Amnesia - Memory Loss

Overview, Causes, & Risk Factors

Memory loss is the inability to recall people, objects, places, or events that took place in the recent or distant past.

What is going on in the body?

The brain stores different types of information in different places. Short-term memory involves recalling details that have been catalogued seconds or minutes before. Examples include reciting a phone number, recognizing a new face, or repeating a list of 3 objects seen 2 or 3 minutes earlier. For this to happen, distinct areas deep in the brain need to function properly.

Long-term memory involves the ability to recall events that took place in the distant past. For short-term memory to convert to long-term memory, other permanent changes to brain cells have to take place. This is similar to creating a permanent file or recording. Other parts of the brain perform this filing function.

Occasional memory lapses or forgetfulness are common. These may be associated with depression, stress, lack of sleep, and normal aging. Memory loss only becomes a problem when it is severe and interferes with daily living.

Amnesia is a severe form of memory loss. It may be a partial or complete lack of recall. Depending on the cause of amnesia, the memory loss may arise suddenly or slowly. It also can be temporary or permanent.

What are the causes and risks of the symptom?

Common medical causes of memory loss include:

normal aging

Alzheimer's disease, a progressive brain disorder causing deterioration in memory and thought processes

depression

head injury

seizures

chronic alcohol abuse

barbiturates, hallucinogens, and medications such as those used for anesthesia

electroconvulsive therapy, or ECT, which is used to treat some mental disorders

surgery in the temporal lobe of the brain, such as a craniotomy for a brain tumor

lack of oxygen to the brain, such as a near drowning

stroke

Huntington's disease

atherosclerosis, or hardening of the arteries

multiple sclerosis, a degenerative disorder caused by destruction of the lining of nerves throughout the body

HIV, the immunodeficiency disorder associated with AIDS

Parkinson's disease, a degenerative disorder of part of the nervous system

Creutzfeldt-Jakob disease, a rapidly progressing degenerative disorder of the nervous system causing problems with walking, talking, and the senses

Pick's disease, a disorder of the brain that causes slowly progressing dementia

viral or bacterial encephalitis, an inflammation of the brain

Lewy body disease, a degenerative disease of the nervous system

normal pressure hydrocephalus, or increased cerebrospinal fluid in the brain

chronic subdural hematoma, or bleeding between the brain lining and brain tissue

brain tumor

Wilson disease, a rare disease causing an accumulation of copper in the liver, brain, kidneys, and corneas

neurosyphilis, an infection of the nervous system by the Treponema pallidum bacteria. Less often, syphilis is transmitted from a pregnant woman to her baby. This form of syphilis is known as congenital syphilis. ',CAPTION,'Syphilis');" onmouseout="return nd();">syphilis bacteria which causes weakness and mental deterioration

Certain abnormalities of a person's metabolism or hormones may also be responsible for memory loss. These include:

hypothyroidism, which is an underactive thyroid gland

hyperthyroidism, which is an overactive thyroid gland

high-dose steroid abuse

deficiency, or low body levels, of B1

pantothenic acid

folic acid

niacin

biotin

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vitamin B2

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vitamin B6

vitamin B12

folate

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deficiency of niacin, which is vitamin B3

chronic alcohol abuse

chronic exposure to metals, such as lead or mercury, and to dyes, such as aniline

medication side effects or drug interactions

Symptoms & Signs

What other signs and symptoms are associated with this symptom?

Many people with progressive memory loss may not be aware of their worsening forgetfulness. Their family members or friends may be more able to judge whether their memory lapses are getting worse. Depending on whether the memory loss involves short-term or long-term memory, the individual or family may notice certain events, such as:

inability to recognize family members

forgetting one's phone number or home address

forgetting how to return home from a familiar location

forgetting to eat, bathe, or maintain one's hygiene

forgetting friends' or family members' names

Diagnosis & Tests

How is the symptom diagnosed?

A person does not need to see a healthcare professional about simple memory loss that happens only once in a while. If memory loss is severe and progressive, Alzheimer's disease must be considered. Dementia can be diagnosed only if a healthcare provider is made aware of the problem.

The family should be able to discuss the range of the person's symptoms over time. Included should be how symptoms progressed and whether the symptoms improved or deteriorated. Also, the family should report how suddenly or gradually symptoms came on. The healthcare provider should also know all medications that the individual is taking. This includes over-the-counter products, herbal remedies, and all prescription medications.

Combinations of drugs may impair memory at times. The healthcare provider will look for other medical conditions that may contribute to the symptoms.

To determine if other medical conditions are contributing to the symptoms, tests may be done. Tests may include:

blood tests, such as a complete blood count, or CBC, thyroid function tests, tests for infectious diseases and vitamin levels in the blood

memory testing

electroencephalogram, or EEG, which measures brain waves

electrocardiogram, or ECG, which measures the electrical activity of the heart

cranial MRI or cranial CT scans, which look at the structures of the brain

spinal tap, a procedure in which a small amount of fluid is withdrawn from the spinal column to look for infection or bleeding

Prevention & Expectations

What can be done to prevent the symptom?

Mild memory loss comes normally with aging. Keeping the brain active may help to preserve brain cells. Reading, singing, doing puzzles, conversing, exercising, and eating a balanced diet stimulate blood flow and activity in the brain.

Many cases of memory loss are due to Alzheimer's disease. Although there are no proven methods to prevent Alzheimer's disease, recent research findings provide some options that may slow the onset of the disease or the progression of symptoms. These findings, which need further study, include:

low doses of aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs), which may work by making blood cells and vessels less sticky and improving blood flow

actively engaging in cognitive activities such as reading, which may increase the nerve connections in the brain and delay the onset of the disease

taking antioxidants such as Vitamin E and selignine. In the Alzheimer's Disease Cooperative Study, a dose of 1,000 IU of Vitamin E and 5 mg of selignine twice daily delayed nursing home placement, loss of the ability to perform self-care, and severe dementia.

hormone replacement therapy for menopausal women, which may delay the onset of symptoms of Alzheimer's disease. The relationship between the hormone estrogen and Alzheimer's disease still needs further investigation.

avoiding head injuries. A person should wear a seat belt at all times when riding in a motor vehicle. Sports safety guidelines for children, adolescents, and adults can be helpful in avoiding other head injuries.

Strokes are another major cause of memory loss. Preventing or treating high blood pressure, obesity, diabetes, high cholesterol, and alcohol abuse can lower the risk of stroke.

What are the long-term effects of the symptom?

Occasional memory lapses do not usually disrupt daily life. However, individuals with long-term, progressive dementia will continue to lose mental abilities. Ultimately, this makes independent living impossible. A person suffering from the condition often requires nursing home care. The family may face considerable financial expense in caring for the person. Extensive medical care due to falls, trauma, infections, and depression may also result.

What are the risks to others?

Memory loss is not contagious and poses no risk to others. If the memory loss is caused by an infection such as AIDS, the infection may be contagious.

Treatment & Monitoring

What are the treatments for the symptom?

There are several steps a person can take to improve his or her memory. These include:

following a regular routine when possible

setting up a reminder system. This may include a book, calendar, or pocket diary.

making daily lists

keeping track of daily medications. This can be done with a medication reminder box or a chart posted on the refrigerator.

keeping track of appointments, birthdays, and bills to pay

keeping a list of names and telephone numbers

keeping keys in the same place

The 3 medications currently approved by the Food and Drug Administration for treatment of Alzheimer's disease are donepezil, tacrine, and rivastigmine. These medications are designed to improve memory by increasing the amount of acetylcholine in the body.

Other medications, such as risperidone or quetiapine, may also be used to help behavioral problems such as hallucinations, delusions, or agitation. Some individuals with memory loss may also need medications for depression, anxiety, or insomnia.

Other treatments include support and education for those caring for people with memory loss. Individual and family counseling can be beneficial. It's also been found that support groups assist caregivers. As the memory loss progresses, many families are unable to care for the person at home, and placement in a special facility becomes necessary.

What are the side effects of the treatments?

Medications used to treat memory loss can damage the liver, so periodic liver function tests are needed. Other side effects may include nausea, diarrhea, insomnia, vomiting, fatigue, or muscle cramps.

What happens after treatment for the symptom?

In most cases, memory loss is a degenerative condition without a cure. Treatment is lifelong. Because the course of memory loss is unpredictable, individuals with the condition should make plans for end-of-life care while they are still able to participate in the decision-making process.

Difficult issues that family members may face include:

promoting independence while making sure the individual is safe

removing driving privileges

finding supportive care among family or in an assisted living facility or nursing home

making business decisions

determining executors of written wills and making sure advanced directives are in the individual's patient file at his or her doctor's office

How is the symptom monitored?

Individuals with memory loss will have periodic visits to the healthcare provider for evaluation and treatment. Periodic liver function tests may be ordered if the person is taking one of the medications that can cause liver damage. Any new or worsening symptoms should be reported to the healthcare provider.