|Title: ||The use of cueing to influence gait in Parkinson's disease patients with and without freezing of gait|
|Other Titles: ||Het gebruik van cues ter beïnvloeding van het gangpatroon van Parkinson patiënten met en zonder freezing|
|Authors: ||Willems, Anne-Marie|
|Issue Date: ||1-Jun-2006 |
|Abstract: ||Despite advances in pharmacological therapy and surgical techniques, gait and balance deficits still pervade the daily lives of patients with Parkinson’s disease. Given the loss of independence, immobility and associated cost, the development of rehabilitation approaches that work in conjunction with current medical treatment is important to manage these problems. The present thesis addresses such a rehabilitation method by investigating the effects of cueing therapy and looking at factors which facilitate and inhibit its efficacy.
The first part of this thesis investigated the immediate effects of auditory cueing on gait parameters in persons with PD. In each study, a group of patients experiencing episodic gait events (freezers) was compared to a group of patients not experiencing these problems (non-freezers).
In Chapter 1 spatiotemporal gait parameters were presented of straight line walking in 10 healthy age-matched controls, 10 freezers and 10 non-freezers. The purpose of this study was to examine the effect of 5 different auditory cueing frequencies on gait and to compare the effects in freezers and non-freezers in the ‘on-phase’ of the medication cycle. Auditory cues were delivered at each person’s preferred step frequency (baseline); 10 and 20% above baseline and 10 and 20% below baseline. Although the spatiotemporal gait parameters in the non-cued walking condition did not differ between freezers and non-freezers, the patient subgroups reacted differently to auditory cueing in the +10% condition. Non-freezers increased their stride length and walking speed, whereas freezers’ walking speed remained constant while stride length decreased. The results showed that even under the influence of medication freezers had greater difficulty in keeping up their stride length when an increased stepping frequency was imposed. Freezers were unable to modify gait speed above their preferred mode in response to cueing. Different clinical guidelines for freezers and non-freezers were drawn up, recommending 10% higher cueing rhythms for non-freezers and discouraging such rhythms for freezers. These guidelines were incorporated in a practical and evidence-based tool for cueing therapy published on CD-Rom. This CD-Rom can be found on www.rescueproject.org.
To examine the influence of auditory cueing on performing a turn Chapter 2 reported on turning parameters during a 180° turn in 9 age-matched controls, 9 freezers and 10 non-freezers. The turn was performed in an auditory cued and non-cued condition during the ‘on-phase’ of the medication cycle. Cueing frequency was set at each person’s preferred step frequency during straight line walking. The purpose of the study was to compare turning parameters in PD and controls, freezers and non-freezers with and without cues. In comparison to controls, PD patients’ turns were larger, slower and consisted of more steps. The turning steps were smaller, narrower and the gait timing variability was increased. Turning parameters in non-freezers and freezers were very similar, except for the fact that freezers made larger turning arcs, indicating that freezers were even more inclined than non-freezers to use a “wide-arc” strategy rather than rotate the body. It is difficult to interpret at this point whether this altered strategy pointed to a compensatory mechanism to avoid freezing or was an inherent feature of turning performance in freezers.
Under influence of cueing, persons with PD reduced their gait timing variability. In addition, cueing seemed to exaggerate the differences between the turning arcs of patients and controls. Freezers did not change their turning parameters in response to cueing. The turning arcs of non-freezers became larger as a result of cueing, indicating a more pronounced “wide-arc” strategy. The clinical implications of these results are unclear at present, although it was considered encouraging that gait timing variability became smaller in both groups.
Chapter 3 addressed the question whether auditory cueing would have similar effects when patients were not responding well to medication and might suffer from freezing and festination episodes. Spatiotemporal gait parameters of normal and dual task walking were collected in 10 freezers and 11 non-freezers. In contrast to Chapter 1 and Chapter 2 this study was conducted in the ‘off-phase’ of the medication cycle, 12 hours after medication intake. During the dual task persons with PD were asked to carry a tray while walking. Normal and dual task walking was performed with and without cues. Auditory cues were administered at each person’s preferred step frequency (baseline), 10% above and below baseline. In this experiment freezers walked with smaller steps than non-freezers, but none of the expected differences in gait timing variability were found. When comparing the interference of the dual task on the walking pattern group differences became more pronounced. Although spatiotemporal variables changed in both groups, freezers walked more slowly and festination and freezing episodes occurred during dual tasking. Gait timing variability however was not affected by double tasking.
The differential effects of cueing in freezers and non-freezers were more pronounced than in Chapter 1. Freezers experienced negative effects from cueing (especially in the +10% condition) both during normal and dual task walking, as it provoked episodic gait events. In contrast, non-freezers benefited from the +10% cueing condition, as it resulted in an increased walking speed, larger step length and smaller dual task interference effects. Cueing did not result in any changes of gait timing variability in both groups.
Part two of the thesis took a different approach in looking more closely at the training effect of cues in different subgroups of patients with PD. Cues were not applied in a single session experiment but as part of clinical intervention. Different modalities and parameters of mainly rhythmical cues were offered, embedded in a 3 week physiotherapy training program aimed at improving gait. Chapter 4 examined the factors that might explain the intervention effects of this cueing program in a regression analysis. This study was conducted on 153 persons with PD. The purpose of this study was to examine if all persons with PD could benefit equally from cueing therapy and if therapy characteristics also predicted the intervention effects. It was found that persons with more severe symptoms and better executive function benefited more from cueing therapy. Freezers, fallers and older patients benefited equally well from cueing therapy. When looking at the freezing of gait questionnaire as a predictor, it revealed that cueing was able to reduce freezing symptoms in those with more severe freezing problems. Whereas the cueing modality did not predict the cueing effects, the therapy time spent to improve a specific gait parameter was a significant determinant of the targeted effect. Interestingly, focusing cueing on improving step length rather than gait speed in freezers induced a better outcome in these patients.
In summary, this dissertation demonstrated the complexity of cueing and the importance of making informed clinical decisions. It showed the importance of using cueing frequencies that are adapted to the patient’s clinical profile. In addition, the frequency settings have to account for carrying out activities such as turning and dual-tasking and the medication phase. Especially in freezers caution is warranted when applying cues in clinical practice as it may provoke episodic gait events under certain circumstances. However, a cueing program, based on these individually and situation-specific principles is effective in most of the patients.
Further knowledge is required, particularly on the nature of turning problems, the origins of freezing and the interactions with executive dysfunction to be able to fully exploit the compensatory possibilities of cueing in rehabilitation.
|Table of Contents: ||PART 1 IMMEDIATE EFFECTS OF CUEING
Chapter 1 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
Chapter 2 Rhythmic auditory cues for turning in Parkinson’s disease: differential effects for freezers and non-freezers?
Chapter 3 The use of rhythmic auditory cues to influence gait and the occurrence of freezing and festination in the ‘off-phase’ of the medication cycle.
PART II TRAINING EFFECTS OF CUEING
Chapter 4 How do clinical and therapy factors influence the intervention effect of home-based cue training in Parkinson’s disease patients?
SUMMARY AND CONCLUSIONS
|Publication status: ||published|
|KU Leuven publication type: ||TH|
|Appears in Collections:||Movement Control & Neuroplasticity Research Group|
Research Group Experimental Neurology
Research Group for Neuromotor Rehabilitation