Alzheimer's Disease Health Center

Alzheimer’s Disease Diagnosis

Unfortunately, getting an Alzheimer’s disease diagnosis is not simple. Your doctor can’t check for the disease by doing a quick blood test. That’s because signs of Alzheimer’s disease don't appear in your blood. Instead, Alzheimer’s disease is the result of a problem inside your brain.

The only way to be 100% certain a person suffers from Alzheimer’s disease is to examine samples of brain tissue. This can only be done during an autopsy, after a person has died.

Steps Toward an Alzheimer’s Disease Diagnosis

Doctors are still looking for ways to directly check the brain for Alzheimer’s disease. In the meantime, your doctor has many tests that help him or her diagnose this condition. These tests can provide an Alzheimer’s disease diagnosis with about 90% accuracy.

Because it is difficult to diagnosis this condition, it’s a good idea to work with a doctor experienced in Alzheimer’s disease diagnosis. Doctors to consider include:

• Primary care doctors with experience in treating people with Alzheimer’s disease
• Neurologists
• Psychiatrists
• Psychologists

When looking for Alzheimer’s disease, doctors eliminate all other possible explanations of the symptoms. Dementia, for example, has many other causes besides Alzheimer’s disease. Some of these causes include vitamin deficiency and thyroid problems. With treatment, both these problems can be resolved.

Your doctor makes a “probable” Alzheimer’s disease diagnosis only when all other causes have been ruled out. Following are the steps your doctor will take while deciding on an Alzheimer’s disease diagnosis.

Step 1: A Complete Health History

Knowing about your health history helps your doctor discover whether there are other possible causes for your symptoms. For example, apathy is common in early stage Alzheimer’s disease. Apathy may also be caused by depression. Your doctor will ask you about:

• Medications you currently take
• Past and present illnesses
• Your mental health

Step 2: Lab Work and Other Tests

Your doctor will check for signs of other problems, such as liver, thyroid, or glucose problems. You may have these tests to rule out other medical issues:

• Blood
• Urine
• Spinal fluid
• Chest X-ray
• Electrocardiogram (EKG)

Step 3: A Physical Exam

A complete physical exam may show problems that signal something other than Alzheimer’s disease. Your exam should include:

• A complete physical exam
• Hearing and vision tests
• Blood pressure and pulse

Step 4: Neurological and Psychological Testing

Tests of how you think can help your doctor decide whether there is another cause for your symptoms. You may take oral and written tests to check these areas:

• Memory
• Ability to focus
• Communication skills
• Problem-solving skills

Step 5: Brain Tests

Your doctor may request tests of your brain and its function. These can help determine if other problems such as blood clots or tumors are causing your Alzheimer's disease symptoms. These tests may include the following:

• Electroencephalography (EEG)
• Magnetic resonance imaging (MRI) or magnetic resonance spectroscopy imaging (MRSI)
• Computed tomography (CT) or single photon emission computed tomography (SPECT) scan
• Positron emission tomography (PET) scan

Beyond an Alzheimer’s Disease Diagnosis

While not curable, a number of medications are available to improve symptoms of Alzheimer’s disease, including memory and cognition. These medications won't slow the progression of the disease; but, they may improve symptoms. Medications include:

• Aricept and Exelon, which are used for mild to moderate Alzheimer’s disease.
• Namenda, which is used for moderate to severe Alzheimer’s disease.