Effects of visual and auditory cues on gait initiation in people with Parkinson's disease

Connecting the dots: Sensory cueing enhances functional connectivity between pre-motor and supplementary motor areas in Parkinson's disease

People with Parkinson's disease often exhibit improvements in motor tasks when exposed to external sensory cues. While the effects of different types of sensory cues on motor functions in Parkinson's disease have been widely studied, the underlying neural mechanism of these effects and the potential of sensory cues to alter the motor cortical activity patterns and functional connectivity of cortical motor areas are still unclear. This study aims to compare changes in oxygenated haemoglobin, deoxygenated haemoglobin and correlations among different cortical regions of interest during wrist movement under different external stimulus conditions between people with Parkinson's disease and controls. Ten Parkinson's disease patients and 10 age- and sex-matched neurologically healthy individuals participated, performing repetitive wrist flexion and extension tasks under auditory and visual cues. Changes in oxygenated and deoxygenated haemoglobin in motor areas were measured using functional near-infrared spectroscopy, along with electromyograms from wrist muscles and wrist movement kinematics. The functional near-infrared spectroscopy data revealed significantly higher neural activity changes in the Parkinson's disease group's pre-motor area compared to controls (p = 0.006), and functional connectivity between the supplementary motor area and pre-motor area was also significantly higher in the Parkinson's disease group when external sensory cues were present (p = 0.016). These results indicate that external sensory cues' beneficial effects on motor tasks are linked to changes in the functional connectivity between motor areas responsible for planning and preparation of movements.

Investigating the Brain Mechanisms of Externally Cued Sit-to-Stand Movement in Parkinson's Disease

BACKGROUND

One of the more challenging daily-life actions for Parkinson's disease patients is starting to stand from a sitting position. Parkinson's disease patients are known to have difficulty with self-initiated movements and benefit from external cues. However, the brain processes underlying external cueing as an aid remain unknown. The advent of mobile electroencephalography (EEG) now enables the investigation of these processes in dynamic sit-to-stand movements.

OBJECTIVE

To identify cortical correlates of the mechanisms underlying auditory cued sit-to-stand movement in Parkinson's disease.

METHODS

Twenty-two Parkinson's disease patients and 24 healthy age-matched participants performed self-initiated and externally cued sit-to-stand movements while cortical activity was recorded through 32-channel mobile EEG.

RESULTS

Overall impaired integration of sensory and motor information can be seen in the Parkinson's disease patients exhibiting less modulation in the θ band during movement compared to healthy age-matched controls. How Parkinson's disease patients use external cueing of sit-to-stand movements can be seen in larger high β power over sensorimotor brain areas compared to healthy controls, signaling sensory integration supporting the maintenance of motor output. This appears to require changes in cognitive processing to update the motor plan, reflected in frontal θ power increases in Parkinson's disease patients when cued.

CONCLUSION

These findings provide the first neural evidence for why and how cueing improves motor function in sit-to-stand movement in Parkinson's disease. The Parkinson's disease patients' neural correlates indicate that cueing induces greater activation of motor cortical areas supporting the maintenance of a more stable motor output, but involves the use of cognitive resources to update the motor plan. © 2024 International Parkinson and Movement Disorder Society.

Comparison of externally and internally guided dance movement to address mobility, cognition, and psychosocial function in people with Parkinson's disease and freezing of gait: a case series

Objective

The aim of this study is to explore the impact of internally guided (IG) versus externally guided (EG) adapted tango (AT) dance training (i.e., dancing the IG "Leader" role or the EG "Follower" role), on motor and non-motor functions in individuals with Parkinson's disease and freezing of gait (PD-FOG). The "Leader" role, a proxy for IG movements, conveys direction, timing, and amplitude of steps with tactile cues. The "Follower" role, a proxy for EG movements, detects and responds to the leader's tactile cues.

Case description

Six participants were randomly assigned to the IG ("Leader") or EG ("Follower") roles for 20, 90-min AT lessons over 12 weeks. Participants were assessed for PD-specific and non-PD-specific functions before and twice after the end of the 12-week intervention, at 1-week and 1-month post-intervention.

Results

EG participants improved and/or maintained performance on more outcomes across all domains than IG participants. Five participants improved in PD motor symptoms, dynamic gait, global cognitive function, and the FOG Questionnaire immediately or 1 month after intervention. All participants expressed positive attitudes toward the intervention, including improvements in walking, balance, and endurance.

Conclusion

AT training in the follower role may benefit individuals with PD-FOG to a greater extent compared to the leader role.

Impact

This case series study could inform additional research with the goal of enhancing physical therapy or music-based therapy approaches for addressing PD-FOG.

Gait initiation in Parkinson's disease: comparison of timing and displacement during anticipatory postural adjustments as a function of motor severity and apathy in a large cohort

Introduction

Gait initiation is preceded by three anticipatory postural adjustment (APA) phases. In Parkinson's disease (PD) generated force, displacement and timing during APA differ from healthy controls. APA might be influenced by disease status, weight or emotion. It is unknown how motor severity, disease duration or presence of apathy influences APA timing and displacement.

Methods

We included 99 people with PD and 50 healthy controls (HC) to perform five gait initiation trials following an auditory cue. Force plates measured timing and center of pressure (CoP) displacement during APA phases.

Results

Time to gait initiation (tGI) was higher in the PD group (p < 0.001, t = 2.74, 95%CI (0.008, 0.066)). The first two APA phases (APA1 and APA2a) lasted longer in PD (respectively p < 0.001, t = 3.87, 95%CI (0.091, 0.28) and p < 0.001, t = 4.1, 95%CI (0.031, 0.091)). Mean CoP displacement, variability in timing and displacement did not differ. A multiple regression model was used to determine if clinical variables were related to gait initiation parameters. tGI was predicted by age (p < 0.001) and weight (p = 0.005). The duration of APA1 was predicted by weight (p = 0.006) and APA2a by age (p < 0.001). Variability in duration of the locomotor phase (LOC) was predicted by age (p < 0.001).

Conclusion

tGI and initial APA phases are longer in PD than in HC. There are no significant differences in variability of timing or displacement between the two groups. Gait initiation parameters are independent of disease duration, motor severity, medication usage or apathy in PD. Our findings suggest that cueing does not speed up gait initiation but reduces variability.

Visual Exploration While Walking With and Without Visual Cues in Parkinson's Disease: Freezer Versus Non-Freezer

BACKGROUND

Visual cues can improve gait in Parkinson's disease (PD), including those experiencing freezing of gait (FOG). However, responses are variable and underpinning mechanisms remain unclear. Visuo-cognitive processing (measured through visual exploration) has been implicated in cue response, but this has not been comprehensively examined.

OBJECTIVE

To examine visual exploration and gait with and without visual cues in PD who do and do not self-report FOG, and healthy controls (HC).

METHODS

17 HC, 21 PD without FOG, and 22 PD with FOG walked with and without visual cues, under single and dual-task conditions. Visual exploration (ie, saccade frequency, duration, peak velocity, amplitude, and fixation duration) was measured via mobile eye-tracking and gait (ie, gait speed, stride length, foot strike angle, stride time, and stride time variability) with inertial sensors.

RESULTS

PD had impaired gait compared to HC, and dual-tasking made gait variables worse across groups (all P < .01). Visual cues improved stride length, foot strike angle, and stride time in all groups (P < .01). Visual cueing also increased saccade frequency, but reduced saccade peak velocity and amplitude in all groups (P < .01). Gait improvement related to changes in visual exploration with visual cues in PD but not HC, with relationships dependent on group (FOG vs non-FOG) and task (single vs dual).

CONCLUSION

Visual cues improved visual exploration and gait outcomes in HC and PD, with similar responses in freezers and non-freezers. Freezer and non-freezer specific associations between cue-related changes in visual exploration and gait indicate different underlying visuo-cognitive processing within these subgroups for cue response.

One cue does not fit all: a systematic review with meta-analysis of the effectiveness of cueing on freezing of gait in Parkinson's disease

The difficulty in assessing FOG and the variety of existing cues, hamper to determine which cueing modality should be applied and which FOG-related aspect should be targeted to reach personalized treatments for FOG. This systematic review aimed to highlight: i) whether cues could reduce FOG and improve FOG-related gait parameters, ii) which cues are the most effective, iii) whether medication state (ON-OFF) affects cues-related results. Thirty-three repeated measure design studies assessing cueing effectiveness were included and subdivided according to gait tasks (gait initiation, walking, turning) and to the medication state. Main results reveal that: preparatory phase of gait initiation benefit from visual and auditory cues; spatio-temporal parameters (e.g., step and stride length) and are improved by visual cues during walking; turning time and step time variability are reduced by applying auditory and visual cues. Some findings on the potential benefits of cueing on FOG and FOG gait-related parameters were found. Questions remain about which are the best behavioral strategies according to FOG features and PD clinical characteristics.

Effects of wearable visual cueing on gait pattern and stability in patients with Parkinson’s disease

The present study examined the effects of wearable visual cues, provided by a wearable laser device, on the gait pattern and stability in patients with Parkinson’s disease (PD). In total, 18 patients with a clinical diagnosis of idiopathic PD (Hoehn and Yahr stage II-III) and 18 healthy controls were included. The main outcome measures included spatiotemporal parameters, sagittal plane kinematic parameters of joints in lower limbs, and dynamic center of pressure (COP) parameters. Significant intra-group improvement in gait parameters was observed in PD patients. Compared with that at baseline, the gait pattern improved in PD patients under the cued condition, with longer stride length and higher toe clearance, as well as shortening of double stance phase, especially the stride length, double stance phase and toe clearance were not significantly different between cued condition and healthy control groups. In kinematics, the ankle peak dorsiflexion in swing phase and the hip range of motion (ROM) in gait cycle was significantly improved in PD patients with visual cues and close to healthy controls. Decreased anteroposterior (AP) position of COP improved gait stability in patients with PD under the cued condition. Multiple linear regression analysis showed that the AP position has a negative correlation with ankle peak dorsiflexion in swing phase. Pearson’s correlation coefficients showed that the minimum toe clearance (Mini TC) was positively correlated with the ankle peak dorsiflexion in swing phase. The immediate effect of wearable visual cues improved the gait pattern and stability in PD patients, suggesting that it may be effective when applied as an alternative technique in rehabilitation training for PD patients.

Socially Assistive Robots for Parkinson's Disease: Needs, Attitudes and Specific Applications as Identified by Healthcare Professionals

To explore how socially assistive robots (SARs) may assist the specific needs of individuals with Parkinson's disease (IwPD), we conducted three focus groups with 12 clinicians who treat IwPD. We present a thematic analysis of their perceptions of the needs of the patients, and their own expectations, perceived advantages, disadvantages and concerns regarding the use of SARs for IwPD. Clinicians were positive towards using SARs for IwPD, if used in the patient's home, for motor, communication, emotional, and cognitive needs, especially for practice and for help with activities of daily living. They were concerned that a SAR might be used to replace clinicians’ work, and stressed it should only augment the clinicians’ work. They thought a SAR may relieve some of the burden experienced by informal caregivers, and identified specific applications for SARs for PD. We asked 18 stakeholders (nine IwPD, nine family members) to rate their level of agreement with the clinicians’ statements. The greatest divergence between their views and those of the clinicians was on the topic of using a SAR as a companion, or as a feeding assistant, to which they objected. This work may be used as a basis for future studies designing SARs for IwPD.

Does visual cueing improve gait initiation in people with Parkinson's disease?

Anticipatory postural adjustments (APAs) prior to gait initiation are impaired in people with Parkinson's disease (PD), particularly in those who report Freezing of Gait (FOG). External cues can improve gait parameters in people with PD, but the effects of visual cues on gait initiation are poorly known. The study aimed to (i) assess differences, during gait initiation, between people with PD with (FOG+) and without FOG (FOG-) and healthy controls (HC), (ii) explore the effect of disease severity on gait initiation and (iii) investigate the acute effect of visual cueing on gait initiation and straight-ahead gait. Twenty FOG- and twenty FOG+, and eighteen HC participated in this study. Participants were asked to perform self-initiated gait with and without visual cues presented as transverse taped lines on the floor. Gait initiation and gait were characterized with wireless inertial measurement units. Results showed that FOG+ had smaller APAs than HC and FOG-; although no differences were detected between FOG+ and FOG- when taking into account disease severity. Significant correlations between MDS-UPDRS III scores and gait initiation/straight-ahead gait variables confirmed that differences between FOG+ and FOG- were driven by disease severity. In gait initiation, visual cues elicited different behaviors in people with and without PD. Particularly, people with PD showed smaller and longer APAs, whereas HC showed longer first step durations, compared to baseline. However, the adopted visual cues improved gait speed and stride length in all individuals. These results suggest that people with PD, despite the presence of FOG, utilize different motor strategies, compared to HC, to adapt to the new biomechanical requirements of gait initiation dictated by the visual cues.

Motor learning in hemi-Parkinson using VR-manipulated sensory feedback

AIMS

Modalities for rehabilitation of the neurologically affected upper-limb (UL) are generally of limited benefit. The majority of patients seriously affected by UL paresis remain with severe motor disability, despite all rehabilitation efforts. Consequently, extensive clinical research is dedicated to develop novel strategies aimed to improve the functional outcome of the affected UL. We have developed a novel virtual-reality training tool that exploits the voluntary control of one hand and provides real-time movement-based manipulated sensory feedback as if the other hand is the one that moves. The aim of this study was to expand our previous results, obtained in healthy subjects, to examine the utility of this training setup in the context of neuro-rehabilitation.

METHODS

We tested the training setup in patient LA, a young man with significant unilateral UL dysfunction stemming from hemi-parkinsonism. LA underwent daily intervention in which he intensively trained the non-affected upper limb, while receiving online sensory feedback that created an illusory perception of control over the affected limb. Neural changes were assessed using functional magnetic resonance imaging (fMRI) scans before and after training.

RESULTS

Training-induced behavioral gains were accompanied by enhanced activation in the pre-frontal cortex and a widespread increase in resting-state functional connectivity.

DISCUSSION

Our combination of cutting edge technologies, insights gained from basic motor neuroscience in healthy subjects and well-known clinical treatments, hold promise for the pursuit of finding novel and more efficient rehabilitation schemes for patients suffering from hemiplegia.Implications for rehabilitationAssistive devices used in hospitals to support patients with hemiparesis require expensive equipment and trained personnel - constraining the amount of training that a given patient can receive. The setup we describe is simple and can be easily used at home with the assistance of an untrained caregiver/family member. Once installed at the patient's home, the setup is lightweight, mobile, and can be used with minimal maintenance . Building on advances in machine learning, our software can be adapted to personal use at homes. Our findings can be translated into practice with relatively few adjustments, and our experimental design may be used as an important adjuvant to standard clinical care for upper limb hemiparesis.

Therapeutic Devices for Motor Symptoms in Parkinson’s Disease: Current Progress and a Systematic Review of Recent Randomized Controlled Trials

Background

Pharmacotherapy is the first-line treatment option for Parkinson’s disease, and levodopa is considered the most effective drug for managing motor symptoms. However, side effects such as motor fluctuation and dyskinesia have been associated with levodopa treatment. For these conditions, alternative therapies, including invasive and non-invasive medical devices, may be helpful. This review sheds light on current progress in the development of devices to alleviate motor symptoms in Parkinson’s disease.

Methods

We first conducted a narrative literature review to obtain an overview of current invasive and non-invasive medical devices and thereafter performed a systematic review of recent randomized controlled trials (RCTs) of these devices.

Results

Our review revealed different characteristics of each device and their effectiveness for motor symptoms. Although invasive medical devices are usually highly effective, surgical procedures can be burdensome for patients and have serious side effects. In contrast, non-pharmacological/non-surgical devices have fewer complications. RCTs of non-invasive devices, especially non-invasive brain stimulation and mechanical peripheral stimulation devices, have proven effectiveness on motor symptoms. Nearly no non-invasive devices have yet received Food and Drug Administration certification or a CE mark.

Conclusion

Invasive and non-invasive medical devices have unique characteristics, and several RCTs have been conducted for each device. Invasive devices are more effective, while non-invasive devices are less effective and have lower hurdles and risks. It is important to understand the characteristics of each device and capitalize on these.

Neural correlates of speech and limb motor timing deficits revealed by aberrant beta band desynchronization in Parkinson's disease

OBJECTIVE

We used a classical motor reaction time paradigm to examine the effects of Parkinson's disease (PD) on the mechanisms of speech production and upper limb movement.

METHODS

Electro-encephalography (EEG) signals were recorded in PD and control groups during speech vowel production and button press tasks in response to temporally predictable and unpredictable visual stimuli.

RESULTS

Motor reaction times were slower in PD vs. control group independent of stimulus timing and movement modality. This effect was accompanied by stronger desynchronizations of low beta (13-18 Hz) and high beta (18-25 Hz) band neural oscillations in PD vs. control prior to the onset of speech and hand movement. In addition, pre-movement desynchronization of beta band oscillations were correlated with motor reaction time in control subjects with faster responses associated with weaker beta band desynchronizations during the planning phase of movement. However, no such effect was found in the PD group.

CONCLUSIONS

We suggest that the aberrant pattern of beta band desynchronization is a neural correlate of speech and upper limb motor timing deficits as a result of cortico-striatal pathology in PD.

SIGNIFICANCE

These findings motivate interventions targeted toward normalizing beta band activities for improving speech and upper limb movement timing in PD.

Efficacy of dance for Parkinson's disease: a pooled analysis of 372 patients

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative disorder that presents with motor and nonmotor symptoms such as bradykinesia, resting tremor, postural instability, and cognitive and neuropsychiatric manifestations. Dance therapy or complex motor activity, besides pharmacological treatment, may have benefits in PD patients.

OBJECTIVE

To assess the effect of dance in patients with PD.

METHODS

We searched for clinical trials in PubMed, Scopus, and Web of Science, and Cochrane till April 2020 using relevant keywords. Data were extracted and pooled as mean difference (MD) with 95% confidence interval (CI) by Review Manager 5.3.

RESULTS

Fourteen randomized controlled trials with 372 patients were included. Dance showed a significant improvement over the control group in term of the Unified Parkinson's Disease Rating Scale III (UPDRS III) after three (MD = - 4.49, 95% CI [- 6.78, - 2.21], p = 0.00001), six, (MD = - 5.96, 95% CI [- 8.89, - 3.02], p < 0.0001), and 12 months (MD = - 14.58, 95% CI [- 24.76, - 4.4], p = 0.005), and Mini-BES test after 12 months. Compared to exercise, dance showed a significant improvement in Timed Up and Go (TUG) test, Berg Balance Scale (BBS), and Mini-BES test.

CONCLUSION

In comparison to other types of exercise or no activity, dance improves the symptoms and outcomes in patients with PD, especially motor symptoms. Dance also has positive effects on balance, functional mobility, and cognition.

Visual cues added to a virtual environment paradigm do not improve motor arrests in Parkinson's disease

Objective. Elucidating how cueing alleviates freezing of gait (FOG) in Parkinson's disease (PD) would enable the development of more effective, personalized cueing strategies. Here, we aimed to validate a visual cueing virtual environment (VE) paradigm for future use in e.g. neuroimaging studies and behavioral studies on motor timing and scaling in PD patients with FOG.Approach. We included 20 PD patients with FOG and 16 age-matched healthy control subjects. Supine participants were confronted with a VE displaying either no cues, bars or staircases. They navigated forward using alternate suppression of foot pedals. Motor arrests (as proxy for FOG), and measures of motor timing and scaling were compared across the three VE conditions for both groups.Main results. VE cues (bars and staircases) did not reduce motor arrests in PD patients and healthy control subjects. The VE cues did reduce pedal amplitude in healthy control subjects, without effects on other motor parameters.Conclusion. We could not validate a visual cueing VE paradigm to study FOG. The VE cues possibly failed to convey the necessary spatial and temporal information to support motor timing and scaling. We discuss avenues for future research.

The effects of light touch cue on gait initiation in patients with Parkinson's disease

INTRODUCTION

One of the common impairments in patients with Parkinson's disease (PD) is disturbance of gait initiation. A light touch cue improves postural stability in patients with PD. Little is known about the effects of a light touch cue on gait initiation. This study investigated the effects of a light touch on gait initiation in patients with PD.

METHODS

This study was a cross-sectional study design. Sixteen patients with PD (Hoehn & Yahr stage 2-3) participated in the study and were evaluated two gait conditions (no touch (NT) and light touch (LT) conditions). Gait initiation was divided into 5 events including event A, B, C, D, and E. Outcome measures included maximum center of pressure (COP) displacement and velocity in anteroposterior (AP) and mediolateral (ML) directions, and the first step time.

RESULTS

Participants with LT had greater COP displacement compared with the NT condition in all events of gait initiation except COP-AP displacement in event D. Additionally, the COP velocity in LT condition was faster than the NT condition in COP-ML velocity in event A, COP-AP velocity in event B, COP-AP velocity and COP-ML velocity in event C. Moreover, participants with LT presented significantly shorter the first step time than the NT condition.

CONCLUSIONS

These findings demonstrated that a light touch cue improved gait initiation in patients with PD by increased weight shifting to initial stance limb, increased postural stability of stance limb, increased velocity of weight transfer toward stance limb, and a shortened first step time.

A novel instrumented walker for individualized visual cue setting for gait training in patients with Parkinson's disease

Patients with Parkinson's disease suffer from gait disturbances, such as a shuffling and festinating gait, which reduces their quality of life. To circumvent this problem, external visual cues may be applied in gait training to maintain the integrity of motor function. However, conventional training methods, such as transverse lines stuck on the ground, are difficult to adjust and adapt to personalized gait ability. This study proposes a convenient instrumented wheel walker that provides gap adjustable visual cues and selectable projection modes onto the ground with and without motion relative to the user. Ten subjects with Parkinson's disease were recruited, and the efficacy of the proposed device for their gait training was assessed. We demonstrated the applicability of our device to address personalized demands in gait guidance. With a personalized setting for patients with Parkinson's disease, a significantly lengthened stride length may be achieved.

The effect of tactile feedback on gait initiation in people with Parkinson's disease: A pilot study

BACKGROUND

Gait initiation and turning are common triggers for Freezing of Gait (FOG) in people with Parkinson's disease (PD). Recently, it has been shown that closed-loop tactile feedback (CLTF) can be effective to improve turning performance in people with FOG.

RESEARCH QUESTION

Does CLTF change the preparation and execution of the first step during gait initiation?

METHODS

People (n = 36) with PD with FOG (PD + FOG) (n = 18) and without FOG (PD-FOG) (n = 18) were included in the study and performed self-initiated gait with or without CLTF under single and dual task conditions. Anticipatory postural adjustments (APAs) and step kinematics were quantified with inertial measurement units (IMUs). Muscle activity of the right and left tensor fasciae latae (TFL) was measured via EMG recordings.

RESULTS

PD + FOG and PD-FOG did not differ in age, gender and disease duration and severity (p > 0.05). PD + FOG performed smaller APAs (F = 4.559, p = 0.04) with a higher amount of TFL co-contraction (F = 6.034, p = 0.02) compared to PD-FOG. CLTF had no effect on APAs but led to an increase in first step duration (F = 7.921, p = 0.008).

CONCLUSIONS

PD + FOG had smaller APAs and higher left and right TFL co-contraction during gait initiation. CLTF did not impact preparation of the first step but led to a slower execution of the first step. We speculate that, similarly to findings from turning, CLTF might result in the participant attending more closely to the first step compared to without CLTF. Whether increased attention on gait initiation is beneficial in diminishing FOG should be investigated in more detail.

Rhythmic movement and rhythmic auditory cues enhance anticipatory postural adjustment of gait initiation

The purpose of this study was to determine whether the rhythmic movements or cues enhance the anticipatory postural adjustment (APA) of gait initiation. Healthy humans initiated gait in response to an auditory start cue (third cue). A first auditory cue was given 8 s before the start cue, and a second auditory cue was given 3 s before the start cue. The participants performed the rhythmic medio-lateral weight shift (ML-WS session), rhythmic anterior-posterior weight shift (AP-WS session), or rhythmic arm swing (arm swing session) in the time between the first and second cues. In the rhythmic cues session, rhythmic auditory cues with a frequency of 1 Hz were given in this time. In the stationary session, the participants maintained stationary stance in this time. The APA and initial step movement preceded by those rhythmic movements or cues were compared with those in the stationary session. The temporal characteristics of the initial step movement of the gait initiation were not changed by the rhythmic movements or cues. The medio-lateral displacement of the APA in the ML-WS and arm swing sessions was significantly greater than that in the stationary session. The anterior-posterior displacement of the APA in the rhythmic cues and arm swing sessions was significantly greater than that in the stationary session. Taken together, the rhythmic movements and cues enhance the APA of gait initiation. The present finding may be a clue or motive for the future investigation for using rhythmic movements or cues as the preparatory activity to enlarge the small APA of gait initiation in the patients with Parkinson's disease.

Treatment of Dysphagia in Parkinson's Disease: A Systematic Review

The incidence of oropharyngeal dysphagia in Parkinson’s disease (PD) is very high. It is necessary to search for effective therapies that could prevent pneumonia. Previous results should be interpreted cautiously as there is a lack of evidence to support the use of compensatory or rehabilitative approaches to dysphagia. We reviewed the scientific literature to describe the treatments of dysphagia in PD. A systematic review was performed in PubMed, Scopus, Elsevier, and Medline according to PRISMA standards in 2018. The articles that did not mention dysphagia secondary to PD or used surgical treatment were excluded. Eleven articles met the criteria with information from 402 patients. The review relates to different protocols, such as training in expiratory muscle strength, postural techniques, oral motor exercises, video-assisted swallowing therapy, surface electrical stimulation, thermal stimulation, touch, compensatory interventions, training regime for swallowing, neuromuscular electrical stimulation, Lee Silverman voice treatment, swallow maneuver, airway protection, and postural compensation maneuvers. This review identifies the rationing interventions in each trial, if they are efficient and equitable. Several rehabilitative therapies have been successful. An improvement was seen in the degenerative function (coordination, speed, and volume), quality of life, and social relationships of people with PD. Further investigations concerning the clinical applicability of these therapies based on well-designed randomized controlled studies are needed. Larger patient populations need to be recruited to evaluate the effectiveness, long-term effects, and new treatment techniques.

Prediction of Freezing of Gait in Parkinson's Disease Using Statistical Inference and Lower-Limb Acceleration Data

The freezing of gait (FoG) is a common type of motor dysfunction in advanced Parkinson's disease (PD) associated with falls. Over the last decade, a significant amount of studies has been focused on detecting FoG episodes in clinical and home environments. Yet, there remains a paucity of techniques regarding real-time prediction of FoG before its occurrence. In this paper, a new algorithm was employed to define the best combination of sensor position, axis, sampling window length, and features to predict FoG. We hypothesized that gait deterioration before FoG onsets can be discriminated from normal gait using statistical analysis of features from successive windows of data collected from lower-limb accelerometers. We defined a new performance measure, "predictivity", to compare the number of correctly predicted FoG events among different combinations. We characterized the system performance using data from 10 PD patients, who experienced FoG while performing several walking tasks in a lab environment. The analysis of 120 different combinations revealed that prediction of FoG can be realized by using an individual shank sensor and sample entropy calculated from the horizontal forward axis with window length of 2 s (88.8%, 92.5%, and 89.0% for average predictivity, sensitivity, and specificity, respectively).

The effects of anodal tDCS over the supplementary motor area on gait initiation in Parkinson's disease with freezing of gait: a pilot study

OBJECTIVE

We investigated if anodal transcranial direct current stimulation (A-tDCS), applied over the supplementary motor areas (SMAs), could improve gait initiation in Parkinson's disease (PD) with freezing of gait (FOG).

METHODS

In this double-blinded cross-over pilot study, ten PD with FOG underwent two stimulation sessions: A-tDCS (1 mA, 10 min) and sham stimulation. Eight blocks of gait initiation were collected per session: (1) pre-tDCS, with acoustic cueing; (2) pre-tDCS, self-initiated (no cue); and (3-8) post-tDCS, self-initiated. Gait initiation kinetics were analyzed with two-way repeated measures ANOVAs for the effects of A-tDCS.

RESULTS

A-tDCS did not significantly improve the magnitude or timing of anticipatory postural adjustments or the execution of the first step during self-initiated gait compared with baseline measures (p > .13). The lack of significant change was not due to an inability to generate functional APAs since external cueing markedly improved gait initiation (p < .01).

CONCLUSIONS

A single dose of A-tDCS over the SMAs did not improve self-initiated gait in PD and FOG. Alternative approaches using a different dose or cortical target are worthy of exploration since individuals demonstrated the capacity to improve.

SIGNIFICANCE

Neuromodulation strategies tailored to facilitate SMA activity may be ineffective for the treatment of gait initiation impairment in people with PD and FOG.

Kinect4FOG: monitoring and improving mobility in people with Parkinson's using a novel system incorporating the Microsoft Kinect v2

Parkinson's is a neurodegenerative condition associated with several motor symptoms including tremors and slowness of movement. Freezing of gait (FOG); the sensation of one's feet being "glued" to the floor, is one of the most debilitating symptoms associated with advanced Parkinson's. FOG not only contributes to falls and related injuries, but also compromises quality of life as people often avoid engaging in functional daily activities both inside and outside the home. In the current study, we describe a novel system designed to detect FOG and falling in people with Parkinson's (PwP) as well as monitoring and improving their mobility using laser-based visual cues cast by an automated laser system. The system utilizes a RGB-D sensor based on Microsoft Kinect v2 and a laser casting system consisting of two servo motors and an Arduino microcontroller. This system was evaluated by 15 PwP with FOG. Here, we present details of the system along with a summary of feedback provided by PwP. Despite limitations regarding its outdoor use, feedback was very positive in terms of domestic usability and convenience, where 12/15 PwP showed interest in installing and using the system at their homes. Implications for Rehabilitation Providing an automatic and remotely manageable monitoring system for PwP gait analysis and fall detection. Providing an automatic, unobtrusive and dynamic visual cue system for PwP based on laser line projection. Gathering feedback from PwP about the practical usage of the implemented system through focus group events.

Neurophysiological and clinical effects of blindfolded balance training (BBT) in Parkinson's disease patients: a preliminary study

BACKGROUND

Recent evidence supports the hypothesis that rehabilitative strategies based on sensorimotor stimulation in the neurorehabilitation of Parkinson's disease (PD) may be useful to improve gait in PD patients.

AIM

We supposed that sensorimotor stimulation produces modulation of anticipatory postural adjustments (APAs) arising from the supplementary motor area (SMA). We aimed to investigate the clinical and neurophysiological effects of a blindfolded balance training (BBT).

DESIGN

Randomized controlled trial.

SETTING

Italian hospital.

POPULATION

Sixteen PD patients.

METHODS

The patients were randomized in two groups, one group treated with two-weeks BBT and one group treated with two-weeks of physical therapy (PT). We assessed gait parameters (swing, stance, double stance phase of cycle gait) and neurophysiological measurement (functional connectivity between SMA and motor area M1) before and after treatments.

RESULTS

We found a decrease of stance and double stance phase and increase of swing phase respect to gait cycle, in BBT group compared to PT group, paralleled by a selective modulation in functional connectivity between M1 and SMA for BBT group.

CONCLUSIONS

Our findings support that BBT represents a complementary rehabilitative strategy, based on visual deprivation and proprioceptive perturbation in recovery of gait in PD patients, in short time window, likely involving vestibular system and its connections with motor areas.

CLINICAL REHABILITATION IMPACT

The use of vestibular system stimulation, involving SMA-M1 circuits, may be useful to improve gait control in PD patients.

Effect of auditory stimulus on executive function and execution time during cognitively demanding stepping task in patients with Parkinson's disease

Start hesitation in patients with Parkinson's disease (PD) occurs predominantly during distractive and conflictual situations. The aim of this study was to investigate how differently an auditory stimulus (AS) influences execution function and execution time during a cognitively demanding stepping task in PD patients as compared to healthy controls. PD patients and healthy controls stepped forward in response to a visual imperative stimulus of an arrow. We applied a Simon task that comprised congruent and incongruent conditions. Direction and location of the arrow matched in the congruent condition, while they didn't in the incongruent condition. AS were randomly and simultaneously presented with the visual stimulus. An error in the direction of an anticipatory postural adjustment (APA), termed an APA error, and temporal parameters (reaction onset of APA and APA duration) were analyzed. As a result, the AS increased the APA error rate in the control group regardless of the condition, but they did not influence it in the PD group. The AS also speeded the reaction onset in both groups regardless of the condition. The APA duration was prolonged by the AS for the control group, while it was unaffected by the AS for the PD group in both conditions. These findings indicate that AS could facilitate a step initiation, conceivably by facilitating a stimulus identification process and increasing attentional control of stepping behavior, without influencing a decision-making process even in a cognitively demanding condition in patients with PD.

COMplex Fracture Orthopedic Rehabilitation (COMFORT) - Real-time visual biofeedback on weight bearing versus standard training methods in the treatment of proximal femur fractures in the elderly: study protocol for a multicenter randomized controlled trial

Background

Proximal femur fractures are a common injury after low energy trauma in the elderly. Most rehabilitation programs are based on restoring mobility and early resumption of weight-bearing. However, therapy compliance is low in patients following lower extremity fractures. Moreover, little is known about the relevance of gait parameters and how to steer the rehabilitation after proximal femur fractures in the elderly. Therefore, the aim of this prospective, randomized controlled trial is to gain insight in gait parameters and evaluate if real-time visual biofeedback can improve therapy compliance after proximal femur fractures in the elderly.

Methods

This is a two-arm, parallel-design, prospective, randomized controlled trial. Inclusion criteria are age ≥ 60 years, a proximal femur fracture following low energy trauma, and unrestricted-weight bearing. Exclusion criteria are cognitive impairment and limited mobility before trauma. Participants are randomized into either the control group, which receives care as usual, or the intervention group, which receives real-time visual biofeedback about weight-bearing during gait in addition to care as usual. Spatiotemporal gait parameters will be measured in 94 participants per group during a 30-m walk with an ambulatory biofeedback system (SensiStep). The progress of rehabilitation will be evaluated by the primary outcome parameters maximum peak load and step duration in relation to the discharge date. Secondary outcome parameters include other spatiotemporal gait parameters in relation to discharge date. Furthermore, the gait parameters will be related to three validated clinical tests: Elderly Mobility Scale; Functional Ambulation Categories; and Visual Analogue Scale. The primary hypothesis is that participants in the intervention group will show improved and faster rehabilitation compared to the control group.

Discussion

The first aim of this multicenter trial is to investigate the normal gait patterns after proximal femur fractures in the elderly. The use of biofeedback systems during rehabilitation after proximal femur fractures in the elderly is promising; therefore, the second aim is to investigate the effect of real-time visual biofeedback on gait after proximal femur fractures in the elderly. This could lead to improved outcome. In addition, analysis of the population may indicate characteristics of subgroups that benefit from feedback, making a differentiated approach in rehabilitation strategy possible.

Trial registration

TrialRegister.nl, NTR6794. Registered on 31 October 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2612-9) contains supplementary material, which is available to authorized users.

Saccade frequency response to visual cues during gait in Parkinson's disease: the selective role of attention

Gait impairment is a core feature of Parkinson's disease (PD) with implications for falls risk. Visual cues improve gait in PD, but the underlying mechanisms are unclear. Evidence suggests that attention and vision play an important role; however, the relative contribution from each is unclear. Measurement of visual exploration (specifically saccade frequency) during gait allows for real-time measurement of attention and vision. Understanding how visual cues influence visual exploration may allow inferences of the underlying mechanisms to response which could help to develop effective therapeutics. This study aimed to examine saccade frequency during gait in response to a visual cue in PD and older adults and investigate the roles of attention and vision in visual cue response in PD. A mobile eye-tracker measured saccade frequency during gait in 55 people with PD and 32 age-matched controls. Participants walked in a straight line with and without a visual cue (50 cm transverse lines) presented under single task and dual-task (concurrent digit span recall). Saccade frequency was reduced when walking in PD compared to controls; however, visual cues ameliorated saccadic deficit. Visual cues significantly increased saccade frequency in both PD and controls under both single task and dual-task. Attention rather than visual function was central to saccade frequency and gait response to visual cues in PD. In conclusion, this study highlights the impact of visual cues on visual exploration when walking and the important role of attention in PD. Understanding these complex features will help inform intervention development.

Effect of rhythmic auditory cueing on parkinsonian gait: A systematic review and meta-analysis

The use of rhythmic auditory cueing to enhance gait performance in parkinsonian patients' is an emerging area of interest. Different theories and underlying neurophysiological mechanisms have been suggested for ascertaining the enhancement in motor performance. However, a consensus as to its effects based on characteristics of effective stimuli, and training dosage is still not reached. A systematic review and meta-analysis was carried out to analyze the effects of different auditory feedbacks on gait and postural performance in patients affected by Parkinson's disease. Systematic identification of published literature was performed adhering to PRISMA guidelines, from inception until May 2017, on online databases; Web of science, PEDro, EBSCO, MEDLINE, Cochrane, EMBASE and PROQUEST. Of 4204 records, 50 studies, involving 1892 participants met our inclusion criteria. The analysis revealed an overall positive effect on gait velocity, stride length, and a negative effect on cadence with application of auditory cueing. Neurophysiological mechanisms, training dosage, effects of higher information processing constraints, and use of cueing as an adjunct with medications are thoroughly discussed. This present review bridges the gaps in literature by suggesting application of rhythmic auditory cueing in conventional rehabilitation approaches to enhance motor performance and quality of life in the parkinsonian community.

Real-time visual biofeedback during weight bearing improves therapy compliance in patients following lower extremity fractures

BACKGROUND

Individuals with lower extremity fractures are often instructed on how much weight to bear on the affected extremity. Previous studies have shown limited therapy compliance in weight bearing during rehabilitation. In this study we investigated the effect of real-time visual biofeedback on weight bearing in individuals with lower extremity fractures in two conditions: full weight bearing and touch-down weight bearing.

METHODS

11 participants with full weight bearing and 12 participants with touch-down weight bearing after lower extremity fractures have been measured with an ambulatory biofeedback system. The participants first walked 15m and the biofeedback system was only used to register the weight bearing. The same protocol was then repeated with real-time visual feedback during weight bearing. The participants could thereby adapt their loading to the desired level and improve therapy compliance.

RESULTS

In participants with full weight bearing, real-time visual biofeedback resulted in a significant increase in loading from 50.9±7.51% bodyweight (BW) without feedback to 63.2±6.74%BW with feedback (P=0.0016). In participants with touch-down weight bearing, the exerted lower extremity load decreased from 16.7±9.77kg without feedback to 10.27±4.56kg with feedback (P=0.0718). More important, the variance between individual steps significantly decreased after feedback (P=0.018).

CONCLUSIONS

Ambulatory monitoring weight bearing after lower extremity fractures showed that therapy compliance is low, both in full and touch-down weight bearing. Real-time visual biofeedback resulted in significantly higher peak loads in full weight bearing and increased accuracy of individual steps in touch-down weight bearing. Real-time visual biofeedback therefore results in improved therapy compliance after lower extremity fractures.

Usability of Three-dimensional Augmented Visual Cues Delivered by Smart Glasses on (Freezing of) Gait in Parkinson's Disease

External cueing is a potentially effective strategy to reduce freezing of gait (FOG) in persons with Parkinson's disease (PD). Case reports suggest that three-dimensional (3D) cues might be more effective in reducing FOG than two-dimensional cues. We investigate the usability of 3D augmented reality visual cues delivered by smart glasses in comparison to conventional 3D transverse bars on the floor and auditory cueing via a metronome in reducing FOG and improving gait parameters. In laboratory experiments, 25 persons with PD and FOG performed walking tasks while wearing custom-made smart glasses under five conditions, at the end-of-dose. For two conditions, augmented visual cues (bars/staircase) were displayed via the smart glasses. The control conditions involved conventional 3D transverse bars on the floor, auditory cueing via a metronome, and no cueing. The number of FOG episodes and percentage of time spent on FOG were rated from video recordings. The stride length and its variability, cycle time and its variability, cadence, and speed were calculated from motion data collected with a motion capture suit equipped with 17 inertial measurement units. A total of 300 FOG episodes occurred in 19 out of 25 participants. There were no statistically significant differences in number of FOG episodes and percentage of time spent on FOG across the five conditions. The conventional bars increased stride length, cycle time, and stride length variability, while decreasing cadence and speed. No effects for the other conditions were found. Participants preferred the metronome most, and the augmented staircase least. They suggested to improve the comfort, esthetics, usability, field of view, and stability of the smart glasses on the head and to reduce their weight and size. In their current form, augmented visual cues delivered by smart glasses are not beneficial for persons with PD and FOG. This could be attributable to distraction, blockage of visual feedback, insufficient familiarization with the smart glasses, or display of the visual cues in the central rather than peripheral visual field. Future smart glasses are required to be more lightweight, comfortable, and user friendly to avoid distraction and blockage of sensory feedback, thus increasing usability.

Transcranial direct current stimulation associated with gait training in Parkinson's disease: A pilot randomized clinical trial

OBJECTIVE

The aim of this study is to investigate the effects of transcranial direct current stimulation (tDCS) combined with cueing gait training (CGT) on functional mobility in patients with Parkinson´s disease (PD).

METHODS

A pilot double-blind controlled, randomized clinical trial was conducted with 22 patients with PD assigned to the experimental (anodal tDCS plus CGT) and control group (sham tDCS plus CGT). The primary outcome (functional mobility) was assessed by 10-m walk test, cadence, stride length, and Timed Up and Go test. Motor impairment, bradykinesia, balance, and quality of life were analyzed as secondary outcomes. Minimal clinically important differences (MCIDs) were observed when assessing outcome data.

RESULTS

Both groups demonstrated similar gains in all outcome measures, except for the stride length. The number of participants who showed MCID was similar between groups.

CONCLUSION

The CGT provided many benefits to functional mobility, motor impairment, bradykinesia, balance, and quality of life. However, these effect magnitudes were not influenced by stimulation, but tDCS seems to prolong the effects of cueing therapy on functional mobility.

Effect of Cue Timing and Modality on Gait Initiation in Parkinson Disease With Freezing of Gait

OBJECTIVE

To examine the effects of cue timing, across 3 sensory modalities, on anticipatory postural adjustments (APAs) during gait initiation in people with Parkinson disease (PD).

DESIGN

Observational study.

SETTING

Biomechanics research laboratory.

PARTICIPANTS

Individuals with idiopathic PD (N=25; 11 with freezing of gait [FOG]) were studied in the off-medication state (12-h overnight withdrawal).

INTERVENTIONS

Gait initiation was tested without cueing (self-initiated) and with 3 cue timing protocols: fixed delay (3s), random delay (4-12s), and countdown (3-2-1-go, 1-s intervals) across 3 sensory modalities (acoustic, visual, and vibrotactile).

MAIN OUTCOME MEASURES

The incidence and spatiotemporal characteristics of APAs during gait initiation were analyzed, including vertical ground reaction forces and center of pressure.

RESULTS

All cue timings and modalities increased the incidence and amplitude of APAs compared with self-initiated stepping. Acoustic and visual cues, but not vibrotactile stimulation, improved the timing of APAs. Fixed delay or countdown timing protocols were more effective at decreasing APA durations than random delay cues. Cue-evoked improvements in APA timing, but not amplitude, correlated with the level of impairment during self-initiated gait. Cues did not improve the late push-off phase in the FOG group.

CONCLUSIONS

External cueing improves gait initiation in PD regardless of cue timing, modality, or clinical phenotype (with and without FOG). Acoustic or visual cueing with predictive timing provided the greatest improvements in gait initiation; therefore, these protocols may provide the best outcomes when applied by caregivers or devices.

The Effects of Sensory Manipulations on Motor Behavior: From Basic Science to Clinical Rehabilitation

Modifying sensory aspects of the learning environment can influence motor behavior. Although the effects of sensory manipulations on motor behavior have been widely studied, there still remains a great deal of variability across the field in terms of how sensory information has been manipulated or applied. Here, the authors briefly review and integrate the literature from each sensory modality to gain a better understanding of how sensory manipulations can best be used to enhance motor behavior. Then, they discuss 2 emerging themes from this literature that are important for translating sensory manipulation research into effective interventions. Finally, the authors provide future research directions that may lead to enhanced efficacy of sensory manipulations for motor learning and rehabilitation.

Anticipatory postural adjustments are unaffected by age and are not absent in patients with the freezing of gait phenomenon

In bipedal gait, the initiation of the first step is preceded by a complex sequence of movements which shift the centre of mass of the body towards the stance foot to allow for a step of the swing foot. These anticipatory postural adjustments (APAs) have been investigated in order to elucidate movement strategies in healthy and diseased persons. We studied the influence of several external parameters (age, type of step initiation) on APAs and investigated whether Parkinsonian patients may have different APAs. As a result, we found that externally elicited steps were preceded by faster and larger APAs than self-timed steps. Parkinsonian patients without the freezing of gait (FOG) phenomenon showed overall slightly reduced APAs but did not clearly differ from patients with FOG. Multiple APAs were seen in up to 25 % of the steps of the patients and in a much lower percentage of the steps of control subjects. The results indicate that APAs are significantly influenced by the timing of a step, i.e. are larger in externally elicited steps. The patients showed an overall preserved APA pattern but slowed movements and amplitude, indicating that increased bradykinesia due to progressive illness is a plausible explanation for these findings. The freezing phenomenon is not explained by a general absence or massive reduction in APA measures.

Paradoxical kinesia in Parkinson's disease revisited: Anticipation of temporal constraints is critical

Slowness of movement, called bradykinesia is the cardinal symptom of Parkinson's disease. Under distinct but not yet well-defined circumstances, patients with Parkinson's disease are able to overcome bradykinesia. One common hypothesis for this phenomenon termed paradoxical kinesia in Parkinson's disease postulates that the presentation of external sensory triggers is pivotal to elicit significant increase of motor velocity. In the present study, we examined an alternative hypothesis, namely that an internal cue in the absence of sensory cues are linked to paradoxical kinesia. To test this alternative hypothesis, patients with Parkinson's disease and healthy age-matched controls (n=9 per group) performed two movement tasks. In the stationary-object prehension task, subjects had to pick up a stationary target object. For the escaping-object task, the participants had to pick up the target object before it moved out of reach. The time available to reach for the object was adjusted individually to ensure comparable difficulty across participants. Reaction time, movement duration, and maximum velocity were assessed for both movement tasks. In Parkinson's disease patients and healthy controls, anticipation of the imminent movement of a target object significantly decreased reaction time, movement duration, and increased maximum movement velocity. The increase of maximum movement velocity in the escape-condition was significantly more pronounced for Parkinson's disease patients as compared to healthy controls. We provide evidence that internal cues such as temporal constraints are sufficient to diminish the cardinal clinical symptom of bradykinesia in Parkinson's disease. Our results suggest that expectations rather than sensory cues are critical for the emergence of paradoxical kinesia and we discuss the implications of our findings for an account of paradoxical kinesia.

Blindfolded Balance Training in Patients with Parkinson's Disease: A Sensory-Motor Strategy to Improve the Gait

Aim. Recent evidence suggested that the use of treadmill training may improve gait parameters. Visual deprivation could engage alternative sensory strategies to control dynamic equilibrium and stabilize gait based on vestibulospinal reflexes (VSR). We aimed to investigate the efficacy of a blindfolded balance training (BBT) in the improvement of stride phase percentage reliable gait parameters in patients with Parkinson's Disease (PD) compared to patients treated with standard physical therapy (PT). Methods. Thirty PD patients were randomized in two groups of 15 patients, one group treated with BBT during two weeks and another group treated with standard PT during eight weeks. We evaluated gait parameters before and after BBT and PT interventions, in terms of double stance, swing, and stance phase percentage. Results. BBT induced an improvement of double stance phase as revealed (decreased percentage of double stance phase during the gait cycle) in comparison to PT. The other gait parameters swing and stance phase did not differ between the two groups. Discussion. These results support the introduction of complementary rehabilitative strategies based on sensory-motor stimulation in the traditional PD patient's rehabilitation. Further studies are needed to investigate the neurophysiological circuits and mechanism underlying clinical and motor modifications.

Effect of three cueing devices for people with Parkinson's disease with gait initiation difficulties

BACKGROUND

Freezing of gait (FOG) remains one of the most common debilitating aspects of Parkinson's disease and has been linked to injuries, falls and reduced quality of life. Although commercially available portable cueing devices exist claiming to assist with overcoming freezing; their immediate effectiveness in overcoming gait initiation failure is currently unknown. This study investigated the effects of three different types of cueing device in people with Parkinson's disease who experience freezing.

METHODS

Twenty participants with idiopathic Parkinson's disease who experienced freezing during gait but who were able to walk short distances indoors independently were recruited. At least three attempts at gait initiation were recorded using a 10 camera Qualisys motion analysis system and four force platforms. Test conditions were; Laser Cane, sound metronome, vibrating metronome, walking stick and no intervention.

RESULTS

During testing 12 of the 20 participants had freezing episodes, from these participants 100 freezing and 91 non-freezing trials were recorded. Clear differences in the movement patterns were seen between freezing and non-freezing episodes. The Laser Cane was most effective cueing device at improving the forwards/backwards and side to side movement and had the least number of freezing episodes. The walking stick also showed significant improvements compared to the other conditions. The vibration metronome appeared to disrupt movement compared to the sound metronome at the same beat frequency.

CONCLUSION

This study identified differences in the movement patterns between freezing episodes and non-freezing episodes, and identified immediate improvements during gait initiation when using the Laser Cane over the other interventions.

Effects of sensory cueing in virtual motor rehabilitation. A review

OBJECTIVES

To critically identify studies that evaluate the effects of cueing in virtual motor rehabilitation in patients having different neurological disorders and to make recommendations for future studies.

METHODS

Data from MEDLINE®, IEEExplore, Science Direct, Cochrane library and Web of Science was searched until February 2015. We included studies that investigate the effects of cueing in virtual motor rehabilitation related to interventions for upper or lower extremities using auditory, visual, and tactile cues on motor performance in non-immersive, semi-immersive, or fully immersive virtual environments. These studies compared virtual cueing with an alternative or no intervention.

RESULTS

Ten studies with a total number of 153 patients were included in the review. All of them refer to the impact of cueing in virtual motor rehabilitation, regardless of the pathological condition. After selecting the articles, the following variables were extracted: year of publication, sample size, study design, type of cueing, intervention procedures, outcome measures, and main findings. The outcome evaluation was done at baseline and end of the treatment in most of the studies. All of studies except one showed improvements in some or all outcomes after intervention, or, in some cases, in favor of the virtual rehabilitation group compared to the control group.

CONCLUSIONS

Virtual cueing seems to be a promising approach to improve motor learning, providing a channel for non-pharmacological therapeutic intervention in different neurological disorders. However, further studies using larger and more homogeneous groups of patients are required to confirm these findings.

Validity and reliability of an IMU-based method to detect APAs prior to gait initiation

Anticipatory postural adjustments (APAs) prior to gait initiation have been largely studied in traditional, laboratory settings using force plates under the feet to characterize the displacement of the center of pressure. However clinical trials and clinical practice would benefit from a portable, inexpensive method for characterizing APAs. Therefore, the main objectives of this study were (1) to develop a novel, automatic IMU-based method to detect and characterize APAs during gait initiation and (2) to measure its test-retest reliability. Experiment I was carried out in the laboratory to determine the validity of the IMU-based method in 10 subjects with PD (OFF medication) and 12 control subjects. Experiment II was carried out in the clinic, to determine test-retest reliability of the IMU-based method in a different set of 17 early-to-moderate, treated subjects with PD (tested ON medication) and 17 age-matched control subjects. Results showed that gait initiation characteristics (both APAs and 1st step) detected with our novel method were significantly correlated to the characteristics calculated with a force plate and motion analysis system. The size of APAs measured with either inertial sensors or force plate was significantly smaller in subjects with PD than in control subjects (p<0.05). Test-retest reliability for the gait initiation characteristics measured with inertial sensors was moderate-to-excellent (0.56<ICC<0.82) for both groups. Our findings support the feasibility of automatically characterizing postural preparation and gait initiation with body-worn inertial sensors that would be practical for unsupervised clinical and home settings.

Context-Dependent Neural Activation: Internally and Externally Guided Rhythmic Lower Limb Movement in Individuals With and Without Neurodegenerative Disease

Parkinson’s disease is a neurodegenerative disorder that has received considerable attention in allopathic medicine over the past decades. However, it is clear that, to date, pharmacological and surgical interventions do not fully address symptoms of PD and patients’ quality of life. As both an alternative therapy and as an adjuvant to conventional approaches, several types of rhythmic movement (e.g., movement strategies, dance, tandem biking, and Tai Chi) have shown improvements to motor symptoms, lower limb control, and postural stability in people with PD (1–6). However, while these programs are increasing in number, still little is known about the neural mechanisms underlying motor improvements attained with such interventions. Studying limb motor control under task-specific contexts can help determine the mechanisms of rehabilitation effectiveness. Both internally guided (IG) and externally guided (EG) movement strategies have evidence to support their use in rehabilitative programs. However, there appears to be a degree of differentiation in the neural substrates involved in IG vs. EG designs. Because of the potential task-specific benefits of rhythmic training within a rehabilitative context, this report will consider the use of IG and EG movement strategies, and observations produced by functional magnetic resonance imaging and other imaging techniques. This review will present findings from lower limb imaging studies, under IG and EG conditions for populations with and without movement disorders. We will discuss how these studies might inform movement disorders rehabilitation (in the form of rhythmic, music-based movement training) and highlight research gaps. We believe better understanding of lower limb neural activity with respect to PD impairment during rhythmic IG and EG movement will facilitate the development of novel and effective therapeutic approaches to mobility limitations and postural instability.

Functional Performance and Associations between Performance Tests and Neurological Assessment Differ in Men and Women with Parkinson's Disease

BACKGROUND

Neurological assessment of a patient with Parkinson's disease (PD) is expected to reflect upon functional performance. As women are known to report more limitations even for same observed functional performance level, present study was designed to examine whether associations between neurological assessments and functional performance differ across genders.

METHODS

14 men and 14 women with PD participated. Functional performance was assessed by measuring walking speeds on 10-meter walk test (10MWT) and by performing timed-up-and-go-test (TUG). Neurological assessment included Hoehn and Yahr Scale (HY), Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Schwab and England Activities of Daily Living Scale (S-E), and Mini Mental State Examination (MMSE).

RESULTS

In women with PD, Kendall's tau-b correlation analyses revealed significant correlations between functional performance tests and neurological assessment measures, with the exception in MMSE. No corresponding associations were found for men, although they demonstrated better functional performance, as expected.

CONCLUSION

Men in similar clinical stage of the PD perform better on functional tests than women. Disease severity reflects upon functional performance differently in men and women with PD. Results indicate that when interpreting the assessment results of both functional performance and neurological assessment tests, the gender of the patient should be taken into consideration.

Effects of Auditory Rhythm and Music on Gait Disturbances in Parkinson's Disease

Gait abnormalities, such as shuffling steps, start hesitation, and freezing, are common and often incapacitating symptoms of Parkinson’s disease (PD) and other parkinsonian disorders. Pharmacological and surgical approaches have only limited efficacy in treating these gait disorders. Rhythmic auditory stimulation (RAS), such as playing marching music and dance therapy, has been shown to be a safe, inexpensive, and an effective method in improving gait in PD patients. However, RAS that adapts to patients’ movements may be more effective than rigid, fixed-tempo RAS used in most studies. In addition to auditory cueing, immersive virtual reality technologies that utilize interactive computer-generated systems through wearable devices are increasingly used for improving brain–body interaction and sensory–motor integration. Using multisensory cues, these therapies may be particularly suitable for the treatment of parkinsonian freezing and other gait disorders. In this review, we examine the affected neurological circuits underlying gait and temporal processing in PD patients and summarize the current studies demonstrating the effects of RAS on improving these gait deficits.

Discriminating features of gait performance in progressive supranuclear palsy

INTRODUCTION

Progressive supranuclear palsy (PSP) is the most common form of atypical Parkinsonism; however it is underdiagnosed and often misdiagnosed as Parkinson's disease (PD).

METHODS

We investigated gait initiation (GI) and gait performance in a total of 36 participants (12 PSP, 12 PD and 12 healthy age- and gender-matched controls) to gain further insight into specific motor deficits that characterize dynamic postural control and gait in PSP. Anticipatory postural adjustments (APAs), quantified by center of pressure (COP) displacement and speed prior to an initial heel off, and the maximum distance (COPCOM) between COP and center of mass (COM) during all three GI phases were calculated to evaluate dynamic postural control. Steady-state gait performance was also evaluated and compared across the groups.

RESULTS

APAs in PSP were significantly altered such that the posterior COP shift is profoundly diminished when compared to PD (p < 0.05). Moreover, proper velocity control during GI in PSP was affected, particularly in the mediolateral direction, when compared to PD (p < 0.05). The diminished COPCOM distance is further indicative of more severe dynamic postural instability in PSP than in PD (p < 0.05). Significant differences in spatiotemporal parameters, inter-step variability, and asymmetry during gait in PSP, in comparison with PD were also identified (all p's < 0.05).

CONCLUSION

The present study reveals that the compensatory GI strategy in PSP is distinct from PD and paradoxically induces lateral instability. Further, gait performance in PSP is slower and more variable which could be the consequence of lateral instability and fear of falling.

Monaural Auditory Cue Affects the Process of Choosing the Initial Swing Leg in Gait Initiation

The authors investigated the effect of an auditory cue on the choice of the initial swing leg in gait initiation. Healthy humans initiated a gait in response to a monaural or binaural auditory cue. When the auditory cue was given in the ear ipsilateral to the preferred leg side, the participants consistently initiated their gait with the preferred leg. In the session in which the side of the monaural auditory cue was altered trial by trial randomly, the probability of initiating the gait with the nonpreferred leg increased when the auditory cue was given in the ear contralateral to the preferred leg side. The probability of choosing the nonpreferred leg did not increase significantly when the auditory cue was given in the ear contralateral to the preferred leg side in the session in which the auditory cue was constantly given in the ear contralateral to the preferred leg side. The reaction time of anticipatory postural adjustment was shortened, but the probability of choosing the nonpreferred leg was not significantly increased when the gait was initiated in response to a binaural auditory cue. An auditory cue in the ear contralateral to the preferred leg side weakens the preference for choosing the preferred leg as the initial swing leg in gait initiation when the side of the auditory cue is unpredictable.

Effects of physical activity in Parkinson's disease: A new tool for rehabilitation

Parkinson’s disease (PD) is a common neurodegenerative disease characterized by bradykinesia, tremor, rigidity, and postural instability. Motor disorders are composite and combined, adversely affecting the patient’s health. Tremor and rigidity are correlated with worsening manual dexterity as well as postural changes such as akinesia and camptocormia. Moreover, gait alteration as well as postural instability, with consequent impairment in balance, increase the risk of falls. It is well known that these symptoms respond poorly to pharmacologic therapy in PD patients. Physical therapy is the most effective non-pharmacological aid to PD patients. Available data in the literature indicate that any rehabilitation protocol has to focus on: cognitive movement strategies, cueing strategies, and improved physical capacity and balance. Different training programs for PD patients have been designed and evaluated but only specific training strategies, tailored and individualized for each patient, may produce improvements in gait speed and stride length, decrease motor and balance symptoms and improve quality of life. Furthermore, aerobic training may improve muscle trophism, strength and mobility. It seems reasonable to state that tailored physical activity is a valid tool to be included in the therapeutic program of PD patients, considering that this approach may ameliorate the symptoms as well as the overall physical incapacity, reduce the risk of falls and injuries, and ultimately improve quality of life.

Immediate effects of rhythmic auditory stimulation with tempo changes on gait in stroke patients

[Purpose] The aim of this study was to investigate the effects of tempo changes in rhythmic auditory stimulation (RAS) on gait in stroke patients. [Subjects] Forty-one chronic stroke patients who had had a stroke with more than 6 months previously were recruited for this study. [Methods] All participants were asked to walk under 5 different conditions in random order: (1) no RAS (baseline); (2) baseline-matched RAS (0%); and (3) −10%, (4) +10%, and (5) +20% of the baseline. A GAITRite system was used to evaluate the spatial and temporal parameters of gait. [Results] Compared with under the RAS 0% conditions, the gait velocity, cadence, and stride length on the affected side were significantly decreased under the RAS −10% conditions. Gait velocity and cadence were significantly improved, but gait symmetry was significantly decreased under the RAS +10% and +20% conditions compared with under the RAS 0% conditions. [Conclusion] A faster RAS tempo significantly improved gait velocity and cadence, and applying RAS significantly improved the gait symmetry of stroke patients.

External cues benefit walking ability of ambulatory patients with spinal cord injury

BACKGROUND/OBJECTIVES

Sensorimotor dysfunction following spinal cord injury (SCI) reduces ability of the patients to perceive information and control movements. They may need alternative sources of input to optimize their walking ability. This study investigated effects of external cues on walking ability in 33 independent ambulatory participants with SCI.

METHODS

Participants' walking ability was cross-sectionally assessed under three conditions including self-determined fastest walking speed (uncued condition), and fastest walking speed with the use of external cues (visual cue and visuotemporal cue conditions). Walking ability was measured in terms of walking speed, stride length, cadence, and percent step symmetry. Findings of the three conditions were compared using the one-way analysis of variance with repeated measures.

RESULTS

When using external cues particularly the visuotemporal cue, participants showed a significant increase in walking speed, stride length, and cadence as compared with those of the uncued condition (P < 0.005). The increment of walking speed was demonstrated even in participants at a chronic stage of injury (post-injury time ≥ 12 months), with severe SCI (American Spinal Injury Association Impairment Scale C), or who required a walking device.

CONCLUSION

The results suggested the benefit of external cues, particularly the visuotemporal cues, as a potential rehabilitation tool to improve walking speed of individuals with SCI.