Brook Galna

Background: We investigated how commonly telehealth is used by people with MS, their satisfaction with telehealth during the COVID-19 period, and recommendations to improve their experiences with telehealth.

Methods: In October-December 2020 we surveyed Australians with MS. We collected demographic, disease- related and social health determinant data, data on telehealth use and experiences during the COVID-19 pandemic, and recommendations on telehealth improvements. We conducted univariate analysis to compare factors associated with telehealth use versus no use, established frequencies of experiences and suggestions for improvement, and conducted thematic analysis on free-text suggestions for improvement.

Results: Of the 1485 participants, 69.7% had used telehealth since the start of the COVID-19 pandemic, there were small differences in demographical, disease and social health determinants to explain telehealth use.Most participants who used telehealth had good or very good experiences (74.3%). Most common
suggestions to improve telehealth experiences was “guidance on preparing for telehealth sessions” (n = 545, 60%). Themes of expansion in telehealth availability and expansion to physical test and physical treatments were wanted by participants.

Conclusion: Persons with MS in Australia commonly used telehealth during the COVID-19 pandemic and were generally satisfied with their experiences. Implementing the suggested improvements will further optimise the use of telehealth.

Background:
We investigated how commonly telehealth is used by people with MS, their satisfaction with telehealth during the COVID-19 period, and recommendations to improve their experiences with telehealth.

Methods:
In October-December 2020 we surveyed Australians with MS. We collected demographic, disease-related and social health determinant data, data on telehealth use and experiences during the COVID-19 pandemic, and recommendations on telehealth improvements. We conducted univariate analysis to compare factors associated with telehealth use versus no use, established frequencies of experiences and suggestions for improvement, and conducted thematic analysis on free-text suggestions for improvement.

Results:
Of the 1485 participants, 69.7% had used telehealth since the start of the COVID-19 pandemic, there were small differences in demographical, disease and social health determinants to explain telehealth use . Most participants who used telehealth had good or very good experiences (74.3%). Most common suggestions to improve telehealth experiences was “guidance on preparing for telehealth sessions” (n = 545, 60%). Themes of expansion in telehealth availability and expansion to physical tests and physical treatments were wanted by participants.

Conclusion:
Persons with MS in Australia commonly used telehealth during the COVID-19 pandemic and were generally satisfied with their experiences. Implementing the suggested improvements will further optimise the use of telehealth.

[Poster] BACKGROUND AND AIM: The ability to safely negotiate obstacles is important for independent mobility. Appropriate processing of visual information helps to identify and distinguish environmental obstacles and their location. Visual function is compromised in people with Parkinson’s disease (PD) with respect to appropriate observation of the environment and is linked to poorer attention[1] and impaired contrast sensitivity[2]. Together they may contribute to falls in PD during challenging tasks such as obstacle crossing[3]. The aim of this study was to determine the effect of obstacle contrast on visual behaviour and whether this was altered in PD. METHODS: Seventeen mild-to-moderate PD fallers (x̅[SD]age:71.1[8.2]y, 10♂) and 18 older adult non-fallers(x̅[SD]age:64.4[7.0]y, 9♂) participated. Participants began the walking trials with their eyes closed and when prompted opened their eyes and walked to the end of a 10-metre walkway. An obstacle of high or low contrast (HxWxD 15cmx60cmx2cm) was placed half way down the walkway and the presentation order was counterbalanced. Visual behaviour was monitored using a mobile eye-tracker (Dikablis) and contextual outcomes were extracted from the approach phase (Approach time[s], movement latency[s], time spent looking at the obstacle[%], time spent looking at the ground preceding the obstacle[%] and time spent looking at the ground past the obstacle[%]). Contrast sensitivity was measured binocularly (Mars CS chart). Group medians were used to complete non-parametric comparisons between groups and obstacle conditions. RESULTS: Contrast sensitivity was significantly reduced in PD (x̅[SD]:1.51[0.16] vs. 1.64[0.07],p=.006). There were no group differences in visual behaviour when negotiating the high contrast obstacle (p=.126), movement latency (p=.858) and the time spent looking at the ground past the obstacle (p=.143). There was a trend for PD to spend longer looking at the obstacle but this was not significant (p=.067). In the low contrast obstacle condition, PD took significantly longer during their approach to the obstacle (4.2s vs. 3.1s, p<.001) and spent longer looking at the obstacle as a proportion of the approach phase (51.5% vs. 22.7%, p=.025) compared to the older adults who spent proportionally more time looking at the ground beyond the obstacle (75.0% vs. 29%,p=.007). CONCLUSIONS: The clarity of obstacles influences visual behaviour. Our findings suggest that increased contrast improves visual behaviour in PD so that it becomes similar to older adults. When obstacle contrast was low, participants with PD prolonged their visual attention to the obstacle to gather sufficient information regarding the obstacle proximity and dimensions limiting their capacity to scan for future obstacles. Future studies will explore the manipulation of contrast within natural environments where the presence and location of trip hazards such as obstacles are not known. REFERENCES: [1]Galna 2012 BrainRes 1473 35-43 [2]Hwang 2013 J Neurosci 33 14989-14997 [3]Gazibara 2014 Geriatric Nursing 35 364-369

[Poster] INTRODUCTION: People with Parkinson’s disease (PD) commonly report visual problems, such as impaired eye movements [1,2]. Visual dysfunction can impact safe walking capability, particularly if task-relevant visual information is not gathered when walking. Limited research exists that has explored the location of gaze fixations when walking [3], which are important for appropriate visual input during locomotion. AIM: This study aimed to examine the task-relevance of fixation locations during various walking tasks in PD. METHOD: 40 control (68.8[8.8]y, 20m) and 38 PD participants (69.6[8.2]y, 23m) ; one with no additional stimuli and another with additional stimuli (either with visual cues or a high contrast obstacle to transverse) whilst wearing a mobile eye-tracking device. All walks were repeated under dual task (Wechsler digit span) conditions. The location of fixations was manually classified, coded as relevant/irrelevant to the task, and analysed using negative binomial regression. RESULTS: During single task walking, people with PD made significantly more fixations (p=.032) with the difference resulting from more irrelevant fixations (p=.014). Both groups had similar number and relevance of fixations with visual cues (p=.359). However, people with PD required more task-relevant fixations (i.e. looked at the obstacle/floor more) to complete both single task (p=.007) and dual task (p=.007) obstacle crossing trials. CONCLUSION: People with PD make more irrelevant fixations than controls when walking, which may contribute to impaired mobility and falls. High contrast obstacles and visual cues attract visual attention to relevant areas when walking, which may reduce falls risk. An increased frequency of task relevant fixations during both single and dual task obstacle negotiation indicated that home based modifications such as improving the saliency of trip hazards may redirect visual exploration even when attentional demands are high. Further work is required to examine fixations locations when walking in real-world environments which contain more visual distractors. REFERENCES: [1] Chan et al., (2005). Neuropsychologia, 43(5), pp.784-796. [2] Amador et al., (2006). Neuropsychologia, 44(8), pp.1475-1482. [3] Stuart et al., (2016). Neurosci Biobehav Rev, 62, pp.76-88.

[Poster] BACKGROUND AND AIM: Gait impairments are frequent among older adults and associated with fall risk. Intervention programmes aiming to reduce fall risk (e.g. balance exercise programs) usually focus on single risk factors (i.e. either motor or cognitive performance). The effects of interventions on free-living walking activity are still not clear and need to be explored. Recently, the V-TIME study showed that a six week multimodal intervention programme of treadmill training combined with a virtual reality component (TTVR) lowered the incidence of falls more than an intensity-matched intervention with treadmill training (TT) only [1]. The aim of this exploratory analysis was to examine the hypothesis that a lower fall risk due to the TTVR intervention would be mediated by change in volume, pattern and variability (macro gait outcomes) of free living walking activity. METHODS: 165 older adults (age: 74±7 years) including: 72 elderly fallers (EF), 24 people with mild cognitive impairment (MCI) and 69 people with Parkinson's disease (PD), who had fallen twice or more in the previous 6 months were assessed. Participants were randomly assigned to TT or TTVR interventions and tested at baseline and after the intervention (1 week, 1 month and 6 months) [1]. For each assessment free-living data were recorded for 7 days with an accelerometer (Axivity AX3) placed on the lower back. Macro gait outcomes representing the volume (% walking time, number of bouts per day, number of steps, mean bout length), pattern (alpha), and variability of free-living walking activity were extracted in MATLAB® (R2012a) [2]. General linear models were used to examine the effect of Group (EF vs PD vs MCI), Time and Intervention on macro gait, controlling for age and sex. RESULTS: Macro gait outcomes did not changed over time (main effect for Time p > 0.05). In addition, there were no significant Group x Time or Intervention x Time interactions. This suggests the lack of change was consistent between groups and intervention type. We repeated the analysis including different thresholds of bout length (bouts over 10 seconds and 60 seconds) with similar results. Significant group effects (EF vs PD vs MCI) showed that PD had more variable bout lengths compared to EF and MCI (p ≤ 0.016). CONCLUSIONS: This exploratory work showed that despite reducing the incidence of falls, a 6 week treadmill training intervention (with or without VR augmentation) did not change macro gait outcomes (volume, pattern and variability) in older adult fallers who managed to sustain free-living walking activity while reducing fall risk. Reduction in falls rate due to treadmill training does not seem to be mediated by a change in macro gait outcomes of free-living walking activity. REFERENCES: [1]Mirelman A et al, Lancet, 2016; 388(10050):1170-82 [2]Lord S et al, J Neurol., 2013; 260(12):2964-72

[Poster]

Objective: To examine whether gait impairment measured within 4 months of being diagnosed with Parkinson’s disease (PD) can predict decline in attention over the subsequent 3 years.

Background: Impaired cognitive function is associated with gait impairment in incident PD in cross sectional studies1. Our preliminary work suggests walking speed can predict decline in attention in incident PD2. We sought to replicate our preliminary work in a subset of the same cohort once disease advanced a further 18 months. If gait can predict attentional decline, it may provide further evidence for gait as a non-invasive surrogate marker to identify those at risk of cognitive impairment and PD dementia.

Methods: 51 idiopathic PD and 49 age-matched controls completed assessments for gait and attention at baseline and 3 years later. Participants walked continuously for two minutes at their normal pace during which step velocity and step length were collected using a 7m GaitRite™ instrumented walkway. Attention was assessed using the cognitive drug research (CDR) computerized battery. Scatterplots and linear multiple regression analysis were used to assess the predictive value of baseline gait in relation to change in attention over 36 months controlling for age.

Results: In PD but not control participants a decline in fluctuating attention over 3 years was associated with slower velocity (p.013) and a shorter step length (p<.01) at diagnosis. Both step velocity and step length were entered into a regression model controlling for age. Step velocity was found to be an independent predictor of change in fluctuating attention (F(2,50) = 5.513, p<0.05, adjusted r2=.153, β=-.311) step length was a stronger independent predictor (F (2,50)=6.323, p<0.01, adjusted r2=.209, β=-.354). Conversely, fluctuating attention at baseline was unable to predict change in fluctuating attention or change in step length over 3 years.

Conclusions: Baseline step velocity and step length but not baseline fluctuating attention were significantly associated with change in fluctuating attention over 36 months in an incident PD cohort. This confirms earlier findings and suggests that gait may be a useful surrogate marker of change in cognitive function in PD that is not due to the normal ageing process.

1Lord, S et al. Front. Aging Neurosci,6: 249.
2Lord, S. et al. Mov Disord 2013;28 Sup 1: 361

[Poster]

BACKGROUND AND AIM: Successful obstacle negotiation is a complex motor task which relies on adequate vision to distinguish the obstacle from the ground. Reduced visual acuity and contrast sensitivity are common in ageing[1] and people with Parkinson's disease (PD)[2] which may impede safe negotiation of cluttered environments and contribute to increased falls risk. The aim of this study was to investigate the effect of visual contrast on obstacle negotiation in people who fall with and without PD.

METHODS: Gait was measured in 9 people with PD (Mean[SD]age: 68.9[7.1]y, H&Y stage II-III) and 12 older adults (Age:75.5[7.6]y) with a history of recurrent falls. Participants negotiated a small (2x60x2cm), long (2x60x15cm), and high (15x60x2cm) obstacle under high and low contrast (hue (colour) manipulation) conditions. Gait characteristics (speed, step length, duration and width) were measured using an instrumented walkway (GAITRite). A general linear model evaluated the effects of obstacle type (small/long/high); step (penultimate (A2) and final (A1) approach steps, and the lead (Ld) and trail (Tr) crossing steps); and obstacle contrast (high/low) on gait in PD and older adult fallers. Ophthalmologic assessments were obtained binocularly.

RESULTS: The visual acuity of older adult fallers was considerably worse than PD fallers (p=.066) but contrast sensitivity was similar (p=.703). PD fallers widened their step when crossing the small and long obstacles more than older adult fallers when obstacle contrast was high (11% and 14% increase, respectively). When contrast was low, PD fallers widened their step as a function of obstacle type (small-long-high, p=.038). Participants crossed the high obstacle (high contrast) more slowly and slowed down earlier in the approach for the high obstacle under low contrast conditions irrespective of group (p=.035, Figure 1). Increased step length was observed for the long obstacle (low contrast) condition, particularly for the lead step compared to the small and high obstacles (p=.003, Figure 1).

CONCLUSIONS: Obstacle negotiation is altered when contrast is reduced. PD fallers widened their step when negotiating high obstacles under low contrast, suggesting that when task-relevant stimuli are less visually prominent additional motor alterations are required to compensate. The increased lead step length observed for the long obstacle (low contrast) was likely an adaptation in response to reduced obstacle edge definition and therefore both groups exaggerated their step to safely clear the obstacle. Improving the contrast of potential hazards in the home and community is important to reduce trip hazards particularly when object edge definition is reduced (minimal environmental contrast) and environmental hazards are less protrusive within the field of view (relative orientation of long vs. high obstacle).

REFERENCES: [1] Lord (2001) JAGS 508-515 [2] Davidsdottir (2005) Vision Research 1285-1296

[Poster]

Background/Issue of Concern
Visual exploration of the environment through appropriate eye-movements is vital for safe and effective walking, and is influenced by cognitive processes. Cognitive impairment is common in Parkinson’s disease (PD) and likely affects visual exploration, and so contributes to walking problems and falls risk.

Rationale/Purpose or Research Question
To investigate visual exploration using eye-movements during walking in PD in response to environmental and attentional demand, and to examine the association between eye-movements and cognition.

Process – What Did You Do? or Method
30 PD participants and 30 age-matched controls underwent visual, cognitive and clinical assessments. Participants then walked under varied environmental conditions (straight, through a door and turning) and attentional demand (single and dual-task). A Dikablis mobile eye-tracker measured saccadic (fast) eye-movements, a proxy for purposeful visual attention.

Findings/Outcome or Results
PD participants made fewer eye-movements (p=.009) suggesting they explore the environment less. Eye-movement significantly increased with environmental complexity (p < .001) and decreased with attentional demand (dual-task) (p<.001) for both groups. A surprising finding showed a relationship between poorer cognition (particularly attention) and increased eye-movement during several of the walking trials for PD only (e.g. straight walking; r = -0.53, p=.021).

Conclusion
PD made fewer eye-movements than controls when walking but changed their eye-movement frequency the same as controls in response to environmental and attentional demand. Interestingly within PD, poorer cognition was associated with more frequent eye-movements, which may reflect a reduced capacity to cognitively inhibit non-purposeful eye-movements to irrelevant stimuli.

Implications for Practice/Trust/Role or Service
• PD explore their environment less when walking which may increase falls risk
• Attention is associated with exploration and may be a target for intervention