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Multiple Sclerosis (MS) Diagnosis & Tests

Medically Reviewed by Christopher Melinosky, MD on February 16, 2020

It can be a challenge for doctors to diagnose multiple sclerosis (MS). There’s no single test that can prove you have it. And many conditions have symptoms that seem like those of MS.

A neurologist -- a doctor who specializes in treating the disease -- should be able to help. They’ll ask how you’re feeling and help you figure out if your symptoms mean you have MS or another problem.

What Do Doctors Look For?

MS can take some time and a number of tests to diagnose. It starts when you or your doctor notices certain signs or symptoms that could be MS. These might include:

  • Numbness or tingling in the skin (typically, hands or feet)
  • Unusual weakness in arms, legs, or fingers
  • Slurred speech
  • Stumbling or trouble walking
  • Double vision or loss of color
  • Flashing lights that others can’t see
  • Eye pain that gets worse with movement
  • Vision loss in one eye

When you first notice these symptoms, especially if they are serious, your doctor might need to rule out other causes like stroke, tumor, or pressure on the spinal cord. If the symptoms last more than a couple of days, even if they go away on their own, it may be time to see a neurologist who specializes in MS to speed up diagnosis and start treatment.

If your doctors suspect MS, they will look for further symptoms and signs that suggest MS. To make a final MS diagnosis, they will use several tools to try and do three things:

  • Rule out any other conditions that could cause your symptoms
  • Find damage to at least two spots on your brain
  • Prove the damage happened at different points in time

What Are the Tools for Diagnosis?

The doctor will start by asking you about your medical history and your symptoms. They’ll also do a few tests to see if your brain and spinal cord are working as they should. These include:

mri

MRI: This imaging test lets the doctor take a closer look at your brain. They can see changes caused by multiple sclerosis, like signs of inflammation in the deep parts of your brain or spinal cord.

But older people or those with high blood pressure and diabetes also can have the same kinds of spots on a brain MRI. So the doctor will consider other info, including your symptoms, along with the scan results or the enhancement of lesions before they make a diagnosis.

Also, an MRI result that says things are normal doesn’t rule out MS. You could be one of a small number of people who have lesions in places the scan can’t show.

Learn more about using MRI to diagnose MS.

spinal tap

Lumbar puncture: This test, which you may also hear called a spinal tap, checks the fluid that runs through your spinal column. Doctors use it to look for high levels of proteins and other substances that are signs of the disease. It can help diagnose MS, but it, too, isn’t absolute proof.

Know what to expect with a spinal tap to diagnose MS.

Evoked potentials: These electrical nerve tests can help doctors confirm if MS has affected the parts of your brain that help you see, hear, and feel. The doctor will place wires on your scalp to test your brain's response as you watch a pattern on a video screen, hear a series of clicks, or get electrical pulses on your arm or leg.

Find out how evoked potential tests help reach an MS diagnosis.

Blood tests: They can’t diagnose MS, but the doctor will use them to look for substances in your blood that point to it. Most importantly, they can help your doctor rule out conditions that look like MS.

Get more information about other types of demyelinating disorders that look like MS.

Eye exam: An eye exam could reveal problems that MS sometimes causes. Your doctor will test how well you can see detail far away, your field of vision, eye muscle strength, and pressure inside the eyeball, among other things. Possible MS-related conditions might include:

  • Optic neuritis: Damage to the optic nerve that often causes pain as well as blind spots surrounded by areas of normal vision
  • Nystagmus: Eyes move rhythmically back and forth or up and down without conscious effort. May be due to nerve damage, especially in the brainstem or cerebellum.
  • Diplopia: Double vision that happens due to damage to the nerve pathways that control the eyes. It can be an early symptom of MS.

After a Diagnosis

It may take a long time to figure out that you have MS. If you’ve been waiting years or months, the news might be a relief. Or it could be a huge shock. Either way, you’ll have concerns about what the disease means for your life and your family. That's completely understandable.

Talk with others -- your friends, your doctor, a support group, or a counselor -- about your feelings. Your health care team can help you decide the best ways to treat your disease and live with it day to day. MS affects everyone differently, so what works for one person with the condition may not be what’s best for you.

WebMD Medical Reference

Sources

SOURCES:

National Multiple Sclerosis Society: “Diagnosing MS.”

Mayo Clinic: “Multiple sclerosis,” “Optic neuritis.”

MS Brain Health: “Referral and diagnosis,” “Revisions to criteria used in the diagnosis of MS.”

Maine Medical Partners: “Multiple Sclerosis Referral Guideline.”

Multiple Sclerosis Trust: “Visual Problems.”

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