Alzheimer's Disease is much more than just becoming a bit forgetful in old age. It is a neurodegenerative disease that actually causes the structure of the brain to break down, and build ups of peptide plaques within the brain itself. The cognitive symptoms - forgetfulness, disorientation - are present in the early stages and look a lot like "just losing it a bit" with age. The disease eventually progresses to behavioural issues, problems with language, and eventually the breakdown of motor function and death. Despite having a relatively good grip on the symptoms and effects of the disease, scientists have no real idea how to cure or even treat the disease. We don't even know why it happens in the first place and there are a range of theories. Trials for various drugs, neural pacemakers and even a pill to artificially enlarge the brain have all left the disease puzzlingly untouched. We don't really know why nothing seems to work, which is pretty unhelpful in the quest to find something that will.
