Alzheimer's disease is diagnosed with a medical history and a physical exam. A physical exam is used to help find out if a physical problem may be causing a person's dementia symptoms. It may be possible to correct some of these problems. For example, sometimes a simple hearing or vision problem can cause confusion, social withdrawal, or a change in behavior, such as hostility or unresponsiveness. The person may have an undiagnosed illness or infection that is causing the symptoms.
Personal medical history
The physician will need the following:
- A detailed description of changes in mental abilities, personality, mood, and behavior, including when and how the changes began and how they have affected the individual's ability to function. Letters, checkbooks, household lists, or other materials that illustrate changes in cognition may also be helpful.
- Information about physical complaints or symptoms, such as loss of coordination, sudden vision problems, or weakness.
- A complete medical history, including injuries and recent illnesses.
- A list of medications the patient is taking, including nonprescription drugs and herbal supplements.
- Information about the medical problems of family members, especially relatives with a similar illness.
- This may seem like a lot of information, but the person's history provides the foundation for the doctor's diagnostic workup. It enables the physician to construct a list of possible diagnoses that will guide the medical evaluation that follows.
Disorders as diverse as heart failure, liver disease, kidney failure, thyroid disorders, and respiratory diseases can cause dementia-like changes. What's more, elderly people don't always have typical symptoms of an illness. The sensation of pain is often dulled in the older person, for example, and it's not unusual for confusion, rather than chest pain, to be the main symptom of a heart attack.
Therefore, the physician will evaluate the cardiovascular system, lungs, and other organs for any signs of abnormalities. Because sensory losses can add significantly to a person's cognitive difficulties, the doctor will also test the individual's vision and hearing. The physician will also pay close attention to the nervous system, because neurologic abnormalities may signal a brain disorder other than Alzheimer's disease.
Muscle tone and strength, coordination, reflexes, senses, eye movement, and the pupils' reaction to light can tell the physician about the health of specific areas of the brain. For example, unequal reflexes or weakness on one side of the body suggests localized brain damage (perhaps from stroke or tumor), while tremors or other involuntary movements may indicate a degenerative disorder such as Parkinson's disease. These types of abnormalities are not usually features of early Alzheimer's disease.
Summarizing, the following tests should be included in the physician’s examination:
- Vital signs (temperature, blood pressure, pulse)
- Height and weight
- Head, eyes, ears, nose
- Chest, including lungs and heart
- Bones and muscles
- Rectal/genital area
A small number of people with dementia have a condition that proper treatment can reverse (unlike Alzheimer's disease). Lab tests may be done to rule out other possible causes of a person's symptoms, such as levels of certain minerals or chemicals in the blood that are too high or too low, liver disease, abnormal thyroid levels, or nutritional problems, such as folate or vitamin B12 deficiencies. Treatment for these conditions may slow or reverse mental decline.
Blood tests often done to check for these conditions include:
- Complete blood count (CBC), which shows the kinds and number of cells in your blood to help your doctor evaluate your symptoms.
- Liver function tests (AST, ALT, alkaline phosphatase, bilirubin), which detect liver damage or disease.
- Folate (folic acid) test, which detects the level of the B vitamin folic acid either inplasma (the liquid part of blood) or in the red blood cells. Folic acid is needed for the production of both red and white blood cells.
- Vitamin B12 concentration, which detects the level of vitamin B12 in your blood. Vitamin B12 is needed to produce red blood cells and to maintain a healthy nervous system.
- Electrolyte and blood glucose levels (sodium, potassium, creatinine, glucose,calcium), which are needed to keep the body's balance of fluids at the proper level and to maintain normal functions, such as heart rhythm, muscle contraction, and brain function.
- Thyroid function tests. Abnormal thyroid hormone levels are a common cause of forgetfulness, confusion, lethargy, and other symptoms of dementia in older people. Medicine can easily improve symptoms if a thyroid problem is present.
- Human immunodeficiency virus (HIV) infection test, if the person has risk factors for HIV or the medical history suggests it. Untreated HIV can cause symptoms such as personality changes or problems concentrating.
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