Coping with Memory Loss
Mild Cognitive Impairment
People with MCI have memory impairments, but otherwise function well and don't meet the clinical criteria for dementia. Whereas normal memory loss associated with aging may involve forgetting a name, memory loss associated with MCI is more severe and persistent.
MCI is often a transition stage between normal aging and more serious problems caused by AD. Most, but not all, people with MCI get worse. According to some studies, each year about 12 to 15 percent of people with MCI develop AD.
"Some people never decline in five years and with others, we might see a decline in the third year," says Reisa Sperling, M.D., associate professor of neurology at Harvard Medical School and director of clinical research at the Memory Disorders Unit at Brigham and Women's Hospital. "In older people with MCI, if the memory loss is slowly getting worse, the chances of developing AD are about 60 percent to 70 percent."
Research is under way on whether the drugs approved to treat symptoms of AD may help some people with MCI. Scientists hope that some day, accurate and early evaluation and treatment of people with MCI may help prevent further cognitive decline.
AD is the most common form of dementia in people older than age 65, and affects more than 5 million Americans, according to the Alzheimer's Association. AD is a progressive, neurodegenerative disease characterized in the brain by abnormal protein deposits (amyloid plaques) and tangled bundles of fibers within nerve cells (neurofibrillary tangles). The biggest risk factors are age and family history. Having a history of serious concussion is also a risk factor.
AD gradually destroys a person's memory and ability to learn, reason, make judgments, communicate, and carry out daily activities. Memory loss becomes severe and is marked by disorientation, general confusion, and an inability to recall recent events. A person with mild-to-moderate AD may remember things that happened to them a long time ago, but they might get lost easily in a familiar place. People with AD may also experience changes in personality and behavior such as withdrawal and suspicion. They eventually experience a loss of speech and movement, incapacitation, and death. Some facts about AD treatment follow:
- Most clinical trials of drug treatments for memory loss focus on people with AD.
- Five drugs are approved by FDA to treat the symptoms of AD, but there is no cure for the disease.
- Four drugs are known as cholinesterase inhibitors and are thought to work in a similar way. Cognex (tacrine), Exelon (rivastigmine), and Razadyne (galantamine) are approved for mild-to-moderate AD. Aricept (donepezil) is approved to treat all degrees of severity of the disease--from mild to severe. Cholinesterase inhibitors prevent the breakdown of acetylcholine, a chemical that nerves use to communicate with each other. "These drugs may help delay or decrease the severity of symptoms for a limited time in some people," says Susan Molchan, M.D., formerly program director for the Alzheimer's Disease Neuroimaging Initiative project at the National Institute on Aging (NIA), part of the National Institutes of Health. Side effects of cholinesterase inhibitors are gastrointestinal, such as nausea and diarrhea.
- Namenda (memantine), approved for moderate-to-severe AD, is believed to block the action of glutamate, a brain chemical that may be overactive in people with AD. Namenda may help some patients maintain certain daily functions a little longer. Common side effects include dizziness, headache, constipation, and confusion. Sometimes, Namenda is prescribed along with a cholinesterase inhibitor.
- Behavioral symptoms of AD may include agitation, sleeplessness, anxiety, and depression, which can be treated.
- Inhibiting and/or decreasing amyloid is an intense area of research because amyloid is the major component of the plaques that develop in the brains of people with AD and is associated with nerve cell death. Drugs called secretase inhibitors are being developed and tested to block beta-amyloid formation. Also under study is immunotherapy against beta amyloid--it's possible that a vaccine may help reduce deposits of amyloid.