Stroke

Approximately one third of stroke survivors become depressed and up to two thirds experience cognitive impairment (e.g., problems with paying attention, remembering information and communicating effectively). Not only are depression and cognitive impairment major problems in themselves, they are associated with other negative outcomes including earlier death, greater rates of institutionalisation, poorer quality of life and higher health care costs. Finding simple, easy to apply interventions that protect against depression and cognitive impairment after stroke would be extremely valuable in improving outcomes for stroke survivors.

Increasing early physical activity after stroke is a very attractive intervention: broadly applicable, inexpensive and widely available. At present, there is no clear evidence that exercise early after stroke reduces depression or cognitive impairment. The AVERT trial provides a unique and exciting opportunity to test this possibility. In 2008 we published results from Phase II AVERT demonstrating that early and frequent mobilisation after stroke was associated with reduced depression at 7 days post-stroke. Assessing cognitive function after stroke is more difficult – no measure that is brief, easy to administer and valid in stroke has been identified. For this reason, we are running a study with the aim of identifying a valid and feasible screening tool for cognitive impairment after stroke. Recruitment to this study is steady and we expect to complete the study in 2011.

Phase III AVERT includes depression assessment at 3 and 12 months post-stroke, and now also includes cognitive assessment at 3 months. A cohort of more than 300 stroke patients have been tested on this cognitive assessment to date, and these results are currently being written up for publication. At the conclusion of the trial, We aim to determine the effect of increased physical activity on depression and cognition following stroke, and isolate the underlying mechanisms. This will require the use of assessments of mood and cognitive function, electronic activity monitors to record continuous physical activity, blood samples to measure relevant physiological markers, and brain imaging to detect structural and functional changes brought about by exercise.