Grant: Project Grant - PA: Neurosciences, Mental Health and Addiction

Alzheimer's disease (AD) is a type of dementia that causes problems with memory, thinking, function and behaviour. Currently, a group of drugs called cholinesterase inhibitors are used to improve memory, but have important side-effects such as loss of appetite, nausea, vomiting and diarrhea and sometimes slow heart rates and fainting. Moreover, benefits from these drugs are modest and AD patients eventually worsen even with continued use. There remains a critical need for treatments focused on early stages of the disease, when quality of life is still potentially excellent. While transcranial direct current stimulation (tDCS; neurostimulation with a non-painful current to the brain) has been shown to improve memory in some people with mild AD with minimal side-effects, recent evidence suggests that tDCS works better when brain circuits are active. As exercise increases brain activity using mechanisms that may support tDCS response, it may be an effective primer given before tDCS. This study will assess whether combining exercise and tDCS can help improve memory in mild AD, and whether this combination improves memory better than exercise alone, tDCS alone, or neither (exercise education only with non-active tDCS). Patients will be randomly assigned to receive either 1) combined exercise and tDCS, 2) exercise and non-active tDCS, 3) exercise education only and tDCS, or 4) exercise education only with non-active tDCS for two weeks. Memory, mood and behaviour, as well as measures of brain activity, and brain and blood vessel health will be assessed before, during, and after treatment. This study may identify a new, non-invasive therapy that preserves memory in early stages of AD, therefore having major health implications.