Overview of Alzheimer Disease
Alzheimer disease (AD) is an acquired disorder characterized by behavioral and cognitive impairment that greatly interferes with social and occupational interactions. This incurable disease has a long, progressive illness course, where plaques and neurofibrillary tangles (bundles) develop in the hippocampus of the brain. Because the hippocampus is responsible for memory and decision-making, people with this chronic condition have trouble with these cognitive functions, such as language, thought, and memory. The risk of developing AD increases with age, and around 5 million people in the U.S. have this disease. While AD affects all ethnic groups and races, it appears to affect women more than men.
Signs and Symptoms
A person with AD may appear completely normal. The symptoms and signs are divided by stage of illness: mild, moderate, and severe:
- Memory loss
- Taking longer to finish daily tasks
- Confusion regarding familiar places
- Difficulty paying bills
- Compromised judgment
- Loss of sense of initiative
- Personality and mood changes
- Shortened attention span
- Problems reading and writing
- Restlessness, anxiety, and agitation
- Wandering, especially during evening or night hours
- Paranoia, hallucinations, delusions, and irritability
- Loss of impulse control
- Perceptual-motor problems
- Cannot recognize family members or friends
- Cannot communicate in any way
- Inability to do activities of daily living
- Weight loss
- Groaning, grunting, or moaning
- Loss of bowel and/or bladder control
Researchers and cognitive scientists do not know the cause of Alzheimer disease. They do suspect that a number of factors contribute to the condition. While age is a risk factor for AD, age alone is not the cause. Also, less than 10 percent of AD cases are hereditary. One gene associated with AD controls the production of a protein called apolipoprotein E (apoE).
Experts do know that AD adversely affects the brain by damaging and destroying brain cells. A person with AD has fewer brain cells and fewer connections among existing cells than a healthy person's brain. As the brain cells die, the brain shrinks. Plaques are clumps of protein called beta-amyloid that develop in the brains of people with AD. The beta-amyloid protein destroys brain cells and interferes with cell-to-cell communication. In AD threads of a protein called tau twists into abnormal tangles inside the brain cells, which causes failure of the transport system necessary to carry essential materials and nutrients. This failure results in the decline and death of brain cells.
The only known way to confirm a diagnosis of AD is to examine the brain tissue for senile plaques and neurofibrillary tangles. In the living patient, the diagnosis is made based on signs and symptoms and by ruling out other disorders and diseases. To pinpoint cognitive problems, neuropsychological testing is done. In research settings, patients with AD were found to have elevated levels of tau and low levels of amyloid in cerebrospinal fluid obtained via lumbar puncture.
There is no known cure for AD at this time. Several medications are used, however, to treat the symptoms of AD. These include:
- Cholinesterase inhibitors – These drugs work by enhancing levels of the communication chemical in the brain. Examples are Aricept and Razadyne.
- Namenda – This drug works by altering the brain cell communication network to slow the progression of AD.
- Antiparkinsonian agents
To prevent injury, family members should create a safe and supportive environment for the person with AD. This involves:
- Removing clutter, throw rugs, and excess furniture
- Installing handrails in bathrooms and stairways
- Removing mirrors (they often frighten or confuse the patient)
- Provide shoes and slippers with adequate traction
There are no proven measures for prevention of AD, but research suggests that a healthy lifestyle can reduce the risk of this condition. This includes:
- Regular exercise
- Nutritious diet
- Respiratory fitness
- Diabetic control
- Blood pressure control
- Lowering cholesterol