Question: @Rebecca what part of the brain does Alzheimer's affect and how does it affect it?

Rebecca Dewey answered on 22 Jun 2015:

Alzheimer’s disease affects the whole brain. It causes the grey matter (the cells that do the hard work) to shrink and not be replaced by new healthy ones. It causes the ventricles (gaps in the brain that are filled with protective cerebrospinal fluid) to get bigger and take up valuable space.

Also, amyloid plaques and neurofibrillary tangles (different shaped blobs of protien that stop the brain working normally) to appear. They can appear pretty much anywhere and where they do appear, the function of this area can get worse (e.g. motor control, eyesight, hearing).

Finally, Alzheimer’s disease causes the hippocampus to shrink most extremely such that it is very small. The hippocampus is involved in converting short term memory to long term memory – so if this part of someone’s brain is compromised, they will have difficulty forming new memories and will think they are living in the past.