Improvement of balance after audio-biofeedback. A 6-week intervention study in patients with progressive supranuclear palsy

The Growing Role of Telerehabilitation and Teleassessment in the Management of Movement Disorders in Rare Neurological Diseases: A Scoping Review

Background: People with rare neurological diseases (RNDs) often experience symptoms related to movement disorders, requiring a multidisciplinary approach, including rehabilitation. Telemedicine applied to rehabilitation and symptom monitoring may be suitable to ensure treatment consistency and personalized intervention. The objective of this scoping review aimed to emphasize the potential role of telerehabilitation and teleassessment in managing movement disorders within RNDs. By providing a systematic overview of the available literature, we sought to highlight potential interventions, outcomes, and critical issues. Methods: A literature search was conducted on PubMed, Google Scholar, IEEE, and Scopus up to March 2024. Two inclusion criteria were followed: (1) papers focusing on telerehabilitation and teleassessment and (2) papers dealing with movement disorders in RNDs. Results: Eighteen papers fulfilled the inclusion criteria. The main interventions were home-based software and training programs, exergames, wearable sensors, smartphone applications, virtual reality and digital music players for telerehabilitation; wearable sensors, mobile applications, and patient home video for teleassessment. Key findings revealed positive outcomes in gait, balance, limb disability, and in remote monitoring. Limitations include small sample sizes, short intervention durations, and the lack of standardized protocols. Conclusion: This review highlighted the potential of telerehabilitation and teleassessment in addressing movement disorders within RNDs. Data indicate that these modalities may play a major role in supporting conventional programs. Addressing limitations through multicenter studies, longer-term follow-ups, and standardized protocols is essential. These measures are essential for improving remote rehabilitation and assessment, contributing to an improved quality of life for people with RNDs.

Balance and gait in progressive supranuclear palsy: a narrative review of objective metrics and exercise interventions

Background

The use of objective gait and balance metrics is rapidly expanding for evaluation of atypical parkinsonism, and these measures add to clinical observations. Evidence for rehabilitation interventions to improve objective measures of balance and gait in atypical parkinsonism is needed.

Aim

Our aim is to review, with a narrative approach, current evidence on objective metrics for gait and balance and exercise interventions in progressive supranuclear palsy (PSP).

Methods

Literature searches were conducted in four computerized databases from the earliest record up to April 2023: PubMed, ISI's Web of Knowledge, Cochrane's Library, and Embase. Data were extracted for study type (cross-sectional, longitudinal, and rehabilitation interventions), study design (e.g., experimental design and case series), sample characteristics, and gait and balance measurements.

Results

Eighteen gait and balance (16 cross-sectional and 4 longitudinal) and 14 rehabilitation intervention studies were included. Cross-sectional studies showed that people with PSP have impairments in gait initiation and steady-state gait using wearable sensors, and in static and dynamic balance assessed by posturography when compared to Parkinson's disease (PD) and healthy controls. Two longitudinal studies observed that wearable sensors can serve as objective measures of PSP progression, using relevant variables of change in turn velocity, stride length variability, toe off angle, cadence, and cycle duration. Rehabilitation studies investigated the effect of different interventions (e.g., balance training, body-weight supported treadmill gait, sensorimotor training, and cerebellar transcranial magnetic stimulation) on gait, clinical balance, and static and dynamic balance assessed by posturography measurements. No rehabilitation study in PSP used wearable sensors to evaluate gait and balance impairments. Although clinical balance was assessed in 6 rehabilitation studies, 3 of these studies used a quasi-experimental design, 2 used a case series, only 1 study used an experimental design, and sample sizes were relatively small.

Conclusion

Wearable sensors to quantify balance and gait impairments are emerging as a means of documenting progression of PSP. Robust evidence for improving balance and gait in PSP was not found for rehabilitation studies. Future powered, prospective and robust clinical trials are needed to investigate the effects of rehabilitation interventions on objective gait and balance outcomes in people with PSP.

Training high level balance and stepping responses in atypical progressive supranuclear palsy: a case report

BACKGROUND

Progressive supranuclear palsy (PSP) is a neurodegenerative condition, typically presenting with, but not limited to, impairments of postural instability, gait, and gaze stability.

PURPOSE

This case report describes the multifactorial assessment and rehabilitation of a patient with atypical PSP who has significant gaze deficits, asymmetrical stepping responses, trunk rigidity, and reduced posterior excursion on limits of stability.

CASE DESCRIPTION

Evaluation utilized computerized gait and balance assessments, foot clearance analysis, a squat test, and a timed stepping test. The intervention included boxing, stepping tasks, and treadmill training each with eye movement challenges. A total of 15 hours of physical therapy was provided; 1 hour, 2 times a week.

OUTCOMES

Post-intervention improvements were noted subjectively, on eye-body coordination, and objectively, on limits of stability, foot clearance, and task performance (squats, timed stepping). Follow-up demonstrated some decline from posttest results; however, patient-reported adherence to the program was less than recommended.

CONCLUSION

A multifactorial rehabilitation program can improve balance, eye-body coordination, and strength in a high functioning patient with atypical PSP. Longitudinal randomized controlled studies are suggested to further investigate this interventional approach in high functioning individuals diagnosed with atypical PSP.

Effect of therapeutic exercise on the balance of patients with progressive supranuclear palsy: A pilot study

Background

Progressive supranuclear palsy (PSP) is a parkinsonian-like progressive neurodegenerative syndrome. Key clinical features include ocular motor dysfunction, postural instability, and cognitive dysfunction. Maintaining and improving balance function and gait function are very important for patients with PSP with severe postural dysfunction and repeated falls. In addition, patients with PSP have a poor response to pharmacological treatment; hence, rehabilitation is a key approach in dealing with this syndrome. However, no conclusion on the beneficial effects of rehabilitation for patients with PSP have been established in the literature.

Objectives

The effectiveness of multiple therapeutic exercise program with probable or possible PSP according to the Movement Disorder Society criteria for the clinical diagnosis of PSP was validated.

Methods

Participants underwent multiple therapeutic exercise program customized for each participant, including resistance training, balance training, and walking exercises that were performed for 60–80 minutes a day, 5 days a week for 4 weeks. The outcomes measured were as follows: pull test, Berg Balance Scale (BBS), timed up and go test (TUG), and gait speed test.

Results

A total of 117 patients with PSP were enrolled and the analysis was performed on 20 patients with probable PSP. Four-week rehabilitation significantly improved pull test (p = 0.034) and BBS scores (p = 0.001). There were no significant differences both TUG (p = 0.502) and gait speed (p = 0.813).

Conclusion

The multiple therapeutic exercise program had beneficial effects on balance performance in patients with PSP in 4 weeks and could be an essential element in their rehabilitation. Although this pilot study was conducted without a control group, it provided valuable information for future prospective randomized controlled trials.

An Embodied Sonification Model for Sit-to-Stand Transfers

Interactive sonification of biomechanical quantities is gaining relevance as a motor learning aid in movement rehabilitation, as well as a monitoring tool. However, existing gaps in sonification research (issues related to meaning, aesthetics, and clinical effects) have prevented its widespread recognition and adoption in such applications. The incorporation of embodied principles and musical structures in sonification design has gradually become popular, particularly in applications related to human movement. In this study, we propose a general sonification model for the sit-to-stand (STS) transfer, an important activity of daily living. The model contains a fixed component independent of the use-case, which represents the rising motion of the body as an ascending melody using the physical model of a flute. In addition, a flexible component concurrently sonifies STS features of clinical interest in a particular rehabilitative/monitoring situation. Here, we chose to represent shank angular jerk and movement stoppages (freezes), through perceptually salient pitch modulations and bell sounds. We outline the details of our technical implementation of the model. We evaluated the model by means of a listening test experiment with 25 healthy participants, who were asked to identify six normal and simulated impaired STS patterns from sonified versions containing various combinations of the constituent mappings of the model. Overall, we found that the participants were able to classify the patterns accurately (86.67 ± 14.69% correct responses with the full model, 71.56% overall), confidently (64.95 ± 16.52% self-reported rating), and in a timely manner (response time: 4.28 ± 1.52 s). The amount of sonified kinematic information significantly impacted classification accuracy. The six STS patterns were also classified with significantly different accuracy depending on their kinematic characteristics. Learning effects were seen in the form of increased accuracy and confidence with repeated exposure to the sound sequences. We found no significant accuracy differences based on the participants' level of music training. Overall, we see our model as a concrete conceptual and technical starting point for STS sonification design catering to rehabilitative and clinical monitoring applications.

Rehabilitation in movement disorders: From basic mechanisms to clinical strategies

Movement disorders encompass a variety of conditions affecting the nervous system at multiple levels. The pathologic processes underlying movement disorders alter the normal neural functions and could lead to aberrant neuroplastic changes and to clinical phenomenology that is not expressed only through mere motor symptoms. Given this complexity, the responsiveness to pharmacologic and surgical therapies is often disappointing. Growing evidence supports the efficacy of neurorehabilitation for the treatment of movement disorders. Specific form of training involving both goal-based practice and aerobic training could drive and modulate neuroplasticity in order to restore the circuitries dysfunctions and to achieve behavioral gains. This chapter provides an overview of the alterations expressed in some movement disorders in terms of clinical signs and symptoms and plasticity, and suggests which ones and why tailored rehabilitation strategies should be adopted for the management of the different movement disorders.

Falls in Progressive Supranuclear Palsy

BACKGROUND

Despite falls being an almost universal clinical feature and central to the presentation and diagnostic criteria of progressive supranuclear palsy, our understanding of falls is surprisingly limited and there are few effective treatment options.

OBJECTIVES

To provide an overview of the topic of the impact, assessment, mechanism, and management of falls in progressive supranuclear palsy.

METHODS

We performed a literature search for "falls" and "progressive supranuclear palsy" and included additional relevant literature known to us. We synthesized this literature with experience from clinical practice.

RESULTS

We review current understanding of the pathophysiology of falls, highlighting the roles of the indirect pathway and the pedunculopontine nucleus. We go on to identify shortcomings in commonly used assessments to measure falls. We discuss medical and nonmedical fall prevention strategies, and finally we discuss balancing falls risk against promoting independence.

CONCLUSION

Falls are central to progressive supranuclear palsy presentation and diagnosis. Indirect locomotor and pedunculopontine nucleus dysfunction are thought to be the neural substrate of falls in this condition. Attempts to measure and prevent falls, by medical and nonmedical means, are currently limited. A personalized approach is advocated in the management of falls.

Exercise and Progressive Supranuclear Palsy: the need for explicit exercise reporting

BACKGROUND

Progressive Supranuclear Palsy (PSP) is the most frequent form of atypical Parkinsonism. Although there is preliminary evidence for the benefits of gait rehabilitation, balance training and oculomotor exercises in PSP, the quality of reporting of exercise therapies appears mixed. The current investigation aims to evaluate the comprehensiveness of reporting of exercise and physical activity interventions in the PSP literature.

METHODS

Two independent reviewers used the Consensus on Exercise Reporting Template (CERT) to extract all exercise intervention data from 11 studies included in a systematic review. CERT items covered: 'what' (materials), 'who' (instructor qualifications), 'how' (delivery), 'where' (location), 'when', 'how much' (dosage), 'tailoring' (what, how), and 'how well' (fidelity) exercise delivery complied with the protocol. Each exercise item was scored '1' (adequately reported) or '0' (not adequately reported or unclear). The CERT score was calculated, as well as the percentage of studies that reported each CERT item.

RESULTS

The CERT scores ranged from 3 to 12 out of 19. No PSP studies adequately described exercise elements that would allow exact replication of the interventions. Well-described items included exercise equipment, exercise settings, exercise therapy scheduling, frequency and duration. Poorly described items included decision rules for exercise progression, instructor qualifications, exercise adherence, motivation strategies, safety and adverse events associated with exercise therapies.

DISCUSSION

The results revealed variability in the reporting of physical therapies for people living with PSP. Future exercise trials need to more comprehensively describe equipment, instructor qualifications, exercise and physical activity type, dosage, setting, individual tailoring of exercises, supervision, adherence, motivation strategies, progression decisions, safety and adverse events.

CONCLUSION

Although beneficial for people living with PSP, exercise and physical therapy interventions have been inadequately reported. It is recommended that evidence-based reporting templates be utilised to comprehensively document therapeutic exercise design, delivery and evaluation.

Exercise and physical activity for people with Progressive Supranuclear Palsy: a systematic review

Objective:

To conduct a systematic review to evaluate exercise and structured physical activity for people living with Progressive Supranuclear Palsy.

Data sources:

AMED, CINAHL, Cochrane, EMBASE, Informit, MEDLINE, PEDro, PsycINFO, PubMed and SportDiscus were searched until 18 August 2019. Reference lists of included studies were hand-searched.

Methods:

Cochrane guidelines informed review methods. English language peer-reviewed studies of any design, in any setting, were included. Method quality was appraised with the Physiotherapy Evidence Database scale and Joanna Briggs Institute instruments. Data were extracted for study design, sample characteristics and therapy content. Effectiveness was calculated where possible.

Results:

Eleven studies were included. Method appraisal showed moderate to high risk of bias. Research designs included three randomized controlled trials, two quasi-experimental studies, one cohort study, four case studies and one case series. Sample sizes ranged from 1 to 24. Exercise interventions included supported and robot-assisted gait training, gaze training, balance re-education and auditory-cued motor training. Dosage ranged from two to five sessions per week over four to eight weeks. End-of-intervention effect sizes were small (6-minute walk test: –0.07; 95% confidence interval (CI): –0.87, 0.73) to moderate (balance: –0.61; 95% CI: –1.40, 0.23; Timed Up and Go: 0.42; 95% CI: –0.49, 1.33) and statistically non-significant. Function, quality of life and adverse events were inconsistently reported.

Conclusions:

For people with Progressive Supranuclear Palsy, robust evidence was not found for therapeutic exercises. Reported improvements in walking were derived from two clinical trials. The effects of structured physical activity for people with advanced Progressive Supranuclear Palsy are not known.

Real-time use of audio-biofeedback can improve postural sway in patients with degenerative ataxia

Objective

Cerebellar ataxia essentially includes deficient postural control. It remains unclear whether augmented sensory information might help cerebellar patients, as the cerebellum underlies processing of various sensory modalities for postural control. Here, we hypothesized that patients with cerebellar degeneration can still exploit audio-biofeedback (ABF) of trunk acceleration as a real-time assistive signal to compensate for deficient postural control.

Methods

Effects on postural sway during stance were assessed in an ABF intervention group versus a no-ABF disease control group (23 vs. 17 cerebellar patients) in a clinico-experimental study. A single-session ABF paradigm of standing plus short exergaming under ABF was applied. Postural sway with eyes open and eyes closed was quantified prior to ABF, under ABF, and post ABF.

Results

Postural sway in the eyes closed condition was significantly reduced under ABF. Both benefit of ABF and benefit of vision correlated with the extent of postural sway at baseline, and both types of sensory benefits correlated with each other. Patients with strongest postural sway exhibited reduced postural sway also with eyes open, thus benefitting from both vision and ABF. No changes were observed in the no-ABF control group.

Interpretation

Our findings provide proof-of-principle evidence that subjects with cerebellar degeneration are still able to integrate additional sensory modalities to compensate for deficient postural control: They can use auditory cues functionally similar to vision in the absence of vision, and additive to vision in the presence of vision (in case of pronounced postural sway). These findings might inform future assistive strategies for cerebellar ataxia.

Effectiveness of allied health therapy in the symptomatic management of progressive supranuclear palsy: a systematic review

BACKGROUND

Progressive supranuclear palsy (PSP) is an adult onset neurodegenerative condition associated with mobility, balance, speech, swallowing, vision and cognitive changes. The condition is diagnosed using the National Institute for Neurological Disorders and Stroke (NINDS) and the Society of Progressive Supranuclear Palsy (SPSP) criteria. Therapeutic interventions for PSP are important, and a healthcare team should include a physiotherapist, occupational therapist and speech therapist. Mobility, speech and swallowing problems are commonly experienced, and aspiration pneumonia is the leading cause of death. A preliminary search of the literature has indicated that beyond small case series, there is very little evidence to guide specific allied health therapies in PSP. Many strategies for optimizing independence and function for PSP predominately rely on data extrapolated from the study of Parkinson's disease.

OBJECTIVES

The objective of this review was to examine the effectiveness of physical, occupational and speech therapy interventions in the symptomatic management of PSP.

INCLUSION CRITERIA TYPES OF PARTICIPANTS

This review included participants with PSP as per the NINDS and the SPSP criteria, aged over 40 years of age from all community and clinical settings.

TYPES OF INTERVENTIONS

This review included studies evaluating any allied health therapy that addressed mobility, vision, swallowing, communication or cognitive/neuropsychiatric difficulties experienced by patients with PSP. Studies examining interventions within the current scope of practice, and emerging interventions (non-invasive brain stimulation therapy) were eligible for inclusion.

TYPES OF COMPARATOR

The effectiveness of interventions of interest was compared with usual care and/or baseline measurements.

OUTCOMES

Outcomes of interest included the degree of change, or no change, in the symptoms experienced by patients with PSP relevant to allied health. These included difficulties with mobility, vision, swallowing, communication and cognition.

TYPES OF STUDIES

All types of quantitative study designs published in English from the time of development of the NINDS and the SPSP criteria in 1996-2014 were considered for inclusion.

SEARCH STRATEGY

A broad range of synonyms for PSP and a three-step search strategy was utilized to identify possible published and unpublished studies from 11 different databases. An initial limited search via MEDLINE (PubMed), CINAHL, Health Informit, PsycINFO, PEDRO, OTSeeker and SpeechBite was undertaken followed by analysis of the text words contained in the title and abstract, and of the index terms used to describe the article. A second search using all identified keywords and index terms was then undertaken across all included databases. Third, hand-searching was conducted and the reference list of all identified reports and articles was searched for additional studies.

METHODOLOGICAL QUALITY

Critical appraisal was conducted by two independent reviewers using standardized instruments.

DATA EXTRACTION

Quantitative data were extracted from articles included in the review using standardized data extraction tools.

DATA SYNTHESIS

As the quantitative articles examined different interventions, pooling of data was not appropriate. Instead, the findings were presented in narrative summary and tabular form.

RESULTS

Following methodological appraisal, six studies were included in the review. Aside from one small quasi-randomized control study, most studies were small case series and one was a case report. Five of the six studies examined the effectiveness of a range of different physiotherapy rehabilitation programs targeting gait, balance and physical capability, with one study also targeting gaze control. The sixth study examined non-invasive brain stimulation in improving gait and midline symptoms in PSP. No studies examined the effectiveness of occupational therapy or speech therapy interventions in PSP.

CONCLUSIONS

Research into the effectiveness of allied health therapeutic interventions for PSP symptoms is in its infancy. This review found preliminary evidence to support the use of various physiotherapy rehabilitation programs to improve balance, gait and gaze control in people affected by PSP. Further research is urgently required to identify effective interventions to manage mobility, vision, swallowing, communication and cognitive/neuropsychiatric symptoms associated with this devastating condition.

The Role of Rehabilitation in Patients With Progressive Supranuclear Palsy: A Narrative Review

Progressive supranuclear palsy (PSP) is a progressive neurodegenerative disorder caused by the deposition of abnormal proteins in neurons of the basal ganglia that limit motor ability, resulting in disability and reduced quality of life. So far, no pharmacologic therapy has been developed, and the treatment remains symptomatic. The aim of the present study is to perform a systematic investigation of the literature, and to determine the types and effects of rehabilitative interventions used for PSP. A search of all studies was conducted in MEDLINE/PubMed, the Cochrane Central Register of Controlled Trials, CINAHL, and EMBASE. Twelve studies were identified, including 6 case reports, 3 case series, one case-control study, one quasi-randomized trial (i.e. not truly random) with crossover design, and one randomized controlled trial, with 88 patients investigated overall. Rehabilitative interventions varied in type, number, frequency, and duration of sessions. The most commonly used clinical measures were the Progressive Supranuclear Palsy Rating Scale (PSPRS) and Unified Parkinson's Disease Rating Scale (UPDRS). Physical exercises were the main rehabilitative strategy but were associated with other interventions and rehabilitative devices, in particular treadmill and robot-assisted gait training. All studies showed an improvement in balance and gait impairment with a reduction of falls after rehabilitation treatment. Because of poor methodological quality and the variety of rehabilitative approaches including different and variable strategies, there was insufficient evidence of the effectiveness of any specific rehabilitation intervention in PSP. Despite this finding, rehabilitation might improve balance and gait, thereby reducing falls in PSP patients.

LEVEL OF EVIDENCE

IV.

Vestibular Deficits in Neurodegenerative Disorders: Balance, Dizziness, and Spatial Disorientation

The vestibular system consists of the peripheral vestibular organs in the inner ear and the associated extensive central nervous system projections—from the cerebellum and brainstem to the thalamic relays to cortical projections. This system is important for spatial orientation and balance, both of critical ecological importance, particularly for successful navigation in our environment. Balance disorders and spatial disorientation are common presenting features of neurodegenerative diseases; however, little is known regarding central vestibular processing in these diseases. A ubiquitous aspect of central vestibular processing is its promiscuity given that vestibular signals are commonly found in combination with other sensory signals. This review discusses how impaired central processing of vestibular signals—typically in combination with other sensory and motor systems—may account for the impaired balance and spatial disorientation in common neurodegenerative conditions. Such an understanding may provide for new diagnostic tests, potentially useful in detecting early disease while a mechanistic understanding of imbalance and spatial disorientation in these patients may enable a vestibular-targeted therapy for such problems in neurodegenerative diseases. Studies with state of the art central vestibular testing are now much needed to tackle this important topic.

Continuous Auditory Feedback of Eye Movements: An Exploratory Study toward Improving Oculomotor Control

As eye movements are mostly automatic and overtly generated to attain visual goals, individuals have a poor metacognitive knowledge of their own eye movements. We present an exploratory study on the effects of real-time continuous auditory feedback generated by eye movements. We considered both a tracking task and a production task where smooth pursuit eye movements (SPEM) can be endogenously generated. In particular, we used a visual paradigm which enables to generate and control SPEM in the absence of a moving visual target. We investigated whether real-time auditory feedback of eye movement dynamics might improve learning in both tasks, through a training protocol over 8 days. The results indicate that real-time sonification of eye movements can actually modify the oculomotor behavior, and reinforce intrinsic oculomotor perception. Nevertheless, large inter-individual differences were observed preventing us from reaching a strong conclusion on sensorimotor learning improvements.

Rehabilitation in progressive supranuclear palsy: Effectiveness of two multidisciplinary treatments

BACKGROUND

to date, there are no medical or surgical treatments for progressive supranuclear palsy (PSP). It is possible to speculate that patients with PSP could benefit from rehabilitative treatments designed for Parkinson's disease, including the use of robot-assisted walking training.

OBJECTIVE

to evaluate whether the use of the robotic device Lokomat® is superior in PSP patients to the use of treadmill with visual cues and auditory feedbacks (treadmill-plus) in the context of an aerobic, multidisciplinary, intensive, motor-cognitive and goal-based rehabilitation treatment (MIRT) conceived for Parkinsonian patients.

METHODS

we enrolled twenty-four PSP patients. Twelve subjects underwent a 4-week MIRT exploiting the use of the treadmill-plus (MIRT group). Twelve subjects underwent the same treatment, but replacing the treadmill-plus with Lokomat® (MIRT-Lokomat group). Subjects were evaluated with clinical and functional scales at admission and discharge. The primary outcomes were the total PSP Rating Scale (PSPRS) score and its "limb" and "gait" sub-scores. Secondary outcomes were Berg Balance Scale (BBS), Six Minutes Walking test (6MWT) and the number of falls.

RESULTS

total PSPRS, PSPRS-gait sub-score, BBS, 6MWT and number of falls improved significantly in both groups (p ≤ 0.003 all, except 6MWT, p = 0.032 and p = 0.018 in MIRT-Lokomat and MIRT group respectively). The PSPRS-limb sub-score improved significantly only in the MIRT group (p = 0.002). A significant difference between groups was observed only for total PSPRS, indicating a slightly better improvement for patients in the MIRT group (p = 0.047). No differences between groups were revealed for the other outcomes, indicating that the effect of rehabilitation was similar in both groups.

CONCLUSIONS

Lokomat® training, in comparison with treadmill-plus training, does not provide further benefits in PSP patients undergoing MIRT. Our findings suggest the usefulness of an aerobic, multidisciplinary, intensive, motor-cognitive and goal-based approach for the rehabilitation of patients suffering from such a complex disease as PSP.

TRIAL REGISTRATION

This trial was registered on ClinicalTrials.gov, NCT02109393.

Intermittent Hypoxia and Locomotor Training Enhances Dynamic but Not Standing Balance in Patients With Incomplete Spinal Cord Injury

OBJECTIVE

To test the effect of combined intermittent hypoxia (IH) and body weight-supported treadmill training (BWSTT) on standing and dynamic balance in persons with incomplete spinal cord injury (iSCI).

DESIGN

Randomized, triple-blind, placebo-controlled study.

SETTING

Rehabilitation medical centers.

PARTICIPANTS

Study participants (N=35) with chronic iSCI with American Spinal Injury Association grades C and D (>1y postinjury) were randomly assigned to either IH plus BWSTT (n=18) or continued normoxia (placebo) plus BWSTT protocol (n=17).

INTERVENTIONS

Participants received either IH (alternating 1.5min 9% inspired O₂ with 1.5min 21% inspired O₂, 15 cycles per day) or continued normoxia (21% O₂) combined with 45 minutes of BWSTT for 5 consecutive days, followed by 3 times per week IH or normoxia plus BWSTT, for 3 additional weeks.

MAIN OUTCOME MEASURES

Standing balance (normalized jerk and root-mean-square [RMS]) and dynamic balance (turning duration, cadence in a turn, and turn-to-sit duration) were assessed before and after IH and normoxia protocol by means of instrumented sway and instrumented timed Up and Go test.

RESULTS

There was no significant difference in standing balance between interventions for both normalized jerk and RMS instrumented sway components (both P>.05). There was a significantly faster cadence (P<.001), turning duration (P<.001), and turn-to-sit duration (P=.001) in subjects receiving IH plus BWSTT, compared with placebo.

CONCLUSIONS

A 4-week protocol of IH combined with locomotor training improves dynamic, but not standing, balance in persons with iSCI.

Technical and clinical view on ambulatory assessment in Parkinson's disease

With the progress of technologies of recent years, methods have become available that use wearable sensors and ambulatory systems to measure aspects of--particular axial--motor function. As Parkinson's disease (PD) can be considered a model disorder for motor impairment, a significant number of studies have already been performed with these patients using such techniques. In general, motion sensors such as accelerometers and gyroscopes are used, in combination with lightweight electronics that do not interfere with normal human motion. A fundamental advantage in comparison with usual clinical assessment is that these sensors allow a more quantitative, objective, and reliable evaluation of symptoms; they have also significant advantages compared to in-lab technologies (e.g., optoelectronic motion capture) as they allow long-term monitoring under real-life conditions. In addition, based on recent findings particularly from studies using functional imaging, we learned that non-motor symptoms, specifically cognitive aspects, may be at least indirectly assessable. It is hypothesized that ambulatory quantitative assessment strategies will allow users, clinicians, and scientists in the future to gain more quantitative, unobtrusive, and everyday relevant data out of their clinical evaluation and can also be designed as pervasive (everywhere) and intensive (anytime) tools for ambulatory assessment and even rehabilitation of motor and (partly) non-motor symptoms in PD.

A wearable system for gait training in subjects with Parkinson's disease

In this paper, a system for gait training and rehabilitation for Parkinson's disease (PD) patients in a daily life setting is presented. It is based on a wearable architecture aimed at the provision of real-time auditory feedback. Recent studies have, in fact, shown that PD patients can receive benefit from a motor therapy based on auditory cueing and feedback, as happens in traditional rehabilitation contexts with verbal instructions given by clinical operators. To this extent, a system based on a wireless body sensor network and a smartphone has been developed. The system enables real-time extraction of gait spatio-temporal features and their comparison with a patient's reference walking parameters captured in the lab under clinical operator supervision. Feedback is returned to the user in form of vocal messages, encouraging the user to keep her/his walking behavior or to correct it. This paper describes the overall concept, the proposed usage scenario and the parameters estimated for the gait analysis. It also presents, in detail, the hardware-software architecture of the system and the evaluation of system reliability by testing it on a few subjects.

Biofeedback in rehabilitation

This paper reviews the literature relating to the biofeedback used in physical rehabilitation. The biofeedback methods used in rehabilitation are based on biomechanical measurements and measurements of the physiological systems of the body. The physiological systems of the body which can be measured to provide biofeedback are the neuromuscular system, the respiratory system and the cardiovascular system. Neuromuscular biofeedback methods include electromyography (EMG) biofeedback and real-time ultrasound imaging (RTUS) biofeedback. EMG biofeedback is the most widely investigated method of biofeedback and appears to be effective in the treatment of many musculoskeletal conditions and in post cardiovascular accident (CVA) rehabilitation. RTUS biofeedback has been demonstrated effective in the treatment of low back pain (LBP) and pelvic floor muscle dysfunction. Cardiovascular biofeedback methods have been shown to be effective in the treatment of a number of health conditions such as hypertension, heart failure, asthma, fibromyalgia and even psychological disorders however a systematic review in this field has yet to be conducted. Similarly, the number of large scale studies examining the use of respiratory biofeedback in rehabilitation is limited. Measurements of movement, postural control and force output can be made using a number of different devices and used to deliver biomechanical biofeedback. Inertial based sensing biofeedback is the most widely researched biomechanical biofeedback method, with a number of studies showing it to be effective in improving measures of balance in a number of populations. Other types of biomechanical biofeedback include force plate systems, electrogoniometry, pressure biofeedback and camera based systems however the evidence for these is limited. Biofeedback is generally delivered using visual displays, acoustic or haptic signals, however more recently virtual reality (VR) or exergaming technology have been used as biofeedback signals. VR and exergaming technology have been primarily investigated in post-CVA rehabilitation, however, more recent work has shown this type of biofeedback to be effective in improving exercise technique in musculoskeletal populations. While a number of studies in this area have been conducted, further large scale studies and reviews investigating different biofeedback applications in different clinical populations are required.

iBalance-ABF: a smartphone-based audio-biofeedback balance system

This paper proposes an implementation of a Kalman filter, using inertial sensors of a smartphone, to estimate 3-D angulation of the trunk. The developed system monitors the trunk angular evolution during bipedal stance and helps the user to improve balance through a configurable and integrated auditory-biofeedback (ABF) loop. A proof-of-concept study was performed to assess the effectiveness of this so-called iBalance-ABF--smartphone-based audio-biofeedback system--in improving balance during bipedal standing. Results showed that young healthy individuals were able to efficiently use ABF on sagittal trunk tilt to improve their balance in the medial-lateral direction. These findings suggest that the iBalance-ABF system as a telerehabilitation system could represent a suitable solution for ambient assisted living technologies.

Evaluation of accelerometer-based fall detection algorithms on real-world falls

Despite extensive preventive efforts, falls continue to be a major source of morbidity and mortality among elderly. Real-time detection of falls and their urgent communication to a telecare center may enable rapid medical assistance, thus increasing the sense of security of the elderly and reducing some of the negative consequences of falls. Many different approaches have been explored to automatically detect a fall using inertial sensors. Although previously published algorithms report high sensitivity (SE) and high specificity (SP), they have usually been tested on simulated falls performed by healthy volunteers. We recently collected acceleration data during a number of real-world falls among a patient population with a high-fall-risk as part of the SensAction-AAL European project. The aim of the present study is to benchmark the performance of thirteen published fall-detection algorithms when they are applied to the database of 29 real-world falls. To the best of our knowledge, this is the first systematic comparison of fall detection algorithms tested on real-world falls. We found that the SP average of the thirteen algorithms, was (mean±std) 83.0%±30.3% (maximum value = 98%). The SE was considerably lower (SE = 57.0%±27.3%, maximum value = 82.8%), much lower than the values obtained on simulated falls. The number of false alarms generated by the algorithms during 1-day monitoring of three representative fallers ranged from 3 to 85. The factors that affect the performance of the published algorithms, when they are applied to the real-world falls, are also discussed. These findings indicate the importance of testing fall-detection algorithms in real-life conditions in order to produce more effective automated alarm systems with higher acceptance. Further, the present results support the idea that a large, shared real-world fall database could, potentially, provide an enhanced understanding of the fall process and the information needed to design and evaluate a high-performance fall detector.

Direction specific preserved limits of stability in early progressive supranuclear palsy: a dynamic posturographic study

OBJECTIVES

To quantitatively detect the nature of balance impairment in patients with progressive supranuclear palsy (PSP) using dynamic posturography.

METHODS

Twenty clinically diagnosed PSP patients (8 women, 12 men; age: 62.1 ± 7.7 years; duration: 2.6 ± 1.3 years) and 20 healthy controls were studied. All subjects were right side dominant. They were evaluated by dynamic posturography (Biodex, USA). The measurements included (i) balance indices: ability to control balance in all directions (overall balance index, OBI), front to back (anterior-posterior index, API) and side-to-side (medio-lateral index, MLI), and (ii) the limits of stability (LOS) in 8 directions: forward (FW), backward (BW), right (RT), left (LT), forward-right (FW-RT), forward-left (FW-LT), backward-right (BW-RT) and backward-left (BW-LT).

RESULTS

Compared to controls, patients showed significantly higher OBI (p<0.001), API (p=0.003) and MLI (p<0.001), implying impaired balance. The total LOS score was significantly lower (implying poor stability) in PSP than in controls (18.3 ± 7.3 vs. 28.4 ± 8.5, p<0.001). Patients took significantly longer time to complete LOS test (262.7 ± 33.0 s vs. 135.4 ± 20.6 s, p<0.001). Direction-wise analysis showed that PSP patients had significantly lower LOS scores in FW, BW, RT, FW-RT, BW-RT and BW-LT directions compared to controls. However the scores in LT and FW-LT did not differ significantly.

CONCLUSIONS

PSP patients showed impaired balance indices and decreased overall LOS compared to controls. Though LOS is affected in PSP, the scores in the left (non-dominant side) and forward-left (non-dominant forward diagonal) directions were preserved.

Impaired trunk stability in individuals at high risk for Parkinson's disease

Background

The search for disease-modifying treatments for Parkinson's disease advances, however necessary markers for early detection of the disease are still lacking. There is compelling evidence that changes of postural stability occur at very early clinical stages of Parkinson's disease, making it tempting to speculate that changes in sway performance may even occur at a prodromal stage, and may have the potential to serve as a prodromal marker for the disease.

Methodology/Principal Findings

Balance performance was tested in 20 individuals with an increased risk of Parkinson's disease, 12 Parkinson's disease patients and 14 controls using a cross-sectional approach. All individuals were 50 years or older. Investigated groups were similar with respect to age, gender, and height. An accelerometer at the centre of mass at the lower spine quantified sway during quiet semitandem stance with eyes open and closed, as well as with and without foam. With increasing task difficulty, individuals with an increased risk of Parkinson's disease showed an increased variability of trunk acceleration and a decrease of smoothness of sway, compared to both other groups. These differences reached significance in the most challenging condition, i.e. the eyes closed with foam condition.

Conclusions/Significance

Individuals with an increased risk of Parkinson's disease have subtle signs of a balance deficit under most challenging conditions. This preliminary finding should motivate further studies on sway performance in individuals with an increased risk of Parkinson's disease, to evaluate the potential of this symptom to serve as a biological marker for prodromal Parkinson's disease.

Subjects with hip osteoarthritis show distinctive patterns of trunk movements during gait-a body-fixed-sensor based analysis

Background

Compensatory trunk movements during gait, such as a Duchenne limp, are observed frequently in subjects with osteoarthritis of the hip, yet angular trunk movements are seldom included in clinical gait assessments. Hence, the objective of this study was to quantify compensatory trunk movements during gait in subjects with hip osteoarthritis, outside a gait laboratory, using a body-fixed-sensor based gait analysis. Frontal plane angular movements of the pelvis and thorax and spatiotemporal parameters of persons who showed a Duchenne limp during gait were compared to healthy subjects and persons without a Duchenne limp.

Methods

A Body-fixed-sensor based gait analysis approach was used. Two body-fixed sensors were positioned at the dorsal side of the pelvis and on the upper thorax. Peak-to-peak frontal plane range of motion (ROM) and spatiotemporal parameters (walking speed, step length and cadence) of persons with a Duchenne limp during gait were compared to healthy subjects and persons without a Duchenne limp. Participants were instructed to walk at a self-selected low, preferred and high speed along a hospital corridor. Generalized estimating equations (GEE) analyses were used to assess group differences between persons with a Duchenne limp, without a Duchenne limp and healthy subjects.

Results

Persons with a Duchenne limp showed a significantly larger thoracic ROM during walking compared to healthy subjects and to persons without a Duchenne limp. In both groups of persons with hip osteoarthritis, pelvic ROM was lower than in healthy subjects. This difference however only reached significance in persons without a Duchenne limp. The ratio of thoracic ROM relative to pelvic ROM revealed distinct differences in trunk movement patterns. Persons with hip osteoarthritis walked at a significantly lower speed compared to healthy subjects. No differences in step length and cadence were found between patients and healthy subjects, after correction for differences in walking speed.

Conclusions

Distinctive patterns of frontal plane angular trunk movements during gait could be objectively quantified in healthy subjects and in persons with hip osteoarthritis using a body-fixed-sensor based gait analysis approach. Therefore, frontal plane angular trunk movements should be included in clinical gait assessments of persons with hip osteoarthritis.

Audio-biofeedback training for posture and balance in patients with Parkinson's disease

Background

Patients with Parkinson's disease (PD) suffer from dysrhythmic and disturbed gait, impaired balance, and decreased postural responses. These alterations lead to falls, especially as the disease progresses. Based on the observation that postural control improved in patients with vestibular dysfunction after audio-biofeedback training, we tested the feasibility and effects of this training modality in patients with PD.

Methods

Seven patients with PD were included in a pilot study comprised of a six weeks intervention program. The training was individualized to each patient's needs and was delivered using an audio-biofeedback (ABF) system with headphones. The training was focused on improving posture, sit-to-stand abilities, and dynamic balance in various positions. Non-parametric statistics were used to evaluate training effects.

Results

The ABF system was well accepted by all participants with no adverse events reported. Patients declared high satisfaction with the training. A significant improvement of balance, as assessed by the Berg Balance Scale, was observed (improvement of 3% p = 0.032), and a trend in the Timed up and go test (improvement of 11%; p = 0.07) was also seen. In addition, the training appeared to have a positive influence on psychosocial aspects of the disease as assessed by the Parkinson's disease quality of life questionnaire (PDQ-39) and the level of depression as assessed by the Geriatric Depression Scale.

Conclusions

This is, to our knowledge, the first report demonstrating that audio-biofeedback training for patients with PD is feasible and is associated with improvements of balance and several psychosocial aspects.

Wearable systems with minimal set-up for monitoring and training of balance and mobility

With the objective to release solutions which can be easily manageable by their final users, including older users, we worked to design methods and devices which rely on a minimal set-up for monitoring and rehabilitation of balance and mobility. A single inertial sensing unit, typically worn on the trunk, was hence engineered to accomplish for activity monitoring and event detection (including fall detection), tremor rejection, instrumented clinical tests (e.g. stabilometry, Timed-Up and Go), and sensory biofeedback (audio, visual or tactile). The sensing unit is wirelessly connected with a processing unit, which can in turn act as a gateway to remote applications or caregivers. Promising results were obtained, which may pave the way to novel intensive and pervasive neurorehabilitation strategies.