Alzheimer’s Disease is the most common cause of dementia. lzheimer’s disease is an irreversible, progressive brain disease that slowly destroys memory, thinking, understanding, language, and eventually even the most basic functions of swallowing are impacted. The disease has early (mild), middle (moderate) and late (severe) stages. In the early stage of AD people have problems with their recent memory such as who called them on the phone, keeping track of appointments and remembering to take their medications. In the early stage of Alzheimer’s long term memory is not impaired. People with early Alzheimer’s disease can easily remember many details about their childhood and other earlier phases of their life.
With time other areas of thinking become affected. These may include new difficulty with:
- Planning or initiating activities
- Completing familiar tasks at home or work
- Keeping track of time and/or place
- Seeing or understanding visual information (e.g. reading)
- Recalling words or keeping up with a conversation
- Misplacing things
- Making good decisions and solving problems
- Participating in work or social activities as they have done during this lifetime
- Changes in personality and/or mood
In the middle stage of Alzheimer’s disease short term memory is significantly impaired and people become repetitive. Problems with long term memory become more evident. Families begin to notice changes in their loved ones ability to do daily activities such as grooming and dressing. While they are still physically capable of dressing they often begin to change clothes less frequently or wear the same clothes over and over again. At about the same time people with Alzheimer’s disease may begin to bathe less frequently than has been their life long pattern. Sometimes these changes have been so gradual that families have been compensating without realizing the significance of these changes.
During the middle stage of AD people often begin to have changes in personality and behavior. Some of these changes present major challenges to the family and require the family to learn new skills to cope with the changes.
Today we believe that the changes in the brain associated with Alzheimer’s disease begin a decade or more before problems become evident. During this time period people are free of symptoms, but lethal changes are taking place in the brain. Abnormal deposits of proteins form amyloid plaques and tau tangles in the brain, causing the neurons to work less efficiently. Over time, these neurons stop functioning all together and eventually die. The neuron death eventually spread to the hippocampus, which is essential in forming memories. As more neurons die, affected brain regions begin to shrink
Young Onset Alzheimer’s: the Disease in your 40’s and 50’s
Young-onset Alzheimer's occurs in your 30’s, 40’s and 50’s. It affects approximately 500,000 people and accounts for 10 percent of Alzheimer's cases. Since health care providers generally don't look for Alzheimer's disease in younger people, getting an accurate diagnosis of young onset Alzheimer's can be a long and frustrating process. Often Symptoms may be incorrectly attributed to stress, hormones, Attention Deficit Disorder, diet, or menopause.
Young onset Alzheimer’s is particularly d devastating when it strikes because of the loss of work productivity and tremendous emotional and financial strain placed on other working family members and young children.
Efforts to find the genetic basis of AD began in the 1980’s and focused on families that transmitted young-onset AD from one generation to the next. Genetic studies with these young onset families led to the discovery of mutations in three genes:
- amyloid precursor protein
- presenilin 1
- presenilin 2.
However, these genetic mutations represent only 10% of the Young onset families. Considering the importance of young-onset Alzheimer’s disease, the Emory ADRC is exploring the genetic basis of the remaining 90% of individuals with young-onset AD without a family history of young-onset AD. Using national U.S. data, we found that those individuals likely inherit the disease in a recessive manner. In other words, they inherit two mutations that when combined cause AD. Considering how revolutionary the initial discoveries of mutations in amyloid precursor protein, presenilin 1, and presenilin 2 were to AD research, a new recessive genetic cause would likely have a similar impact. This is a new hypothesis, and one we are vigorously pursuing to identify new genetic causes of the disease.