Patients of Alzheimers progressively weaken as their symptoms grow in number and virulence and eventually succomb to the disease.
Death often comes in the form of pneumonia know as aspiration pneumonia.
In such a case, the patient normally inhales some food or some other substance and gets this lodged within their lungs. The following images compare a normal brain to that of an Alzheimer patient's brain. The following images take the above diagram and show the actual images one would see upon examining a healthy brain and an Alzheimer's patient's brain. Our thanks go out to them.