The effects of environmental enrichment on clinical measures of disease progression and quality of life for patients with Huntington's disease.

Environmental enrichment; a 9 month cognitive and physical stimulation intervention (occupational therapy, physical exercise) to directly target affected brain regions. Participants will be randomly allocated into two cohorts: one group will receive the environmental enrichment intervention and the other group will not. Carers (healthy volunteers) will also be recruited to assist with participant compliance and to complete questionnaires regarding the participant. Carers of participants who undertake the environmental enrichment intervention may also voluntarily undertake the exercise regimen and therefore may act as a control group for the exercise-related measures such as balance tests, and questionnaires. The Occupational Therapy intervention will be client centered and delivered using the group and individual model. The model of service delivery will be guided by the Goal Attainment scale which will support the assessment of individual needs and goals. Each participant will work individually with their therapist to achieve this. The Goal Attainment Scale will be used to measure outcomes specific to the Occupational Therapy Intervention. The exercise intervention will involve one session per week of approximately 60 minutes duration at an exercise clinic. Sessions will commence with a 10 minute warm-up period and finish with a 5 minute cool-down period consisting of low-level aerobic exercise on cycle ergometers and stretching. All exercise sessions will be conducted in small groups of up to 10 participants, with participants exercising in pairs under direct supervision to ensure correct technique and minimise the risk of injury. In order to minimise the possibility of boredom and overreaching, the exercise programs will be periodized by cycling with an emphasis on intensity and volume. All participants will be asked to maintain otherwise customary physical activity and dietary patterns throughout the intervention period. There will be two main components to the exercise program. 1) Resistance training, to provide optimal stimulus to enhance neuromuscular strength, including 6 exercises each session targeting major upper and lower body muscle groups, modified to suit people with Huntington's disease. Repetition maximums will be set per individual and participants will be encouraged to exceed this to ensure a progressive nature to the training program, with an inter-set rest period of 3 minutes. 2) Aerobic training will provide optimal stimulus to enhance the cardiorespiratory capacity while maintaining a healthy level of body fat and cardiovascular and metabolic risk. Participants will be encouraged to accumulate 150 minutes per week of continuous or intermittent exercise with a target heart rate of 60-85% of maximum. Activities in the exercise clinic will include cycling, treadmill, cross trainer and rowing ergometer exercise supplemented with other activities in and around the home and community (eg walking, swimming). At the end of the 9 month intervention period, participants in the control group and intervention groups will be offered the opportunity to participate in another 9 month intervention.