Dual Task Training for Cerebellar Ataxia

Frequent falls in people with cerebellar ataxia (CA) is a significant problem because it increases the burden of disease to both the individual and the healthcare system. Therefore, an intervention that could improve balance and reduce the number of falls is of paramount importance from the patients' perspective. Although the incidence of CA in the population is not as high as the other neurological disorders such as stroke and Parkinson's disease, the disability and its negative impact on quality of life are significant for those suffering from CA. Moreover, research that results in more knowledge regarding the factors that contribute to falls and the efficacy of treatments that reduce falls in this population could inform research into fall prevention in other populations of individuals at risk for falls, including otherwise healthy elderly adults. Individuals with CA have poor coordination, balance and postural control; all of these contribute to them having frequent falls. People with CA also present with varying degrees of cognitive impairments making it difficult for them to perform dual-tasks in daily activities. Dual tasking has been found to deteriorate the performance of either or both tasks in people with CA. The deficiency in dual-task performance relative to single-task performance referred to as dual-task cost is high in CA. Falls incidence in people with CA increases during daily activities that involve dual tasking. Tai-Chi is a form of dual-task training. Previous study of the Tai-Chi to improve balance and prevent falls in people with CA found some beneficial effects of Tai-Chi on improving balance, but it did not reduce falls incidence. The investigaotrs speculate the lack of beneficial effects of Tai-Chi on falls incidence was due to the Tai-Chi intervention being inadequately intense, especially with respect to its cognitive demand. Other available interventions to improve balance and reduce falls do not address the dual-task cost of balance performance in this population. However, dual-task training is found to reduce dual-task cost and reduce falls in people other neurological disorders and therefore has the potential to reduce falls in CA. To evaluate this possibility, the investigators developed and piloted the Cognitive-coupled Intensive Balance Training (CIBT) that combines cognitive demand to intensive balance and coordination training for reducing the dual-task cost of balance and cognitive performance, improve balance and consequently reduce the number of falls. The pilot study found that CIBT is safe, feasible and potentially effective in reducing the dual-task cost of balance performance, improving functional balance and reducing falls in people with CA. Evaluating the efficacy of this program in a fully powered clinical trial and understanding the mechanisms underlying the effectiveness of the CIBT on balance and falls are important next steps of our research program. Here the investigators propose a randomized controlled trial (RCT) to compare the treatment benefits of the dual-task (experimental: CIBT) training against the single-task (active control: conventional balance, coordination and cognition) training for reducing dual-task cost, improving balance and reduce the number of falls in participants with CA, evaluating both the efficacy and the mechanisms of dual-task training. In addition, the investigators propose to conduct an economic evaluation alongside the RCT at a healthcare perspective of Hong Kong to compare the cost-effectiveness of dual-task training against single-task training, in preparation for the development of any future trials. This study finding will have important clinical implications by clarifying if adding a cognitive demand to routine balance and coordination training will result in additional benefits on improving balance and reducing falls in comparison with usual care in people with CA. The findings will also have important implications for increasing the efficacy of falls prevention programs in other populations with neurological deficits who are at risk for falls. Our specific objectives are:

Objective 1: To evaluate the effectiveness of the dual-task (CIBT- experimental) training compared with single task (conventional intensive balance, coordination and cognitive- active control) training on functional balance and number of falls.

Hypothesis 1: Both dual-task and single-task training will improve functional balance, however, the dual-task training will be more effective in reducing the number of falls.

Objective 2: To identify the mechanism underlying the effectiveness of the dual-task training on functional balance and the number of falls; that is, to evaluate the extent to which treatment-related changes in the functional balance and dual-task cost of balance and cognitive performance mediate the reduction in the number of falls.

Hypothesis 2: Improvement in functional balance resulting in the reduction of number of falls will be mediated by the reduction in the dual-task cost of balance and cognitive performances.

Objective 3: Compare the cost-effectiveness of the dual-task and single-task training for preventing falls.

Hypothesis 3: Dual-task training will be superior in terms of cost-effectiveness than the single-task from a health-care perspective of Hong Kong