Transforming Parkinson's Care in Africa (TraPCAf): protocol for a multimethodology National Institute for Health and Care Research Global Health Research Group project.

BACKGROUND: Parkinson's disease (PD) is the second most common neurodegenerative disorder and, according to the Global Burden of Disease estimates in 2015, was the fastest growing neurological disorder globally with respect to associated prevalence, disability, and deaths. Information regarding the awareness, diagnosis, phenotypic characteristics, epidemiology, prevalence, risk factors, treatment, economic impact and lived experiences of people with PD from the African perspective is relatively sparse in contrast to the developed world, and much remains to be learned from, and about, the continent. METHODS: Transforming Parkinson's Care in Africa (TraPCAf) is a multi-faceted, mixed-methods, multi-national research grant. The study design includes multiple sub-studies, combining observational (qualitative and quantitative) approaches for the epidemiological, clinical, risk factor and lived experience components, as appropriate, and interventional methods (clinical trial component). The aim of TraPCAf is to describe and gain a better understanding of the current situation of PD in Africa. The countries included in this National Institute for Health and Care Research (NIHR) Global Health Research Group (Egypt, Ethiopia, Ghana, Kenya, Nigeria, South Africa and Tanzania) represent diverse African geographies and genetic profiles, with differing resources, healthcare systems, health and social protection schemes, and policies. The research team is composed of experts in the field with vast experience in PD, jointly led by a UK-based and Africa-based investigator. DISCUSSION: Despite the increasing prevalence of PD globally, robust data on the disease from Africa are lacking. Existing data point towards the poor awareness of PD and other neurological disorders on the continent and subsequent challenges with stigma, and limited access to affordable services and medication. This multi-site study will be the first of its kind in Africa. The data collected across the proposed sub-studies will provide novel and conclusive insights into the situation of PD. The selected country sites will allow for useful comparisons and make results relevant to other low- and middle-income countries. This grant is timely, as global recognition of PD and the public health challenge it poses builds. The work will contribute to broader initiatives, including the World Health Organization's Intersectoral global action plan on epilepsy and other neurological disorders. TRIAL REGISTRATION: https://doi.org/10.1186/ISRCTN77014546 .

Psychomotor Dance Therapy Intervention (DANCIN) for people with dementia in care homes: a multiple-baseline single-case study.

BACKGROUND: A Psychomotor DANCe Therapy INtervention (DANCIN) using Latin Ballroom (Danzón) in care homes has previously been shown to enhance well-being for both residents with dementia and staff. The aim of this study was to understand the effect of this approach on the mood and behavior of individual people living with mild to moderate dementia. METHOD: A multiple-baseline single-case study across two care homes and one nursing home with 3-6 weeks baseline, 12-weeks DANCIN (30 minutes/twice-weekly sessions), and 12-weeks follow-up was conducted. Seventeen items from the Dementia Mood Assessment Scale (DMAS) outcome measure were adapted with input from senior staff to match participants' behavior and mood symptoms. Daily monitoring diaries were collected from trained staff on reporting individualized items for ten residents. Data were analyzed, using a non-parametric statistical method known as Percentage of All Non-Overlapping Data (PAND) which provides Phi effect size (ES). Medication use, falls, and life events were registered. RESULTS: Seven residents participated throughout DANCIN whilst three became observers owing to health deterioration. One participant showed adverse effects in three DMAS items. Nine participants, dancers and observers, showed a small to medium magnitude of change (PAND) in 21 DMAS items, indicating a decrease in the frequency of behavior and mood indices which were regarded as problematic; eight items showed no change. CONCLUSION: Despite methodological challenges, the DANCIN model has the potential to facilitate and sustain behavior change and improve mood (e.g. decrease irritability, increase self-esteem) of the residents living with dementia. The study was conducted in two care homes and one nursing home, strengthening the interventions' validity. Findings suggest DANCIN is appropriate for a larger controlled feasibility study.

Dancing as a psychosocial intervention in care homes: a systematic review of the literature.

BACKGROUND: There is a need to find meaningful and engaging interventions to improve mood and behaviour for residents of care homes. The demand on care staff might diminish opportunities for them to encourage these activities. Staff anecdotal information attests that dancing as an activity improves mood in residents and staff. Hence, the importance of investigating what dancing brings to the care home social environment. AIMS: To provide a systematic review of the evidence from studies related to dancing interventions for older people with dementia living in care homes. METHOD: Electronic databases were searched. Previous reviews were also included, and recognised experts were consulted up to January 2012. Inclusion criteria considered study methodology and evidence that the impact of the dance intervention had been measured. RESULTS: Ten studies were identified that satisfied the inclusion criteria: seven qualitative and three quantitative. Studies used different approaches such as therapeutic dance, dance movement therapy, dance therapy, social dancing and psychomotor dance-based exercise. There was evidence that problematic behaviours decreased; social interaction and enjoyment in both residents and care staff improved. A few adverse effects were also acknowledged. CONCLUSION: The evidence on the efficacy of dancing in care homes is limited in part owing to the methodological challenges facing such research. This review aims to raise awareness of the possibility of implementing dance work as an engaging activity in care homes. We shall also consider options for future dance work research as a means to encourage relationships and sensory stimulation for both residents and staff.

Development and validation of a physical activity monitor for use on a wheelchair.

STUDY DESIGN: Keeping physically active is important for people who mobilize using a wheelchair. However, current tools to measure physical activity in the wheelchair are either not validated or limited in their application. The purpose of this study was to develop and validate a monitoring system to measure wheelchair movement. METHODS: The system developed consisted of a tri-axial accelerometer placed on the wheel of a wheelchair and an analysis algorithm to interpret the acceleration signals. The two accelerometer outputs in the plane of the wheel were used to calculate the angle of the wheel. From this, outcome measures of wheel revolutions, absolute angle and duration of movement were derived and the direction of movement (forwards or backwards) could be distinguished. Concurrent validity was assessed in comparison with video analysis in 14 people with spinal cord injury using their wheelchair on an indoor track and outdoor wheelchair skills course. Validity was assessed using intraclass correlation coefficients (ICC(2,1)) and Bland-Altman plots. RESULTS: The monitoring system demonstrated excellent validity for wheel revolutions, absolute angle and duration of movement (ICC(2,1)>0.999, 0.999, 0.981, respectively) in both manual and powered wheelchairs, when the wheelchair was propelled forwards and backwards, and for movements of various durations. CONCLUSION: This study has found this monitoring system to be an accurate and objective tool for measuring detailed information on wheelchair movement and maneuvering regardless of the propulsion technique, direction and speed.

Trajectories of pain over 6 years in early Parkinson's disease: ICICLE-PD.

INTRODUCTION: Pain is a common non-motor symptom in Parkinson's disease (PD), affecting up to 85% of patients. The frequency and stability of pain over time has not been extensively studied. There is a paucity of high-quality studies investigating pain management in PD. To develop interventions, an understanding of how pain changes over the disease course is required. METHODS: One hundred and fifty-four participants with early PD and 99 age-and-sex-matched controls were recruited as part of a longitudinal study (Incidence of Cognitive Impairment in Cohorts with Longitudinal Evaluation in PD, ICICLE-PD). Pain data were collected at 18-month intervals over 72 months in both groups using the Nonmotor Symptom Questionnaire (NMSQ), consisting of a binary yes/no response. Two questions from the Parkinson's Disease Questionnaire (PDQ-39) were analysed for the PD group only. RESULTS: Unexplained pain was common in the PD group and occurred more frequently than in age-matched controls. 'Aches and pains' occurred more frequently than 'cramps and muscle spasms' at each time point (p < 0.001) except 54 months. CONCLUSIONS: This study shows that pain is prevalent even in the early stages of PD, yet the frequency and type of pain fluctuates as symptoms progress. People with PD should be asked about their pain at clinical consultations and given support with describing pain given the different ways this can present.

'PDSAFE' - a multi-dimensional model of falls-rehabilitation for people with Parkinson's. A mixed methods analysis of therapists' delivery and experience.

OBJECTIVE: To explore the clinical reasoning of physiotherapists using PDSAFE; according to disease severity and their experiences of treatment delivery in a large fall-prevention trial for people with Parkinson's (PwP). DESIGN: A descriptive study of delivering PDSAFE. Semi-structured interviews explored therapists' experiences. SETTING: A two-group, home-based, multi-centred, single-blinded, randomised controlled trial showed no overall effect on fall reduction between groups but demonstrated a significant secondary effect relating to disease severity with benefits to balance, falls efficacy and near-falls for all. PARTICIPANTS: Physiotherapists with a background in neurology and older-person rehabilitation were trained in the delivery of PDSAFE INTERVENTION: A multi-dimensional, individually tailored and progressive, home-based programme. RESULTS: Fifteen physiotherapists contributed to the 2587 intervention sessions from the PDSAFE trial and six of those physiotherapists took part in the interviews. The personalised intervention was reflected in the range of strategies and exercises prescribed. Most commonly prescribed fall-avoidance strategies were 'Avoiding tripping', 'Turning' and 'Freezing Cues' and all possible combinations of balance and strength training within the programme were selected. PwP with greater disease severity were more likely to have received less challenging strategies, balance and strengthening exercises than those with lower disease severity. Therapists considered the focus on fall events and fall avoidance strategies an improvement on 'impairment only' treatment. The presence of cognitive deficits, co-morbidities and dyskinesia were the most challenging aspects of delivering the intervention. CONCLUSION: Falls management for PwP is complex and compounded by the progressive nature of the condition. Physiotherapists both delivered and positively received PDSAFE. (248 words) The trial registration number is ISRCTN 48152791.

Mobility in Community Dwelling Older Adults: Predicting Successful Mobility Using an Instrumented Battery of Novel Measures.

Mobility in older adults is associated with better quality of life. However, evidence suggests that older people spend less time out-of-home than younger adults. Traditional methods for assessing mobility have serious limitations. Wearable technologies provide the possibility of objectively assessing mobility over extended periods enabling better estimates of levels of mobility to be made and possible predictors to be explored. Eighty-six community dwelling older adults (mean age 79.8 years) had their mobility assessed for one week using GPS, accelerometry and self-report. Outcomes were: number of steps, time spent in dynamic outdoor activity, total distance travelled and total number of journeys made over the week. Assessments were also made of personal, cognitive, psychological, physical and social variables. Four regression models were calculated (one for each outcome). The models predicted 32 to 43% of the variance in levels of mobility. The ability to balance on one leg significantly predicted all four outcomes. In addition, cognitive ability predicted number of journeys made per week and time spent engaged in dynamic outdoor activity, and age significantly predicted total distance travelled. Overall estimates of mobility indicated step counts that were similar to those shown by previous research but distances travelled, measured by GPS, were lower. These findings suggest that mobility in this sample of older adults is predicted by the ability to balance on one leg. Possible interventions to improve out-of-home mobility could target balance. The fact that participants travelled shorter distances than those reported in previous studies is interesting since this high-functioning subgroup would be expected to demonstrate the highest levels.

Walking and talking: an investigation of cognitive-motor dual tasking in multiple sclerosis.

BACKGROUND: Deficits in motor functioning, including walking, and in cognitive functions, including attention, are known to be prevalent in multiple sclerosis (MS), though little attention has been paid to how impairments in these areas of functioning interact. OBJECTIVES: This study investigated the effects of performing a concurrent cognitive task when walking in people with MS. Level of task demand was manipulated to investigate whether this affected level of dual-task decrement. METHOD: Eighteen participants with MS and 18 healthy controls took part. Participants completed walking and cognitive tasks under single- and dual-task conditions. RESULTS: Compared to healthy controls, MS participants showed greater decrements in performance under dual-task conditions in cognitive task performance, walking speed and swing time variability. In the MS group, the degree of decrement under dual-task conditions was related to levels of fatigue, a measure of general cognitive functioning and self-reported everyday cognitive errors, but not to measures of disease severity or duration. CONCLUSIONS: Difficulty with walking and talking in MS may be a result of a divided attention deficit or of overloading of the working memory system, and further investigation is needed. We suggest that difficulty with walking and talking in MS may lead to practical problems in everyday life, including potentially increasing the risk of falls. Clinical tools to assess cognitive-motor dual-tasking ability are needed.

Everyday walking with Parkinson's disease: understanding personal challenges and strategies.

PURPOSE: This qualitative study was designed to explore the personal experience of everyday walking with Parkinson's disease (PD), the challenges and the strategies employed to compensate for difficulties, to help contextualise the scientific knowledge base. METHODS: Semi-structured interviews were undertaken with a sample of 20 people with idiopathic PD (12 male, 8 female; mean age 65 years (range 50 - 80); mean disease duration 10 years (range 2.5 - 26). Verbatim interview transcripts were analyzed thematically using NUD*IST N6 qualitative data analysis software. RESULTS: Walking was invariably performed as an integral part of a purposeful activity within a specific context, termed walking 'plus', with challenges encountered by people with PD in three main areas: Undertaking tasks; negotiating environments; and making transitions to walking. The two key strategies to compensate for difficulties experienced were monitoring through the use of concentration, and correcting through generating rhythm and size of steps. Carers supported monitoring and correcting. CONCLUSION: People with PD need to constantly assess and drive their walking performance. Attentional resources, which can themselves be compromised in PD, were used to accomplish what is normally a largely automatic activity. Personal accounts support scientific hypotheses. Rehabilitation interventions and measurements in PD need to reflect both the physical and psychosocial context of everyday walking.

Do you see what I see? Mobile eye-tracker contextual analysis and inter-rater reliability.

Mobile eye-trackers are currently used during real-world tasks (e.g. gait) to monitor visual and cognitive processes, particularly in ageing and Parkinson's disease (PD). However, contextual analysis involving fixation locations during such tasks is rarely performed due to its complexity. This study adapted a validated algorithm and developed a classification method to semi-automate contextual analysis of mobile eye-tracking data. We further assessed inter-rater reliability of the proposed classification method. A mobile eye-tracker recorded eye-movements during walking in five healthy older adult controls (HC) and five people with PD. Fixations were identified using a previously validated algorithm, which was adapted to provide still images of fixation locations (n = 116). The fixation location was manually identified by two raters (DH, JN), who classified the locations. Cohen's kappa correlation coefficients determined the inter-rater reliability. The algorithm successfully provided still images for each fixation, allowing manual contextual analysis to be performed. The inter-rater reliability for classifying the fixation location was high for both PD (kappa = 0.80, 95% agreement) and HC groups (kappa = 0.80, 91% agreement), which indicated a reliable classification method. This study developed a reliable semi-automated contextual analysis method for gait studies in HC and PD. Future studies could adapt this methodology for various gait-related eye-tracking studies.

Cueing training in the home improves gait-related mobility in Parkinson's disease: the RESCUE trial.

OBJECTIVES: Gait and mobility problems are difficult to treat in people with Parkinson's disease. The Rehabilitation in Parkinson's Disease: Strategies for Cueing (RESCUE) trial investigated the effects of a home physiotherapy programme based on rhythmical cueing on gait and gait-related activity. METHODS: A single-blind randomised crossover trial was set up, including 153 patients with Parkinson's disease aged between 41 and 80 years and in Hoehn and Yahr stage II-IV. Subjects allocated to early intervention (n = 76) received a 3-week home cueing programme using a prototype cueing device, followed by 3 weeks without training. Patients allocated to late intervention (n = 77) underwent the same intervention and control period in reverse order. After the initial 6 weeks, both groups had a 6-week follow-up without training. Posture and gait scores (PG scores) measured at 3, 6 and 12 weeks by blinded testers were the primary outcome measure. Secondary outcomes included specific measures on gait, freezing and balance, functional activities, quality of life and carer strain. RESULTS: Small but significant improvements were found after intervention of 4.2% on the PG scores (p = 0.005). Severity of freezing was reduced by 5.5% in freezers only (p = 0.007). Gait speed (p = 0.005), step length (p<0.001) and timed balance tests (p = 0.003) improved in the full cohort. Other than a greater confidence to carry out functional activities (Falls Efficacy Scale, p = 0.04), no carry-over effects were observed in functional and quality of life domains. Effects of intervention had reduced considerably at 6-week follow-up. CONCLUSIONS: Cueing training in the home has specific effects on gait, freezing and balance. The decline in effectiveness of intervention effects underscores the need for permanent cueing devices and follow-up treatment. Cueing training may be a useful therapeutic adjunct to the overall management of gait disturbance in Parkinson's disease.

Exercise for improving balance in older people.

BACKGROUND: Diminished ability to maintain balance may be associated with an increased risk of falling. In older adults, falls commonly lead to injury, loss of independence, associated illness and early death. Although some exercise interventions with balance and muscle strengthening components have been shown to reduce falls it is not known which elements, or combination of elements, of exercise interventions are most effective for improving balance in older people. OBJECTIVES: To present the best evidence for effectiveness of exercise interventions designed to improve balance in older people living in the community or in institutional care. SEARCH STRATEGY: We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (Feb 2006), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2006, Issue 1), MEDLINE (1966 to February 2006), EMBASE (1980 to February 2006), other databases and reference lists of articles. No language restrictions were applied. SELECTION CRITERIA: Randomised controlled trials and quasi-randomised trials testing exercise interventions designed to improve balance in older people were included. We excluded trials of interventions targeting individuals with specific conditions in order not to broaden the scope of this review too widely. Trials were included where participants were randomised to receive the following: a single exercise intervention or a multiple exercise intervention and a control group (usual activities or attention or recreational activity). Trials comparing two or more exercise interventions and a control group were also included. DATA COLLECTION AND ANALYSIS: Three pairs of members of the review team independently assessed trial quality and extracted data. For each trial, relative risk and 95% confidence intervals were calculated for dichotomous outcomes, and mean differences and 95% confidence intervals calculated for continuous outcomes. Where appropriate, results of comparable groups of trials were pooled and 95% confidence intervals calculated. MAIN RESULTS: For the 34 included studies there were 2883 participants at entry. Statistically significant improvements in balance ability were observed for exercise interventions compared to usual activity. Interventions involving gait; balance; co-ordination and functional exercises; muscle strengthening; and multiple exercise types appear to have the greatest impact on indirect measures of balance. There was trend towards an improvement in balance with cycling on a static cycle. However, there was limited evidence that effects were long-lasting. AUTHORS' CONCLUSIONS: Exercise appears to have statistically significant beneficial effects on balance ability in the short term but the strength of evidence contained within these trials is limited. Many of these mainly small studies demonstrated a range of methodological weaknesses. The failure across the included studies to apply a core set of standardised outcome measures to determine balance ability restricts the capacity to compare or pool different trials from which firm conclusions regarding efficacy can be made. Further standardisation in timing of outcome assessment is also required as is longer term follow-up of outcomes to determine any lasting effects.

fNIRS response during walking - Artefact or cortical activity? A systematic review.

This systematic review aims to (i) evaluate functional near infrared spectroscopy (fNIRS) walking study design in young adults, older adults and people with Parkinson's disease (PD); (ii) examine signal processing techniques to reduce artefacts and physiological noise in fNIRS data; and (iii) provide evidence-based recommendations for fNIRS walking study design and signal analysis techniques. An electronic search was undertaken. The search request detailed the measurement technique, cohort and walking task. Thirty-one of an initial yield of 73 studies satisfied the criteria. Protocols and methods for removing artefacts and noise varied. Differences in fNIRS signals between studies were found in rest vs. walking, speed of walking, usual vs. complex walking and easy vs. difficult tasks. In conclusion, there are considerable technical and methodological challenges in conducting fNIRS studies during walking which can introduce inconsistencies in study findings. We provide recommendations for the construction of robust methodologies and suggest signal processing techniques implementing a theoretical framework accounting for the physiology of haemodynamic responses.

Objective clinical measurement of physical functioning after treatment for lower extremity sarcoma - A systematic review.

BACKGROUND: Physical impairments and activity restrictions cause significant morbidity after surgery for sarcoma. Yet objective assessment of key components of balance, gait and physical activity (PA), using valid and reliable outcome measures, is lacking in routine clinical practice. PURPOSE OF REVIEW: We therefore performed a systematic review to identify studies quantifying balance, gait and PA in clinically useful ways, after treatment for lower extremity sarcoma. PATIENTS AND METHODS: Relevant articles quantifying balance, gait and PA in patients who underwent surgery for lower extremity bone or soft tissue sarcoma were identified from Medline, Embase, Scopus, and Web of Science up to February 2016. Results were compiled by principal research findings, objective measures used, their ability to detect differences between important clinical groups, change over time and reliability. RESULTS: Eighteen articles were included. Surgery had a significant impact on outcomes (p < 0.05). A wide range of measures and concerns about accuracy of measurement were noted, as gait and PA measures did not discriminate between distinct clinical groups such as limb sparing surgery and amputation, and did not detect changes over time. Few studies investigated reliability (n = 1) and sensitivity to change (n = 4). CONCLUSION: There is a deficit of studies quantifying balance, gait and PA in patients with lower extremity sarcoma. Studies did not use consistent, valid and reliable instruments. There is an urgent need to develop novel objective measures of physical functioning in this patient group to encourage evidence-based clinical care.

The effect of rhythmic somatosensory cueing on gait in patients with Parkinson's disease.

BACKGROUND AND AIMS: Gait and gait related activities in patients with Parkinson's disease (PD) can be improved with rhythmic auditory cueing (e.g. a metronome). In the context of a large European study, a portable prototype cueing device was developed to provide an alternative for rhythmic auditory cueing: rhythmic somatosensory cueing (RSC, a miniature vibrating cylinder attached to the wrist). We investigated whether PD patients could adapt their walking pattern using RSC under conditions of changing walking speed and the presence of potentially distracting visual flow while walking on a treadmill. METHODS: A total of 17 patients with PD participated (mean age 63.4+/-10.3 years; Hoehn-Yahr score 2.5+/-0.9, mean Unified Parkinson's Disease Rating Scale score 49.8+/-13.7, mean disease duration 7.7+/-5.1 years). They performed systematic walking speed manipulations under 4 conditions in a random order: (1) no cue, no visual flow, (2) no cue, visual flow, (3) cue, no visual flow and (4) cue, visual flow. Visual flow in the form of a virtual corridor that moved at the current walking speed was projected on a 2 x 2 m rear-projection screen. The cueing rhythm was set at -10% of preferred stride frequency at each speed. Stride frequency was assessed using peaks in the trajectories of thigh sagittal plane segmental angles. RESULTS: Walking with RSC resulted in lower stride frequencies, and thus larger step lengths (p-values <0.05), regardless of walking speed. The presence of visual flow did not impair the use of RSC, as evidenced by the lack of differences between conditions 3 and 4 (p>0.05). CONCLUSION: Rhythmic somatosensory cueing may be a viable alternative for auditory cueing and is robust to changes in walking speed and visual distractors.

The effects of visual rhythms and optic flow on stride patterns of patients with Parkinson's disease.

This study was aimed at determining the effects of rhythmic visual cueing under changing visual conditions on stride frequency in patients with Parkinson's disease (PD; n = 21) and healthy age matched controls (n = 7) while walking at different speeds on a treadmill. Stride frequency and stride length in patients with PD as well as controls were not rigidly coupled to walking speed and could be manipulated with walking speed as well as by using spatial and temporal rhythmic visual cues.

The use of rhythmic auditory cues to influence gait in patients with Parkinson's disease, the differential effect for freezers and non-freezers, an explorative study.

PURPOSE: To study the effect of rhythmic auditory cues on gait in Parkinson's disease subjects with and without freezing and in controls. METHOD: A volunteer sample of 20 patients (10 freezers, 10 non-freezers) and 10 age-matched controls performed five randomized cued walking conditions in a gait-laboratory. Auditory cues were administered at baseline frequency, at an increased step frequency of 10 and 20% above baseline and at a decreased step frequency of 10 and 20% below baseline. Mean step frequency, walking speed, stride length and double support duration were collected. RESULTS: Rhythmical auditory cueing induced speed changes in all subjects. Stride length was not influenced by rhythmical auditory cues in controls, whereas patients showed a larger stride length in the -10% condition (p < 0.01). Freezers and non-freezers showed the same response to rhythmical auditory cues. Within group analysis for stride length showed different cueing effects. Stride length decreased at the +10% condition for freezers (p < 0.05), whereas it increased for non-freezers. CONCLUSIONS: This study points to fact that physiotherapists might need to carefully adjust the cueing frequency to the needs of patients with and without freezing. On the basis of the present results we recommend to lower the frequency setting for freezers, whereas for non-freezers an increase of up to +10% may have potential therapeutic use.

Accuracy and re-test reliability of mobile eye-tracking in Parkinson's disease and older adults.

Mobile eye-tracking is important for understanding the role of vision during real-world tasks in older adults (OA) and people with Parkinson's disease (PD). However, accuracy and reliability of such devices have not been established in these populations. We used a novel protocol to quantify accuracy and reliability of a mobile eye-tracker in OA and PD. A mobile eye-tracker (Dikablis) measured the saccade amplitudes of 20 OA and 14 PD on two occasions. Participants made saccades between targets placed 5°, 10° and 15° apart. Impact of visual correction (glasses) on saccadic amplitude measurement was also investigated in 10 OA. Saccade amplitude accuracy (median bias) was -1.21° but a wide range of bias (-7.73° to 5.81°) was seen in OA and PD, with large vertical saccades (15°) being least accurate. Reliability assessment showed a median difference between sessions of <1° for both groups, with poor to good relative agreement (Spearman rho: 0.14 to 0.85). Greater accuracy and reliability was observed in people without visual correction. Saccade amplitude can be measured with variable accuracy and reliability using a mobile eye-tracker in OA and PD. Human, technological and study-specific protocol factors may introduce error and are discussed along with methodological recommendations.

Vision, visuo-cognition and postural control in Parkinson's disease: An associative pilot study.

INTRODUCTION: Impaired postural control (PC) is common in patients with Parkinson's disease (PD) and is a major contributor to falls, with significant consequences. Mechanisms underpinning PC are complex and include motor and non-motor features. Research has focused predominantly on motor and sensory inputs. Vision and visuo-cognitive function are also integral to PC but have largely been ignored to date. The aim of this observational cross-sectional pilot study was to explore the relationship of vision and visuo-cognition with PC in PD. METHODS: Twelve people with PD and ten age-matched healthy controls (HC) underwent detailed assessments for vision, visuo-cognition and postural control. Vision assessments included visual acuity and contrast sensitivity. Visuo-cognition was measured by visuo-perception (object identification), visuo-construction (ability to copy a figure) and visuo-spatial ability (judge distances and location of object within environment). PC was measured by an accelerometer for a range of outcomes during a 2-min static stance. Spearman's correlations identified significant associations. RESULTS: Contrast sensitivity, visuo-spatial ability and postural control (ellipsis) were significantly impaired in PD (p=0.017; p=0.001; and p=0.017, respectively). For PD only, significant correlations were found for higher visuo-spatial function and larger ellipsis (r=0.64; p=0.024) and impaired attention and reduced visuo-spatial function (r=-0.62; p=0.028). CONCLUSIONS: Visuo-spatial ability is associated with PC deficit in PD, but in an unexpected direction. This suggests a non-linear pattern of response. Further research is required to examine this novel and important finding.

Measuring gait and gait-related activities in Parkinson's patients own home environment: a reliability, responsiveness and feasibility study.

The aim of this study was to assess reliability, responsiveness and feasibility of gait and gait related tests in the home of patients with Parkinson's disease (PD). The Unified Parkinson's Disease Rating Scale, a timed walking test, the Timed Get Up and Go test the Berg Balance Scale and the Functional Reach test were applied by three independent observers on 26 PD patients. Moderate to high Intraclass Correlation Coefficients were found, ranging from 0.74 to 0.88 and 0.64 to 0.87 for the intra- and inter-observer reliability, respectively. All test showed Reliable Change Indexes under 11% and the whole test battery was applicable within 30 min.