Alzheimer’s disease is a progressive form of dementia, a group of disorders characterized by brain changes that lead to a decrease in memory, language, problem-solving and thinking abilities, as well as behavior changes that can impair your daily functioning. Alzheimer’s disease is the most common cause of dementia, accounting for 60 to 80 percent of all dementia cases.
Alzheimer’s disease is more common in older adults. It is estimated that 6.2 million Americans age 65 and older are living with Alzheimer’s disease today. And unless a cure or a way to prevent the disease is discovered, the number of American affected by it could balloon to nearly 14 million by 2060.
According to the National Institute on Aging, Alzheimer’s disease is the sixth leading cause of death in the US. But, other recent data suggest it may be the third leading cause of death, just behind heart disease and cancer.
Alzheimer’s disease most often affects people 65 and older, but it can also affect people in their 30s, 40s and 50s. This is called early-onset Alzheimer’s disease or younger-onset Alzheimer’s disease. This type affects about 5 percent of all people with the disease or around 200,000 US adults under age 65.
The exact cause of Alzheimer’s disease is unknown, but certain factors increase your risk for developing the condition. Risk factors for Alzheimer’s disease include: Age, family history, genetics (certain genes have been linked to both late-onset and early-onset forms of the disease), high blood pressure, high cholesterol, diabetes, smoking and obesity.
Among the complex brain changes that occur with Alzheimer’s disease, the development of the condition is associated with an abnormal build-up of proteins in the brain called beta-amyloid and tau. It is believed that amyloid protein builds up and forms masses called plaques and twisted fibers of tau form into tangles. These plaques and tangles interfere with communication between brain cells, which prevents normal brain function and leads to symptoms.
The symptoms of Alzheimer’s disease generally present gradually, and the effects on the brain are degenerative. This results in a slow, progressive decline in your condition. Symptoms of Alzheimer’s disease include:
- Memory loss that impacts daily life
- Inability to learn new things
- Trouble with familiar tasks
- Difficulty with problem-solving
- Trouble with speech or writing
- Disorientation with time or places
- Impaired judgement or reasoning
- Difficulty recognizing family or friends
- Changes in mood and personality
- Difficulty sleeping
- Impulsive behavior
- Withdrawal from friends, family and community
- Hallucinations, delusions or paranoia
Alzheimer’s disease can be definitively diagnosed only after death, when the doctor can actually visualize the plaques and tangles in your brain tissue. Your doctor can make a presumptive diagnosis of Alzheimer’s disease while you are alive.
There is no single test for diagnosing Alzheimer’s disease. Your doctor will begin by asking you about your experiences, symptoms and medical history. The doctor will perform a physical and neurological exam to rule out other medical causes for your symptoms such as infection or stroke.
Your doctor may order imaging tests to get a clearer picture of your brain. These tests may include CT, which can show abnormal characteristic in your brain; MRI, which can reveal inflammation and bleeding, as well as structural issues; and PET, which can help your doctor detect abnormal activity in your brain.
Blood tests may also be recommended to look for specific genes that are linked to the development of Alzheimer’s disease.
Currently, there’s no cure for Alzheimer’s disease, but there are medications that can help ease the symptoms and temporarily delay disease progression. Donepezil (Aricept), rivastigmine (Exelon) and galantamine (Razadyne) work to maintain high levels of the neurotransmitter acetylcholine in the brain. Acetylcholine helps nerve cells communicate so the brain functions better. These medications are often used in early to moderate Alzheimer’s disease.
If you have moderate to severe Alzheimer’s disease, your doctor may prescribe memantine (Namenda), which helps block the effects of glutamine. Glutamine is a brain chemical that is released in high amounts in people with Alzheimer’s disease. Glutamine damages brain cells; blocking it keeps brain cells healthier.
Many people with Alzheimer’s disease experience behavior-related symptoms as well, such as depression, anxiety, restlessness, aggression, agitation, paranoia and hallucinations. Your doctor may prescribe antidepressant, antianxiety, anticonvulsant or antipsychotic medications to treat these symptoms.
Unfortunately, there’s no sure-fire way to prevent Alzheimer’s disease, but practicing healthy lifestyle habits may help you avoid cognitive decline. The following measures have been suggested: quit smoking, exercise regularly, maintain a healthy weight, eat a plant-based diet, consume more antioxidants, try cognitive training exercises and maintain an active social life.
The prognosis for people with Alzheimer’s disease varies from person to person. On average, people with Alzheimer’s disease live four to eight years after diagnosis, but some can live as long as 20 years after diagnosis.