Functional freezing of gait: lessons from compensation

We highlight a specific and hitherto poorly characterised phenotype of functional gait impairments: functional freezing of gait. Unique to the presented case is the use of compensation strategies, many of which at first sight might appear to hint towards the presence of freezing of gait typical of Parkinson's disease or another form of Parkinsonism. Importantly, however, this patient's compensation strategies involved various inconsistent and incongruent elements, supporting the diagnosis of a functional neurological disorder. Recognising the features of functional freezing also helps to appreciate better the classical manifestations of freezing of gait in Parkinson's disease.

Arm Swing while Walking and Running: A New Clinical Feature to Separate Parkinson's Disease from Functional Parkinsonism

BACKGROUND

Functional parkinsonism is an important differential diagnosis of Parkinson's disease (PD). Based on anecdotal experience, we hypothesized that arm swing while walking and running could differentiate these two conditions, but this assumption has not been previously explored systematically.

OBJECTIVES

To examine differences in arm swing while walking and running between patients with PD and functional parkinsonism.

METHODS

We analyzed blinded video assessments of arm swing and other gait parameters in patients with asymmetrical PD (n = 81) and functional parkinsonism (n = 8) while walking and running. The groups were matched for age, sex and disease duration.

RESULTS

In contrast to those with PD, patients with functional parkinsonism (i) were more likely to have a marked asymmetry in arm swing while walking (5/8 vs. 25/81; P = 0.06), (ii) were less likely to improve arm swing while running with full effort (3/8 vs. 72/81; P < 0.001) and (iii) demonstrated normal passive arm swing even when asymmetry of arm swing was marked during running/walking (6/6 vs. 9/33; P = 0.002).

CONCLUSIONS

Assessment of arm swing while walking and running and passive arm swing could be important differentiating clinical features between functional parkinsonism and PD.

The Use of the Voice Trainer App for Vocal Control in People with a Degenerative Ataxia: A Pilot Intervention Study

Dysarthria is disabling in persons with degenerative ataxia. There is limited evidence for speech therapy interventions. In this pilot study, we used the Voice trainer app, which was originally developed for patients with Parkinson's disease, as a feedback tool for vocal control. We hypothesized that patients with ataxic dysarthria would benefit from the Voice trainer app to better control their loudness and pitch, resulting in a lower speaking rate and better intelligibility. This intervention study consisted of five therapy sessions of 30 min within 3 weeks using the principles of the Pitch Limiting Voice Treatment. Patients received real-time visual feedback on loudness and pitch during the exercises. Besides, they were encouraged to practice at home or to use the Voice trainer in daily life. We used observer-rated and patient-rated outcome measures. The primary outcome measure was intelligibility, as measured by the Dutch sentence intelligibility test. Twenty-one out of 25 included patients with degenerative ataxia completed the therapy. We found no statistically significant improvements in intelligibility (p = .56). However, after the intervention, patients were speaking slower (p = .03) and the pause durations were longer (p < .001). The patients were satisfied about using the app. At the group level, we found no evidence for an effect of the Voice trainer app on intelligibility in degenerative ataxia. Because of the heterogeneity of ataxic dysarthria, a more tailor-made rather than generic intervention seems warranted.

Clinical neurophysiology of functional motor disorders: IFCN Handbook Chapter

Functional Motor Disorders are common and disabling. Clinical diagnosis has moved from one of exclusion of other causes for symptoms to one where positive clinical features on history and examination are used to make a "rule in" diagnosis wherever possible. Clinical neurophysiological assessments have developed increasing importance in assisting with this positive diagnosis, not being used simply to demonstrate normal sensory-motor pathways, but instead to demonstrate specific abnormalities that help to positively diagnose these disorders. Here we provide a practical review of these techniques, their application, interpretation and pitfalls. We also highlight particular areas where such tests are currently lacking in sensitivity and specificity, for example in people with functional dystonia and functional tic-like movements.

Comparison of state-of-the-art deep learning architectures for detection of freezing of gait in Parkinson's disease

Introduction

Freezing of gait (FOG) is one of the most debilitating motor symptoms experienced by patients with Parkinson's disease (PD). FOG detection is possible using acceleration data from wearable sensors, and a convolutional neural network (CNN) is often used to determine the presence of FOG epochs. We compared the performance of a standard CNN for the detection of FOG with two more complex networks, which are well suited for time series data, the MiniRocket and the InceptionTime.

Methods

We combined acceleration data of people with PD across four studies. The final data set was split into a training (80%) and hold-out test (20%) set. A fifth study was included as an unseen test set. The data were windowed (2 s) and five-fold cross-validation was applied. The CNN, MiniRocket, and InceptionTime models were evaluated using a receiver operating characteristic (ROC) curve and its area under the curve (AUC). Multiple sensor configurations were evaluated for the best model. The geometric mean was subsequently calculated to select the optimal threshold. The selected model and threshold were evaluated on the hold-out and unseen test set.

Results

A total of 70 participants (23.7 h, 9% FOG) were included in this study for training and testing, and in addition, 10 participants provided an unseen test set (2.4 h, 11% FOG). The CNN performed best (AUC = 0.86) in comparison to the InceptionTime (AUC = 0.82) and MiniRocket (AUC = 0.76) models. For the CNN, we found a similar performance for a seven-sensor configuration (lumbar, upper and lower legs and feet; AUC = 0.86), six-sensor configuration (upper and lower legs and feet; AUC = 0.87), and two-sensor configuration (lower legs; AUC = 0.86). The optimal threshold of 0.45 resulted in a sensitivity of 77% and a specificity of 58% for the hold-out set (AUC = 0.72), and a sensitivity of 85% and a specificity of 68% for the unseen test set (AUC = 0.90).

Conclusion

We confirmed that deep learning can be used to detect FOG in a large, heterogeneous dataset. The CNN model outperformed more complex networks. This model could be employed in future personalized interventions, with the ultimate goal of using automated FOG detection to trigger real-time cues to alleviate FOG in daily life.

Predictors and Pathophysiology of Axial Postural Abnormalities in Parkinsonism: A Scoping Review

Background

Postural abnormalities involving the trunk are referred to as axial postural abnormalities and can be observed in over 20% of patients with Parkinson's disease (PD) and in atypical parkinsonism. These symptoms are highly disabling and frequently associated with back pain and a worse quality of life in PD. Despite their frequency, little is known about the pathophysiology of these symptoms and scant data are reported about their clinical predictors, making it difficult to prompt prevention strategies.

Objectives

We conducted a scoping literature review of clinical predictors and pathophysiology of axial postural abnormalities in patients with parkinsonism to identify key concepts, theories and evidence on this topic.

Methods

We applied a systematic approach to identify studies, appraise quality of evidence, summarize main findings, and highlight knowledge gaps.

Results

Ninety-two articles were reviewed: 25% reported on clinical predictors and 75% on pathophysiology. Most studies identified advanced disease stage and greater motor symptoms severity as independent clinical predictors in both PD and multiple system atrophy. Discrepant pathophysiology data suggested different potential central and peripheral pathogenic mechanisms.

Conclusions

The recognition of clinical predictors and pathophysiology of axial postural abnormalities in parkinsonism is far from being elucidated due to literature bias, encompassing different inclusion criteria and measurement tools and heterogeneity of patient samples. Most studies identified advanced disease stage and higher burden of motor symptoms as possible clinical predictors. Pathophysiology data point toward many different (possibly non-mutually exclusive) mechanisms, including dystonia, rigidity, proprioceptive and vestibular impairment, and higher cognitive deficits.

Exploring the levodopa-paradox of freezing of gait in dopaminergic medication-naïve Parkinson's disease populations

The relationship between dopaminergic treatment and freezing of gait (FOG) in Parkinson's disease (PD) is complex: levodopa is the most effective symptomatic treatment for FOG, but long-term pulsatile levodopa treatment has also been linked to an increase in the occurrence of FOG. This concept, however, continues to be debated. Here, we compared the occurrence of FOG between a levodopa-naive PD cohort and a levodopa-treated cohort. Forty-nine treatment-naive patients and 150 levodopa-treated patients were included. The time since first motor symptoms was at least 5 years. Disease severity was assessed using the MDS-UPDRS part III. Occurrence of FOG was assessed subjectively (new freezing-of-gait-questionnaire) and objectively (rapid turns test and Timed Up-and-Go test). The presence of FOG was compared between the levodopa-treated and levodopa-naive groups using a chi-square test of homogeneity. We also performed a binomial Firth logistic regression with disease duration, disease severity, country of inclusion, location of measurement, and executive function as covariates. Subjective FOG was more common in the levodopa-treated cohort (n = 41, 27%) compared to the levodopa-naive cohort (n = 2, 4%, p < 0.001). The association between FOG and levodopa treatment remained after adjustment for covariates (OR = 6.04, 95%Cl [1.60, 33.44], p = 0.006). Objectively verified FOG was more common in the levodopa-treated cohort (n = 21, 14%) compared to the levodopa-naive cohort (n = 1, 2%, p = 0.02). We found an association between long-term pulsatile levodopa treatment and an increased occurrence of FOG. Future studies should further explore the role of nonphysiological stimulation of dopamine receptors in generating FOG, as a basis for possible prevention studies.

Improved walking capacity after complementary ankle-foot surgery and gait training in a person with an incomplete tetraplegia; a case report

INTRODUCTION

The population of people with a spinal cord injury (SCI) is changing to a diverse population with an increasing number of incomplete lesions. Often, these individuals have the capacity to walk, but experience disabling gait impairments.

CASE PRESENTATION

The course of a 34-year-old male with a chronic incomplete traumatic cervical SCI who initially could walk no more than a few steps with supervision or a wheeled walker is described. He participated in a clinical trial with Targeted Epidural Spinal Stimulation (TESS). After this trial, he was able to walk with a wheeled walker and bilateral orthosis over a distance of 100 meters. Despite these improvements, his main complaints were (1) difficulty to correctly preposition the feet, and (2) pain in his toe and calf muscles. An interdisciplinary approach and the use of structured gait analysis formed the basis for shared decision-making with the team and the patient to perform ankle-foot surgery followed by 2-month gait training with a body weight support system. After this trajectory his walking distance increased to 250 meters, with a wheeled walker; but now without orthosis and with an increased walking speed compared to pre-surgery. Additionally, there was reduction of pain and he experienced no disturbances during sleeping, washing and clothing anymore.

DISCUSSION

This case shows that surgical interventions can improve the gait capacity even in case of chronic incomplete SCI. Furthermore, training with a body weight support system after medical-technical interventions is useful to utilize the full potential of these interventions.

Quantitative assessment of plantar pressure patterns in relation to foot deformities in people with hereditary motor and sensory neuropathies

BACKGROUND

Hereditary motor and sensory neuropathies (HMSN), also known as Charcot-Marie-Tooth disease, are characterized by affected peripheral nerves. This often results in foot deformities that can be classified into four categories: (1) plantar flexed first metatarsal, neutral hindfoot, (2) plantar flexed first metatarsal, correctable hindfoot varus, (3) plantar flexed first metatarsal, uncorrectable hindfoot varus, and (4) hindfoot valgus. To improve management and for the evaluation of surgical interventions, a quantitative evaluation of foot function is required. The first aim of this study was to provide insight into plantar pressure of people with HMSN in relation to foot deformities. The second aim was to propose a quantitative outcome measure for the evaluation of surgical interventions based on plantar pressure.

METHODS

In this historic cohort study, plantar pressure measurements of 52 people with HMSN and 586 healthy controls were evaluated. In addition to the evaluation of complete plantar pressure patterns, root mean square deviations (RMSD) of plantar pressure patterns from the mean plantar pressure pattern of healthy controls were calculated as a measure of abnormality. Furthermore, center of pressure trajectories were calculated to investigate temporal characteristics. Additionally, plantar pressure ratios of the lateral foot, toes, first metatarsal head, second/third metatarsal heads, fifth metatarsal head, and midfoot were calculated to measure overloading of foot areas.

RESULTS

Larger RMSD values were found for all foot deformity categories compared to healthy controls (p < 0.001). Evaluation of the complete plantar pressure patterns revealed differences in plantar pressure between people with HMSN and healthy controls underneath the rearfoot, lateral foot, and second/third metatarsal heads. Center of pressure trajectories differed between people with HMSN and healthy controls in the medio-lateral and anterior-posterior direction. The plantar pressure ratios, and especially the fifth metatarsal head pressure ratio, differed between healthy controls and people with HMSN (p < 0.05) and between the four foot deformity categories (p < 0.05).

CONCLUSIONS

Spatially and temporally distinct plantar pressure patterns were found for the four foot deformity categories in people with HMSN. We suggest to consider the RMSD in combination with the fifth metatarsal head pressure ratio as outcome measures for the evaluation of surgical interventions in people with HMSN.

The effect of walking with reduced trunk motion on dynamic stability in healthy adults

BACKGROUND

Most people with Parkinson's disease (PD) walk with a smaller mediolateral base of support (BoS) compared to healthy people, but the underlying mechanisms remain unknown. Reduced trunk motion in people with PD might be related to this narrow-based gait. Here, we study the relationship between trunk motion and narrow-based gait in healthy adults. According to the extrapolated center of mass (XCoM) concept, a decrease in mediolateral XCoM excursion would require a smaller mediolateral BoS to maintain a constant margin of stability (MoS) and remain stable.

RESEARCH QUESTION

As proof of principle, we assessed whether walking with reduced trunk motion results in a smaller step width in healthy adults, without altering the mediolateral MoS.

METHODS

Fifteen healthy adults walked on a treadmill at preferred comfortable walking speed in two conditions. First, the 'regular walking' condition without any instructions, and second, the 'reduced trunk motion' condition with the instruction: 'Keep your trunk as still as possible'. Treadmill speed was kept the same in the two conditions. Trunk kinematics, step width, mediolateral XCoM excursion and mediolateral MoS were calculated and compared between the two conditions.

RESULTS

Walking with the instruction to keep the trunk still significantly reduced trunk kinematics. Walking with reduced trunk motion resulted in significant decreases in step width and mediolateral XCoM excursion, but not in the mediolateral MoS. Furthermore, step width and mediolateral XCoM excursion were strongly correlated during both conditions (r = 0.887 and r = 0.934).

SIGNIFICANCE

This study shows that walking with reduced trunk motion leads to a gait pattern with a smaller BoS in healthy adults, without altering the mediolateral MoS. Our findings indicate a strong coupling between CoM motion state and the mediolateral BoS. We expect that people with PD who walk narrow-based, have a similar mediolateral MoS as healthy people, which will be further investigated.

Dealing with the heterogeneous presentations of freezing of gait: how reliable are the freezing index and heart rate for freezing detection?

BACKGROUND

Freezing of gait (FOG) is an unpredictable gait arrest that hampers the lives of 40% of people with Parkinson's disease. Because the symptom is heterogeneous in phenotypical presentation (it can present as trembling/shuffling, or akinesia) and manifests during various circumstances (it can be triggered by e.g. turning, passing doors, and dual-tasking), it is particularly difficult to detect with motion sensors. The freezing index (FI) is one of the most frequently used accelerometer-based methods for FOG detection. However, it might not adequately distinguish FOG from voluntary stops, certainly for the akinetic type of FOG. Interestingly, a previous study showed that heart rate signals could distinguish FOG from stopping and turning movements. This study aimed to investigate for which phenotypes and evoking circumstances the FI and heart rate might provide reliable signals for FOG detection.

METHODS

Sixteen people with Parkinson's disease and daily freezing completed a gait trajectory designed to provoke FOG including turns, narrow passages, starting, and stopping, with and without a cognitive or motor dual-task. We compared the FI and heart rate of 378 FOG events to baseline levels, and to stopping and normal gait events (i.e. turns and narrow passages without FOG) using mixed-effects models. We specifically evaluated the influence of different types of FOG (trembling vs akinesia) and triggering situations (turning vs narrow passages; no dual-task vs cognitive dual-task vs motor dual-task) on both outcome measures.

RESULTS

The FI increased significantly during trembling and akinetic FOG, but increased similarly during stopping and was therefore not significantly different from FOG. In contrast, heart rate change during FOG was for all types and during all triggering situations statistically different from stopping, but not from normal gait events.

CONCLUSION

When the power in the locomotion band (0.5-3 Hz) decreases, the FI increases and is unable to specify whether a stop is voluntary or involuntary (i.e. trembling or akinetic FOG). In contrast, the heart rate can reveal whether there is the intention to move, thus distinguishing FOG from stopping. We suggest that the combination of a motion sensor and a heart rate monitor may be promising for future FOG detection.

Modulating arousal to overcome gait impairments in Parkinson's disease: how the noradrenergic system may act as a double-edged sword

In stressful or anxiety-provoking situations, most people with Parkinson's disease (PD) experience a general worsening of motor symptoms, including their gait impairments. However, a proportion of patients actually report benefits from experiencing-or even purposely inducing-stressful or high-arousal situations. Using data from a large-scale international survey study among 4324 people with PD and gait impairments within the online Fox Insight (USA) and ParkinsonNEXT (NL) cohorts, we demonstrate that individuals with PD deploy an array of mental state alteration strategies to cope with their gait impairment. Crucially, these strategies differ along an axis of arousal-some act to heighten, whereas others diminish, overall sympathetic tone. Together, our observations suggest that arousal may act as a double-edged sword for gait control in PD. We propose a theoretical, neurobiological framework to explain why heightened arousal can have detrimental effects on the occurrence and severity of gait impairments in some individuals, while alleviating them in others. Specifically, we postulate that this seemingly contradictory phenomenon is explained by the inherent features of the ascending arousal system: namely, that arousal is related to task performance by an inverted u-shaped curve (the so-called Yerkes and Dodson relationship). We propose that the noradrenergic locus coeruleus plays an important role in modulating PD symptom severity and expression, by regulating arousal and by mediating network-level functional integration across the brain. The ability of the locus coeruleus to facilitate dynamic 'cross-talk' between distinct, otherwise largely segregated brain regions may facilitate the necessary cerebral compensation for gait impairments in PD. In the presence of suboptimal arousal, compensatory networks may be too segregated to allow for adequate compensation. Conversely, with supraoptimal arousal, increased cross-talk between competing inputs of these complementary networks may emerge and become dysfunctional. Because the locus coeruleus degenerates with disease progression, finetuning of this delicate balance becomes increasingly difficult, heightening the need for mental strategies to self-modulate arousal and facilitate shifting from a sub- or supraoptimal state of arousal to improve gait performance. Recognition of this underlying mechanism emphasises the importance of PD-specific rehabilitation strategies to alleviate gait disability.

Good vibrations: tactile cueing for freezing of gait in Parkinson's disease

BACKGROUND

Cueing strategies can alleviate freezing of gait (FOG) in people with Parkinson's disease (PD). We evaluated tactile cueing delivered via vibrating socks, which has the benefit of not being noticeable to bystanders.

OBJECTIVE

To evaluate the effect of tactile cueing compared to auditory cueing on FOG.

METHODS

Thirty-one persons with PD with FOG performed gait tasks during both ON and OFF state. The effect of open loop and closed loop tactile cueing, as delivered by vibrating socks, was compared to an active control group (auditory cueing) and to a baseline condition (uncued gait). These four conditions were balanced between subjects. Gait tasks were videotaped and annotated for FOG by two experienced raters. Motion data were collected to analyze spatiotemporal gait parameters. Responders were defined as manifesting a relative reduction of > 10% in the percent time frozen compared to uncued gait.

RESULTS

The average percent time frozen during uncued gait was 11.2% in ON and 21.5% in OFF state. None of the three tested cueing modalities affected the percentage of time frozen in either the ON (p = 0.20) or OFF state (p = 0.12). The number of FOG episodes and spatiotemporal gait parameters were also not affected. We found that 22 out of 31 subjects responded to cueing, the response to the three types of cueing was highly individual.

CONCLUSIONS

Cueing did not improve FOG at the group level; however, tactile as well as auditory cueing improved FOG in many individuals. This highlights the need for a personalized approach when using cueing to treat FOG.

Specialized Versus Generic Allied Health Therapy and the Risk of Parkinson's Disease Complications

BACKGROUND

Specialized versus generic physiotherapy (PT) reduces Parkinson's disease (PD)-related complications. It is unclear (1) whether other specialized allied heath disciplines, including occupational therapy (OT) and speech and language therapy (S&LT), also reduce complications; (2) whether there is a synergistic effect among multiple specialized disciplines; and (3) whether each allied health discipline prevents specific complications.

OBJECTIVES

To longitudinally assessed whether the level of expertise (specialized vs. generic training) of PT, OT, and S&LT was associated with the incidence rate of PD-related complications.

METHODS

We used claims data of all insured persons with PD in the Netherlands between January 1, 2010, and December 31, 2018. ParkinsonNet-trained therapists were classified as specialized, and other therapists as generic. We used mixed-effects Poisson regression models to estimate rate ratios adjusting for sociodemographic and clinical characteristics.

RESULTS

The population of 51,464 persons with PD (mean age, 72.4 years; standard deviation 9.8) sustained 10,525 PD-related complications during follow-up (median 3.3 years). Specialized PT was associated with fewer complications (incidence rate ratio [IRR] of specialized versus generic = 0.79; 95% confidence interval, [0.74-0.83]; P < 0.0001), as was specialized OT (IRR = 0.88 [0.77-0.99]; P = 0.03). We found a trend of an association between specialized S&LT and a lower rate of PD-related complications (IRR = 0.88 [0.74-1.04]; P = 0.18). The inverse association of specialized OT persisted in the stratum, which also received specialized PT (IRR = 0.62 [0.42-0.90]; P = 0.001). The strongest inverse association of PT was seen with orthopedic injuries (IRR = 0.78 [0.73-0.82]; P < 0.0001) and of S&LT with pneumonia (IRR = 0.70 [0.53-0.93]; P = 0.03).

CONCLUSIONS

These findings support a wider introduction of specialized allied health therapy expertise in PD care and conceivably for other medical conditions. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Gait-Adaptability Training in People With Hereditary Spastic Paraplegia: A Randomized Clinical Trial

BACKGROUND AND OBJECTIVES

In people with hereditary spastic paraplegia (HSP), reduced gait adaptability is common and disabling. Gait impairments result from lower extremity spasticity, muscle weakness, and impaired proprioception. The aim of this study was to assess the efficacy of a 5-week gait-adaptability training in people with pure HSP.

METHOD

We conducted a randomized clinical trial with a cross-over design for the control group, and a 15-week follow-up period after training. Thirty-six people with pure HSP were randomized to 5 weeks of (i) gait-adaptability training (10 hours of C-Mill training-a treadmill equipped with augmented reality) or (ii) a waiting-list control period followed by 5 weeks gait-adaptability training. Both groups continued to receive usual care. The primary outcome was the obstacle subtask of the Emory Functional Ambulation Profile. Secondary outcome measures consisted of clinical balance and gait assessments, fall rates, and spatiotemporal gait parameters assessed via 3D motion analysis.

RESULTS

The gait-adaptability training group (n = 18) did not significantly decrease the time required to perform the obstacle subtask compared to the waiting-list control group (n = 18) after adjusting for baseline differences (mean: -0.33 seconds, 95% CI: -1.3, 0.6). Similar, non-significant results were found for most secondary outcomes. After merging both groups (n = 36), the required time to perform the obstacle subtask significantly decreased by 1.3 seconds (95% CI: -2.1, -0.4) directly following 5 weeks of gait-adaptability training, and this effect was retained at the 15-week follow-up.

CONCLUSIONS

We found insufficient evidence to conclude that 5 weeks of gait-adaptability training leads to greater improvement of gait adaptability in people with pure HSP.

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.

Comparison of ground reaction force and marker-based methods to estimate mediolateral center of mass displacement and margins of stability during walking

Dynamic balance control during human walking can be described by the distance between the mediolateral (ML) extrapolated center of mass (XCoM) position and the base of support, the margin of stability (MoS). The ML center of mass (CoM) position during treadmill walking can be estimated based on kinematic data (marker-based method) and a combination of ground reaction forces and center of pressure positions (GRF-based method). Here, we compare a GRF-based method with a full-body marker-based method for estimating the ML CoM, ML XCoM and ML MoS. Fifteen healthy adults walked on a dual-belt treadmill at comfortable walking speed for three minutes. Kinetic and kinematic data were collected and analyzed using a GRF-based and marker-based method to compare the ML CoM, ML XCoM and ML MoS. High correlation coefficients (r > 0.98) and small differences (Root Mean Square Difference < 0.0072 m) in ML CoM and ML XCoM were found between the GRF-based and marker-based methods. The GRF-based method resulted in larger ML XCoM excursion (0.0118 ± 0.0074 m) and smaller ML MoS values (0.0062 ± 0.0028 m) than the marker-based method, but these differences were consistent across participants. In conclusion, the GRF-based method is a valid method to determine the ML CoM, XCoM and MoS. One should be aware of higher ML XCoM and smaller ML MoS values in the GRF-based method when comparing absolute values between studies. The GRF-based method strongly reduces measurement times and can be used to provide real-time CoM-CoP feedback during treadmill gait training.

Shoulder-Touch test to reveal incongruencies in persons with functional motor disorders

BACKGROUND AND PURPOSE

Clinical experience suggests that many patients with functional motor disorders (FMD), despite reporting severe balance problems, typically do not fall frequently. This discrepancy may hint towards a functional component. Here, we explored the role of the Shoulder-Touch test, which features a light touch on the patient's shoulders, to reveal a possible functional etiology of postural instability.

METHODS

We enrolled consecutive outpatients with a definite diagnosis of FMD. Patients with Parkinson's disease (PD) or progressive supranuclear palsy (PSP) with postural instability served as controls. Each patient underwent a clinical evaluation including testing for postural instability using the retropulsion test. Patients with an abnormal retropulsion test (score ≥ 1) also received a light touch on their shoulders to explore the presence (S-Touch+) or absence (S-Touch-) of an incongruent, exaggerated postural response, defined as taking three or more steps to recover or a fall if not caught by the examiner.

RESULTS

From a total sample of 52 FMD patients, 48 patients were recruited. Twenty-five patients (52%) had an abnormal retropulsion test. Twelve of these 25 patients (48%) had an S-Touch+, either because of need to take two or more steps (n = 4) or a fall if not caught by the examiner (n = 8). None of the 23 PD/PSP patients manifested S-Touch+. The sensitivity of the S-Touch test was 48%, whereas its specificity was 100%.

CONCLUSION

The S-Touch test has a high specificity, albeit with a modest sensitivity, to reveal a functional etiology of postural instability in persons with FMD.

Evaluation of Compensation Strategies for Gait Impairment in Patients With Parkinson Disease

BACKGROUND AND OBJECTIVES

Compensation strategies are essential in Parkinson disease (PD) gait rehabilitation. However, besides external cueing, these strategies have rarely been investigated systematically. We aimed to perform the following: (1) establish the patients' perspective on the efficacy and usability of 5 different compensation strategies; (2) quantify the efficacy of these strategies on spatiotemporal gait parameters; and (3) explore associations between the effects of specific strategies and patient characteristics.

METHODS

We recruited persons with PD and self-reported disabling gait impairments for this laboratory-based, within-subject study. Clinimetrics included the following: questionnaires (New Freezing of Gait Questionnaire, Vividness of Movement Imagery Questionnaire, Goldsmiths Musical Sophistication Index), cognitive assessments (Attentional Network Test and Montreal Cognitive Assessment [MoCA], Brixton), and physical examinations (Movement Disorders Society Unified Parkinson's Disease Rating Scale [MDS-UPDRS III], Mini-Balance Evaluation Systems Test, tandem gait, and rapid turns test). Gait assessment consisted of six 3-minute trials of continuous walking around a 6-m walkway. Trials comprised the following: (1) baseline gait; (2) external cueing; (3) internal cueing; (4) action observation; (5) motor imagery; and (6) adopting a new walking pattern. Spatiotemporal gait parameters were acquired using 3-dimensional motion capture analysis. Strategy efficacy was determined by the change in gait variability compared with baseline gait. Associated patient characteristics were explored using regression analyses.

RESULTS

A total of 101 participants (50 men; median [range] age: 66 [47-91] years) were included. The effects of the different strategies varied greatly among participants. While participants with higher baseline variability showed larger improvements using compensation strategies, participants without freezing of gait, with lower MDS-UPDRS III scores, higher balance capacity, and better performance in orienting attention also showed greater improvements in gait variability. Higher MoCA scores were associated with greater efficacy of external cueing.

DISCUSSION

Our findings support the use of compensation strategies in gait rehabilitation for PD but highlight the importance of a personalized approach. Even patients with high gait variability are able to improve through the application of compensation strategies, but certain levels of cognitive and functional reserve seem necessary to optimally benefit from them.

The Grey Area of Freezing of Gait Annotation: a Guideline and Open‐source Practical Tool

Background

Freezing of gait, a disabling episodic symptom, is difficult to assess as the exact begin‐ and endpoint of an episode is not easy to specify. This hampers scientific and clinical progress. The current golden standard is video annotation by two independent raters. However, the comparison of the two ratings gives rise to non‐overlapping, gray areas.

Objective

To provide a guideline for dealing with these gray areas.

Methods/Results

We propose a standardized procedure for handling the gray areas based on two parameters, the tolerance and correction parameter. Furthermore, we recommend the use of positive agreement, negative agreement, and prevalence index to report interrater agreement instead of the commonly used intraclass correlation coefficient or Cohen's kappa. This theoretical guideline was implemented in an open‐source practical tool, FOGtool (https://github.com/helenacockx/FOGtool).

Conclusion

This paper aims to contribute to the standardization of freezing of gait assessment, thereby improving data sharing procedures and replicability of study results.

Dance classes improve self-esteem and quality of life in persons with Parkinson's disease

INTRODUCTION

Dance can reduce motor symptoms in persons with Parkinson's disease (PD). However, the effect on psychosocial wellbeing, including self-esteem and quality of life is less clear.

METHODS

Forty-nine persons with PD (Hoehn and Yahr stage 1-4) participated in weekly dance classes for a consecutive period of 22 weeks, 36 participants completed the classes. Two baseline measurements (T1a and T1b) were performed during a 2-week control period prior to the dance classes. Post-measurements (T2) were performed immediately after 22 weeks of dance classes. Primary outcome was self-esteem as measured with the Rosenberg Self-Esteem Score.

RESULTS

Self-esteem scores were stable across the two baseline measurements and improved significantly after the dance classes (1.5 points improvement between T1b and T2, 95% CI 0.3, 2.7; p = 0.012). Additionally, quality of life as measured with the Parkinson's Disease Questionnaire 39 improved significantly (3.4 points reduction between T1b and T2, 95%CI - 5.7, - 1.2; p = 0.003) as did motor symptoms as measured with the Movement Disorders Society-Unified Parkinson's Disease Rating Scale-part III (6.2 points reduction between T1b and T2, 95%CI - 10.1, - 2.4; p = 0.002). Balance confidence as measured with the Activities-Specific Balance Confidence Scale did not change.

DISCUSSION AND CONCLUSIONS

Dance classes seem to improve self-esteem, quality of life and motor symptoms in persons with PD. These effects should be investigated further in a randomized clinical trial.

CLINICAL MESSAGE

Dance classes may be a valuable complementary treatment option in people with PD to improve not only motor symptoms, but also self-esteem and quality of life.

Increased trunk movements in people with hereditary spastic paraplegia: do these involve balance correcting strategies?

Objective

Hereditary spastic paraplegia (HSP) is characterized by a bilaterally spastic gait pattern. During gait, increased trunk movements are often observed. People with HSP likely generate trunk movements to improve foot clearance and step length, but there may be additional explanations. Here, we investigate whether there is an association between reduced balance performance and increased trunk movements, as an increase in trunk movements may partly reflect balance correcting strategies.

Methods

We analyzed an historic cohort of 86 people with HSP who underwent gait analysis and balance examination. Two researchers reviewed gait analyses videos and classified the observed trunk movement as (1) normal, (2) moderately increased, or (3) markedly increased, and categorized participants as ‘toe walkers’ (yes/no). Balance performance and spatiotemporal gait parameters were collected from the medical files. Parameters were compared between people with normal vs. moderately increased trunk movements, moderately vs. markedly increased trunk movements, and normal vs. markedly increased trunk movements.

Results

Patients with moderately increased trunk movements during gait scored lower on the Berg Balance Scale (p = 0.002) and/or the Mini Balance Evaluation Test (p = 0.043) than patients with normal trunk movements. Likewise, patients with markedly increased trunk movements performed worse on the BBS (p = 0.037) and/or the Mini-BESTest (p = 0.004) than patients with moderately increased trunk movements. Patients with markedly increased trunk movements were more often toe walkers than patients with moderately increased (68% vs. 6%; p < 0.001).

Conclusions

We found an association between increased trunk movements and reduced balance capacity. This may have several—not mutually exclusive—explanations. One of these explanations is that trunk movements, at least partly, reflect balance correcting strategies. With the disease progression, ankle strategies and foot placement strategies become impaired and insufficient to restore balance after intrinsic perturbations. Hip strategies are then potentially recruited to maintain balance, resulting in increased trunk movements.

Cortical correlates of gait compensation strategies in Parkinson's disease

Objective

Gait impairment in persons with Parkinson disease is common and debilitating. Compensation strategies (eg, external cues) are an essential part of rehabilitation, but their underlying mechanisms remain unclear. Using electroencephalography (EEG), we explored the cortical correlates of 3 categories of strategies: external cueing, internal cueing, and action observation.

Methods

Eighteen participants with Parkinson disease and gait impairment were included. We recorded 126‐channel EEG during both stance and gait on a treadmill under 4 conditions: (1) uncued, (2) external cueing (listening to a metronome), (3) internal cueing (silent rhythmic counting), and (4) action observation (observing another person walking). To control for the effects of sensory processing of the cues, we computed relative power changes as the difference in power spectral density between walking and standing for each condition.

Results

Relative to uncued gait, the use of all 3 compensation strategies induced a decrease of beta band activity in sensorimotor areas, indicative of increased cortical activation. Parieto‐occipital alpha band activity decreased with external and internal cueing, and increased with action observation. Only internal cueing induced a change in frontal cortical activation, showing a decrease of beta band activity compared to uncued gait.

Interpretation

The application of compensation strategies resulted in changed cortical activity compared to uncued gait, which could not be solely attributed to sensory processing of the cueing modality. Our findings suggest there are multiple routes to control gait, and different compensation strategies seem to rely on different cortical mechanisms to achieve enhanced central motor activation in persons with Parkinson disease. ANN NEUROL 2022;91:329–341

A Practical Guide to the Evaluation of Compensation Strategies for Gait Impairment in Parkinson's Disease

The application of compensation strategies is an important element of gait rehabilitation in persons with Parkinson's disease. While the efficacy of these strategies is generally very high, a tailored, personalized approach is necessary to determine the optimal strategies for every patient. We propose a straightforward, practical guide to the evaluation of compensation strategies in clinical practice: considering the primary gait target(s) to optimize functional mobility, the context in which the strategies will be employed in daily life, and patient-specific personal preferences. Furthermore, we introduce www.walkingwithparkinson.com as a resource on the available compensation strategies, developed specifically for persons with Parkinson's disease, their carers, and (allied) healthcare professionals.

Perception and Use of Compensation Strategies for Gait Impairment by Persons With Parkinson Disease

BACKGROUND AND OBJECTIVES

Gait impairments are common and disabling in Parkinson disease (PD). Applying compensation strategies helps to overcome these gait deficits. Clinical observations suggest that the efficacy of different compensation strategies varies depending on both individual patient characteristics and the context in which the strategies are applied. This has never been investigated systematically, hampering the ability of clinicians to provide a more personalized approach to gait rehabilitation. We had 3 aims: (1) to evaluate patients' awareness and actual use of compensation categories for gait impairments in PD, (2) to investigate the patient-rated efficacy of the various compensation strategies and whether this efficacy depends on the context in which the strategies are applied, and (3) to explore differences in the efficacy between subgroups based on sex, age, disease duration, freezing status, and ability to perform a dual task.

METHODS

A survey was conducted among 4,324 adults with PD and self-reported disabling gait impairments.

RESULTS

The main findings are as follows: (1) compensation strategies for gait impairments are commonly used by persons with PD, but their awareness of the full spectrum of available strategies is limited; (2) the patient-rated efficacy of compensation strategies is high but varies depending on the context in which they are applied; and (3) compensation strategies are useful for all types of patients with PD, but the efficacy of the different strategies varies per person.

DISCUSSION

The choice of compensation strategies for gait impairment in PD should be tailored to the individual patient and to the context in which the strategy needs to be applied.

CLASSIFICATION OF EVIDENCE

This data provides Class IV evidence that compensation strategies are an effective treatment for gait impairment in patients with PD.

Perceptions of Compensation Strategies for Gait Impairments in Parkinson's Disease: A Survey Among 320 Healthcare Professionals

Compensation strategies are an essential part of managing gait impairments in people with Parkinson’s disease (PD). We conducted an online survey among 320 healthcare professionals with specific expertise in PD management, to evaluate their knowledge of compensation strategies for gait impairments in people with PD, and whether they applied these in daily practice. Only 35% of professionals was aware of all categories of compensation strategies. Importantly, just 23% actually applied all seven available categories of strategies when treating people with PD in clinical practice. We discuss the clinical implications, and provide recommendations to overcome this knowledge gap.

Management of gait impairments in people with Charcot-Marie-Tooth disease: A treatment algorithm

ABSTRACT

Gait impairments in people with Charcot-Marie-Tooth disease are the combined result of ankle-foot deformities, muscle weakness, and somatosensory impairments. People with Charcot-Marie-Tooth disease often experience pain and difficulties when walking, especially barefoot. They also trip and fall frequently and have a lower than normal gait speed and distance. Because these gait impairments and related complaints are disabling, clinical management aimed at improving gait is important. Management involves both conservative and surgical treatment options, each with limited scientific evidence. However, a treatment algorithm that describes both conservative and surgical treatment options is currently lacking. This study sets out a step-wise treatment algorithm, based on evidence, if available, and otherwise reflecting practice-based experience. The treatment algorithm will be of value in daily clinical practice, and will serve as a template for future research.

LAY ABSTRACT

Treatment of gait impairments in people with Charcot-Marie-Tooth disease is crucial, because it is a source of great disability. However, many clinicians find it difficult to treat these gait impairments in their daily clinical practice. This challenge is compounded by a lack of clear treatment protocols that take the whole spectrum of treatment options into account. As a result, there is wide variation in clinical practice. To address the widely felt need for a treatment algorithm, we present here a stepwise approach to the management of gait impairments in patients with Charcot-Marie-Tooth disease.

Improved Gait Capacity after Bilateral Achilles Tendon Lengthening for Irreducible Pes Equinus Due to Hereditary Spastic Paraplegia: a Case Report

Objective

Toe walking due to progressive shortening of the calf muscles is common in people with hereditary spastic paraplegia. Achilles tendon lengthening is a treatment option, but clinicians are often hesitant to use this procedure, as it may result in weakening of the calf muscles and, subsequently, in reduced ankle power and knee instability during the stance phase of gait. We report here a case report supporting that these negative side-effects can be avoided in well-selected people with hereditary spastic paraplegia.

Method

Bilateral Achilles tendon lengthening, combined with bilateral tenotomy of the tibialis posterior and toe flexors, was performed in a 29-year-old woman with uncomplicated hereditary spastic paraplegia who experienced progressive gait instability due to shortening of the soleus and gastrocnemius muscles (resulting in irreducible pes equinus).

Results

Bilateral Achilles tendon lengthening resulted in improvement in both subjective and objective outcomes. Self-selected gait speed improved from 0.75 m/s before surgery to 1.07 m/s after surgery (p < 0.001). Knee instability during the stance phase did not occur post-surgery. The ankle moment trajectories normalized after surgery, while peak ankle powers increased.

Conclusion

Correction of bilateral irreducible pes equinus by Achilles tendon lengthening may improve gait capacity in well-selected subjects with hereditary spastic paraplegia.

Multimodal Balance Training Supported by Rhythmical Auditory Stimuli in Parkinson's Disease: A Randomized Clinical Trial

Background:

Balance impairment in Parkinson’s disease (PD) improves only partially with dopaminergic medication. Therefore, non-pharmacological interventions such as physiotherapy are important elements in clinical management. External cues are often applied to improve gait, but their effects on balance control are unclear.

Objective/Methods:

We performed a prospective, single-blind, randomized clinical trial to study the effectiveness of balance training with and without rhythmical auditory cues. We screened 201 volunteers by telephone; 154 were assigned randomly into three groups: (1) multimodal balance training supported by rhythmical auditory stimuli (n = 56) (RAS-supported multimodal balance training); (2) regular multimodal balance training without rhythmical auditory stimuli (n = 50); and (3) control intervention involving a general education program (n = 48). Training was performed for 5 weeks, two times/week. Linear mixed models were used for all outcomes. Primary outcome was the Mini-BESTest (MBEST) score immediately after the training period. Assessments were performed by a single, blinded assessor at baseline, immediately post intervention, and after one and 6-months follow-up.

Results:

Immediately post intervention, RAS-supported multimodal balance training was more effective than regular multimodal balance training on MBEST (difference 3.5 (95% Confidence Interval (CI) 2.2; 4.8)), p < 0.001). Patients allocated to both active interventions improved compared to controls (MBEST estimated mean difference versus controls 6.6 (CI 5.2; 8.0), p < 0.001 for RAS-supported multimodal balance training; and 3.0 (CI 2.7; 5.3), p < 0.001 for regular multimodal balance training). Improvements were retained at one-month follow-up for both active interventions, but only the RAS-supported multimodal balance training group maintained its improvement at 6 months.

Conclusion:

Both RAS-supported multimodal balance training and regular multimodal balance training improve balance, but RAS-supported multimodal balance training–adding rhythmical auditory cues to regular multimodal balance training–has greater and more sustained effects.

TAILORED USE OF COMPENSATION STRATEGIES TO ENABLE EXERCISE DESPITE FESTINATION IN PARKINSON'S DISEASE

Despite increasing evidence for, and heightened awareness of, the importance of exercise in Parkinson’s disease, many patients remain sedentary. This tendency to lead an inactive lifestyle has various underlying reasons, including the presence of gait and balance impairments that complicate the patients’ ability to perform sports activities. This case report illustrates that a personally tailored approach may be required in these patients, supported, if needed, by the use of compensation strategies or novel technological advances.

Pallidal stimulation as treatment for camptocormia in Parkinson's disease

Camptocormia is a common and often debilitating postural deformity in Parkinson’s disease (PD). Few treatments are currently effective. Deep brain stimulation (DBS) of the globus pallidus internus (GPi) shows potential in treating camptocormia, but evidence remains limited to case reports. We herein investigate the effect of GPi-DBS for treating camptocormia in a retrospective PD cohort. Thirty-six consecutive PD patients who underwent GPi-DBS were reviewed. The total and upper camptocormia angles (TCC and UCC angles) derived from video recordings of patients who received GPi-DBS were used to compare camptocormia alterations. Correlation analysis was performed to identify factors associated with the postoperative improvements. DBS lead placement and the impact of stimulation were analyzed using Lead-DBS software. Eleven patients manifested pre-surgical camptocormia: seven had lower camptocormia (TCC angles ≥ 30°; TCC-camptocormia), three had upper camptocormia (UCC angles ≥ 45°; UCC-camptocormia), and one had both. Mean follow-up time was 7.3 ± 3.3 months. GPi-DBS improved TCC-camptocormia by 40.4% (angles from 39.1° ± 10.1° to 23.3° ± 8.1°, p = 0.017) and UCC-camptocormia by 22.8% (angles from 50.5° ± 2.6° to 39.0° ± 6.7°, p = 0.012). Improvement in TCC angle was positively associated with pre-surgical TCC angles, levodopa responsiveness of the TCC angle, and structural connectivity from volume of tissue activated to somatosensory cortex. Greater improvement in UCC angles was seen in patients with larger pre-surgical UCC angles. Our study demonstrates potential effectiveness of GPi-DBS for treating camptocormia in PD patients. Future controlled studies with larger numbers of patients with PD-related camptocormia should extend our findings.

The European Reference Network for Rare Neurological Diseases

While rare diseases (RDs) are by definition of low prevalence, the total number of patients suffering from an RD is high, and the majority of them have neurologic manifestations, involving central, peripheral nerve, and muscle. In 2017, 24 European Reference Networks (ERNs), each focusing on a specific group of rare or low-prevalence complex diseases, were formed to improve the care for patients with an RD. One major aim is to have “the knowledge travel instead of the patient,” which has been put into practice by the implementation of the Clinical Patient Management System (CPMS) that enables clinicians to perform pan-European virtual consultations. The European Reference Network for Rare Neurological Diseases (ERN-RND) provides an infrastructure for knowledge sharing and care coordination for patients affected by a rare neurological disease (RND) involving the most common central nervous system pathological conditions. It covers the following disease groups: (i) Cerebellar Ataxias and Hereditary Spastic Paraplegias; (ii) Huntington's disease and Other Choreas; (iii) Frontotemporal dementia; (iv) Dystonia, (non-epileptic) paroxysmal disorders, and Neurodegeneration with Brain Iron Accumulation; (v) Leukoencephalopathies; and (vi) Atypical Parkinsonian Syndromes. At the moment, it unites 32 expert centers and 10 affiliated partners in 21 European countries, as well as patient representatives, but will soon cover nearly all countries of the European Union as a result of the ongoing expansion process. Disease expert groups developed and consented on diagnostic flowcharts and disease scales to assess the different aspects of RNDs. ERN-RND has started to discuss diagnostically unclear patients in the CPMS, is one of four ERNs that serve as foundation of Solve-RD, and has established an RND training and education program. The network will facilitate trial readiness through the establishment of an ERN-RND registry with a minimal data of all patients seen at the ERN-RND centers, thus providing a unique overview of existing genotype-based cohorts. The overall aim of the ERNs is to improve access for patients with RDs to quality diagnosis, care, and treatment. Based on this objective, ERNs are monitored by the European Commission on a regular basis to provide transparency and reassurance to the RD community and the general public.

Improving gait adaptability in patients with hereditary spastic paraplegia (Move-HSP): study protocol for a randomized controlled trial

Background

People with hereditary spastic paraplegia (HSP) experience difficulties adapting their gait to meet environmental demands, a skill required for safe and independent ambulation. Gait adaptability training is possible on the C-Mill, a treadmill equipped with augmented reality, enabling visual projections to serve as stepping targets or obstacles. It is unknown whether gait adaptability can be trained in people with HSP.

Aim

The aim of Move-HSP is to study the effects of ten 1-h sessions of C-Mill training, compared with usual care, on gait adaptability in people with pure HSP. In addition, this study aims to identify key determinants of C-Mill training efficacy in people with pure HSP.

Method

Move-HSP is a 5-week, two-armed, open-label randomized controlled trial with a cross-over design for the control group. Thirty-six participants with pure HSP will be included. After signing informed consent, participants are randomized (1:1) to intervention or control group. All participants register (near) falls for 15 weeks, followed by the first assessment (week 16), and, thereafter, wear an Activ8 activity monitor for 7 days (week 16). The intervention group receives 10 sessions of C-Mill training (twice per week, 1-h sessions; weeks 17–21), whereas control group continues with usual care (weeks 17–21). Afterwards, both groups are re-assessed (week 22). Subsequently, the intervention group enter follow-up, whereas control group receives 10 sessions of C-Mill training (weeks 23–27), is re-assessed (week 28), and enters follow-up. During follow-up, both groups wear Activ8 activity monitors for 7 days (intervention group: week 23, control group: week 29) and register (near) falls for 15 weeks (intervention group: weeks 23–37, control group: weeks 29–43), before the final assessment (intervention group: week 38, control group: week 44). The primary outcome is the obstacle subtask of the Emory Functional Ambulation Profile. Secondary outcomes consist of clinical tests assessing balance and walking capacity, physical activity, and fall monitoring.

Discussion

Move-HSP will be the first RCT to assess the effects of C-Mill gait adaptability training in people with pure HSP. It will provide proof of concept for the efficacy of gait adaptability training in people with pure HSP.

Trial registration

Clinicaltrials.gov NCT04180098. Registered on November 27, 2019.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s13063-020-04932-9.

[Movement technology in the rehabilitation after stroke: hype or hope?]

Application of movement technology in the rehabilitation of neurological disorders has gained a firm position within a short time span, but the effectiveness of many technological innovations is still poorly supported by evidence. Should this burst of movement technology be considered a hype or is it offering realistic hope? This perspective focuses on motor rehabilitation after unilateral stroke and addresses the value of rehabilitation robots, virtual-reality training, peripheral neurostimulation, and brain stimulation. Current rehabilitation robots offer added value compared to conventional training, but only early after stroke for patients who are not yet able to walk independently. The effects of peripheral neurostimulation or brain stimulation are still hard to prove or relatively small. Virtual-reality training seems to be most promising for regaining motor skills, particularly when adjusted to individual capacities. Overall, functional benefits of movement technology in the rehabilitation of neurological disorders keep the middle between hype and hope.

Freezing of gait detection in Parkinson's disease via multimodal analysis of EEG and accelerometer signals

Parkinson's disease (PD) patients with freezing of gait (FOG) can suddenly lose their forward moving ability leading to unexpected falls. To overcome FOG and avoid the falls, a real-time accurate FOG detection or prediction system is desirable to trigger on-demand cues. In this study, we designed and implemented an in-place movement experiment for PD patients to provoke FOG and meanwhile acquired multimodal physiological signals, such as electroencephalography (EEG) and accelerometer signals. A multimodal model using brain activity from EEG and motion data from accelerometers was developed to improve FOG detection performance. In the detection of over 700 FOG episodes observed in the experiments, the multimodal model achieved 0.211 measured by Matthews Correlation Coefficient (MCC) compared with the single-modal models (0.127 or 0.139).Clinical Relevance- This is the first study to use multimodal: EEG and accelerometer signal analysis in FOG detection, and an improvement was achieved.

[Heterotopic ossifications after COVID-19 pneumonia]

COVID-19 patients admitted to the Intensive Care Unit may develop painful range of motion restrictions of the large joints due to heterotopic ossifications. Here we describe two patients who developed restricted and painful passive and active mobility of the hips, shoulders and elbows after mechanical ventilation because of respiratory failure due to COVID-19 pneumonia. Conventional radiography showed extensive heterotopic ossifications. Retrospectively, alkaline phosphatase levels were elevated. It is likely that local and systemic factors contribute to the development of heterotopic ossifications. Early diagnosis is important to provide complementary non-pharmacological interventions (gentle passive mobilization) and medication (non-steroidal anti-inflammatory drugs, such as indomethacin). If pain and limited joint mobility remain present, surgical removal of ectopic bone could be considered. Future trials are needed to systematically map the prevalence of heterotopic ossifications in COVID-19 patients who were admitted to the Intensive Care Unit, andto evaluate whether prophylactic treatment with non-steroidal anti-inflammatory drug is of relevance.