What You Should Know About Testing for Alzheimer’s Disease

Learn how doctors make an Alzheimer’s diagnosis, and what to expect if you go to get checked out.

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More than 5 million Americans live with Alzheimer’s disease, a debilitating, progressive dementia that attacks the brain’s neurons. A half million people under 65 live with Alzheimer’s and other forms of dementia. As the American population ages, both numbers will grow, increasing the need for a better understanding of what causes this disease and exactly how it causes neural degeneration.

While certain proteins have been found in the brains of those diagnosed with the disease, how these proteins are related to the development of dementia and what other factors contribute to who gets Alzheimer’s and who doesn’t is still unknown. As a result, there’s no treatment available to reverse or halt the progress of Alzheimer’s. A diagnosis helps those affected and the people who care about them learn about and plan for what’s to come.

Diagnosing Alzheimer’s can be tricky because the symptoms aren’t clear cut. Here’s what you need to know about how the diagnosis is made.

Medical History

When making a diagnosis, your doctor will ask you a variety of questions about different aspects of your life and family that could put you at risk. This will include questions about:

  • Family medical history, including any history of dementia.
  • Your diet and any history of alcohol use.
  • Any medications you’re taking.
  • Any health conditions you’ve been diagnosed with.

Physical Exam

Alzheimer’s is only one type of dementia, which is why it’s important to do a thorough check both of your overall health as well as of specific aspects of brain health. The exam could include several components:

  • Checking pulse, blood pressure, temperature, heart and lungs
  • Doing a neurologic exam to check for basic nerve and brain function throughout the body.
  • Doing a mental status test to see how well the brain is processing information.

Laboratory Tests

The lab tests your doctor might do are generally to check for other causes of the symptoms you’re experiencing. While that memory loss could be Alzheimer’s, it could also be a vitamin deficiency or a metabolic condition. You may have blood taken or urine collected.

Genetic Testing

Genetic testing isn’t normally done in those who are suspected of having Alzheimer’s. One gene, Apo-E, is a gene that leads to increased risk. Genetic testing is most commonly used by researchers to look for other genes or factors that might be associated with risk for Alzheimer’s. Unfortunately, knowing what form of the gene you have won’t tell you if you’re going to get Alzheimer’s. Some people with the gene won’t get the disease and many without it will get the disease.

The other gene occasionally tested for is one that causes a hereditary form of Alzheimer’s that is rare and accounts for only 5% of all cases diagnosed. Those affected tend to have symptoms when they’re young and have an extensive family history. The test is used to confirm what is already a strong suspicion.

Brain Imaging

Your doctor may recommend a CT or MRI scan. This is done to rule out some of the other diseases that might be causing your symptoms, like a brain tumor, stroke or excess fluid around the brain. While experimental imaging has begun to look for some of the proteins associated with Alzheimer’s, these modalities aren’t good enough to make a diagnosis and aren’t ready to be used on large numbers of people.

Certainty of Diagnosis and Home Testing

Diagnosis can be made with 90% accuracy using all of the measures above. The problem is a definite diagnosis can only be made by looking at the brain directly under a microscope, which, of course, would never be done in a living person.

A number of companies offer home testing for Alzheimer’s. While they may hit on some symptoms associated with the disease, they are less accurate than seeing a professional and can’t help you deal with the consequences of the diagnosis. If you’re concerned you might have early signs of dementia, see your doctor.