When Alzheimer’s disease was first identified by German doctor Alois Alzheimer in 1906, it was considered a rare condition. Today, Alzheimer’s disease, a degenerative brain disease, is recognized as the most common cause of dementia (a disorder in which mental functions deteriorate and break down). An estimated 5.7 million Americans have Alzheimer’s disease. According to the Alzheimer’s Association, this number includes an estimated 200,000 people younger than 65 who have early-onset Alzheimer’s.
Alzheimer’s advances in stages, progressing from mild forgetfulness and cognitive impairment to widespread loss of mental abilities. In advanced Alzheimer’s, people become dependent on others for every aspect of their care. The time course of the disease varies by individual, ranging from five to 20 years. In people with Alzheimer’s, the most common cause of death is infections such as pneumonia.
Alzheimer’s disease usually affects people older than 65, but occasionally it may affect those younger than 40. Less than 5 percent of people between 65 and 74 have Alzheimer’s disease. For people 85 and older, that number jumps to nearly 50 percent.
Risk factors for Alzheimer’s disease include:
- A first-degree relative (a parent, sister or brother) with Alzheimer’s. Researchers have identified a few genetic mutations that increase risk in some families.
- Hypertension (high blood pressure)
- High cholesterol
- Poorly controlled diabetes
- Being a person with Down syndrome
Exercise and good nutrition may help prevent and control Alzheimer’s. Some clinical studies have also suggested that remaining mentally active throughout life, especially in later years, may reduce the risk for Alzheimer’s disease.
What causes Alzheimer’s disease?
The causes of Alzheimer’s are unclear, but plaques and tangles in brain tissue are considered hallmarks of the disease. Plaques are formed when beta-amyloid, usually a harmless protein, hardens. This causes another protein to make corkscrew-like tangles. Plaques and tangles block cell-to-cell communication, and the caustic plaques burn holes in the brain, destroying more and more nerve cells called neurons.
When neurons die, lower levels of neurotransmitters are produced, creating signaling problems in the brain. One neurotransmitter, acetylcholine, has been found to be deficient in the brains of those with Alzheimer’s disease. Medication treatment is based around increasing the amount of acetylcholine in the brain.
In addition, the internal support structure for brain neurons depends on the normal functioning of a protein called tau. In people with Alzheimer’s disease, threads of tau protein undergo alterations that cause them to become twisted or tangled. Many researchers believe that this may seriously damage neurons, causing them to die.
Diagnosis and next steps
If someone you love shows early signs of Alzheimer’s or other memory loss, get a professional evaluation right away, as symptoms may be related to another condition or medication side effects. While there is no cure for Alzheimer’s, treatment can slow its progress.
Alzheimer’s disease treatment can include medications to assist in managing some of the most troubling symptoms, such as depression, behavioral disturbances and sleeplessness.
Advance directives, power of attorney and other legal actions may make it easier to decide about the care of the person with dementia. Legal advice should be sought early before the person with dementia is unable to make such decisions.
The Fleming Memory Center at Lehigh Valley Hospital–17th Street offers care and support for people affected by dementia and their families. LVHN also offers a support group for the adult children of parents with Alzheimer’s disease and memory loss. Family counseling can help family members cope.