6.3 Alzheimer’s Disease
Open Resources for Nursing (Open RN)
Alzheimer’s disease is an irreversible, progressive brain disorder that slowly destroys memory and thinking skills and eventually the ability to carry out the simplest tasks. It is the most common cause of dementia. In most people with Alzheimer’s disease, symptoms first appear in their mid-60s. Five percent of people age 65 to 74, 13.2% of people age 75 to 84, and 33.4% of people age 85 or older have Alzheimer’s disease.[1]
Scientists continue to unravel the complex brain changes involved in the onset and progression of Alzheimer’s disease. Researchers have found many genes that increase or decrease the risk of Alzheimer’s dementia. In 2022 researchers identified 31 new genes that appear to affect biological processes associated with Alzheimer’s disease. Changes in the brain may begin a decade or more before memory and other cognitive problems appear. Abnormal deposits of proteins form amyloid plaques and tau tangles throughout the brain. Previously healthy neurons stop functioning, lose connections with other neurons, and die. The damage initially appears to take place in the hippocampus and cortex, the parts of the brain essential in forming memories. As more neurons die, additional parts of the brain are affected and begin to shrink. By the final stage of Alzheimer’s, damage is widespread, and brain tissue has shrunk significantly.[2],[3] See Figure 6.6[4] for an image of the changes occurring in the brain during Alzheimer’s disease.
View a video of the changes that occur in the brain during Alzheimer’s disease:[5]
Symptoms of Early Alzheimer’s Disease
There are ten symptoms of early Alzheimer’s disease[6]:
- Memory loss that disrupts daily life. This includes forgetting important dates or events, asking the same questions over and over, and increasingly needing to rely on memory aids (e.g., reminder notes or electronic devices) or family members for things they used to handle on their own. This is different than a typical age-related change of sometimes forgetting names or appointments, but remembering them later.
- Challenges in planning or solving problems. This includes changes in an individual’s ability to develop and follow a plan or work with numbers. For example, they may have trouble following a familiar recipe or keeping track of monthly bills. They may have difficulty concentrating and take much longer to do things than they did before. This is different from a typical age-related change of making occasional errors when managing finances or household bills.
- Difficulty completing familiar tasks. This includes trouble driving to a familiar location, organizing a grocery list, or remembering the rules of a favorite game. This symptom is different from a typical age-related change of occasionally needing help to use microwave settings or to record a TV show.
- Confusion with time or place. This includes losing track of dates, seasons, and the passage of time. Individuals ma