Potential of APDM mobility lab for the monitoring of the progression of Parkinson's disease

Fall Risk Associated with Taxanes: Focus on Chemotherapy-Induced Peripheral Neuropathy

OBJECTIVES

Chemotherapy-induced peripheral neuropathy (CIPN) remains a significant toxicity for women with breast cancer receiving taxane-based treatment. This analysis has been done within the context of an ongoing 16-week randomized clinical trial consisting of a gait, balance, and strength training exercise intervention for the lower extremities in women with persistent CIPN who received taxane-based chemotherapy for breast cancer. The aim of this analysis is to determine the baseline fall risk among 62 study participants with persistent taxane-induced CIPN assigned to the control group.

METHODS

This analysis used the baseline demographic, medical data, nerve conduction, gait, balance, and muscle strength variables of participants prior to randomization to develop an explanatory model of fall risk. The analytic approach utilized generalized linear modeling with Lasso to select baseline risk factors for future falls.

RESULTS

Characteristics of the study sample by intervention and control group revealed no significant differences between the groups at baseline. The only baseline risk factors that were significantly associated with future falls were near falls within the last month (β = 0.90, P = .056) with an odds ratio = 2.46, 95% confidence interval 0.31 to 17, and right ankle plantar flexion torque. (β = 0. 05, P = .006) with an odds ratio = 1.05, 95% confidence interval 1.01 to 1.10. Demographic and medical data, nerve conduction parameters, gait, balance, or muscle strength variables did not significantly influence fall risk in this population.

CONCLUSIONS

The potential for injury and disability from falls is a considerable concern among oncology clinicians and women with breast cancer and persistent CIPN. While falls and fall risk have been previously examined in other studies of breast cancer survivors, the majority of studies fail to capture the occurrence of "near falls" a significant predictor of fall risk. In addition, it is possible that ankle strength may prove to be a potential target for fall prevention in this population. Evidence-based interventions focused on improving neuropathic symptoms, physical function, and quality of life in persons with CIPN are still needed.

IMPLICATION FOR NURSING PRACTICE

Oncology nurses and nurse practitioners should query patients who received taxane-based chemotherapy for not only the incidence and frequency of falls but the occurrence of near falls. A prompt referral to physical therapy may be useful in strengthening the lower extremities to improve balance and prevent falls.

Clinical and physiological risk factors contributing to the restricted mobility in older adults: a longitudinal analysis

BACKGROUND

Mobility limitations (e.g., using wheelchair) have been closely linked to diminished functional independence and quality of life in older adults. The regulation of mobility is pertaining to multiple neurophysiologic and sociodemographic factors. We here aimed to characterize the relationships of these factors to the risk of restricted mobility in older adults.

METHODS

In this longitudinal study, 668 older adults with intact mobility at baseline completed the baseline assessments of clinical characteristics, cognitive function, sleep quality, activities of daily living (ADL), walking performance, beat-to-beat blood pressure, and structural MRI of the brain. Then 506 of them (mean age = 70.7 ± 7.5 years) responded to the follow-up interview on the mobility limitation (as defined by if using wheelchair, cane, or walkers, or being disabled and lying on the bed) after 18 ± 3.5 months. Logistic regression analyses were performed to examine the relationships between the baseline characteristics and the follow-up mobility restriction.

RESULTS

At baseline, compared to intact-mobility group (n = 475), restricted-mobility group (n = 31) were older, with lower score of ADL and the Montreal Cognitive Assessment (MoCA), greater score of Pittsburgh Sleep Quality Index (PSQI), poorer cardio- and cerebral vascular function, and slower walking speeds (ps < 0.05). The logistic regression analysis demonstrated that participants who were with history of falls, uncontrolled-hypertension, and/or greater Fazekas scale (odds ratios (ORs):1.3 ~ 13.9, 95% confidence intervals (CIs) = 1.1 ~ 328.2), walked slower, and/or with lower ADL score (ORs: 0.0026 ~ 0.9; 95%CI: 0.0001 ~ 0.99) at baseline, would have significantly greater risk of restricted mobility (p < 0.05; VIFs = 1.2 ~ 1.9).

CONCLUSIONS

These findings provide novel profile of potential risk factors, including vascular characteristics, psycho-cognitive and motor performance, for the development of restricted mobility in near future in older adults, ultimately helping the design of appropriate clinical and rehabilitative programs for mobility in this population.

Associations Between Music and Dance Relationships, Rhythmic Proficiency, and Spatiotemporal Movement Modulation Ability in Adults with and without Mild Cognitive Impairment

Background

Personalized dance-based movement therapies may improve cognitive and motor function in individuals with mild cognitive impairment (MCI), a precursor to Alzheimer's disease. While age- and MCI-related deficits reduce individuals' abilities to perform dance-like rhythmic movement sequences (RMS)-spatial and temporal modifications to movement-it remains unclear how individuals' relationships to dance and music affect their ability to perform RMS.

Objective

Characterize associations between RMS performance and music or dance relationships, as well as the ability to perceive rhythm and meter (rhythmic proficiency) in adults with and without MCI.

Methods

We used wearable inertial sensors to evaluate the ability of 12 young adults (YA; age = 23.9±4.2 years; 9F), 26 older adults without MCI (OA; age = 68.1±8.5 years; 16F), and 18 adults with MCI (MCI; age = 70.8±6.2 years; 10F) to accurately perform spatial, temporal, and spatiotemporal RMS. To quantify self-reported music and dance relationships and rhythmic proficiency, we developed Music (MRQ) and Dance Relationship Questionnaires (DRQ), and a rhythm assessment (RA), respectively. We correlated MRQ, DRQ, and RA scores against RMS performance for each group separately.

Results

The OA and YA groups exhibited better MRQ and RA scores than the MCI group (p < 0.006). Better MRQ and RA scores were associated with better temporal RMS performance for only the YA and OA groups (r2 = 0.18-0.41; p < 0.045). DRQ scores were not associated with RMS performance in any group.

Conclusions

Cognitive deficits in adults with MCI likely limit the extent to which music relationships or rhythmic proficiency improve the ability to perform temporal aspects of movements performed during dance-based therapies.

Validation of Pelvis and Trunk Range of Motion as Assessed Using Inertial Measurement Units

Trunk and pelvis range of motion (ROM) is essential to perform activities of daily living. The ROM may become limited with aging or with neuromusculoskeletal disorders. Inertial measurement units (IMU) with out-of-the box software solutions are increasingly being used to assess motion. We hypothesize that the accuracy (validity) and reliability (consistency) of the trunk and pelvis ROM during steady-state gait in normal individuals as measured using the Opal APDM 6 sensor IMU system and calculated using Mobility Lab version 4 software will be comparable to a gold-standard optoelectric motion capture system. Thirteen healthy young adults participated in the study. Trunk ROM, measured using the IMU was within 5-7 degrees of the motion capture system for all three planes and within 10 degrees for pelvis ROM. We also used a triad of markers mounted on the sternum and sacrum IMU for a head-to-head comparison of trunk and pelvis ROM. The IMU measurements were within 5-10 degrees of the triad. A greater variability of ROM measurements was seen for the pelvis in the transverse plane. IMUs and their custom software provide a valid and reliable measurement for trunk and pelvis ROM in normal individuals, and important considerations for future applications are discussed.

Associations between music and dance relationships, rhythmic proficiency, and spatiotemporal movement modulation ability in adults with and without mild cognitive impairment

Background

Personalized dance-based movement therapies may improve cognitive and motor function in individuals with mild cognitive impairment (MCI), a precursor to Alzheimer's disease. While age- and MCI-related deficits reduce individuals' abilities to perform dance-like rhythmic movement sequences (RMS)-spatial and temporal modifications to movement-it remains unclear how individuals' relationships to dance and music affect their ability to perform RMS.

Objective

Characterize associations between RMS performance and music or dance relationships, as well as the ability to perceive rhythm and meter (rhythmic proficiency) in adults with and without MCI.

Methods

We used wearable inertial sensors to evaluate the ability of 12 young adults (YA; age=23.9±4.2 yrs; 9F), 26 older adults without MCI (OA; age=68.1±8.5 yrs; 16F), and 18 adults with MCI (MCI; age=70.8±6.2 yrs; 10F) to accurately perform spatial, temporal, and spatiotemporal RMS. To quantify self-reported music and dance relationships and rhythmic proficiency, we developed Music (MRQ) and Dance Relationship Questionnaires (DRQ), and a rhythm assessment (RA), respectively. We correlated MRQ, DRQ, and RA scores against RMS performance for each group separately.

Results

The OA and YA groups exhibited better MRQ and RA scores than the MCI group (p<0.006). Better MRQ and RA scores were associated with better temporal RMS performance for only the YA and OA groups (r2=0.18-0.41; p<0.045). DRQ scores were not associated with RMS performance in any group.

Conclusions

Cognitive deficits in adults with MCI likely limit the extent to which music relationships or rhythmic proficiency improve the ability to perform temporal aspects of movements performed during dance-based therapies.

Examining the validity of smart glasses in measuring spatiotemporal parameters of gait among people with Parkinson's disease

BACKGROUND

Gait impairment is an early marker of Parkinson's disease (PD) and is frequently monitored to evaluate disease progression. Wearable sensors are increasingly being used to quantify gait in the real-world setting among people with PD (pwPD). Particularly, embedding wearables on devices or clothing that are worn daily may represent a useful strategy to improve compliance and regular monitoring of gait.

RESEARCH QUESTION

The current investigation examined the validity of innovative smart glasses to measure gait among pwPD.

METHODS

Participants wore the smart glasses and 6 APDM gait sensors simultaneously, while performing two walking tasks: the 3-meters Timed Up and Go test (TUG) and the 7-meters Stand and Walk (SAW) test. The following spatiotemporal gait parameters were calculated from the data collected using the two different devices: step time, step length, swing percentage, TUG duration, turn duration, and turn velocity.

RESULTS

A total of 31 pwPD (mean age=68.6±8.5 years; 35.48 % female(N=11), mean Unified Parkinson's Disease Rating Scale (UPDRS) total score=32.1±14.7) participated in the study. Smart glasses achieved high validity in measuring step time (ICC=0.92, p=0.01) and TUG duration (ICC=0.96, p=0.03) compared to APDM sensors. On the other hand, the smart glasses did not achieve adequate validity when measuring step length, swing percentage, turn duration or turn velocity.

SIGNIFICANCE

The current study suggests that smart glasses has the potential to measure TUG and step time in individuals living with PD. However, further research is needed to improve algorithms for sensors worn on the head.

Assessment of Mobility Trajectories Using Wearable Inertial Sensors During Autologous Hematopoietic Cell Transplant

OBJECTIVE

This study aimed to characterize mobility patterns using wearable inertial sensors and serial assessment across autologous hematopoietic cell transplant (autoHCT) and investigate the relation between mobility and perceived function in patients with hematologic cancer.

DESIGN

Prospective longitudinal study.

SETTING

Hospital adult transplant clinic followed by discharge.

PARTICIPANTS

78 patients with hematological cancer receiving autoHCT.

MAIN OUTCOME MEASURES

Mobility was measured across 3 clinical phases (pretransplant, pre-engraftment, and post-engraftment) in using inertial sensors worn during prescribed performance tests in the hospital. Perceived function was assessed using validated provider-reported (Eastern Cooperative Oncology Group [ECOG] Performance Status Scale) and patient-reported [European Organization for Research and Treatment of Cancer Quality of Life Questionnaire [EORTC QLQ-C30]) measures. Trajectories of 5 selected mobility characteristics (turn duration, gait speed, stride time variability, double support time, and heel strike angle) across the clinical phases were also evaluated using piecewise linear mixed-effects models.

RESULTS

Using Principal Components Analysis, 4 mobility patterns were identified pretransplant: Gait Limitation, Sagittal Sway, Coronal Sway, and Balance Control. Gait Limitation measured pretransplant was significantly inversely associated with perceived function reported by the provider- (β = -0.11; 95% CI: -0.19, -0.02) and patient- (β = -4.85; 95% CI: -7.72, -1.99) post-engraftment in age-adjusted linear regression models. Mobility characteristics demonstrated immediate declines early pre-engraftment with stabilization by late pre-engraftment.

CONCLUSION

Patients with hematological cancer experiencing gait limitations pretransplant are likely to have worse perceived function post-engraftment. Mobility declines in early phases post-transplant and may not fully recover, indicating an opportunity for timely rehabilitation referrals. Wearable inertial sensors can be used to identify early mobility problems and patients who may be at risk for future functional decline who may be candidates for early physical rehabilitation.

Behavioural change for Parkinson's Disease: A randomised controlled feasibility study to promote physical activity and exercise adherence among people with Parkinson's: study protocol

Background

Parkinson's is a common progressive neurological condition characterized by motor and non-motor deficits. Physical activity and exercise can improve health, but many people with Parkinson's (PwP) have trouble reaching the recommended dosage. Our recent literature review found improvements in exercise adherence with behavioural change interventions, but it remains unclear which are most effective. Further qualitative research and patient and public involvement has informed a novel behavioural change intervention to be tested alongside an existing exercise program.

Objective

To examine the feasibility of behavioural change techniques delivered alongside an exercise programme to improve physical activity, function, and self-efficacy in PwP (and study procedures) to inform a future pilot RCT trial.

Methods

A parallel-arm single blinded randomised feasibility study. Twenty participants with Parkinson's (Hoehn and Yahr stage 1-3) will be recruited from a physiotherapy primary-care waiting list. Following written consent, and baseline assessment, the participants will be randomly allocated to the intervention (n=10) or the control group (n=10). Both groups will receive usual care, which includes a weekly program of a multidisciplinary education, a supervised exercise class and a prescribed home exercise program. The intervention group will receive additional behavioural change techniques, targeting behaviour regulation, belief about capabilities and social influences. Class and home exercise adherence, behavioural component uptake and adherence, and negative events will be recorded. Outcomes will include enrolment and maintenance rates, physical function, falls, physical activity, and exercise self-efficacy measured pre- and post- the 12-week program (in-person). Surveys will be used to compare experiences and satisfaction between groups. Exit interviews will be completed with the intervention group only, exploring their experience of the behavioural change techniques.

Discussion

The results will help inform a future pilot RCT, based on the intervention acceptability, consent rate, maintenance, and protocol integrity.

Trial Registration

ClincialTrials.gov NCT06192628.

International validation of meaningfulness of postural sway and gait to assess myeloneuropathy in adults with adrenoleukodystrophy

BACKGROUND

The most common manifestation of X-linked adrenoleukodystrophy (ALD) is a slowly progressive myeloneuropathy, which leads to imbalance and gait disturbances. The variable progression of the disease complicates evaluation of its progression rate. Wearable sensors allow for easy and frequent balance and gait collection. This study reports baseline data from a longitudinal study on the quantitative assessment of balance and gait with wearable sensors and their clinical relevance.

METHODS

Data were collected from adult patients in two institutions. Postural body sway and gait parameters were measured using accelerometers. Disease severity was measured by the Expanded Disability Severity Scale (EDSS). Falling frequency and quality of life (QOL) were collected in men. The relationship between sway and gait variables and EDSS score, participants' use of a walking aid, and falling frequency was evaluated.

RESULTS

One hundred twenty individuals with ALD were included. Sway variables significantly differentiate participants' assistive device use. Sway and gait variables were correlated to the EDSS in both sexes. Both gait speed and sway were correlated with falling frequency in men from one institution. Select QOL subscores were correlated with the EDSS in males from one institution. Accelerometry generated comparable results across sites.

DISCUSSION

This study confirms the clinical correlation between spinal cord disease and imbalance and gait in ALD. For the first time, this study shows clinically meaningful relationships for sway and gait with use of an assistive device, falling frequency and QOL. Wearable accelerometers are a valid means to measure sway and gait in ALD. These measures are promising outcomes for clinical trial designs to assess myeloneuropathy in ALD and to monitor disease progression in individuals.

Validity and reliability of inertial measurement units for gait assessment within a post stroke population

BACKGROUND

The ability to objectively measure spatiotemporal metrics within individuals post-stroke is integral to plan appropriate intervention, track recovery, and ultimately improve efficacy of rehabilitation programs. Inertial measurement units (IMUs) provide a means to systematically collect gait-specific metrics that could not otherwise be obtained from clinical outcomes. However, the use of IMUs to measure spatiotemporal parameters in stroke survivors has yet to be validated. The purpose of this study is to determine the validity and reliability of IMU-recorded spatiotemporal gait metrics as compared to a motion capture camera system (MCCS) in individuals post-stroke.

METHODS

Participants (n = 23, M/F = 12/11, mean (SD) age = 50.2(11.1) spatiotemporal data were collected simultaneously from a MCCS and APDM Opal IMUs during a five-minute treadmill walking task at a self-selected speed. Criterion validity and test-retest reliability were assessed using Lin's concordance correlation coefficients (CCCs) and intraclass correlation coefficients (ICCs), respectively. Spatiotemporal values from MCCS and IMU were used to calculate gait asymmetry, and a t-test was used to assess the difference between asymmetry values.

RESULTS

There were fair-to-excellent agreement between IMU and MCCS of temporal parameters (CCC 0.56-0.98), excellent agreement of spatial parameters (CCC >0.90), and excellent test-retest reliability for all parameters (ICC >0.90).

CONCLUSIONS

Compared to motion capture, the APDM Opal IMUs produced accurate and reliable measures of spatiotemporal parameters. Findings support the use of IMUs to assess spatiotemporal parameters in individual's post-stroke.

Improved measurement of disease progression in people living with early Parkinson's disease using digital health technologies

BACKGROUND

Digital health technologies show promise for improving the measurement of Parkinson's disease in clinical research and trials. However, it is not clear whether digital measures demonstrate enhanced sensitivity to disease progression compared to traditional measurement approaches.

METHODS

To this end, we develop a wearable sensor-based digital algorithm for deriving features of upper and lower-body bradykinesia and evaluate the sensitivity of digital measures to 1-year longitudinal progression using data from the WATCH-PD study, a multicenter, observational digital assessment study in participants with early, untreated Parkinson's disease. In total, 82 early, untreated Parkinson's disease participants and 50 age-matched controls were recruited and took part in a variety of motor tasks over the course of a 12-month period while wearing body-worn inertial sensors. We establish clinical validity of sensor-based digital measures by investigating convergent validity with appropriate clinical constructs, known groups validity by distinguishing patients from healthy volunteers, and test-retest reliability by comparing measurements between visits.

RESULTS

We demonstrate clinical validity of the digital measures, and importantly, superior sensitivity of digital measures for distinguishing 1-year longitudinal change in early-stage PD relative to corresponding clinical constructs.

CONCLUSIONS

Our results demonstrate the potential of digital health technologies to enhance sensitivity to disease progression relative to existing measurement standards and may constitute the basis for use as drug development tools in clinical research.

Effects of Continuous Dopaminergic Stimulation on Parkinson's Disease Gait: A Longitudinal Prospective Study with Levodopa Intestinal Gel Infusion

Background

Gait issues, including reduced speed, stride length and freezing of gait (FoG), are disabling in advanced phases of Parkinson's disease (PD), and their treatment is challenging. Levodopa/carbidopa intestinal gel (LCIG) can improve these symptoms in PD patients with suboptimal control of motor fluctuations, but it is unclear if continuous dopaminergic stimulation can further improve gait issues, independently from reducing Off-time.

Objective

To analyze before (T0) and after 3 (T1) and 6 (T2) months of LCIG initiation: a) the objective improvement of gait and balance; b) the improvement of FoG severity; c) the improvement of motor complications and their correlation with changes in gait parameters and FoG severity.

Methods

This prospective, longitudinal 6-months study analyzed quantitative gait parameters using wearable inertial sensors, FoG with the New Freezing of Gait Questionnaire (NFoG-Q), and motor complications, as per the MDS-UPDRS part IV scores.

Results

Gait speed and stride length increased and duration of Timed up and Go and of sit-to-stand transition was significantly reduced comparing T0 with T2, but not between T0-T1. NFoG-Q score decreased significantly from 19.3±4.6 (T0) to 11.8±7.9 (T1) and 8.4±7.6 (T2) (T1-T0 p = 0.018; T2-T0 p < 0.001). Improvement of MDS-UPDRS-IV (T0-T2, p = 0.002, T0-T1 p = 0.024) was not correlated with improvement of gait parameters and NFoG-Q from T0 to T2. LEDD did not change significantly after LCIG initiation.

Conclusion

Continuous dopaminergic stimulation provided by LCIG infusion progressively ameliorates gait and alleviates FoG in PD patients over time, independently from improvement of motor fluctuations and without increase of daily dosage of dopaminergic therapy.

Validity and reliability of the DANU sports system for walking and running gait assessment

Objective. Gait assessments have traditionally been analysed in laboratory settings, but this may not reflect natural gait. Wearable technology may offer an alternative due to its versatility. The purpose of the study was to establish the validity and reliability of temporal gait outcomes calculated by the DANU sports system, against a 3D motion capture reference system.Approach. Forty-one healthy adults (26 M, 15 F, age 36.4 ± 11.8 years) completed a series of overground walking and jogging trials and 60 s treadmill walking and running trials at various speeds (8-14 km hr-1), participants returned for a second testing session to repeat the same testing.Main results. For validity, 1406 steps and 613 trials during overground and across all treadmill trials were analysed respectively. Temporal outcomes generated by the DANU sports system included ground contact time, swing time and stride time all demonstrated excellent agreement compared to the laboratory reference (intraclass correlation coefficient (ICC) > 0.900), aside from ground contact time during overground jogging which had good agreement (ICC = 0.778). For reliability, 666 overground and 511 treadmill trials across all speeds were examined. Test re-test agreement was excellent for all outcomes across treadmill trials (ICC > 0.900), except for swing time during treadmill walking which had good agreement (ICC = 0.886). Overground trials demonstrated moderate to good test re-test agreement (ICC = 0.672-0.750), which may be due to inherent variability of self-selected (rather than treadmill set) pacing between sessions.Significance. Overall, this study showed that temporal gait outcomes from the DANU Sports System had good to excellent validity and moderate to excellent reliability in healthy adults compared to an established laboratory reference.

Exploring mobility dysfunction in people with and without impaired cognition in Parkinson disease

INTRODUCTION

The relationship between mobility and cognition has been studied in the aging population and associations have been also reported in people with Parkinson's disease (PD).

OBJECTIVE

To compare different aspects of gait and balance between individuals with PD who have normal cognition and those with impaired cognition, using both clinical and instrumented measures.

METHODS

One-hundred forty-three participants with PD were divided into two groups: 1) normal cognition (n = 71) and 2) impaired cognition (n = 72) based on the Montreal Cognitive Assessment (MoCA) cut-off. Groups were compared using instrumented and clinical measures of gait and balance in the following domains: Sensory Orientation, Anticipatory Postural Adjustments, Automatic Postural Responses and Dynamic Balance for Gait. Instrumented measures were obtained via wearable sensors while performing eight different motor tasks and clinical measures were obtained with the Mini-BESTest.

RESULTS

The total Mini-BESTest score was not different between groups. However, the Dynamic Gait domain was worse in individuals with impaired cognition. Among the instrumented measures across domains, all significant group differences were in the Dynamic Gait domain, specifically, dual-task gait speed, dual-task stride length, stance time, and turn velocity.

CONCLUSIONS

Dynamic balance during gait was more impaired in people with PD who had abnormal cognition than those with normal cognition, for both clinical and instrumented measures. All other balance domains did not differ between groups, for both instrumented and clinical measures.

Validity and reliability of a commercial wearable sensor system for measuring spatiotemporal gait parameters in a post-stroke population: the effects of walking speed and asymmetry

Objective.Commercial wearable sensor systems are a promising alternative to costly laboratory equipment for clinical gait evaluation, but their accuracy for individuals with gait impairments is not well established. Therefore, we investigated the validity and reliability of the APDM Opal wearable sensor system to measure spatiotemporal gait parameters for healthy controls and individuals with chronic stroke.Approach.Participants completed the 10 m walk test over an instrumented mat three times in different speed conditions. We compared performance of Opal sensors to the mat across different walking speeds and levels of step length asymmetry in the two populations.Main results. Gait speed and stride length measures achieved excellent reliability, though they were systematically underestimated by 0.11 m s-1and 0.12 m, respectively. The stride and step time measures also achieved excellent reliability, with no significant errors (median absolute percentage error <6.00%,p> 0.05). Gait phase duration measures achieved moderate-to-excellent reliability, with relative errors ranging from 4.13%-21.59%. Across gait parameters, the relative error decreased by 0.57%-9.66% when walking faster than 1.30 m s-1; similar reductions occurred for step length symmetry indices lower than 0.10.Significance. This study supports the general use of Opal wearable sensors to obtain quantitative measures of post-stroke gait impairment. These measures should be interpreted cautiously for individuals with moderate-severe asymmetry or walking speeds slower than 0.80 m s-1.

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

Background

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

Aim

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

Methods

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

Results

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

Conclusion

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

Comparative Assessment of Gait and Balance in Patients with Parkinson's Disease and Normal Pressure Hydrocephalus

Objectives

We aim to compare balance and gait parameters in patients diagnosed with Parkinson's disease (PD) and normal pressure hydrocephalus (NPH).

Methods

A total of 13 patients with NPH, 20 with PD, and 13 healthy controls (HC) recruited in the study. Three IMU sensors (Ambulatory PD Monitoring Inc., OR, USA) were placed on the lumbar area and the feet of the participants. The balance evaluations comprised eight successive standing tasks; the modified clinical test of sensory interaction on balance test. These tasks involved standing with feet apart and eyes open as well as eyes closed on a firm and foam surface, standing with feet together and eyes open as well as eyes closed, and tandem stance with the right foot front and the left foot front. Functional evaluations of gait were conducted using the 10-M Walk Test (10 MWT), the 2 min-Walk Test (2 MWT), and the timed-up and go (TUG). Parameters of the gait and balance were analyzed and then compared.

Results

NPH patients displayed a notable decrease in both stride length and gait speed as compared with both PD patients and healthy participants. The balance tests revealed that the NPH group demonstrated significantly poorer performance, specifically in the feet-apart eyes-closed foam-surface test, and the tandem stance test. During the tasks while eyes were open on firm and foam surfaces, PD and NPH groups showed an increase in root mean square sway, range, and mean velocity (p<0.05) of sway in the anteroposterior plane. In addition, during the TUG test, the NPH group exhibited a significant prolongation in the time needed to complete the task and a decline in turning velocity as compared to PD, but no notable difference was seen in comparison to the HC group.

Conclusion

Our study indicated that the patients with NPH exhibited notably worse gait and balance measurements in comparison to both the PD patients and HC groups. These findings emphasize the significance of monitoring and managing gait and balance impairments in NPH patients. Sensor-based technologies may offer objective parameters for a more precise and efficient follow-up of these patients in terms of gait and balance.

How to prevent cognitive overload in the walking-arithmetic dual task among patients with Parkinson's disease

BACKGROUND

Participants with Parkinson's disease (PD) may experience difficulty during certain dual-task (DT) tests. Thus, it is necessary to keep the cognitive load within the limits of their ability.

OBJECTIVE

To identify cognitive overload and its influence on the walking and auditory addition and subtraction (AAS, all values within the range of 0-20) DT performance of patients with PD.

STUDY DESIGN

A cross-sectional observational study with convenience sampling.

SETTING

Outpatient clinic of the Department of Neurology.

SUBJECTS

Sixteen patients with PD and 15 sex- and age- matched people elderly healthy controls (HCs).

METHODS

Verbal calculation responses and gait parameters were collected from the two groups in the 2-min single arithmetic task (2-min SAT), 2-min single walking task (2-min SWT), and 2-min walking-arithmetic dual task (2-min WADT).

RESULTS

The group differences in the lower-limb gait parameters increased in the 2-min WADT (P < 0.01), and those in the arm, trunk, and waist parameters did not change (P > 0.05). In the 2-min SAT, the calculation speed of the PD group was significantly lower than that of the HC group (P < 0.01). In the 2-min WADT, both groups made more errors (P < 0.05), especially the PD group (P = 0.00). PD group miscalculations occurred in the first half of the 2-min SAT but were uniformly distributed in the 2-min WADT. The HC group and PD group had subtraction self-correction rates of 31.25% and 10.25%, respectively. The PD group tended to make subtraction errors when the value of the first operand was 20 or 13.46 ± 2.60 and when the value of the second and third operands were 7.75 ± 2.51 (P = 0.3657) and 8.50 ± 4.04 (P = 0.170), respectively.

CONCLUSIONS

Cognitive overload was observed in patients with PD. This was mainly reflected in the failure of gait control and accurate calculation, indicated by gait parameters of the lower limbs and accuracy of calculation. To impose a constant cognitive load, the amount added or subtracted, especially in subtraction with borrowing, should not be mixed during a sequential arithmetic problem in the DT, and equations with the value of the first operand equal to 20 or approximately 13, the value of the second operand approximately 7, or the value of the third operand of approximately 9 should be excluded in the AAS DT.

TRIAL REGISTRATION

Clinical trial registration number: ChiCTR1800020158.

Combination of Clinical and Gait Measures to Classify Fallers and Non-Fallers in Parkinson's Disease

Although the multifactorial nature of falls in Parkinson's disease (PD) is well described, optimal assessment for the identification of fallers remains unclear. Thus, we aimed to identify clinical and objective gait measures that best discriminate fallers from non-fallers in PD, with suggestions of optimal cutoff scores.

METHODS

Individuals with mild-to-moderate PD were classified as fallers (n = 31) or non-fallers (n = 96) based on the previous 12 months' falls. Clinical measures (demographic, motor, cognitive and patient-reported outcomes) were assessed with standard scales/tests, and gait parameters were derived from wearable inertial sensors (Mobility Lab v2); participants walked overground, at a self-selected speed, for 2 min under single and dual-task walking conditions (maximum forward digit span). Receiver operating characteristic curve analysis identified measures (separately and in combination) that best discriminate fallers from non-fallers; we calculated the area under the curve (AUC) and identified optimal cutoff scores (i.e., point closest-to-(0,1) corner).

RESULTS

Single gait and clinical measures that best classified fallers were foot strike angle (AUC = 0.728; cutoff = 14.07°) and the Falls Efficacy Scale International (FES-I; AUC = 0.716, cutoff = 25.5), respectively. Combinations of clinical + gait measures had higher AUCs than combinations of clinical-only or gait-only measures. The best performing combination included the FES-I score, New Freezing of Gait Questionnaire score, foot strike angle and trunk transverse range of motion (AUC = 0.85).

CONCLUSION

Multiple clinical and gait aspects must be considered for the classification of fallers and non-fallers in PD.

IoT-Enabled Gait Assessment: The Next Step for Habitual Monitoring

Walking/gait quality is a useful clinical tool to assess general health and is now broadly described as the sixth vital sign. This has been mediated by advances in sensing technology, including instrumented walkways and three-dimensional motion capture. However, it is wearable technology innovation that has spawned the highest growth in instrumented gait assessment due to the capabilities for monitoring within and beyond the laboratory. Specifically, instrumented gait assessment with wearable inertial measurement units (IMUs) has provided more readily deployable devices for use in any environment. Contemporary IMU-based gait assessment research has shown evidence of the robust quantifying of important clinical gait outcomes in, e.g., neurological disorders to gather more insightful habitual data in the home and community, given the relatively low cost and portability of IMUs. The aim of this narrative review is to describe the ongoing research regarding the need to move gait assessment out of bespoke settings into habitual environments and to consider the shortcomings and inefficiencies that are common within the field. Accordingly, we broadly explore how the Internet of Things (IoT) could better enable routine gait assessment beyond bespoke settings. As IMU-based wearables and algorithms mature in their corroboration with alternate technologies, such as computer vision, edge computing, and pose estimation, the role of IoT communication will enable new opportunities for remote gait assessment.

Using a smartwatch and smartphone to assess early Parkinson's disease in the WATCH-PD study

Digital health technologies can provide continuous monitoring and objective, real-world measures of Parkinson's disease (PD), but have primarily been evaluated in small, single-site studies. In this 12-month, multicenter observational study, we evaluated whether a smartwatch and smartphone application could measure features of early PD. 82 individuals with early, untreated PD and 50 age-matched controls wore research-grade sensors, a smartwatch, and a smartphone while performing standardized assessments in the clinic. At home, participants wore the smartwatch for seven days after each clinic visit and completed motor, speech and cognitive tasks on the smartphone every other week. Features derived from the devices, particularly arm swing, the proportion of time with tremor, and finger tapping, differed significantly between individuals with early PD and age-matched controls and had variable correlation with traditional assessments. Longitudinal assessments will inform the value of these digital measures for use in future clinical trials.

Gait asymmetry in stroke patients with unilateral spatial neglect

The recovery of independent gait represents one of the main functional goals of the rehabilitative interventions after stroke but it can be hindered by the presence of unilateral spatial neglect (USN). The aim of the paper is to study if the presence of USN in stroke patients affects lower limb gait parameters between the two body sides, differently from what could be expected by the motor impairment alone, and to explore whether USN is associated to specific gait asymmetry. Thirty-five stroke patients (right or left lesion and ischemic or hemorrhagic etiology) who regained independent gait were assessed for global cognitive functioning and USN. All patients underwent a gait analysis session by using a wearable inertial system, kinematic parameters were computed. Enrolled patients presented altered motion parameters. Stroke patients with USN showed specific asymmetries in the following parameters: stance phase, swing phase, and knee range of motion. No differences in the clinical scores were found as the presence of USN. The presence of USN was associated with a specific form of altered gait symmetry. These findings may help clinicians to develop more tailored rehabilitative training to enhance gait efficacy of patients with motor defects complicated by the presence of selected cognitive impairments. Overview of the experiment setup. The workflow shows: diagnosis of unilateral spatial neglect by the neuropsychologist, sensors placement, gait analysis protocol and evaluation of the gait asymmetry together with the statistically significant features.

Wearable sensors for assessing disease severity and progression in Progressive Supranuclear Palsy

INTRODUCTION

Progressive supranuclear palsy (PSP) is an atypical parkinsonism characterized by prominent gait and postural impairment. The PSP rating scale (PSPrs) is a clinician-administered tool to evaluate disease severity and progression. More recently, digital technologies have been used to investigate gait parameters. Therefore, object of this study was to implement a protocol using wearable sensors evaluating disease severity and progression in PSP.

METHODS

Patients were evaluated with the PSPrs as well as with three wearable sensors located on the feet and lumbar area. Spearman coefficient was used to assess the relationship between PSPrs and quantitative measurements. Furthermore, sensor parameters were included in a multiple linear regression model to assess their ability in predicting the PSPrs total score and sub-scores. Finally, differences between baseline and three-month follow-up were calculated for PSPrs and each quantitative variable. The significance level in all analyses was set at ≤ 0.05.

RESULTS

Fifty-eight evaluations from thirty-five patients were analyzed. Quantitative measurements showed multiple significant correlations with the PSPrs scores (r between 0.3 and 0.7; p < 0.05). Linear regression models confirmed the relationships. After three months visit, significant worsening from baseline was observed for cadence, cycle duration and PSPrs item 25, while PSPrs item 10 showed a significant improvement.

CONCLUSION

We propose wearable sensors can provide an objective, sensitive quantitative evaluation and immediate notification of gait changes in PSP. Our protocol can be easily introduced in outpatient and research settings as a complementary tool to clinical measures as well as an informative tool on disease severity and progression in PSP.

Motor and cognitive deficits limit the ability to flexibly modulate spatiotemporal gait features in older adults with mild cognitive impairment

Introduction: Dance-based therapies are an emerging form of movement therapy aiming to improve motor and cognitive function in older adults with mild cognitive impairments (MCIs). Despite the promising effects of dance-based therapies on function, it remains unclear how age-related declines in motor and cognitive function affect movement capacity and influence which movements and rhythms maximize dance therapy efficacy. Here, we evaluated the effects of age and MCI on the ability to accurately modulate spatial (i.e., joint kinematics), temporal (i.e., step timing), and spatiotemporal features of gait to achieve spatial and temporal targets during walking. Methods: We developed novel rhythmic movement sequences-nine spatial, nine temporal, and four spatiotemporal-that deviated from typical spatial and temporal features of walking. Healthy young adults (HYA), healthy older adults (HOA), and adults with MCI were trained on each gait modification before performing the modification overground, with kinematic data recorded using wearable sensors. Results: HOA performed spatial (p = 0.010) and spatiotemporal (p = 0.048) gait modifications less accurately than HYA. Individuals with MCI performed spatiotemporal gait modifications less accurately than HOA (p = 0.017). Spatial modifications to the swing phase of gait (p = 0.006, Cohen's d = -1.3), and four- and six-step Duple rhythms during temporal modifications (p ≤ 0.030, Cohen's d ≤ 0.9) elicited the largest differences in gait performance in HYA vs. HOA and HOA vs. MCI, respectively. Discussion: These findings suggest that age-related declines in strength and balance reduce the ability to accurately modulate spatial gait features, while declines in working memory in individuals with MCI may reduce the ability to perform longer temporal gait modification sequences. Differences in rhythmic movement sequence performance highlight motor and cognitive factors potentially underlying deficits in gait modulation capacity, which may guide therapy personalization and provide more sensitive indices to track intervention efficacy.

Deep Brain Stimulation and Levodopa Affect Gait Variability in Parkinson Disease Differently

BACKGROUND

Both dopaminergic medication and subthalamic nucleus (STN) deep brain stimulation (DBS) can improve the amplitude and speed of gait in Parkinson disease (PD), but relatively little is known about their comparative effects on gait variability. Gait irregularity has been linked to the degeneration of cholinergic neurons in the pedunculopontine nucleus (PPN).

OBJECTIVES

The STN and PPN have reciprocal connections, and we hypothesized that STN DBS might improve gait variability by modulating PPN function. Dopaminergic medication should not do this, and we therefore sought to compare the effects of medication and STN DBS on gait variability.

MATERIALS AND METHODS

We studied 11 patients with STN DBS systems on and off with no alteration to their medication, and 15 patients with PD without DBS systems on and off medication. Participants walked for two minutes in each state, wearing six inertial measurement units. Variability has previously often been expressed in terms of SD or coefficient of variation over a testing session, but these measures conflate long-term variability (eg, gradual slowing, which is not necessarily pathological) with short-term variability (true irregularity). We used Poincaré analysis to separate the short- and long-term variability.

RESULTS

DBS decreased short-term variability in lower limb gait parameters, whereas medication did not have this effect. In contrast, STN DBS had no effect on arm swing and trunk motion variability, whereas medication increased them, without obvious dyskinesia.

CONCLUSIONS

Our results suggest that STN DBS acts through a nondopaminergic mechanism to reduce gait variability. We believe that the most likely explanation is the retrograde activation of cholinergic PPN projection neurons.

Should we use both clinical and mobility measures to identify fallers in Parkinson's disease?

BACKGROUND

Although much is known about the multifactorial nature of falls in Parkinson's disease (PD), optimal classification of fallers remains unclear.

OBJECTIVE

To identify clinical (demographic, motor, cognitive and patient-reported) and objective mobility (balance and gait) measures that best discriminate fallers from non-fallers in PD.

METHODS

People with mild-to-moderate idiopathic PD were classified as fallers (at least one fall; n = 54) or non-fallers (n = 90) based on previous six months falls. Clinical characteristics included demographic, motor and cognitive status and patient-reported outcomes. Mobility (balance and gait) characteristics were derived from body-worn, inertial sensors while performing walking and standing tasks. To investigate the combinations of (up to four) measures that best discriminate fallers from non-fallers in each scenario (i.e., clinical-only, mobility-only and combined clinical + mobility models), we applied logistic regression employing a 'best subsets selection strategy' with a 5-fold cross validation, and calculated the area under the curve (AUC).

RESULTS

The highest AUCs for the clinical-only, mobility-only and clinical + mobility models were 0.89, 0.88, and 0.94, respectively. The most consistently selected measures in the top-10 ranked models were freezing of gait status (8x), the root mean square of anterior-posterior trunk acceleration while standing on a foam with eyes open (5x), gait double support duration (4x) and the postural instability and gait disorders score from the MDS UPDRS (4x).

CONCLUSIONS

Findings highlight the importance of considering multiple aspects of clinical as well as objective balance and gait characteristics for the classification of fallers and non-fallers in PD.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Postural control of Parkinson's disease: A visualized analysis based on Citespace knowledge graph

Postural control impairment is one of the primary motor symptoms in patients with Parkinson's disease, leading to an increased risk of falling. Several studies have been conducted on postural control disorders in Parkinson's disease patients, but no relevant bibliometric analysis has been found. In this paper, the Web of Science Core Collection database was searched for 1,295 relevant papers on postural control in Parkinson's disease patients from December 2011 to December 2021. Based on the Citespace knowledge graph, these relevant papers over the last decade were analyzed from the perspectives of annual publication volume, countries and institutes cooperation, authors cooperation, dual-map overlay of journals, co-citation literature, and keywords. The purpose of this study was to explore the current research status, research hotspots, and frontiers in this field, and to provide a reference for further promoting the research on postural control in Parkinson's disease patients.

A Logistic Regression Model for Biomechanical Risk Classification in Lifting Tasks

Lifting is one of the most potentially harmful activities for work-related musculoskeletal disorders (WMSDs), due to exposure to biomechanical risk. Risk assessment for work activities that involve lifting loads can be performed through the NIOSH (National Institute of Occupational Safety and Health) method, and specifically the Revised NIOSH Lifting Equation (RNLE). Aim of this work is to explore the feasibility of a logistic regression model fed with time and frequency domains features extracted from signals acquired through one inertial measurement unit (IMU) to classify risk classes associated with lifting activities according to the RNLE. Furthermore, an attempt was made to evaluate which are the most discriminating features relating to the risk classes, and to understand which inertial signals and which axis were the most representative. In a simplified scenario, where only two RNLE variables were altered during lifting tasks performed by 14 healthy adults, inertial signals (linear acceleration and angular velocity) acquired using one IMU placed on the subject’s sternum during repeated rhythmic lifting tasks were automatically segmented to extract several features in the time and frequency domains. The logistic regression model fed with significant features showed good results to discriminate “risk” and “no risk” NIOSH classes with an accuracy, sensitivity and specificity equal to 82.8%, 84.8% and 80.9%, respectively. This preliminary work indicated that a logistic regression model—fed with specific inertial features extracted by signals acquired using a single IMU sensor placed on the sternum—is able to discriminate risk classes according to the RNLE in a simplified context, and therefore could be a valid tool to assess the biomechanical risk in an automatic way also in more complex conditions (e.g., real working scenarios).

A Systematic Review of Wearable Sensor-Based Technologies for Fall Risk Assessment in Older Adults

Falls have been recognized as the major cause of accidental death and injury in people aged 65 and above. The timely prediction of fall risks can help identify older adults prone to falls and implement preventive interventions. Recent advancements in wearable sensor-based technologies and big data analysis have spurred the development of accurate, affordable, and easy-to-use approaches to fall risk assessment. The objective of this study was to systematically assess the current state of wearable sensor-based technologies for fall risk assessment among community-dwelling older adults. Twenty-five of 614 identified research articles were included in this review. A comprehensive comparison was conducted to evaluate these approaches from several perspectives. In general, these approaches provide an accurate and effective surrogate for fall risk assessment. The accuracy of fall risk prediction can be influenced by various factors such as sensor location, sensor type, features utilized, and data processing and modeling techniques. Features constructed from the raw signals are essential for predictive model development. However, more investigations are needed to identify distinct, clinically interpretable features and develop a general framework for fall risk assessment based on the integration of sensor technologies and data modeling.

Identifying and characterising sources of variability in digital outcome measures in Parkinson's disease

Smartphones and wearables are widely recognised as the foundation for novel Digital Health Technologies (DHTs) for the clinical assessment of Parkinson's disease. Yet, only limited progress has been made towards their regulatory acceptability as effective drug development tools. A key barrier in achieving this goal relates to the influence of a wide range of sources of variability (SoVs) introduced by measurement processes incorporating DHTs, on their ability to detect relevant changes to PD. This paper introduces a conceptual framework to assist clinical research teams investigating a specific Concept of Interest within a particular Context of Use, to identify, characterise, and when possible, mitigate the influence of SoVs. We illustrate how this conceptual framework can be applied in practice through specific examples, including two data-driven case studies.

Absolute Reliability of Gait Parameters Acquired With Markerless Motion Capture in Living Domains

Purpose: To examine the between-day absolute reliability of gait parameters acquired with Theia3D markerless motion capture for use in biomechanical and clinical settings. Methods: Twenty-one (7 M,14 F) participants aged between 18 and 73 years were recruited in community locations to perform two walking tasks: self-selected and fastest-comfortable walking speed. Participants walked along a designated walkway on two separate days.Joint angle kinematics for the hip, knee, and ankle, for all planes of motion, and spatiotemporal parameters were extracted to determine absolute reliability between-days. For kinematics, absolute reliability was examined using: full curve analysis [root mean square difference (RMSD)] and discrete point analysis at defined gait events using standard error of measurement (SEM). The absolute reliability of spatiotemporal parameters was also examined using SEM and SEM%. Results: Markerless motion capture produced low measurement error for kinematic full curve analysis with RMSDs ranging between 0.96° and 3.71° across all joints and planes for both walking tasks. Similarly, discrete point analysis within the gait cycle produced SEM values ranging between 0.91° and 3.25° for both sagittal and frontal plane angles of the hip, knee, and ankle. The highest measurement errors were observed in the transverse plane, with SEM >5° for ankle and knee range of motion. For the majority of spatiotemporal parameters, markerless motion capture produced low SEM values and SEM% below 10%. Conclusion: Markerless motion capture using Theia3D offers reliable gait analysis suitable for biomechanical and clinical use.

Closing the loop for patients with Parkinson disease: where are we?

Although levodopa remains the most efficacious symptomatic therapy for Parkinson disease (PD), management of levodopa treatment during the advanced stages of the disease is extremely challenging. This difficulty is a result of levodopa's short half-life, a progressive narrowing of the therapeutic window, and major inter-patient and intra-patient variations in the dose-response relationship. Therefore, a suitable alternative to repeated oral administration of levodopa is being sought. Recent research efforts have focused on the development of novel levodopa delivery strategies and wearable physical sensors that track symptoms and disease progression. However, the need for methods to monitor the levels of levodopa present in the body in real time has been overlooked. Advances in chemical sensor technology mean that the development of wearable and mobile biosensors for continuous or frequent levodopa measurements is now possible. Such levodopa monitoring could help to deliver personalized and timely medication dosing to alleviate treatment-related fluctuations in the symptoms of PD. Therefore, with the aim of optimizing therapeutic management of PD and improving the quality of life of patients, we share our vision of a future closed-loop autonomous wearable 'sense-and-act' system. This system consists of a network of physical and chemical sensors coupled with a levodopa delivery device and is guided by effective big data fusion algorithms and machine learning methods.

A New Paradigm in Parkinson's Disease Evaluation With Wearable Medical Devices: A Review of STAT-ONTM

In the past decade, the use of wearable medical devices has been a great breakthrough in clinical practice, trials, and research. In the Parkinson's disease field, clinical evaluation is time limited, and healthcare professionals need to rely on retrospective data collected through patients' self-filled diaries and administered questionnaires. As this often leads to inaccurate evaluations, a more objective system for symptom monitoring in a patient's daily life is claimed. In this regard, the use of wearable medical devices is crucial. This study aims at presenting a review on STAT-ONTM, a wearable medical device Class IIa, which provides objective information on the distribution and severity of PD motor symptoms in home environments. The sensor analyzes inertial signals, with a set of validated machine learning algorithms running in real time. The device was developed for 12 years, and this review aims at gathering all the results achieved within this time frame. First, a compendium of the complete journey of STAT-ONTM since 2009 is presented, encompassing different studies and developments in funded European and Spanish national projects. Subsequently, the methodology of database construction and machine learning algorithms design and development is described. Finally, clinical validation and external studies of STAT-ONTM are presented.

Assessing gait, balance, and muscle strength among breast cancer survivors with chemotherapy-induced peripheral neuropathy (CIPN): study protocol for a randomized controlled clinical trial

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is a common and understudied consequence of taxane chemotherapy for breast cancer treatment. CIPN symptoms include numbness combined with tingling sensations, persistent shooting, stabbing, or burning pain even in the absence of painful stimuli, lower extremity muscle weakness, and impaired balance. CIPN symptoms often persist for a long time after completion of chemotherapy, causing significant loss of functional abilities and increased risk of falls. Persistent CIPN caused by taxanes represents a therapeutic challenge due to the limited treatment options. Resistance exercise has shown promising results; however, the effect of exercise on CIPN remains understudied. This study aims to assess the effects of exercise on gait, balance, and lower extremity muscle strength after a 16-week home-based exercise program compared to an educational attention control condition.

METHODS

A sample of 312 women who completed taxane-based chemotherapy for breast cancer and have symptomatic neuropathy is recruited from a community-dwelling sample. Participants are randomized to either a 16-week Home-Based Physical Activity Intervention or an Educational Attention control group. The home-based intervention protocol consists of targeted lower extremity stretches, followed by 10 min each of gait/balance and 10 min of resistive training accessed by hyperlink or DVD. An Exercise Diary records quantitative exercise data. The gait assessment includes temporospatial parameters and lower extremity joint angles using APDM motion sensors. Participants' balance is assessed using the Sensory Organization Test (SOT) performed using a NeuroCom Balance Master. Isometric strength of hip, knee, and ankle flexor and extensor muscles is assessed using an isokinetic dynamometer, Biodex BX Advantage. In addition, we assess neuropathy symptoms using the FACT-Taxane Additional Concerns Subscale and nerve conduction velocity of the sural and peroneal nerve action potentials. Outcomes are assessed at baseline (prior to randomization) and 16 weeks.

DISCUSSION

There are currently no evidence-based interventions that address the functional declines associated with CIPN. If successful, this program is simple and easy to implement in the standard of care for individuals with CIPN. Gait and balance training have the potential to reduce physical dysfunction associated with CIPN and reduce the burden of disease in cancer survivors.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04621721 . Registered on August 3, 2020. ClincialTrials.gov is a primary registry of the World Health Organization International Clinical Trials Registry Platform (WHO ICTEP) network and includes all items from the WHO Trial Registration data set in Trial registration.

Review-Emerging Portable Technologies for Gait Analysis in Neurological Disorders

The understanding of locomotion in neurological disorders requires technologies for quantitative gait analysis. Numerous modalities are available today to objectively capture spatiotemporal gait and postural control features. Nevertheless, many obstacles prevent the application of these technologies to their full potential in neurological research and especially clinical practice. These include the required expert knowledge, time for data collection, and missing standards for data analysis and reporting. Here, we provide a technological review of wearable and vision-based portable motion analysis tools that emerged in the last decade with recent applications in neurological disorders such as Parkinson's disease and Multiple Sclerosis. The goal is to enable the reader to understand the available technologies with their individual strengths and limitations in order to make an informed decision for own investigations and clinical applications. We foresee that ongoing developments toward user-friendly automated devices will allow for closed-loop applications, long-term monitoring, and telemedical consulting in real-life environments.

Inertial Sensor Algorithm to Estimate Walk Distance

The “total distance walked” obtained during a standardized walking test is an integral component of physical fitness and health status tracking in a range of consumer and clinical applications. Wearable inertial sensors offer the advantages of providing accurate, objective, and reliable measures of gait while streamlining walk test administration. The aim of this study was to develop an inertial sensor-based algorithm to estimate the total distance walked using older subjects with impaired fasting glucose (Study I), and to test the generalizability of the proposed algorithm in patients with Multiple Sclerosis (Study II). All subjects wore two inertial sensors (Opals by Clario-APDM Wearable Technologies) on their feet. The walking distance algorithm was developed based on 108 older adults in Study I performing a 400 m walk test along a 20 m straight walkway. The validity of the algorithm was tested using a 6-minute walk test (6MWT) in two sub-studies of Study II with different lengths of a walkway, 15 m (Study II-A, n = 24) and 20 m (Study II-B, n = 22), respectively. The start and turn around points were marked with lines on the floor while smaller horizontal lines placed every 1 m served to calculate the manual distance walked (ground truth). The proposed algorithm calculates the forward distance traveled during each step as the change in the horizontal position from each foot-flat period to the subsequent foot-flat period. The total distance walked is then computed as the sum of walk distances for each stride, including turns. The proposed algorithm achieved an average absolute error rate of 1.92% with respect to a fixed 400 m distance for Study I. The same algorithm achieved an absolute error rate of 4.17% and 3.21% with respect to an averaged manual distance for 6MWT in Study II-A and Study II-B, respectively. These results demonstrate the potential of an inertial sensor-based algorithm to estimate a total distance walked with good accuracy with respect to the manual, clinical standard. Further work is needed to test the generalizability of the proposed algorithm with different administrators and populations, as well as larger diverse cohorts.

Surrogates for rigidity and PIGD MDS-UPDRS subscores using wearable sensors

BACKGROUND

Telemedicine has the advantage of expanding access to care for patients with Parkinson's Disease (PD). However, rigidity and postural instability in PD are difficult to measure remotely, and are important measures of functional impairment and fall risk.

RESEARCH QUESTION

Can measures from wearable sensors be used as future surrogates for the MDS-UPDRS rigidity and Postural Instability and Gait Difficulty (PIGD) subscores?

METHODS

Thirty-one individuals with mild to moderate PD wore 3 inertial sensors at home for one week to measure quantity and quality of gait and turning in daily life. Separately, we performed a clinical assessment and balance characterization of postural sway with the same wearable sensors in the laboratory (On medication). We then first performed a traditional correlation analysis between clinical scores and objective measures of gait and balance followed by multivariable linear regression employing a best subset selection strategy.

RESULTS

The number of walking bouts and turns correlated significantly with the rigidity subscore, while the number of turns, foot pitch angle, and sway area while standing correlated significantly with the PIGD subscore (p < 0.05). The multivariable linear regression showed that rigidity subscore was best predicted by the number of walking bouts while the PIGD subscore was best predicted by a combination of number of walking bouts, gait speed, and postural sway.

SIGNIFICANCE

The correlation between objective sensor data and MDS-UPDRS rigidity and PIGD scores paves the way for future larger studies that evaluate use of objective sensor data to supplement remote MDS-UPDRS assessment.

Cognitive correlates of dual tasking costs on the timed up and go test in Parkinson disease

Introduction

Dual tasking impairments are an increasingly recognized contributor to falls in Parkinson disease (PD) and may be a promising therapeutic target for PD fall prevention trials. Depending on the context, ambulatory dual tasking difficulties may be caused by different types of neurocognitive impairments.

Methods

We performed a cross-sectional analysis of 21 participants with PD. All participants underwent detailed neuropsychological testing that was quantified using normative z-scores. All participants completed the 3-meter timed up and go test (TUG), with and without a dual tasking assignment. Biomechanistic properties of the TUG were quantified using APDM wearable OPAL sensors. We explored correlations between dual tasking cost (DTC) in 1) total TUG duration, 2) Sit-to-stand duration, 3) Stand-to-sit duration, and 4) turn velocity.

Results

Impaired total DTC in the TUG correlated inversely with global cognitive performance measured using the Montreal Cognitive Assessment (MoCA) (r = -0.4649, p = 0.0337). Sit-to-stand DTC impairments correlated inversely with processing speed on the WAIS-IV Coding (r = -0.5762, p = 0.0063), semantic fluency (r = -0.5100, p = 0.0182) and learning and memory on the Hopkins Verbal Learning Test-Revised total recall (r = -0.5502, p = 0.0098). Impaired stand-to-sit DTC function corelated inversely with visuospatial cognitive function on the Benton Judgement of Line Orientation (JOLO) test (r = -0.5181, p = 0.0161).

Conclusions

The link between dual tasking and fall risk in PD may be caused by cognitive features other than executive dysfunction and may vary based on the ambulatory task in question. These findings shed light on the cognitive contributions to falls in PD.

Automated Analysis of the Two-Minute Walk Test in Clinical Practice Using Accelerometer Data

One of the core problems for people with multiple sclerosis (pwMS) is the impairment of their ability to walk, which can be severely restrictive in everyday life. Therefore, monitoring of ambulatory function is of great importance to be able to effectively counteract disease progression. An extensive gait analysis, such as the Dresden protocol for multidimensional walking assessment, covers several facets of walking impairment including a 2-min walk test, in which the distance taken by the patient in two minutes is measured by an odometer. Using this approach, it is questionable how precise the measuring methods are at recording the distance traveled. In this project, we investigate whether the current measurement can be replaced by a digital measurement method based on accelerometers (six Opal sensors from the Mobility Lab system) that are attached to the patient’s body. We developed two algorithms using these data and compared the validity of these approaches using the results from 2-min walk tests from 562 pwMS that were collected with a gold-standard odometer. In 48.4% of pwMS, we detected an average relative measurement error of less than 5%, while results from 25.8% of the pwMS showed a relative measurement error of up to 10%. The algorithm had difficulties correctly calculating the walking distances in another 25.8% of pwMS; these results showed a measurement error of more than 20%. A main reason for this moderate performance was the variety of pathologically altered gait patterns in pwMS that may complicate the step detection. Overall, both algorithms achieved favorable levels of agreement (r = 0.884 and r = 0.980) with the odometer. Finally, we present suggestions for improvement of the measurement system to be implemented in the future.

A New Tool for Safety Evaluation and a Combination of Measures for Efficacy Assessment of Cotransplanting Human Allogenic Neuronal Stem Cells and Mesenchymal Stem Cells for the Treatment of Parkinson Disease: Protocol for an Interventional Study

Background

Parkinson disease (PD) is a neurodegenerative disorder associated with a broad spectrum of motor and nonmotor symptoms. Any proposed cure needs to address the many aspects of the disease. Stem cell therapy may have potential in this regard as indicated in recent preclinical and clinical studies.

Objective

This protocol aims to examine the safety and therapeutic benefit of human Wharton jelly-derived mesenchymal stem cells (WJ-MScs) and their derivatives, neuronal stem cells (NSCs) in PD.

Methods

This clinical trial is a double-arm, single-blinded, phase I-II interventional study. Participants have been allocated to 1 of 2 groups: one receiving allogeneic WJ-MSCs alone, the other receiving NSCs and WJ-MScs. Participants are being followed-up and assessed over a period of 6 months. To assess safety, an incidence of treatment-emergent adverse events (TEAEs) tool tailored for PD is being used immediately and up to 6 months after treatment. For efficacy assessment, a number of factors are being used, including the gold standard severity test and the Unified Parkinson Disease Rating Scale. In addition, the following standardized assessments for different common symptoms in PD are being included: motor (both subjectively and objectively assessed with wearable sensors), sensory, quality of life and psychological well-being, cognition, and sleep quality. Furthermore, immune-modulatory cytokines and neuronal damage versus regeneration markers in PD, including the neuronal protein linked to PD, α-synuclein, are being monitored.

Results

Ten patients have been enrolled in this study and thus participant recruitment has been completed. The study status is active and beyond the recruiting stage. Study chart implementation, data collection, and analysis are ongoing.

Conclusions

The combination of NSCs and MSCs in PD may be useful for harnessing the best of the immunomodulation and neural repair characteristics of these cell types. The tailored comprehensive and scaled TEAEs and the variety of evaluation tools used enables a comprehensive assessment of this cellular therapy treatment protocol. A consideration of this expanded tool set is important in the design of future clinical studies for PD.

Trial Registration

ClinicalTrials.gov NCT03684122; https://clinicaltrials.gov/ct2/show/NCT03684122

International Registered Report Identifier (IRRID)

DERR1-10.2196/29695

Parkinson Disease: Translating Insights from Molecular Mechanisms to Neuroprotection

Parkinson disease (PD) used to be considered a nongenetic condition. However, the identification of several autosomal dominant and recessive mutations linked to monogenic PD has changed this view. Clinically manifest PD is then thought to occur through a complex interplay between genetic mutations, many of which have incomplete penetrance, and environmental factors, both neuroprotective and increasing susceptibility, which variably interact to reach a threshold over which PD becomes clinically manifested. Functional studies of PD gene products have identified many cellular and molecular pathways, providing crucial insights into the nature and causes of PD. PD originates from multiple causes and a range of pathogenic processes at play, ultimately culminating in nigral dopaminergic loss and motor dysfunction. An in-depth understanding of these complex and possibly convergent pathways will pave the way for therapeutic approaches to alleviate the disease symptoms and neuroprotective strategies to prevent disease manifestations. This review is aimed at providing a comprehensive understanding of advances made in PD research based on leveraging genetic insights into the pathogenesis of PD. It further discusses novel perspectives to facilitate identification of critical molecular pathways that are central to neurodegeneration that hold the potential to develop neuroprotective and/or neurorestorative therapeutic strategies for PD. SIGNIFICANCE STATEMENT: A comprehensive review of PD pathophysiology is provided on the complex interplay of genetic and environmental factors and biologic processes that contribute to PD pathogenesis. This knowledge identifies new targets that could be leveraged into disease-modifying therapies to prevent or slow neurodegeneration in PD.

Evaluation of movement and brain activity

Clinical neurophysiology studies can contribute important information about the physiology of human movement and the pathophysiology and diagnosis of different movement disorders. Some techniques can be accomplished in a routine clinical neurophysiology laboratory and others require some special equipment. This review, initiating a series of articles on this topic, focuses on the methods and techniques. The methods reviewed include EMG, EEG, MEG, evoked potentials, coherence, accelerometry, posturography (balance), gait, and sleep studies. Functional MRI (fMRI) is also reviewed as a physiological method that can be used independently or together with other methods. A few applications to patients with movement disorders are discussed as examples, but the detailed applications will be the subject of other articles.

A Systematic Review of Machine Learning Based Gait characteristics in Parkinson's disease

OBJECTIVE

Parkinson's disease is a pervasive neuro disorder that affects people's quality of life throughout the world. The unsatisfactory results of clinical rating scales open the door for more research. PD treatment using current biomarkers seems a difficult task. So automatic evaluation at an early stage may enhance the quality and time-period of life.

METHODS

Grading of Recommendations Assessment, Development, and Evaluation (GRADE) and Population, intervention, comparison, and outcome (PICO) search methodology schemes are followed to search the data and eligible studies for this survey. Approximate 1500 articles were extracted using related search strings. After the stepwise mapping and elimination of studies, 94 papers are found suitable for the present review.

RESULTS

After the quality assessment of extracted studies, nine inhibitors are identified to analyze people's gait with Parkinson's disease, where four are critical. This review also differentiates the various machine learning classification techniques with their PD analysis characteristics in previous studies. The extracted research gaps are described as future perspectives. Results can help practitioners understand the PD gait as a valuable biomarker for detection, quantification, and classification.

CONCLUSION

Due to less cost and easy recording of gait, gait-based techniques are becoming popular in PD detection. By encapsulating the gait-based studies, it gives an in-depth knowledge of PD, different measures that affect gait detection and classification.

The Accuracy and Precision of Gait Spatio-Temporal Parameters Extracted from an Instrumented Sock during Treadmill and Overground Walking in Healthy Subjects and Patients with a Foot Impairment Secondary to Psoriatic Arthritis

The objectives of this study were to assess the accuracy and precision of a system combining an IMU-instrumented sock and a validated algorithm for the estimation of the spatio-temporal parameters of gait. A total of 25 healthy participants (HP) and 21 patients with foot impairments secondary to psoriatic arthritis (PsA) performed treadmill walking at three different speeds and overground walking at a comfortable speed. HP performed the assessment over two sessions. The proposed system's estimations of cadence (CAD), gait cycle duration (GCD), gait speed (GS), and stride length (SL) obtained for treadmill walking were validated versus those estimated with a motion capture system. The system was also compared with a well-established multi-IMU-based system for treadmill and overground walking. The results showed a good agreement between the motion capture system and the IMU-instrumented sock in estimating the spatio-temporal parameters during the treadmill walking at normal and fast speeds for both HP and PsA participants. The accuracy of GS and SL obtained from the IMU-instrumented sock was better compared to the established multi-IMU-based system in both groups. The precision (inter-session reliability) of the gait parameter estimations obtained from the IMU-instrumented sock was good to excellent for overground walking and treadmill walking at fast speeds, but moderate-to-good for slow and normal treadmill walking. The proposed IMU-instrumented sock offers a novel form factor addressing the wearability issues of IMUs and could potentially be used to measure spatio-temporal parameters under clinical conditions and free-living conditions.

Positive impact of short-term gait rehabilitation in Parkinson patients: a combined approach based on statistics and machine learning

Parkinson's disease is the second most common neurodegenerative disorder in the world. Assumed that gait dysfunctions represent a major motor symptom for the pathology, gait analysis can provide clinicians quantitative information about the rehabilitation outcome of patients. In this scenario, wearable inertial systems for gait analysis can be a valid tool to assess the functional recovery of patients in an automatic and quantitative way, helping clinicians in decision making. Aim of the study is to evaluate the impact of the short-term rehabilitation on gait and balance of patients with Parkinson's disease. A cohort of 12 patients with Idiopathic Parkinson's disease performed a gait analysis session instrumented by a wearable inertial system for gait analysis: Opal System, by APDM Inc., with spatial and temporal parameters being analyzed through a statistic and machine learning approach. Six out of fourteen motion parameters exhibited a statistically significant difference between the measurements at admission and at discharge of the patients, while the machine learning analysis confirmed the separability of the two phases in terms of Accuracy and Area under the Receiving Operating Characteristic Curve. The rehabilitation treatment especially improved the motion parameters related to the gait. The study shows the positive impact on the gait of a short-term rehabilitation in patients with Parkinson's disease and the feasibility of the wearable inertial devices, that are increasingly spreading in clinical practice, to quantitatively assess the gait improvement.

Using Machine Learning Algorithms for Identifying Gait Parameters Suitable to Evaluate Subtle Changes in Gait in People with Multiple Sclerosis

In multiple sclerosis (MS), gait impairment is one of the most prominent symptoms. For a sensitive assessment of pathological gait patterns, a comprehensive analysis and processing of several gait analysis systems is necessary. The objective of this work was to determine the best diagnostic gait system (DIERS pedogait, GAITRite system, and Mobility Lab) using six machine learning algorithms for the differentiation between people with multiple sclerosis (pwMS) and healthy controls, between pwMS with and without fatigue and between pwMS with mild and moderate impairment. The data of the three gait systems were assessed on 54 pwMS and 38 healthy controls. Gaussian Naive Bayes, Decision Tree, k-Nearest Neighbor, and Support Vector Machines (SVM) with linear, radial basis function (rbf) and polynomial kernel were applied for the detection of subtle walking changes. The best performance for a healthy-sick classification was achieved on the DIERS data with a SVM rbf kernel (κ = 0.49 ± 0.11). For differentiating between pwMS with mild and moderate disability, the GAITRite data with the SVM linear kernel (κ = 0.61 ± 0.06) showed the best performance. This study demonstrates that machine learning methods are suitable for identifying pathologic gait patterns in early MS.

Ergonomic Analysis of Functional Endoscopic Sinus Surgery Using Novel Inertial Sensors

OBJECTIVES/HYPOTHESIS

Suboptimal ergonomics during endoscopic sinus surgery can lead to considerable physical discomfort and fatigue for the surgeon. The purpose of this pilot study is to objectively evaluate the ergonomic positions of trainee and attending surgeons while performing functional endoscopic sinus surgery (FESS).

STUDY DESIGN

Pilot prospective trial.

METHODS

Six surgeons (two attendings and four trainees) performed FESS while wearing 11 inertial measurement units (IMUs) affixed to either side of each major joint. Screen placement was standardized to be 1 m directly in front of the surgeon and on the patient's left, 0-15° declined from the surgeons' eyes. Bed height was standardized such that the workspace was 0 to 10 cm below the elbows. IMU data were analyzed to calculate joint angles. Ideal joint angles (i.e., <10° for neck and trunk) were determined by the validated Rapid Entire Body Assessment tool. Subjects subsequently completed a modified National Aeronautics and Space Administration Task Load Index to assess cognitive and physical burden and pain. Student's t-test was employed to detect differences between groups.

RESULTS

Trainees adopted positions involving significantly greater neck flexion (9.90° vs. -6.48°, P = .03) and reported significantly higher frustration levels (3.04 vs. 1.33, P = .02) while operating than attendings. For both cohorts, increased operative time was significantly correlated with greater back flexion (r = 0.90, P = .02; r = 0.55, P = .04, respectively).

CONCLUSIONS

Our data suggest that trainees operate with higher risk neck postures than do attendings. These data indicate high-risk operative postures may be borne of inexperience and present an opportunity for postural interventions at an early stage of training.

LEVEL OF EVIDENCE

N/A Laryngoscope, 2021.

Quantitative Evaluation of Gait Changes Using APDM Inertial Sensors After the External Lumbar Drain in Patients With Idiopathic Normal Pressure Hydrocephalus

Objectives: Gait and balance disturbances are common symptoms of idiopathic normal pressure hydrocephalus (iNPH). This study aimed to quantitatively evaluate gait and balance parameters after external lumbar drainage (ELD) using APDM inertial sensors.

Methods: Two-minute walkway tests were performed in 36 patients with suspected iNPH and 20 healthy controls. A total of 36 patients underwent ELD. According to clinical outcomes, 20 patients were defined as responders, and the other 16 as non-responders. The gait parameters were documented, and the corresponding differences between responders and non-responders were calculated.

Results: When compared with healthy controls, patients with suspected iNPH exhibited decreased cadence, reduced gait speed, a higher percentage of double support, decreased elevation at mid-swing, reduced foot strike angle, shorter stride length, difficulty in turning, and impaired balance functions. After the ELD, all these manifestations, except elevation at mid-swing and balance functions, were significantly improved in responders. The change of Z-score absolute value in the six parameters, except for foot strike angle, was >1. No significant improvement was observed in non-responders.

Conclusion: APDM inertial sensors are useful for the quantitative assessment of gait impairment in patients with iNPH, which may be a valuable tool for identifying candidates that are suitable for shunting operations.

Development and Validation of a Patient-Reported Outcome Measure of Ataxia

BACKGROUND

Assessment of cerebellar ataxia has been confined to rating scales, gait laboratories, and wearable sensors agnostic to patient input.

OBJECTIVES

The objective of this study was to develop a Patient-Reported Outcome Measure of Ataxia.

METHODS

(1) The conceptual framework, item pool development, and domain selection were developed using online surveys completed by 147 ataxia patients. Responses generated the 70-item Patient-Reported Outcome Measure of Ataxia, scored on a 0-4 Likert scale. (2) Cognitive debrief in 17 patients grouped by ataxia severity assessed content validity, readability, and comprehension. (3) Psychometric validation by 78 anonymized ataxia patients included test-retest reliability, responsiveness to ataxia severity, internal consistency (Cronbach's alpha), and item-total score correlations. (4) Validation was tested against measures of ataxia and quality of life in 20 patients. (5) Items were rank-ordered to develop the Patient-Reported Outcome Measure of Ataxia Short Form.

RESULTS

Three thousand eight hundred fifty-five symptoms were grouped into 3 domains (physical, activities of daily living, mental health) and 14 subdomains. The Patient-Reported Outcome Measure of Ataxia was comprehensible, important, and relevant. Internal consistency, reliability, and test-retest reliability were high. Scores were responsive to ataxia severity stages 1, 2, and 3: mean ± standard deviation 81.0 ± 37.0, 129.6 ± 32.0, and 151.1 ± 41.3, respectively (r = 0.58, P < 0.0001). The Patient-Reported Outcome Measure of Ataxia was validated against measures of motor ataxia, quality of life, and mental health. It had an R² of 0.82 (P < 0.0001) with the preliminary Patient-Reported Outcome Measure of Ataxia Short Form.

CONCLUSIONS

The Patient-Reported Outcome Measure of Ataxia is valid and reliable in cerebellar ataxia patients. It has the potential to improve patient care and natural history studies and quantify the efficacy of novel therapeutics in clinical trials. © 2021 International Parkinson and Movement Disorder Society.