Katherine Baker

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.

The attentional cost of external rhythmical cues and their impact on gait in Parkinson’s disease: effect of cue modality and task complexity

SummaryChanges in gait performance in 153 subjects with PD using three rhythmical cues (auditory, visual and somatosensory) were measured during a simple walking task and a dual walking task in the home. Subjects were ‘on’ medication and were cued at preferred step frequency. Accelerometers recorded gait and walking speed, step amplitude and step frequency were determined from raw data. Data were analysed with SAS using linear regression models. Gait performance during a single task reduced with cues in contrast to a dual task where PD subjects appeared to benefit from rhythmical cues (increased speed and step length). Effects were dependent on cue modality with significant improvements for auditory cues compared to others. A significant short-term carry-over effect of cues reduced 3 weeks later. Cues may reduce attentional demands by facilitating attentional allocation, accounting for differences of cue seen during single and dual task. Furthermore cue modality may influence attentional demand which is an important consideration for rehabilitation.

The Short-Term Effects of Different Cueing Modalities on Turn Speed in People with Parkinson’s Disease

Background. Turning has been associated with instability, falls, and freezing in people with Parkinson’s disease (PD). Objective. To investigate the effect of different modalities of rhythmic cueing on the duration of a functional turn in freezers and nonfreezers. Methods. A total of 133 patients with idiopathic PD while in the on phase of the medication cycle participated in this study as part of a subanalysis from the RESCUE trial. The effect of 3 different cue modalities on functional turning performance was investigated, involving a 180° turn while picking up a tray. Time to perform this task was measured using an activity monitor. Tests were performed without cues and with auditory, visual, and somatosensory cues delivered in a randomized order at preferred straight-line stepping frequency. Results. Cueing (all types) increased the speed of the turn in all subjects. There was no difference between turn performance of freezers and nonfreezers in cued and noncued conditions. Auditory cues made turning significantly faster than visual cues (P < .01) but not compared with somatosensory cues, except in nonfreezers. There was a short-term carryover in the final noncued trial. Conclusions. Rhythmical cueing yielded faster performance of a functional turn in both freezers and nonfreezers. This may be explained by enhancing attentional mechanisms during turning. Although no harmful effects were recorded, the safety of cueing for turning as a therapeutic strategy needs further study.

Gait variability in Parkinson’s disease: an indicator of non-dopaminergic contributors to gait dysfunction?

Gait variability has potential utility as a predictive measure of dysfunction in Parkinson’s disease (PD). Current understanding implicates non-dopaminergic pathways. This study investigated the explanatory characteristics of gait variability in PD on and off medication under single and dual task conditions. Fifty people with PD were assessed twice at home (on and off l-dopa) whilst walking under single and dual task conditions, and variability (coefficient of variation, CV) was calculated for stride time and double limb support (DLS) time. Hierarchical regression analysis was used to identify predictors. The first block of variables included age, gait speed, depression (Hospital Anxiety and Depression Scale) and fatigue (Multidimensional Fatigue Inventory), and the second block included motor severity (UPDRS III), executive function (Hayling and Brixton) and attention (Test of Everyday Attention). Motor severity predicted stride time variability and DLS time variability independent of l-dopa during single task gait. Dual task gait yielded a more complex picture. Depression made a unique contribution of 9.0% on medication and 5.0% off medication to stride time variability, and visual attention and younger age contributed to DLS variability on medication, explaining 3% and 2%, respectively. Motor severity predicted DLS variability off medication, explaining 74% of variance. Different characteristics explain the two measures of gait variability, pointing to different control mechanisms.

Walking speed during single and dual tasks in Parkinson's disease: which characteristics are important?

The impact of dual tasks on gait in Parkinsons disease (PD) reveals lack of automaticity and increased cognitive demands. We explored which characteristics explained walking speed with and without dual task interference and if they reflected the cognitive demands of the task. In 130 people with PD, gait performance was quantified in the home using accelerometers allowing estimates of single and dual task walking speed and interference (difference between dual and single task). Multiple regression analysis was used to explore the effect of 12 characteristics representing four domains (personal, motor symptoms, cognitive, affective) on gait outcomes. Thirty‐seven percent of variance in single task speed was explained by increased fear of falling, sex, age, disease severity, and depression; 34% of variance in dual task speed was explained by increased fear of falling, disease severity, medication, and depression; 12% of variance in interference scores was explained by greater disease severity and impaired executive function. Personal, motor, affective, and cognitive characteristics contribute to walking speed and interference, highlighting the multifactorial nature of gait. Different patterns of characteristics for each outcome indicates the impact of cognitive demand and task complexity, providing cautious support for dual task speed and interference as valid proxy measures of cognitive demand in PD gait.

The pattern of habitual sedentary behavior is different in advanced Parkinson's disease.

Physical behavior changes in Parkinsons disease (PD), however, objective evidence of this is lacking. This study explored methods to objectively quantify sedentary behavior (SB) in advanced PD with the aim of identifying changes that could impact on the burden of disease. We compared the SB of 17 PD (UPDRS III 29.1 ± 5.5; disease duration 12.5 ± 6.4; H&Y (3 & 4) and 17 aged and gender matched healthy subjects. SB was measured objectively over a 7 day period using the activPAL accelerometer. SB was defined as sitting or lying and described in terms of the volume and pattern of SB. Comparison between PD and controls showed that whilst there was no difference in the volume of sedentary time (P = 0.15), there was a significant difference in distribution (P < 0.01) and pattern of accumulation of sedentary time (P < 0.01). Bouts of SB in people with PD tend to last longer than that of controls, whilst the total time spent inactive is the same for the two groups. These results suggest that PD leads to a change in the pattern of SB but not the volume. This may be interpreted as a strategy to conserve energy to maximize function. Studying the pattern of SB appears promising and has the potential to help us to understand the impact of PD and the consequences of changes in SB on the burden of disease.

Targeting dopa-sensitive and dopa-resistant gait dysfunction in Parkinson's disease: Selective responses to internal and external cues

Independence of certain gait characteristics from dopamine replacement therapies highlights its complex pathophysiology in Parkinsons disease (PD). We explored the effect of two different cue strategies on gait characteristics in relation to their response to dopaminergic medications.

Identifying fallers with Parkinson's disease using home-based tests: who is at risk?

The objective of this work is to determine risk factors for falling in patients with Parkinsons disease (PD) using home‐based assessments and develop a prediction model. Data on falls, balance, gait‐related activities, and nonmotor symptoms were obtained from 153 PD patients (Hoehn‐Yahr 2–4) in their home. Fifty‐one candidate determinants for falling were independently tested using bivariate logistic regression analysis. A multivariate logistic regression model was developed to identify patients susceptible to falls. Sixty‐six subjects (43%) were classified as fallers. Eighteen determinants for falling were selected. The final multivariate model showed an accuracy of 74% and included: (1) Freezing of Gait Questionnaire, (2) Timed Get Up and Go (TGUG) score, (3) disease duration, (4) item 15 of the Unified Parkinsons Disease Rating Scale. Based on disease duration, freezing symptoms, walking problems, and a prolonged TGUG duration, assessed in the home situation, it was possible to accurately identify 74% of PD patients as fallers.

Physical assessment as a predictor of mortality in people with Parkinson's disease: a study over 7 years

The primary aim of this study was to ascertain whether a battery of physical function measures in a Parkinsons disease (PD) patient cohort predicted mortality status at 7‐year follow‐up. Secondary aims were establishing which specific tests were the most useful, and whether PD phenotype was a predictor. A retrospective correlation design was used in this study. A cohort of 109 PD patients underwent baseline physiotherapy assessment of gait, balance, posture, muscle strength, and ability to change postural set. We compared mortality status at 7‐year follow‐up and baseline physical assessment tests. Tinetti gait and balance scores, UPDRS score, 10‐m walk test (time, velocity, and number of strides), posture in standing, lying to sitting, sitting to standing, getting up from floor assessments, and time to ascend and descend four steps were found to be statistically significant physical predictors of mortality at 7‐year follow‐up. In addition, age, sex, and mini‐mental state examination were significant nonphysical predictors of mortality. Using Cox regression, a survival model was constructed with age, sex, and Tinetti gait score as independent predictors of mortality. The results of this study suggest that there is a link between reduced physical function and an increased mortality risk in PD populations.

A systematic review and meta-analysis of outcome measures to assess postural control in older adults who undertake exergaming

Exergaming has been shown to be an effective tool to improve postural control (PC) in older community-dwelling individuals. The outcome measures (OMs) used to assess PC are varied and this could limit the estimation of the effectiveness of the intervention. This systematic review and meta-analysis aims to explore the OMs currently used to assess PC in exergaming interventions, for healthy elderly individuals aged over 60 years. The literature search was conducted across five databases (CINAHL, EMBASE, PubMed, ISI, SPORTdiscus and Science Direct) using a range of search terms and combinations relating to exergaming, balance, exercise, falls and elderly. Quality assessment was conducted using the PEDro Scale and a custom-made quality assessment tool. Eleven trials were included in the meta-analysis, with a mean (SD) PEDro score of 5.36 (1.57). Primary and secondary OMs showed small effects in favour of alternative training modes, although these effects were statistically insignificant for all primary OMs. Tertiary OMs could not be included in the meta-analysis due to varying output parameters from different instruments. Heterogeneity remained high across trials and no studies performed long-term follow-up. Exergaming is a potential alternative to PC training, although still in its infancy. Strong and well-designed RCTs are needed, targeting specific populations aged over 60 years. Variability in instrumented OMs prevents generalisation of results. Technological improvements may provide data not currently available from clinical and laboratory-based methods, and may allow PC to be assessed more realistically and specifically in relation to a populations activities of daily living, though this remains a new area of research.