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Multifocal Motor Neuropathy (MMN) Diagnosis

It's important to talk to your doctor right away if you think you might have MMN. Understanding the diagnostic process can help you prepare for this conversation.

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Where to start if you think it's MMN

An accurate diagnosis is important to getting an effective management plan in place. Because it is rare and sometimes looks like other conditions, it may take time to confirm it's MMN.

Be ready to talk about MMN with your doctor by knowing your symptoms and learning about the condition. There are resources that can help you and your doctor connect the dots:

Learn all you can about MMN before visiting with your doctor.

Visit our resource page

Prepare for your doctor's visit by keeping track of your symptoms before your appointment.

Get the symptom tracker
Doctor discussing MMN diagnostic test results with a patient.

How is MMN diagnosed?

Because it's a rare disease, not all doctors are familiar with MMN. So, it helps to know about the diagnostic process and how to talk about MMN with your doctors.

Doctors who specialize in disorders are usually needed to make an MMN diagnosis. Your MMN healthcare team may include a doctor called a neurologist.

The American Association of Neuromuscular & Electrodiagnostic Medicine website may be able to help you find a doctor who specializes in neurological disorders like MMN.

How can a doctor know if it may be MMN?

How can a doctor know if it may be MMN?

A hand holding tightly depicts how MMN can affect one’s dexterity.

Muscle weakness that usually starts out in one hand (eg, difficulty gripping or holding objects)

A red and grey body icon depicts the asymmetric symptom of MMN.

One side of the body is more affected than the other side
( )

A leg icon with a red circle on the knee depicts that spasticity doesn't develop with MMN.

Tendon reflexes may be brisk, but doesn't develop

A hand inside of a forbidden circle depicts that there is no sensory issue with MMN.

Normally no loss of touch or other issues (eg, numbness, tingling)

A speaker inside of a forbidden circle depicts that there is no unusual difficulty speaking or swallowing with MMN.

There is no unusual difficulty speaking or swallowing

Tests used in diagnosing MMN

If your doctor thinks you may have MMN, there are certain tests you may need to do for a diagnosis:

Electromyography test icon.


The electrical activity of a muscle is recorded during a test called an .
This helps determine if muscle weakness is being caused by the muscle itself or by nerves that control the muscle.

Nerve conduction study icon.

Nerve conduction study

A nerve conduction study can test the impulses from the brain to specific nerves, helping pinpoint where the nerve might be damaged.

Blood test icon for GM1 antibody.

Blood test for GM1 antibody

Your doctor also may order a blood test to check for increased levels of GM1 in your blood. Only about half of people with MMN have these antibodies, so the test results do not necessarily rule out a diagnosis. However, the test can help lead to an MMN diagnosis in those patients who have GM1 antibodies.

Thumbnail video of Jen, an MMN patient, doing Yoga on the beach.
After what felt like a revolving door of specialists and doctors, I finally found the right one to help me treat my MMN.
Living with MMN

Take charge of your doctor's appointment

It's essential to be your own advocate when it comes to your health. Preparing for your appointment helps ensure you make the most of the time you have with your doctor.

Bring your Symptom Checker to your doctor's appointment with the following items filled in before you get there:

  • An overview of your symptoms, including the length and severity of each symptom
  • A list of any medications you're taking and how they make you feel

Prepare a list of questions you want to ask your doctor, such as:

  • What are the treatments for this condition?
  • Where can I turn for more information?
  • What tests will I need to have for a diagnosis?


the details about MMN

MMN happens when the immune system mistakenly attacks nerves involved in muscle movement. Symptoms usually begin as weakness in one hand or foot.