (FOG), many people with Parkinson’s disease (PD) also suffer from freezing in the upper limbs (FOUL). Up to now, it is unclear which task constraints provoke and explain upper limb freezing.

Objective

To investigate whether upper limb freezing and other kinematic abnormalities during writing are provoked by (i) gradual changes in amplitude or by (ii) sustained amplitude generation in patients with and without freezing of gait.

Methods

Thirty-four patients with PD, including 17 with and 17 without FOG, performed a writing task on a touch-sensitive writing tablet requiring writing at constant small and large size as well as writing at gradually increasing and decreasing size. Patients of both groups were matched for disease severity, tested while ‘on’ medication and compared to healthy age-matched controls.

Results

Fifty upper limb freezing episodes were detected in 10 patients, including 8 with and 2 without FOG. The majority of the episodes occurred when participants had to write at small or gradually decreasing size. The occurrence of FOUL and the number of FOUL episodes per patient significantly correlated with the occurrence and severity of FOG. Patients with FOUL also showed a significantly smaller amplitude in the writing parts outside the freezing episodes.

Conclusions

Corroborating findings of gait research, the current study supports a core problem in amplitude control underlying FOUL, both in maintaining as well as in flexibly adapting the cycle size.

[On "2015 Guidelines for Prevention and Treatment of Osteoporosis". Osteoporosis in relation to locomotive syndrome]

In the super-aged society of Japan, both osteoporosis and locomotive syndrome are important together from a point of view of the extension of the healthy life expectancy. Osteoporosis is an significant constituting disease of locomotive syndrome, and the measures for locomotive syndrome are important to the prevention of osteoporotic fracture, because it influences the risk of falling. Actually, a rating system and the measures for locomotive syndrome have significant relationship with evaluation and decreace of the risk of falling. To reduce the osteoporotic fracture in Japan, the spread of measures for locomotive syndrome are necessary, as well as the increase of a treatment rate of osteoporosis.

Use of gait parameters to predict the effectiveness of botulinum toxin injection in the spastic rectus femoris muscle of stroke patients with stiff knee gait

BACKGROUND

Botulinum toxin type A (BTX-A) injection in the rectus femoris (RF) is commonly used to treat decreased peak knee flexion in swing phase of the gait in hemiplegic patients. However, the effect of BTX-A varies between 5° to 10° depending on the studies. Peak knee flexion also increases during fast gait and could constitute a way to predict the effect of BTX-A injection in the RF.

AIM

To determine if changes in gait parameters during fast gait before injection could predict the effect of RF BTX-A injection on peak knee flexion in hemiplegic patients.

DESIGN

Prospective observational study.

SETTING

A neurological rehabilitation department in a university hospital

POPULATION

Twenty two hemiplegic patients with stiff knee gait mainly due to spasticity of the RF and treated by RF-BTX-A-injection.

METHODS

Patients' gait was analyzed using a 3D motion analysis system and force plates. The gait recordings were performed before (PRE-RF-BTX-A:spontaneous and fast gait speed) and one month after RF-BTX-A-injection (POST-RF-BTX-A:spontaneous gait speed). Correlations between the percentage change in gait parameters during fast gait before RF-BTX-A-injection and the percentage increase in peak knee flexion POST-RF-BTX-A injection at spontaneous speed were analyzed.

RESULTS

The percentage improvement in peak knee flexion in the fast gait condition before injection was the only parameter correlated with the percentage increase in peak knee flexion POST-RF-BTX-A injection. This was confirmed by a stepwise linear regression. The percentage increase in peak knee flexion POST-RF-BTX-A injection was also correlated with the percentage increase in knee flexion angular velocity at toe-off in the fast gait condition.

CONCLUSION

The percentage increase in peak knee flexion in swing during fast gait before injection is a useful predictor of the increase in peak knee flexion following RF BTX-A injection in chronic stroke patients with RF spasticity.

CLINICAL REHABILITATION IMPACT

In stroke patients with SKG which is mainly caused by spasticity of the RF muscle, evaluating changes which occur during fast gait might help the therapist to identify patients who would benefit the most from BTX-A injection in the RF muscle.

Dual task-related gait changes in patients with mild cognitive impairment

Mild cognitive impairment (MCI) entails a high risk of developing Alzheimer's dementia. In MCI patients gait impairment, which increases the risk of falls and institutionalization, is an early motor sign. A dualtask (DT) paradigm might improve the observation of this phenomenon. The aim of this study was to investigate motor-cognitive interference in a sample of MCI patients and a group of matched healthy controls submitted to DT conditions. To this end, three different cognitive tasks were used: counting backwards, short story recall and a phonemic fluency task. Overall, the patients, compared with the healthy participants, performed worse on the cognitive tasks and showed some degree of gait impairment. In the DT conditions, both groups showed significant gait disruption independently of the concomitant cognitive task. As regards cognitive performance, counting backwards worsened during dual tasking, while short story recall improved in both groups. Overall, our results suggest that the use of a DT paradigm does not improve the early detection of MCI. Our findings of enhanced story recall during walking might have interesting implications for rehabilitation of memory function.

Gait characteristics in individuals with intellectual disabilities: a literature review

Gait is a functionally highly relevant aspect of motor performance. In the general population poorer gait increases the risk of falls and is a predictor for future disability, cognitive impairment, institutionalization and/or mortality. People with intellectual disabilities (ID) show a delayed motor development, which brings to attention the abnormalities that might accompany gait in this population throughout childhood and adulthood. Therefore, this paper aims (a) to provide a focused review of the available literature on gait characteristics in individuals with ID and (b) to gain insight into available instrumentations measuring gait in this population. We searched the database of PubMed for relevant articles and the reference lists of included articles, resulting in 44 included articles. Forty one studies reported gait characteristics during over-ground walking and six studies during perturbed walking conditions. Most studies investigated syndrome-specific ID populations, only five studies investigated the general ID population. The studies show that gait abnormalities are evident during over-ground walking in the ID population, both in people with genetic syndromes and with ID without genetic syndromes. During perturbed conditions people with ID altered their gait with stability-enhancing adaptations. Abnormalities in gait may be partly explained by physical features, but the interrelatedness between gait and cognition may also be an explanation for the gait abnormalities seen in the ID population. Further research regarding gait characteristics of the ID population, and its relation to cognitive functioning, and adverse health outcomes is needed.

[Transdisciplinary Approach for Sarcopenia. Sarcopenia and Locomotive syndrome]

Locomotive syndrome refers to a condition under which the elderly has transfer-difficulties by problems of the locomotive organs. Sarcopenia and osteoporosis are a cause of care requirement and bedridden status. To evaluate and manage these disabled elderly with osteoporosis or sarcopenia, multidisciplinary approach is important.

Freezing of gait subtypes have different cognitive correlates in Parkinson's disease

BACKGROUND

Freezing of gait (FOG) is a major concern for Parkinson's disease (PD) patients because it is a leading cause of falls and is associated with poor quality of life. The pathophysiology is unknown but it is hypothesized that it relates to cognitive abnormalities; particularly executive and visuospatial dysfunction. However, prior results have been discrepant. Pharmacologic subtypes of FOG include those that are responsive and unresponsive to levodopa.

OBJECTIVE

To determine whether executive and visuospatial dysfunction are associated specifically with the levodopa unresponsive subtype of FOG.

METHODS

135 PD subjects completed a single assessment included FOG questionnaire, UPDRS motor scale, comprehensive cognitive battery and measure of hallucinations. Analyses compared unresponsive (n = 16), responsive (n = 20) and no FOG (n = 99) subtypes.

RESULTS

The unresponsive subtype had a significantly older age of onset of PD than the responsive group (p = .03) and had worse motor scores (p = .003) than the no FOG group. Longer disease duration was associated with the responsive group compared to the no FOG group (p = .002). The unresponsive FOG group had significantly poorer visuospatial ability (p = .001) and executive functioning (p = .02) than both the no and responsive FOG subgroups. These latter groups were not significantly different. The responsive FOG group was associated with the presence of hallucinations.

CONCLUSION

Aside from pharmacological differences, unresponsive FOG is associated with executive and visuospatial dysfunction implicating frontostriatal pathways while responsive FOG is associated with hallucinations suggesting involvement of posterior cortical regions. Further study and treatment of FOG should include appropriate subtype classification.

Spatio-temporal gait characteristics in children with Tourette syndrome: a preliminary study

Earlier studies had suggested that variability of stride length in gait is a pathological sign of basal ganglia disease. Some evidence implicates the involvement of the basal ganglia and related thalamocortical circuitry in Tourette syndrome (TS). To date, the gait of subjects with TS has only discussed in case reports. This investigation compared the spatial and temporal gait characteristics of a sample of children with TS (N=8) with those of healthy controls (HC; N=8). All children were instructed to walk under two speed conditions: "preferred" and "fastest." Gait parameters were measured using an electronic walkway. Spatial and temporal gait parameters were compared using a two-way (group)×(conditions) repeated measures ANOVA. The preliminary results suggested that similar to HC children, children with TS were capable of regulating temporal characteristics of gait based on walking speed. They also exhibited subtle gait anomalies such as irregular step length, as evidenced by significant differences in step length differential (p=0.003), detectable despite the small sample size. These findings warrant further investigation into the gait control of children with TS.

Frequency domain analysis of ground reaction force in preadolescents with and without Down syndrome

Children with Down syndrome (DS) display less stable and coordinated gait patterns in the time domain than their healthy peers. However, little is known about whether this group difference exists in the frequency domain. The purpose of this study was to investigate differences in vertical ground reaction force (GRF) in the frequency domain between preadolescents with and without DS. Twenty children at 7-10 years of age with and without DS participated in this study. Participants walked on an instrumented treadmill at two speeds with and without external ankle load. Vertical GRF was collected and the data was processed through a Fourier transform. Frequency content variables included fundamental frequency, power of the first five harmonics, and the frequency and number of harmonics at 95%, 99% and 99.5% of total power. Preadolescents with DS had a similar fundamental frequency as their healthy peers even though the DS group walked at slower speeds. The DS group displayed a different power spectrum of the first five harmonics and had the lower frequency and number of harmonics at 99% and 99.5% of total power. However, walking at a faster speed with external ankle load helped the DS group produce a power spectrum more similar to healthy children. Frequency content of vertical GRF provides additional assessment parameters in functional gait evaluation of children with DS. Treadmill intervention at a faster speed and with external ankle load appears to be clinically promising and needs further investigation.

Tremor syndromes

PURPOSE OF REVIEW

The purpose of this review is to explain a practical clinical approach to the diagnosis and management of tremor.

RECENT FINDINGS

A number of rare but important causes of tremor have been delineated, which means that attention to detail in clinical assessment of patients with tremor is even more important.

SUMMARY

Tremors are best divided into those occurring mainly at rest, mainly on posture, and mainly during action. This basic division leads directly to differential diagnosis and effective treatment.

Can robot-assisted movement training (Lokomat) improve functional recovery and psychological well-being in chronic stroke? Promising findings from a case study

The Lokomat is a robotic device that has been widely used for gait rehabilitation in several neurological disorders, with a positive effect also in the chronic phase. We describe the case of a 54-yearold female with post-stroke moderate-to-severe chronic hemiplegia, whose force, gait and balance significantly improved after intensive training with Lokomat Pro. We also noted a positive impact of Lokomat on mood and coping styles. This may be partly related to the task-oriented exercises with computerized visual feedback, which in turn can be considered an important tool for increasing patients' motor output, involvement and motivation during gait training. Augmented feedback during robot-assisted gait appears to be a promising way of facilitating gait and physical function, but also of improving psychological and cognitive status.

Spatial variability during gait initiation while dual tasking is increased in individuals with mild cognitive impairment

BACKGROUND

Gait initiation (GI) is a complex transition phase of gait that can induce postural instability. Gait impairment has been well documented in people with Alzheimer's disease, but it is still inconclusive in individuals with Mild Cognitive Impairment (MCI). Previous studies have usually investigated gait performance of cognitive impaired persons under steady state walking.

OBJECTIVE

This study aimed to examine spatiotemporal variability during GI under single- and dual-task conditions in people with and without MCI.

METHODS

Spatiotemporal stepping characteristics and variability under single- and dual-task conditions (counting backwards by 3s) were assessed in 30 older adults with MCI and 30 cognitively intact controls. Mean and coefficients of variation (COV) of swing time, step time, step length and step width were compared between the two groups.

RESULTS

Mixed-model repeated measures ANOVA revealed a significant Group x Walking condition interaction for COV of step length and step width (P<0.05). Post-hoc analysis revealed that variability for these measures were significantly larger in the MCI group compared with the control group under the dual-task condition (P<0.05).

CONCLUSIONS

Step length and step width variability is increased in people with MCI during GI, particularly in a condition involving a secondary cognitive task. These findings suggest that individuals with MCI have reduced balance control when undertaking a challenging walking task such as gait initiation, and this is exacerbated with an added cognitive task. Future studies should prospectively investigate the relationship between GI variability and fall risk in this population.

Step length after discrete perturbation predicts accidental falls and fall-related injury in elderly people with a range of peripheral neuropathy

AIMS

Distal symmetric polyneuropathy increases fall risk due to inability to cope with perturbations. We aimed to 1) identify the frontal plane lower limb sensorimotor functions which are necessary for robustness to a discrete, underfoot perturbation during gait; and 2) determine whether changes in the post-perturbed step parameters could distinguish between fallers and non fallers.

METHODS

Forty-two subjects (16 healthy old and 26 with diabetic PN) participated. Frontal plane lower limb sensorimotor functions were determined using established laboratory-based techniques. The subjects' most extreme alterations in step width or step length in response to a perturbation were measured. In addition, falls and fall-related injuries were prospectively recorded.

RESULTS

Ankle proprioceptive threshold (APrT; p=.025) and hip abduction rate of torque generation (RTG; p=.041) independently predicted extreme step length after medial perturbation, with precise APrT and greater hip RTG allowing maintenance of step length. Injured subjects demonstrated greater extreme step length changes after medial perturbation than non-injured subjects (percent change = 18.5 ± 9.2 vs. 11.3 ± 4.57; p = .01).

CONCLUSIONS

The ability to rapidly generate frontal plane hip strength and/or precisely perceive motion at the ankle is needed to maintain a normal step length after perturbation, a parameter which distinguishes between subjects sustaining a fall-related injury and those who did not.

Analysis of neuromuscular parameters in patients with multiple sclerosis and gait disorders

Gait is a motor activity that requires understanding the dynamics and functional anatomical elements that make possible its cyclical conduct. Patients with multiple sclerosis record impaired balance and gait due to the process of demyelination, disorders that can be estimated by quantifying neuromuscular and cortical parameters. The aim of this paper is to present both an analysis of these parameters in the thigh muscles and an evaluation of cortical parameters obtained by visual evoked potentials (VEP).

PATIENTS AND METHODS

The study was conducted on a group of 13 patients (mean age 38 years) with multiple sclerosis (MS), who had clinically detectable gait disturbance. Evaluation methods used were tensiomyography (TMG) and VEP, the monitored parameters were: contraction time (Tc), stance time (Ts), displacement (Dm), if TMG in the two muscle groups of the thigh (biceps femoris and right femoris), and if VEP the assessed waves were N75, P100, N135-145.

RESULTS

There were estimated the average values of latency and duration of the three analyzed waves in VEP, the values of wave N135-145 were far higher than physiological values. In terms of TMG values, they results indicate the existence of a clear right-left functional asymmetry.

DISCUSSION AND CONCLUSIONS

Analyzing these results, we note an increase in the muscular tone of the groups studied, a functional asymmetry agonist/antagonist, low speed response to stimulus. Regarding VEP wave parameters, we find significant variations of these waves' latencies, particularly of P100 wave, while the duration of these waves did not register significant figures. In conclusion, we can emphasize a change in muscle structure with predominantly type I muscular fibers and inter-neuronal connections between areas of the association to substitute the lesions occurred in specific areas.

Gait analysis in a pre- and post-ischemic stroke biomedical pig model

Severity of neural injury including stroke in human patients, as well as recovery from injury, can be assessed through changes in gait patterns of affected individuals. Similar quantification of motor function deficits has been measured in rodent animal models of such injuries. However, due to differences in fundamental structure of human and rodent brains, there is a need to develop a large animal model to facilitate treatment development for neurological conditions. Porcine brain structure is similar to that of humans, and therefore the pig may make a more clinically relevant animal model. The current study was undertaken to determine key gait characteristics in normal biomedical miniature pigs and dynamic changes that occur post-neural injury in a porcine middle cerebral artery (MCA) occlusion ischemic stroke model. Yucatan miniature pigs were trained to walk through a semi-circular track and were recorded with high speed cameras to detect changes in key gait parameters. Analysis of normal pigs showed overall symmetry in hindlimb swing and stance times, forelimb stance time, along with step length, step velocity, and maximum hoof height on both fore and hindlimbs. A subset of pigs were again recorded at 7, 5 and 3 days prior to MCA occlusion and then at 1, 3, 5, 7, 14 and 30 days following surgery. MRI analysis showed that MCA occlusion resulted in significant infarction. Gait analysis indicated that stroke resulted in notable asymmetries in both temporal and spatial variables. Pigs exhibited lower maximum front hoof height on the paretic side, as well as shorter swing time and longer stance time on the paretic hindlimb. These results support that gait analysis of stroke injury is a highly sensitive detection method for changes in gait parameters in pig.

Effectiveness of virtual reality using video gaming technology in elderly adults with diabetes mellitus

BACKGROUND

Diabetes in elderly adults is associated with an increased risk of fall. The aim of study was to determine whether a virtual reality exercise (VRE) program would improve balance, strength, gait, and falls efficacy in elderly adults with diabetes.

SUBJECTS AND METHODS

Fifty-five subjects with diabetes mellitus over 65 years of age were randomly assigned to a VRE group (VREG) (n=27) and a control group (CG) (n=28). The VREG received the VRE program and diabetes education, whereas the CG received only the diabetes education. The VRE program used video gaming (PlayStation(®) 2; Sony, Tokyo, Japan) and was conducted for 50 min twice a week for 10 weeks. Balance, muscle strength, gait, and falls efficacy were measured at baseline and after intervention. Measurements were taken using a clinical tests (the one-leg-standing test, the Berg Balance Scale, the functional reach test, the timed up-and-go test, and the sit-to-stand test), and gait analysis. A self-administered questionnaire was used to measure falls efficacy.

RESULTS

After training, the VREG showed significantly improved balance, decreased sit-to-stand times, and increased gait speed, cadence, and falls efficacy.

CONCLUSIONS

The VRE program was to maximize the effects of exercise by triggering players was to be fully immersed into the games and enhanced major influential factors on the falls of subject. This study suggests VRE programs are feasible and effective for reduced the risk of falls in elderly adults with type 2 diabetes.

Assessing fall risk using wearable sensors: a practical discussion. A review of the practicalities and challenges associated with the use of wearable sensors for quantification of fall risk in older people

Identification of older people most at risk of falling may facilitate early preventative intervention to reduce the likelihood of falls occurring. While many clinical fall risk assessment techniques exist, they often require subjective assessor interpretation, or are not appropriate for unsupervised screening of larger populations owing to a number of issues including safety, ability to reliably perform the assessment, and requirements for unwieldy apparatus. Researchers have more recently attempted to address some of these deficits by instrumenting new or existing physical fall risk assessments with wearable motion sensors to make such assessments more objective, quicker to administer, and potentially more appropriate for deployment for unsupervised use in the community. The objective of this paper is to discuss various practical questions involving sensor-based fall risk assessment (SFRA). Many of the issues discussed contribute to answering the important question of whether SFRA should or can be used in either a supervised or an unsupervised manner, and what possible deployment scenarios exist for it.

[Fall risk and fracture. Falls and fractures in patients with neurological disorders]

Neurological disorders are frequently associated with risk factors for falls, such as gait and balance disorders, deficits of lower extremity strength, sensation and coordination, in addition to cognitive impairments. Patients with various kinds of neurological disorders, including Parkinson's disease, Parkinson's syndrome, amyotrophic lateral sclerosis, peripheral neuropathy, stroke, etc, easily suffer from falls. To prevent falls among such patients, treatments of the underlying neurological diseases and assessments risk factors for falls are most important to cope effectively with these patients. In general, maintenance of the appropriate environment, consideration of the injury prevention, rehabilitation for increasing muscular strength, etc, are useful for the prevention of falls in patients with neurological disorders.