3. Physical changes in the brain
Alzheimer’s and Parkinson’s start in two different areas of the brain. Parkinson’s disease starts in the substantia nigra which is responsible for the production of dopamine. Dopamine is a key neurotransmitter that regulates movement, pleasure, mood and sleep, among other things.
Alzheimer’s starts in the hippocampus, the area of the brain that is responsible for memory, emotions, and spatial coordination. In both diseases, abnormal accumulations of protein in and around nerve cells are present.
Mood changes such as depression and anxiety are common in both Parkinson’s and Alzheimer’s, but it appears that they can be more easily modified with treatment in patients with Parkinson’s. Both people with Alzheimer’s and Parkinson’s often have sleep problems.