Patients may have changes to their brain years before they receive a diagnosis of Alzheimer's disease. The Alzheimer's Association explains that these neurological changes may start 20 or more years before a doctor give a patient the diagnosis of early-stage Alzheimer's disease. Alzheimer's disease causes multiple changes to the brain, such as changes in structure size and formation of plaques and tangles. But how does Alzheimer's disease progress?
The Alzheimer's Association lays out seven stages of Alzheimer's disease. As a patient progresses through each stage of Alzheimer's disease, the impairment becomes worse. For example, in stage one of Alzheimer's disease, the patient has normal function. When she reaches stage two, or mild cognitive decline, she may start having memory lapses, though this may be due to age. With stage three of Alzheimer's disease, the patient develops mild cognitive decline, which affects her ability to remember names, plan or learn new materials through reading.
By stage four of Alzheimer's disease, or moderate cognitive decline, the patient is showing several identifiable problems. For example, the patient may not be able to do challenging arithmetic in her head, such as counting backwards from the number 100 by groups of seven. The memory problems have worsened to affect the patient's memory of her own life. Changes in personality and mood occur, such as becoming withdrawn or having mood swings. In the last three stages of Alzheimer's disease, the cognitive impairment is severely worse. For example, in stage five of Alzheimer's disease, the patient cannot remember her address or telephone number. In stage six of Alzheimer's disease, the patient has trouble remembering the name of her spouse or caregiver. By the last stage of Alzheimer's disease, the patient needs help to carry out basic survival tasks.
Can certain factors affect the progression of Alzheimer's disease? MedlinePlus, a service of the U.S. National Library of Medicine and National Institutes of Health, points out that patients who have early onset Alzheimer's disease, meaning the symptoms start before the patient has reached age 60, tend to have a faster progressing disease. Another factor that may affect the progression of Alzheimer's disease is genetics. Reuters Health reports that a mutation of a gene that regulates the protein tau may affect how the disease progresses. The study included over 800 people and the researchers found one variation of the gene that had a connection to a more aggressive form of Alzheimer's disease. This finding may affect the development of new medications, which could possibly slow down the progression of Alzheimer's disease.