Judith Bek

Tracking motor impairments in the progression of Huntington's disease

The Unified Huntingtons Disease Rating Scale is used to characterize motor impairments and establish motor diagnosis. Little is known about the timing of diagnostic confidence level categories and the trajectory of motor impairments during the prodromal phase. Goals of this study were to estimate the timing of categories, model the prodromal trajectory of motor impairments, estimate the rate of motor impairment change by category, and provide required sample size estimates for a test of efficacy in clinical trials. In total, 1010 gene‐expanded participants from the Neurobiological Predictors of Huntingtons Disease (PREDICT‐HD) trial were analyzed. Accelerated failure time models were used to predict the timing of categories. Linear mixed effects regression was used to model the longitudinal motor trajectories. Age and length of gene expansion were incorporated into all models. The timing of categories varied significantly by gene expansion, with faster progression associated with greater expansion. For the median expansion, the third diagnostic confidence level category was estimated to have a first occurrence 1.5 years before diagnosis, and the second and first categories were estimated to occur 6.75 years and 19.75 years before diagnosis, respectively. Motor impairments displayed a nonlinear prodromal course. The motor impairment rate of change increased as the diagnostic confidence level increased, with added acceleration for higher progression scores. Motor items can detect changes in motor impairments before diagnosis. Given a sufficiently high progression score, there is evidence that the diagnostic confidence level can be used for prodromal staging. Implications for Huntingtons disease research and the planning of clinical trials of efficacy are discussed.

Patients’ views on a combined action observation and motor imagery intervention for Parkinson’s disease

Background. Action observation and motor imagery activate neural structures involved in action execution, thereby facilitating movement and learning. Although some benefits of action observation and motor imagery have been reported in Parkinsons disease (PD), methods have been based on stroke rehabilitation and may be less suitable for PD. Moreover, previous studies have focused on either observation or imagery, yet combining these enhances effects in healthy participants. The present study explores the feasibility of a PD-specific home-based intervention combining observation, imagery, and imitation of meaningful everyday actions. Methods. A focus group was conducted with six people with mild to moderate PD and two companions, exploring topics relating to the utility and feasibility of a home-based observation and imagery intervention. Results. Five themes were identified. Participants reported their experiences of exercise and use of action observation and motor imagery in everyday activities, and the need for strategies to improve movement was expressed. Motivational factors including feedback, challenge, and social support were identified as key issues. The importance of offering a broad range of actions and flexible training was also highlighted. Conclusions. A home-based intervention utilising action observation and motor imagery would be useful and feasible in mild to moderate PD.

Action observation produces motor resonance in Parkinson's disease

Observation of movement activates the observers own motor system, influencing the performance of actions and facilitating social interaction. This motor resonance is demonstrated behaviourally through visuomotor priming, whereby response latencies are influenced by the compatibility between an intended action and an observed (task‐irrelevant) action. The impact of movement disorders such as Parkinsons disease (PD) on motor resonance is unclear, as previous studies of visuomotor priming have not separated imitative compatibility (specific to human movement) from general stimulus‐response compatibility effects. We examined visuomotor priming in 23 participants with mild‐to‐moderate PD and 24 healthy older adults, using a task that pitted imitative compatibility against general stimulus‐response compatibility. Participants made a key press after observing a task‐irrelevant moving human finger or rectangle that was either compatible or incompatible with their response. Imitative compatibility effects, rather than general stimulus‐response compatibility effects, were found specifically for the human finger. Moreover, imitative compatibility effects did not differ between groups, indicating intact motor resonance in the PD group. These findings constitute the first unambiguous demonstration of imitative priming in both PD and healthy ageing, and have implications for therapeutic techniques to facilitate action, as well as the understanding of social cognition in PD.

Conductive education as a method of stroke rehabilitation: A single blinded randomised controlled feasibility study

Background. Conductive Education for stroke survivors has shown promise but randomised evidence is unavailable. This study assessed the feasibility of a definitive randomised controlled trial to evaluate efficacy. Methods. Adult stroke survivors were recruited through local community notices. Those completing the baseline assessment were randomised using an online program and group allocation was independent. Intervention group participants received 10 weekly 1.5-hour sessions of Conductive Education at the National Institute of Conductive Education in Birmingham, UK. The control group participants attended two group meetings. The study evaluated the feasibility of recruitment procedures, delivery of the intervention, retention of participants, and appropriateness of outcome measures and data collection methods. Independent assessments included the Barthel Index, the Stroke Impact Scale, the Timed Up and Go test, and the Hospital Anxiety and Depression Scale. Results. Eighty-two patients were enrolled; 77 completed the baseline assessment (46 men, mean age 62.1 yrs.) and were randomised. 70 commenced the intervention (n = 37) or an equivalent waiting period (n = 33). 32/37 completed the 10-week training and 32/33 the waiting period. There were no missing items from completed questionnaires and no adverse events. Discussion. Recruitment, intervention, and assessment methods worked well. Transport issues for intervention and assessment appointments require review. Conclusion. A definitive trial is feasible. This trial is registered with ISRCTN84064492.