An Educational Program for Remote Training and Supervision of Home-Based Transcranial Electrical Stimulation: Feasibility and Preliminary Effectiveness

OBJECTIVES

There has been recent interest in the administration of transcranial electrical stimulation (tES) by a caregiver, family member, or patient themselves while in their own homes (HB-tES). The need to properly train individuals in the administration of HB-tES is essential, and the lack of a uniform training approach across studies has come to light. The primary aim of this paper is to present the HB-tES training and supervision program, a tele-supervised, instructional, and evaluation program to teach laypersons how to administer HB-tES to a participant and to provide a standardized framework for remote monitoring of participants by teaching staff. The secondary aim is to present early pilot data on the feasibility and effectiveness of the training portion of the program based on its implementation in 379 sessions between two pilot clinical trials.

MATERIALS AND METHODS

The program includes instructional materials, standardized tele-supervised hands-on practice sessions, and a system for remote supervision of participants by teaching staff. Nine laypersons completed the training program. Data on the feasibility and effectiveness of the program were collected.

RESULTS

No adverse events were reported during the training or any of the HB-tES sessions after the training. All laypersons successfully completed the training. The nine laypersons reported being satisfied with the training program and confident in their tES administration capabilities. This was consistent with laypersons requiring technical assistance from teaching staff very infrequently during the 379 completed sessions. The average adherence rate between all administrators was >98%, with seven of nine administrators having 100% adherence to the scheduled sessions.

CONCLUSIONS

These findings indicate that the HB-tES program is effective and is associated with participant satisfaction.

SIGNIFICANCE

We hope that the remote nature of this training program will facilitate increased accessibility to HB-tES research for participants of different demographics and locations. This program, designed for easy adaptation to different HB-tES research applications and devices, also is accessible online. The adoption of this program is expected to facilitate uniformity of study methods among future HB-tES studies and thereby accelerate the pace of tES intervention discovery.

Acceptability of wearable devices for measuring mobility remotely: Observations from the Mobilise-D technical validation study

Background

This study aimed to explore the acceptability of a wearable device for remotely measuring mobility in the Mobilise-D technical validation study (TVS), and to explore the acceptability of using digital tools to monitor health.

Methods

Participants (N = 106) in the TVS wore a waist-worn device (McRoberts Dynaport MM + ) for one week. Following this, acceptability of the device was measured using two questionnaires: The Comfort Rating Scale (CRS) and a previously validated questionnaire. A subset of participants (n = 36) also completed semi-structured interviews to further determine device acceptability and to explore their opinions of the use of digital tools to monitor their health. Questionnaire results were analysed descriptively and interviews using a content analysis.

Results

The device was considered both comfortable (median CRS (IQR; min-max) = 0.0 (0.0; 0-20) on a scale from 0-20 where lower scores signify better comfort) and acceptable (5.0 (0.5; 3.0-5.0) on a scale from 1-5 where higher scores signify better acceptability). Interviews showed it was easy to use, did not interfere with daily activities, and was comfortable. The following themes emerged from participants' as being important to digital technology: altered expectations for themselves, the use of technology, trust, and communication with healthcare professionals.

Conclusions

Digital tools may bridge existing communication gaps between patients and clinicians and participants are open to this. This work indicates that waist-worn devices are supported, but further work with patient advisors should be undertaken to understand some of the key issues highlighted. This will form part of the ongoing work of the Mobilise-D consortium.

Daily-Living Freezing of Gait as Quantified Using Wearables in People With Parkinson Disease: Comparison With Self-Report and Provocation Tests

OBJECTIVE

Freezing of gait (FOG) is an episodic, debilitating phenomenon that is common among people with Parkinson disease. Multiple approaches have been used to quantify FOG, but the relationships among them have not been well studied. In this cross-sectional study, we evaluated the associations among FOG measured during unsupervised daily-living monitoring, structured in-home FOG-provoking tests, and self-report.

METHODS

Twenty-eight people with Parkinson disease and FOG were assessed using self-report questionnaires, percentage of time spent frozen (%TF) during supervised FOG-provoking tasks in the home while off and on dopaminergic medication, and %TF evaluated using wearable sensors during 1 week of unsupervised daily-living monitoring. Correlations between those 3 assessment approaches were analyzed to quantify associations. Further, based on the %TF difference between in-home off-medication testing and in-home on-medication testing, the participants were divided into those responding to Parkinson disease medication (responders) and those not responding to Parkinson disease medication (nonresponders) in order to evaluate the differences in the other FOG measures.

RESULTS

The %TF during unsupervised daily living was mild to moderately correlated with the %TF during a subset of the tasks of the in-home off-medication testing but not the on-medication testing or self-report. Responders and nonresponders differed in the %TF during the personal "hot spot" task of the provoking protocol while off medication (but not while on medication) but not in the total scores of the self-report questionnaires or the measures of FOG evaluated during unsupervised daily living.

CONCLUSION

The %TF during daily living was moderately related to FOG during certain in-home FOG-provoking tests in the off-medication state. However, this measure of FOG was not associated with self-report or FOG provoked in the on-medication state. These findings suggest that to fully capture FOG severity, it is best to assess FOG using a combination of all 3 approaches.

IMPACT

These findings suggest that several complementary approaches are needed to provide a complete assessment of FOG severity.

The Potential of Transcranial Alternating Current Stimulation to Alleviate Dual-Task Gait Costs in Older Adults: Insights from a Double-Blinded Pilot Study

BACKGROUND

The performance of an attention-demanding task while walking, i.e., dual-tasking, leads to dual-task costs (e.g., reduced gait speed) in older adults. Previous studies have shown that dual-task costs in gait are associated with future falls and cognitive decline. According to the communication through coherence hypothesis, transcranial alternating current stimulation (tACS) might help alleviate this problem.

OBJECTIVE

The aim of this study was to examine the effects of a single session of theta-tACS targeting the left fronto-parietal network (L-FPN) on dual-task walking and cognitive function compared to sham stimulation and transcranial direct current stimulation (tDCS) targeting the left dorsolateral prefrontal cortex, a node within the L-FPN.

METHODS

Twenty older adults completed a four-visit, double-blinded, within-subject, cross-over study in which usual-walking, dual-task walking, and cognitive function were evaluated before and immediately after 20 min of tACS, tDCS, or sham (order randomized) stimulation. Dual-task costs to gait speed (primary outcome) and other measures were analyzed.

RESULTS

The dual-task cost to gait speed tended to be lower (i.e., better) after tACS (p = 0.067, Cohen's d = 0.433∼small); tDCS significantly reduced this dual-task cost (p = 0.012, Cohen's d = 0.618∼medium), and sham stimulation had no effect (p = 0.467). tACS significantly reduced the dual-task cost to step length (p = 0.037, Cohen's d = 0.502∼medium); a trend was seen after tDCS (p = 0.069, Cohen's d = 0.443∼small). No statistical differences were found for other measures of gait or cognitive function.

CONCLUSIONS

The positive effects of tACS on dual-task gait speed and step length were roughly similar to those seen with tDCS. These results suggest that tACS affects the fronto-parietal network and, similar to tDCS, tACS may improve dual-tasking. Nonetheless, to achieve larger benefits and differentiate the effects of tACS and tDCS on brain function and dual-task walking in older adults, other stimulation montages and protocols should be tested.

Technical validation of real-world monitoring of gait: a multicentric observational study

INTRODUCTION

Existing mobility endpoints based on functional performance, physical assessments and patient self-reporting are often affected by lack of sensitivity, limiting their utility in clinical practice. Wearable devices including inertial measurement units (IMUs) can overcome these limitations by quantifying digital mobility outcomes (DMOs) both during supervised structured assessments and in real-world conditions. The validity of IMU-based methods in the real-world, however, is still limited in patient populations. Rigorous validation procedures should cover the device metrological verification, the validation of the algorithms for the DMOs computation specifically for the population of interest and in daily life situations, and the users' perspective on the device.

METHODS AND ANALYSIS

This protocol was designed to establish the technical validity and patient acceptability of the approach used to quantify digital mobility in the real world by Mobilise-D, a consortium funded by the European Union (EU) as part of the Innovative Medicine Initiative, aiming at fostering regulatory approval and clinical adoption of DMOs.After defining the procedures for the metrological verification of an IMU-based device, the experimental procedures for the validation of algorithms used to calculate the DMOs are presented. These include laboratory and real-world assessment in 120 participants from five groups: healthy older adults; chronic obstructive pulmonary disease, Parkinson's disease, multiple sclerosis, proximal femoral fracture and congestive heart failure. DMOs extracted from the monitoring device will be compared with those from different reference systems, chosen according to the contexts of observation. Questionnaires and interviews will evaluate the users' perspective on the deployed technology and relevance of the mobility assessment.

ETHICS AND DISSEMINATION

The study has been granted ethics approval by the centre's committees (London-Bloomsbury Research Ethics committee; Helsinki Committee, Tel Aviv Sourasky Medical Centre; Medical Faculties of The University of Tübingen and of the University of Kiel). Data and algorithms will be made publicly available.

TRIAL REGISTRATION NUMBER

ISRCTN (12246987).

Protocol for the DeFOG trial: A randomized controlled trial on the effects of smartphone-based, on-demand cueing for freezing of gait in Parkinson's disease

Background

Freezing of gait (FOG) is a highly incapacitating symptom that affects many people with Parkinson's disease (PD). Cueing triggered upon real-time FOG detection (on-demand cueing) shows promise for FOG treatment. Yet, the feasibility of implementation and efficacy in daily life is still unknown. Therefore, this study aims to investigate the effectiveness of DeFOG: a smartphone and sensor-based on-demand cueing solution for FOG.

Methods

Sixty-two PD patients with FOG will be recruited for this single-blind, multi-center, randomized controlled phase II trial. Patients will be randomized into either the intervention group or the active control group. For four weeks, both groups will receive feedback about their physical activity using the wearable DeFOG system in daily life. In addition, the intervention group will also receive on-demand auditory cueing and instructions. Before and after the intervention, home-based assessments will be performed to evaluate the primary outcome, i.e., “percentage time frozen” during a FOG-provoking protocol. Secondary outcomes include the training effects on physical activity monitored over 7 days and the user-friendliness of the technology.

Discussion

The DeFOG trial will investigate the effectiveness of personalized on-demand cueing in a controlled design, delivered for 4 weeks in the patient's home environment. We anticipate that DeFOG will reduce FOG to a greater degree than in the control group and we will explore the impact of the intervention on physical activity levels. We expect to gain in-depth insight into whether and how patients control FOG using cueing methods in their daily lives.

Trial registration

Clinicaltrials.gov NCT03978507.

Targeted tDCS Mitigates Dual-Task Costs to Gait and Balance in Older Adults

OBJECTIVE

Among older adults, the ability to stand or walk while performing cognitive tasks (ie, dual-tasking) requires coordinated activation of several brain networks. In this multicenter, double-blinded, randomized, and sham-controlled study, we examined the effects of modulating the excitability of the left dorsolateral prefrontal cortex (L-DLPFC) and the primary sensorimotor cortex (SM1) on dual-task performance "costs" to standing and walking.

METHODS

Fifty-seven older adults without overt illness or disease completed 4 separate study visits during which they received 20 minutes of transcranial direct current stimulation (tDCS) optimized to facilitate the excitability of the L-DLPFC and SM1 simultaneously, or each region separately, or neither region (sham). Before and immediately after stimulation, participants completed a dual-task paradigm in which they were asked to stand and walk with and without concurrent performance of a serial-subtraction task.

RESULTS

tDCS simultaneously targeting the L-DLPFC and SM1, as well as tDCS targeting the L-DLPFC alone, mitigated dual-task costs to standing and walking to a greater extent than tDCS targeting SM1 alone or sham (p < 0.02). Blinding efficacy was excellent and participant subjective belief in the type of stimulation received (real or sham) did not contribute to the observed functional benefits of tDCS.

INTERPRETATION

These results demonstrate that in older adults, dual-task decrements may be amenable to change and implicate L-DPFC excitability as a modifiable component of the control system that enables dual-task standing and walking. tDCS may be used to improve resilience and the ability of older results to walk and stand under challenging conditions, potentially enhancing everyday functioning and reducing fall risks. ANN NEUROL 2021.

Combining transcranial direct current stimulation with a motor-cognitive task: the impact on dual-task walking costs in older adults

Background

The performance of a secondary task while walking increases motor-cognitive interference and exacerbates fall risk in older adults. Previous studies have demonstrated that transcranial direct current stimulation (tDCS) may improve certain types of dual-task performance, and, that tDCS delivered during the performance of a task may augment the benefits of stimulation, potentially reducing motor-cognitive interference. However, it is not yet known if combining multi-target tDCS with the simultaneous performance of a task related to the tDCS targets reduces or increases dual-task walking costs among older adults. The objectives of the present work were (1) To examine whether tDCS applied during the performance of a task that putatively utilizes the brain networks targeted by the neuro-stimulation reduces dual-task costs, and (2) to compare the immediate after-effects of tDCS applied during walking, during seated-rest, and during sham stimulation while walking, on dual-task walking costs in older adults. We also explored the impact on postural sway and other measures of cognitive function.

Methods

A double-blind, ‘within-subject’ cross-over pilot study evaluated the effects of 20 min of anodal tDCS targeting both the primary motor cortex (M1) and the left dorsolateral prefrontal cortex (lDLPFC) in 25 healthy older adults (73.9 ± 5.2 years). Three stimulation conditions were assessed in three separate sessions: (1) tDCS while walking in a complex environment (tDCS + walking), (2) tDCS while seated (tDCS + seated), and (3) walking in a complex environment with sham tDCS (sham + walking). The complex walking condition utilized virtual reality to tax motor and cognitive abilities. During each session, usual-walking, dual-task walking, quiet standing sway, and cognitive function (e.g., Stroop test) were assessed before and immediately after stimulation. Dual-task costs to gait speed and other measures were computed.

Results

The dual-task cost to gait speed was reduced after tDCS + walking (p = 0.004) as compared to baseline values. Neither tDCS + seated (p = 0.173) nor sham + walking (p = 0.826) influenced this outcome. Similar results were seen for other gait measures and for Stroop performance. Sway was not affected by tDCS.

Conclusions

tDCS delivered during the performance of challenging walking decreased the dual-task cost to walking in older adults when they were tested just after stimulation. These results support the existence of a state-dependent impact of neuro-modulation that may set the stage for a more optimal neuro-rehabilitation.

Trial registration: Clinical Trials Gov Registrations Number: NCT02954328.

Combining tDCS With a Motor-Cognitive Task to Reduce the Negative Impact of Dual-Tasking on the Gait of Older Adults

The simultaneous performance of a secondary task while walking (i.e., dual tasking) increases motor-cognitive interference and fall risk in older adults. Combining transcranial direct current stimulation (tDCS) with the concurrent performance of a task that putatively involves the same brain networks targeted by the tDCS may reduce the negative impact of dual-tasking on walking. We examined whether tDCS applied while walking reduces the dual-task costs to gait and whether this combination is better than tDCS alone or walking alone (with sham stimulation). In 25 healthy older adults (aged 75.7±10.5yrs), a double-blind, within-subject, cross-over pilot study evaluated the acute after-effects of 20 minutes of tDCS targeting the primary motor cortex and the dorsal lateral pre frontal cortex during three separate sessions:1) tDCS while walking on a treadmill in a virtual-reality environment (tDCS+walking), 2) tDCS while seated (tDCS+seated), and 3) walking in the virtual-reality environment with sham tDCS (sham+walking). The complex walking condition taxed motor and cognitive abilities. During each session, single- and dual-task walking and cognitive function were assessed before and immediately after stimulation. Compared to pre-tDCS performance, tDCS+walking reduced the dual-task cost to gait speed (p=0.004) and other gait features (e.g., variability p=0.02), and improved (p<0.001) executive function (Stroop interference score). tDCS+seated and sham+walking did not affect the dual-task cost to gait speed (p>0.17). These initial findings demonstrate that tDCS delivered during challenging walking ameliorates dual-task gait and executive function in older adults, suggesting that the concurrent performance of related tasks enhances the efficacy of the neural stimulation and mobility.

Validation of the Hebrew Version of the Unified Dyskinesia Rating Scale

BACKGROUND

The Unified Dyskinesia Rating Scale (UDysRS) is a well-established tool for producing comprehensive assessments of severity and disability associated with dyskinesia in patients with Parkinson's disease (PD). The scale was originally developed in English, and a broad international effort has been undertaken to develop and validate versions in additional languages. Our aim was to validate the Hebrew version of the UDysRS.

METHODS

We translated the UDysRS into Hebrew, back-translated it into English, and carried out cognitive pretesting. We then administered the scale to non-demented native Hebrew-speaking patients who fulfilled the Brain Bank diagnostic criteria for probable PD (n = 250). Data were compared to the Reference Standard data used for validating UDysRS translations.

RESULTS

The different portions of the Hebrew UDysRS showed high internal consistency (α ≥ 0.92). A confirmatory factor analysis in which we compared the Hebrew UDysRS to the Reference Standard version produced a comparative fit index (CFI) of 0.98, exceeding the threshold criterion of CFI > 0.9 indicating factor validity. A secondary exploratory factor analysis provided further support to the consistency between the factor structures of the Hebrew and Reference Standard versions of the UDysRS.

CONCLUSION

The UDysRS Hebrew version shows strong clinimetric properties and fulfills the criteria for designation as an official International Parkinson and Movement Disorder Society-approved translation for use in clinical and research settings.

Advantages of timing the duration of a freezing of gait-provoking test in individuals with Parkinson's disease

Evaluating freezing of gait (FOG) and quantifying its severity in patients with Parkinson's disease (PD) is challenging; objective assessment is not sufficiently established. We aimed to improve the ability to objectively evaluate FOG severity by investigating the value of measuring the duration of the test and its components. Seventy-one patients with PD and FOG completed a previously validated FOG-provoking test. The test was performed under three conditions: (1) usual, single task; (2) dual task (walking while carrying a tray); and (3) triple task (walking while holding a tray and subtracting 7 s). FOG and festination were scored using standard procedures. We evaluated effect sizes based on both the original scoring and the test duration for the motor-cognitive cost and before and after anti-Parkinsonian medication intake. Additionally, video recording of the test and total time frozen were measured. As expected, the original test score and the test duration increased across the three conditions of the task and were higher in OFF than in the ON-medication state (p < 0.036). For motor-cognitive cost, higher effect sizes were observed for the test duration of each condition, compared to the original scoring in OFF state (0.85 vs. 0.68, respectively). Change in effect size category was more pronounced in the ON state vs. OFF (0.87 vs. 0.55, respectively). Test duration was the only independent predictor for the self-report of FOG severity and the total time frozen during the test. These findings suggest that quantifying the duration of each condition of the FOG-provoking test improves its sensitivity to medications and task complexity. Timing can be used to provide immediate, objective feedback of freezing severity, and a clear interpretation of a patient's performance.

TARGETED TRANSCRANIAL DIRECT CURRENT STIMULATION IMPROVES DUAL-TASK WALKING PERFORMANCE IN OLDER ADULTS

In older adults, the ability to walk while engaged in an unrelated cognitive task (i.e., dual tasking) depends upon activation of both motor and cognitive brain networks. Noninvasive transcranial direct current stimulation (tDCS) can facilitate the excitability of specific brain regions and their connected neural networks. In this multi-site, randomized controlled within-subject cross-over study, we tested the effects of single, 20-minute sessions of tDCS targeting 1) the primary motor cortex (M1), 2) the left dorsolateral prefrontal cortex (dlPFC, a primary region subserving cognitive function), 3) both M1 and left dlPFC, or 4) neither region (sham). Forty-eight older adults free of overt illness or disease (mean±SD age=75±6 years, 35 women) completed four study visits at least 72 hours apart, during which dual task gait was assessed before and after tDCS administration. Stimulation was delivered using the Starstim™ system (Neuroelectrics Corp) and the same array of six gel electrodes to ensure double-blinding. Participants were successfully blinded to tDCS condition and reported no unexpected tDCS side effects. Repeated-measures ANOVAs adjusted for age and sex revealed that the dual task cost to gait speed was smaller (i.e., better and closer to zero) following tDCS that targeted both M1 and the left dlPFC, as well as the left dlPFC alone, compared to all other time points (condition-time interaction: F=3.0, p=0.04). The dual task costs following these two types of stimulation were similar. These results suggest that noninvasive facilitation of cognitive-motor brain network excitability leads to acute improvement in dual task performance in older adults.

Virtual reality training to enhance behavior and cognitive function among children with attention-deficit/hyperactivity disorder: brief report

Purpose: To examine the feasibility and efficacy of a combined motor-cognitive training using virtual reality to enhance behavior, cognitive function and dual-tasking in children with Attention-Deficit/Hyperactivity Disorder (ADHD). Methods: Fourteen non-medicated school-aged children with ADHD, received 18 training sessions during 6 weeks. Training included walking on a treadmill while negotiating virtual obstacles. Behavioral symptoms, cognition and gait were tested before and after the training and at 6-weeks follow-up. Results: Based on parental report, there was a significant improvement in children's social problems and psychosomatic behavior after the training. Executive function and memory were improved post-training while attention was unchanged. Gait regularity significantly increased during dual-task walking. Long-term training effects were maintained in memory and executive function. Conclusion: Treadmill-training augmented with virtual-reality is feasible and may be an effective treatment to enhance behavior, cognitive function and dual-tasking in children with ADHD.

SPARC: a new approach to quantifying gait smoothness in patients with Parkinson's disease

BACKGROUND

Impairments in biomechanics and neural control can disrupt the timing and muscle pattern activation necessary for smooth gait. Gait is one of the most affected motor characteristics in Parkinson's disease (PD), but its smoothness has not been well-studied. This work applies the recently proposed spectral arc length measure (SPARC) to study, for the first time, gait in patients with PD. We hypothesized that the gait of patients with PD would be less smooth than that of healthy controls, as reflected in the SPARC measures.

METHODS

The gait of 101 PD patients and 39 healthy controls was assessed using an inertial sensor. Smoothness of gait was estimated with SPARC (respectively from acceleration and angular velocity signals, SPARC-Acc and SPARC-Gyro) and harmonic ratios. Correlations between SPARC, traditional gait measures and the motor part of the Unified Parkinson's Disease Rating Scale (UPDRS) were evaluated. Measurements and analysis were conducted with and without anti-PD medication.

RESULTS

SPARC measures were lower (less smooth) in PD than in controls (SPARC-Acc: PD: - 6.11 ± 0.74; CO: -5.17 ± 0.79; p <  0.001). When comparing PD to controls, SPARC-Acc differed more than other measures of gait (i.e., largest effect size, which was > 1). SPARC measures were correlated with UPDRS motor score (r = - 0.65), while they were independent of other measures of gait smoothness. PD gait in the on state was smoother than in the off state (p <  0.001).

CONCLUSIONS

SPARC calculated from trunk acceleration and angular velocity signals provide valid measures of walking smoothness in PD. SPARC is sensitive to Parkinson's disease and PD medications and can be used of as another, complementary measure of the motor control of walking in PD.

Treadmill walking reduces pre-frontal activation in patients with Parkinson's disease

BACKGROUND

Among patients with Parkinson's disease (PD), gait is typically disturbed and less automatic. These gait changes are associated with impaired rhythmicity and increased prefrontal activation, presumably in an attempt to compensate for reduced automaticity.

RESEARCH QUESTION

We investigated whether during treadmill walking, when the pace is determined and fixed, prefrontal activation in patients with PD is lower, as compared to over-ground walking.

METHODS

Twenty patients with PD (age: 69.8 ± 6.5 yrs.; MoCA: 26.9 ± 2.4; disease duration: 7.9 ± 4.2 yrs) walked at a self-selected walking speed over-ground and on a treadmill. A wireless functional near infrared spectroscopy (fNIRS) system measured prefrontal lobe activation, i.e., oxygenated hemoglobin (Hb02) in the pre-frontal area. Gait was evaluated using 3D-accelerometers attached to the lower back and ankles (Opal™, APDM). Dynamic gait stability was assessed using the maximum Lyapunov exponent to investigate automaticity of the walking pattern.

RESULTS

Hb02 was lower during treadmill walking than during over-ground walking (p = 0.001). Gait stability was greater on the treadmill, compared to over-ground walking, in both the anteroposterior and medio-lateral axes (p < 0.001).

SIGNIFICANCE

These findings support the notion that when gait is externally paced, prefrontal lobe activation is reduced in patients with PD, perhaps reflecting a reduced need for compensatory cognitive mechanisms.

Validation of the Hebrew version of the Movement Disorder Society-Unified Parkinson's Disease Rating Scale

BACKGROUND

The Movement Disorders Society (MDS) published the English new Unified Parkinson's Disease Rating Scale (MDS-UPDRS) as the official benchmark scale for Parkinson's disease (PD) in 2008. We aimed to validate the Hebrew version of the MDS-UPDRS, explore its dimensionality and compare it to the original English one.

METHODS

The MDS-UPDRS questionnaire was translated to Hebrew and was tested on 389 patients with PD, treated at the Movement Disorders Unit at Tel-Aviv Medical Center. The MDS-UPDRS is made up of four sections. The higher the score, the worst the clinical situation of the patient is. Confirmatory and explanatory factor analysis were applied to determine if the factor structure of the English version could be confirmed in the Hebrew version.

RESULTS

The Hebrew version of the MDS-UPDRS showed satisfactory clinimetric properties. The internal consistency of the Hebrew-version was satisfactory, with Cronbach's alpha values 0.79, 0.90, 0.93, 0.80, for parts 1 to 4 respectively. In the confirmatory factor analysis, all four parts had high (greater than 0.90) comparative fit index (CFI) in comparison to the original English MDS-UPDRS with high factor structure (0.96, 0.99, 0.94, 1.00, respectively), thus confirming the pre-specified English factor structure. Explanatory factor analysis yielded that the Hebrew responses differed from the English one within an acceptable range: in isolated item differences in factor structure and in the findings of few items having cross loading on multiple factors.

CONCLUSIONS

The Hebrew version of the MDS-UPDRS meets the requirements to be designated as the Official Hebrew Version of the MDS-UPDRS.

Vertical ground reaction force during standing and walking: Are they related to bone mineral density left-right asymmetries?

Osteoporosis is a systemic skeletal disease that is characterized by reduced bone mass, deterioration of bone tissue and skeletal fragility. The purpose of the current study was to determine whether asymmetrical femur bone mineral density (BMD) is associated with asymmetrical gait and standing. We compared measures of gait and standing asymmetry in subjects with (n=38) and without (n=11) significant left-right differences in BMD. Participants walked for 72m at their comfortable speed and stood quietly for 60s while outfitted with pressure-sensitive insoles. Based on the pressure measurements, indices of standing and gait asymmetry were determined. Gait Asymmetry (GA) indices of maximum ground reaction force (GRF) and stance time were significantly higher in the asymmetrical BMD group, compared to the symmetrical group (p<0.03). During quiet standing, maximal GRF was twice as high in those with BMD asymmetry, compared to those without, although this difference was not statistically significant (p=0.10). These preliminary findings indicate that femur BMD asymmetry and gait asymmetry are interrelated in otherwise healthy adults. Nutrition, metabolism and lifestyle are known contributors to BMD; typically, they affect bone health symmetrically. We suggest, therefore, that the BMD asymmetry may be due to previous changes in the loading pattern during walking that might have led to asymmetric bone deterioration. Future larger scale and prospective studies are needed to identify the mechanisms underlying the relationship between standing, gait and BMD and to explore whether gait training and exercises that target gait symmetry might help to reduce BMD asymmetry.

Can a single lower trunk body-fixed sensor differentiate between level-walking and stair descent and ascent in older adults? Preliminary findings

Stair ascent and descent are common forms of ambulation that may be challenging to detect. Here, we propose the first step towards differentiating between stair negotiation and level-walking using a single body-fixed sensor. Seventeen healthy older adults (age: 79.3±4.2 years, 47% women) wore a body-fixed sensor on the lower-back while performing level-walking and stair negotiation. Measures derived from the 3D acceleration and angular-velocity signals included medians, ranges, step duration, step and stride regularity, filtered vertical to horizontal acceleration ratio (VAF/HAF), and wavelet-based features. Friedman's and Wilcoxon tests compared between conditions. Stepwise-binary logistic-regression evaluated classification accuracy. During level-walking, yaw range was lowest and anterior-posterior and vertical step and stride regularity were highest (p≤0.007). Anterior-posterior step regularity (p=0.003), VAF/HAF (p=0.094), and yaw range (p=0.105) identified level-walking (92.2% accuracy). During stair ascent, roll range, median anterior-posterior acceleration and anterior-posterior wavelet-coefficient were lowest (p≤0.006), while VAF/HAF was highest (p=0.0029). Anterior posterior wavelet coefficient (p=0.038) and VAF/HAF (p=0.018) identified stair ascent (94.3% accuracy). During stair descent, vertical and medio-lateral ranges were highest and medio-lateral stride regularity and VAF/HAF were lowest (p≤0.006). VAF/HAF (p=0.01), medio-lateral acceleration range (p=0.069), and medio-lateral stride regularity (p=0.072) identified stair descent (90.2% accuracy). These findings suggest that a single worn body-fixed sensor can be used to differentiate between level-walking and stair negotiation.

Automated detection of missteps during community ambulation in patients with Parkinson's disease: a new approach for quantifying fall risk in the community setting

BACKGROUND

Falls are a leading cause of morbidity and mortality among older adults and patients with neurological disease like Parkinson's disease (PD). Self-report of missteps, also referred to as near falls, has been related to fall risk in patients with PD. We developed an objective tool for detecting missteps under real-world, daily life conditions to enhance the evaluation of fall risk and applied this new method to 3 day continuous recordings.

METHODS

40 patients with PD (mean age ± SD: 62.2 ± 10.0 yrs, disease duration: 5.3 ± 3.5 yrs) wore a small device that contained accelerometers and gyroscopes on the lower back while participating in a protocol designed to provoke missteps in the laboratory. Afterwards, the subjects wore the sensor for 3 days as they carried out their routine activities of daily living. An algorithm designed to automatically identify missteps was developed based on the laboratory data and was validated on the 3 days recordings.

RESULTS

In the laboratory, we recorded 29 missteps and more than 60 hours of data. When applied to this dataset, the algorithm achieved a 93.1% hit ratio and 98.6% specificity. When we applied this algorithm to the 3 days recordings, patients who reported two falls or more in the 6 months prior to the study (i.e., fallers) were significantly more likely to have a detected misstep during the 3 day recordings (p = 0.010) compared to the non-fallers.

CONCLUSIONS

These findings suggest that this novel approach can be applied to detect missteps during daily life among patients with PD and will likely help in the longitudinal assessment of disease progression and fall risk.

Does the Evaluation of Gait Quality During Daily Life Provide Insight Into Fall Risk? A Novel Approach Using 3-Day Accelerometer Recordings

Background. Many approaches are used to evaluate fall risk. While their properties and performance vary, most reflect performance at a specific moment or are based on subjective self-report. Objective. To quantify fall risk in the home setting using an accelerometer. Methods. Seventy-one community-living older adults were studied. In the laboratory, fall risk was assessed using performance-based tests of mobility (eg, Timed Up and Go) and usual walking abilities were quantified. Subsequently, subjects wore a triaxial accelerometer on their lower back for 3 consecutive days. Acceleration-derived measures were extracted from segments that reflected ambulation. These included total activity duration, number of steps taken, and the amplitude and width at the dominant frequency in the power spectral density, that is, parameters reflecting step-to-step variability. Afterwards, self-report of falls was collected for 6 months to explore the predictive value. Results. Based on a history of 2 or more falls, subjects were classified as fallers or nonfallers. The number of steps during the 3 days was similar ( P = .42) in the fallers (7842.1 ± 6135.6) and nonfallers (9055.3 ± 6444.7). Compared with the nonfallers, step-to-step consistency was lower in the fallers in the vertical axis (amplitude fallers, 0.58 ± 0.22 psd; nonfallers, 0.71 ± 0.18 psd; P = .008); in the mediolateral axis, step-to-step consistency was higher in the fallers ( P = .014). The 3-day measures improved the identification of past and future falls status ( P < .005), compared to performance-based tests. Conclusions. Accelerometer-derived measures based on 3-day recordings are useful for evaluating fall risk as older adults perform daily living activities in their everyday home environment.

Executive function and falls in older adults: new findings from a five-year prospective study link fall risk to cognition

Background

Recent findings suggest that executive function (EF) plays a critical role in the regulation of gait in older adults, especially under complex and challenging conditions, and that EF deficits may, therefore, contribute to fall risk. The objective of this study was to evaluate if reduced EF is a risk factor for future falls over the course of 5 years of follow-up. Secondary objectives were to assess whether single and dual task walking abilities, an alternative window into EF, were associated with fall risk.

Methodology/Main Results

We longitudinally followed 256 community-living older adults (age: 76.4±4.5 yrs; 61% women) who were dementia free and had good mobility upon entrance into the study. At baseline, a computerized cognitive battery generated an index of EF, attention, a closely related construct, and other cognitive domains. Gait was assessed during single and dual task conditions. Falls data were collected prospectively using monthly calendars. Negative binomial regression quantified risk ratios (RR). After adjusting for age, gender and the number of falls in the year prior to the study, only the EF index (RR: .85; CI: .74–.98, p = .021), the attention index (RR: .84; CI: .75–.94, p = .002) and dual tasking gait variability (RR: 1.11; CI: 1.01–1.23; p = .027) were associated with future fall risk. Other cognitive function measures were not related to falls. Survival analyses indicated that subjects with the lowest EF scores were more likely to fall sooner and more likely to experience multiple falls during the 66 months of follow-up (p<0.02).

Conclusions/Significance

These findings demonstrate that among community-living older adults, the risk of future falls was predicted by performance on EF and attention tests conducted 5 years earlier. The present results link falls among older adults to cognition, indicating that screening EF will likely enhance fall risk assessment, and that treatment of EF may reduce fall risk.

An instrumented timed up and go: the added value of an accelerometer for identifying fall risk in idiopathic fallers

The Timed Up and Go (TUG) test is a widely used measure of mobility and fall risk among older adults that is typically scored using a stopwatch. We tested the hypothesis that a body-fixed accelerometer can enhance the ability of the TUG to identify community-living older adults with a relatively high fall risk of unknown origin. Twenty-three community-living elderly fallers (76.0 ± 3.9 years) and 18 healthy controls (68.3 ± 9.1 years) performed the TUG while wearing a 3D-accelerometer on the lower back. Acceleration-derived parameters included Sit-to-Stand and Stand-to-Sit times, amplitude range (Range), and slopes (Jerk). Average step duration, number of steps, average step length, gait speed, acceleration-median, and standard-deviation were also calculated. While the stopwatch-based TUG duration was not significantly different between the groups, acceleration-derived TUG duration was significantly higher (p = 0.007) among the fallers. Fallers generally exhibited lower Range and Jerk (p < 0.01). While TUG stopwatch duration successfully identified 63% of the subjects, an accelerometer-derived three-measure-combination correctly classified 87% of the subjects. Accelerometer-derived measures were generally not correlated with TUG duration. These findings demonstrate that fallers have difficulty with specific TUG aspects that can be quantified using an accelerometer. Without compromising simplicity of testing, an accelerometer can apparently be combined with TUG duration to provide complementary, objective measures that allow for a more complete, sensitive TUG-based fall risk assessment.