Identifying balance impairments in people with Parkinson's disease using video and wearable sensors.

BACKGROUND: Falls and near falls are common among people with Parkinson's (PwP). To date, most wearable sensor research focussed on fall detection, few studies explored if wearable sensors can detect instability. RESEARCH QUESTION: Can instability (caution or near-falls) be detected using wearable sensors in comparison to video analysis? METHODS: Twenty-four people (aged 60-86) with and without Parkinson's were recruited from community groups. Movements (e.g. walking, turning, transfers and reaching) were observed in the gait laboratory and/or at home; recorded using clinical measures, video and five wearable sensors (attached on the waist, ankles and wrists). After defining 'caution' and 'instability', two researchers evaluated video data and a third the raw wearable sensor data; blinded to each other's evaluations. Agreement between video and sensor data was calculated on stability, timing, step count and strategy. RESULTS: Data was available for 117 performances: 82 (70%) appeared stable on video. Ratings agreed in 86/117 cases (74%). Highest agreement was noted for chair transfer, timed up and go test and 3 m walks. Video analysts noted caution (slow, contained movements, safety-enhancing postures and concentration) and/or instability (saving reactions, stopping after stumbling or veering) in 40/134 performances (30%): raw wearable sensor data identified 16/35 performances rated cautious or unstable (sensitivity 46%) and 70/82 rated stable (specificity 85%). There was a 54% chance that a performance identified from wearable sensors as cautious/unstable was so; rising to 80% for stable movements. SIGNIFICANCE: Agreement between wearable sensor and video data suggested that wearable sensors can detect subtle instability and near-falls. Caution and instability were observed in nearly a third of performances, suggesting that simple, mildly challenging actions, with clearly defined start- and end-points, may be most amenable to monitoring during free-living at home. Using the genuine near-falls recorded, work continues to automatically detect subtle instability using algorithms.

Falls are unintentional: Studying simulations is a waste of faking time.

Researchers tend to agree that falls are, by definition, unintentional and that sensor algorithms (the processes that allows a computer program to identify a fall among data from sensors) perform poorly when attempting to detect falls 'in the wild' (a phrase some scientists use to mean 'in reality'). Algorithm development has been reliant on simulation, i.e. asking actors to throw themselves intentionally to the ground. This is unusual (no one studies faked coughs or headaches) and uninformative (no one can intend the unintentional). Researchers would increase their chances of detecting 'real' falls in 'the real world' by studying the behaviour of fallers, however, vulnerable, before, during and after the event: the literature on the circumstances of falling is more informative than any number of faked approximations. A complimentary knowledge base (in falls, sensors and/or signals) enables multidisciplinary teams of clinicians, engineers and computer scientists to tackle fall detection and aim for fall prevention. Throughout this paper, I discuss differences between falls, 'intentional falling' and simulations, and the balance between simulation and reality in falls research, finally suggesting ways in which researchers can access examples of falls without resorting to fakery.

Strategies used by people with Parkinson's disease who report difficulty turning.

PURPOSE: Difficulty turning (DT) is common in Parkinson's disease (PD). We set out to answer the questions: (1) do people who do and do not report DT differ in postural stability, heel strike, the use of support and step count when performing functional turns during everyday tasks, (2) is the structured observation of functional tasks an ecologically valid way of assessing an individual's ability to turn and (3) does a history of DT predict freezing and/or falls. METHOD: At home, 75 people (median age 75 years; PD duration 7 years) answered questions about DT, freezing and falls and completed a standard 180 degrees turn test and an everyday task necessitating spontaneous turns, later rated from video by blinded assessors. RESULTS: Forty-two people reported DT, of whom 86% reported frequent freezing and/or falls. Twenty-six people with DT and 15 without completed the functional task. Greater proportions of the former appeared Unstable (12 vs 1; P = 0.014), lacked Heel Strike (25 vs 9; P = 0.006) and Used Support (7 vs 0; P = 0.035): the former took more Turning Steps (medians 6 vs 4; P = 0.001). The 95% limits of agreement between step counts (functional vs standard turns) ran from -6.3 to 3.6 steps. Of 49 people with a history of freezing and/or falls, 36 (73%) reported frequent DT. CONCLUSIONS: People who report DT turn differently to those who report no problems. Standard turn tests poorly reflect step count during real-life turning, whereas unobtrusive structured observation reveals the turning strategies people use, so can guide rehabilitation. Reported DT is a sensitive indicator of freezing and/or falling, both indicators for physiotherapy.

Could In-Home Sensors Surpass Human Observation of People with Parkinson's at High Risk of Falling? An Ethnographic Study.

Self-report underpins our understanding of falls among people with Parkinson's (PwP) as they largely happen unwitnessed at home. In this qualitative study, we used an ethnographic approach to investigate which in-home sensors, in which locations, could gather useful data about fall risk. Over six weeks, we observed five independently mobile PwP at high risk of falling, at home. We made field notes about falls (prior events and concerns) and recorded movement with video, Kinect, and wearable sensors. The three women and two men (aged 71 to 79 years) having moderate or severe Parkinson's were dependent on others and highly sedentary. We most commonly noted balance protection, loss, and restoration during chair transfers, walks across open spaces and through gaps, turns, steps up and down, and tasks in standing (all evident walking between chair and stairs, e.g.). Our unobtrusive sensors were acceptable to participants: they could detect instability during everyday activity at home and potentially guide intervention. Monitoring the route between chair and stairs is likely to give information without invading the privacy of people at high risk of falling, with very limited mobility, who spend most of the day in their sitting rooms.

Postural instability during reaching tasks in Parkinson's disease.

BACKGROUND AND PURPOSE: Reaching, like turning and rising from sitting, is an activity commonly associated with falls by people with Parkinson's disease. We set out to: (a) identify how people with moderate and severe Parkinson's disease performed high and low reaches and (b) to explore in detail the standard functional reach (functional reach) test and the fall histories of those who appeared unstable when reaching. METHOD: In this cross-sectional study, people with moderate or severe Parkinson's disease (Hoehn and Yahr Grade III or IV) were video-recorded at home, reaching above shoulder height and below knee level. Blinded observers rated stability, alignment, foot position, floor contact, use of support and reach type. Functional reach was also measured and participants were interviewed about falls. RESULTS: Of 51 participants, 33 (65%) had moderate Parkinson's disease and 18 (35%) severe. A greater proportion of the latter used support when reaching high (p = 0.029) and aligned forward when reaching low (p = 0.015); otherwise, strategies were similar across groups. Six people (all with severe Parkinson's disease) appeared unstable when reaching: they had a shorter functional reach than the others (median 10 cm versus 18 cm; p = 0.042) and had fallen frequently (median five falls in a year), although rarely when reaching. CONCLUSIONS: Reaching tasks challenge postural stability in severe Parkinson's disease. People who appear unstable when reaching are likely to be repeat-fallers and at risk of further falls during more demanding activities. Research should address whether discouraging potentially destabilizing manoeuvres (such as squatting and toe-standing) and promoting safety-enhancing strategies (such as using support and facing forward), with or without balance retraining, reduces the risk of falling among people with severe Parkinson's disease.

The Association of Grip Strength With Severity and Duration of Parkinson's: A Cross-Sectional Study.

BACKGROUND: Weakness is reported in Parkinson's but always unadjusted for recognized factors that influence muscle strength such as participants' age, gender, and body size. This may obscure the true association of Parkinson's with muscle strength. OBJECTIVE: To evaluate the relationship between grip strength, Parkinson's severity, and duration adjusting for these factors. METHODS: Age, gender, height, weight, grip strength, Unified Parkinson's Disease Rating Score (UPDRS) motor score, Hoehn and Yahr (H&Y) stage, disease duration, number of comorbidities and medications, Barthel score, Mini Mental State Examination (MMSE) score, and Malnutrition Universal Screening Tool (MUST) score were recorded. RESULTS: Fifty-seven of 79 (72%) people with Parkinson's resident in one town were recruited. Age, gender, height, and Parkinson's severity were the most significant determinants of grip strength. Each unit increase in UPDRS motor score and H&Y stage was associated with lower grip strength in univariate linear regression analyses adjusted for gender: -0.3 kg strength (95% confidence interval = -0.51, -0.09), P = .006 for each additional UPDRS point, and -3.87 kg strength (95% confidence interval = -6.54, -1.21), P = .005 for each additional H&Y stage. Disease duration was not associated with grip strength. In multivariate regression, Parkinson's severity remained strongly associated with grip strength (UPDRS score P = .09; H&Y stage P = .04). CONCLUSIONS: This is the first demonstration that increasing severity of Parkinson's was associated with weaker grip after adjustment for known influences on muscle strength. Participants' age, gender, and body size also had a significant impact on strength. Adjustment of reported values for all these factors is essential to allow accurate reporting of grip strength values in intervention trials and comparison between different groups.

Psychometric properties of 3 functional mobility tests for people with Parkinson disease.

BACKGROUND: Standardized outcome measures with high clinical utility are of paramount importance for clinical practice. OBJECTIVE: The purpose of this study was to examine interrater and intrarater reliability, construct validity, discriminant ability, and smallest detectable differences of the sit-to-stand test (STS), Timed "Up & Go" Test (TUG), and bed mobility test for people with Parkinson disease (PD). DESIGN: A cross-sectional, psychometric evaluation study was conducted. METHODS: A group of individuals with PD (PD group) and a group of individuals who were healthy (control group) were recruited through local PD groups and assessed in a movement laboratory in their "on" phase. Measurements of time to perform one STS, TUG, and bed mobility test were collected based on video recordings of that single performance. RESULTS: Thirty-eight individuals with PD (Hoehn and Yahr stages I-IV) and 19 age-matched control participants were recruited. Intraclass correlation coefficients for interrater and intrarater reliability for the PD group ranged from .95 to .99. Bland-Altman plots showed mean differences close to zero and narrow confidence intervals. Construct validity was established by means of moderate to good Spearman rho correlation coefficients with part III of the Unified Parkinson's Disease Rating Scale and the Hoehn and Yahr stage (range=.51-.63). Timings of all tests discriminated participants in the PD group from those in the control group and participants in the PD group in Hoehn and Yahr stages I and II from those in Hoehn and Yahr stages III and IV but did not discriminate "nonfallers" or those with single falls from repeat "fallers" or "nonfreezers" from "freezers." Applicable smallest detectable differences were established. LIMITATIONS: The results are not generalizable to people in the late stage of PD (Hoehn and Yahr stage IV: n=3). CONCLUSIONS: Timings of video recordings of 3 functional mobility tests with high clinical utility showed good psychometric properties for community-dwelling, ambulatory people with PD.

Slow Down and Concentrate: Time for a Paradigm Shift in Fall Prevention among People with Parkinson's Disease?

Introduction. We know little about how environmental challenges beyond home exacerbate difficulty moving, leading to falls among people with Parkinson's (PwP). Aims. To survey falls beyond home, identifying challenges amenable to behaviour change. Methods. We distributed 380 questionnaires to PwP in Southern England, asking participants to count and describe falls beyond home in the previous 12 months. Results. Among 255 responses, 136 PwP (diagnosed a median 8 years) reported falling beyond home. They described 249 falls in detail, commonly falling forward after tripping in streets. Single fallers (one fall in 12 months) commonly missed their footing, walking, or changing position and recovered to standing alone or with unfamiliar help. Repeat fallers (median falls, two) commonly felt shaken or embarrassed and sought medical advice. Very frequent fallers (falling at least monthly; median falls beyond home, six) commonly fell backward, in shops and after collapse but often recovered to standing alone. Conclusion. Even independently active PwP who do not fall at home may fall beyond home, often after tripping. Falling beyond home may result in psychological and/or physical trauma (embarrassment if observed by strangers and/or injury if falling backwards onto a hard surface). Prevention requires vigilance and preparedness: slowing down and concentrating on a single task might effectively prevent falling.

IL-23R is Epigenetically Regulated and Modulated by Chemotherapy in Non-Small Cell Lung Cancer.

The Interleukin-23 (IL-23)/IL-23R signaling axis is an important inflammatory pathway, involved in the stimulation and regulation of the T helper (Th) 17 lymphocytes, resulting in the production of IL-17. Aside from auto-immunity, this cytokine has also been linked to carcinogenesis and polymorphisms in the IL-23R gene are associated with an increased risk for the development of a number of different cancers. Activation of the IL-23 pathway results in the up-regulation of STAT3 and it is thought that the pathological consequences associated with this are in part due to the production of IL-17. We have previously identified IL-23A as pro-proliferative and epigenetically regulated in non-small cell lung cancer (NSCLC). The current study aims to evaluate IL-23R in greater detail in NSCLC. We demonstrate that IL-23R is expressed and epigenetically regulated in NSCLC through histone post-translation modifications and CpG island methylation. In addition, Gemcitabine treatment, a chemotherapy drug used in the treatment of NSCLC, resulted in the up-regulation of the IL-23R. Furthermore, Apilimod (STA 5326), a small molecule which blocks the expression of IL-23 and IL-12, reduced the proliferative capacity of NSCLC cells, particularly in the adenocarcinoma (A549) sub-type. Apilimod is currently undergoing investigation in a number of clinical trials for the treatment of auto-immune conditions such as Crohn's disease and Rheumatoid Arthritis. Our results may have implications for treating NSCLC patients with Gemcitabine or epigenetic targeted therapies. However, Apilimod may possibly provide a new treatment avenue for NSCLC patients. Work is currently ongoing to further delineate the IL-23/IL-23R axis in this disease.

The PIT: SToPP Trial-A Feasibility Randomised Controlled Trial of Home-Based Physiotherapy for People with Parkinson's Disease Using Video-Based Measures to Preserve Assessor Blinding.

Purpose. To trial four-week's physiotherapy targeting chair transfers for people with Parkinson's disease (PwPD) and explore the feasibility of reliance on remote outcome measurement to preserve blinding. Scope. We recruited 47 PwPD and randomised 24 to a focused home physiotherapy programme (exercise, movement strategies, and cueing) and 23 to a control group. We evaluated transfers (plus mobility, balance, posture, and quality of life) before and after treatment and at followup (weeks 0, 4, 8, and 12) from video produced by, and questionnaires distributed by, treating physiotherapists. Participants fed back via end-of-study questionnaires. Thirty-five participants (74%) completed the trial. Excluding dropouts, 20% of questionnaire data and 9% of video data were missing or unusable; we had to evaluate balance in situ. We noted trends to improvement in transfers, mobility, and balance in the physiotherapy group not noted in the control group. Participant feedback was largely positive and assessor blinding was maintained in every case. Conclusions. Intense, focused physiotherapy at home appears acceptable and likely to bring positive change in those who can participate. Remote outcome measurement was successful; questionnaire followup and further training in video production would reduce missing data. We advocate a fully powered trial, designed to minimise dropouts and preserve assessor blinding, to evaluate this intervention.

Impaired bed mobility and disordered sleep in Parkinson's disease.

The contribution of impaired mobility to disordered sleep in Parkinson's disease (PD) remains uncertain. We evaluated the sleep of 38 people with PD and observed their turning strategies. Most reported difficulty maintaining sleep and difficulty turning. Those who hip-hitched rated themselves more disabled and those who sat up had more severe PD than those who used support. Using multiple strategies was associated with sleep disturbance. As the ability to turn deteriorates, we recommend patients identify the single strategy least disruptive to sleep. Research must address whether improving mobility improves sleep quality.

Fall events among people with stroke living in the community: circumstances of falls and characteristics of fallers.

OBJECTIVES: To describe the frequency and circumstances of falls among a community sample of people with stroke and to compare characteristics of fallers and nonfallers. DESIGN: Cross-sectional, observational study. SETTING: Community. PARTICIPANTS: Forty-one community-dwelling people with stroke (26 men, 15 women; mean age, 69.7 +/- 11.6y), of which 23 had right-hemisphere infarction, 16 left-hemisphere infarction, and 2 had a brainstem lesion. Time since onset of stroke ranged from 3 to 288 months (mean, 50mo). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Standardized tests were used to measure mobility, upper limb function, activities of daily living (ADL ability), and mood. Information about fall events was collected by using a questionnaire. RESULTS: Twenty-one participants (50%) were classed as fallers, of whom 10 had fallen repeatedly. No significant differences were found between fallers and nonfallers on any of the measures used. However, those who had 2 or more falls (n = 10) had significantly reduced arm function (P = .018) and ADL ability (P = .010), compared with those who had not fallen or experienced near falls (n = 5). Loss of balance, misjudgment, and foot dragging during walking, turning, and sit to stand were reported by fallers as the suspected causes and activities leading to falls. CONCLUSIONS: The high risk of falling among people with stroke was evident in this community-based sample. Repeat fallers had greater mobility deficits and significantly reduced arm function and ADL ability than those who did not report any instability.