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Symptoms of Multifocal Motor Neuropathy (MMN)

The symptoms of MMN can be easy to brush off at first. That’s because MMN appears gradually. It can also be mistaken or misdiagnosed for other conditions with similar symptoms.

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KNOW the key MMN symptoms

Use the acronym NOW to remember the key early symptoms of :

A hand icon with some thin lines depicts the cramping or spasm symptoms MMN.


No effect on sense of touch, but may involve cramping, spasms, or twitching

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


One side of the body may have more symptoms than the other ( ) at the start

A lifted arm icon with an arrow pointed down depicts that the MMN symptoms could lead to a loss of muscle mass.


Weakness in hands or feet, which eventually leads to loss of muscle mass

MMN is more than muscle weakness

Weak signals from neurons affected by MMN can lead to less frequent use of muscles. If muscles are not used enough they can shrink in size, a term called "muscle atrophy." Muscle atrophy only occurs late in the course of MMN. And there are management options that may help slow down the progression of MMN.

If you have MMN, you
also may experience:

Muscle twitching icon.


The medical term for this symptom is . These look like small, uncontrolled muscle twitches that are visible under the skin.

A half-empty battery inside of a head icon depicts that fatigue can be a symptom of MMN.


People with MMN say that keeps them from doing some of the daily activities that they were once able to do.

Tennis shoe icon depicts how difficult it can be to lift your foot if you have MMN.

Limited ability to walk

You may have trouble lifting your foot if MMN weakens muscles in that foot. This can make it difficult to walk.

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

Limited Dexterity

If MMN affects your , you may have difficulty extending your wrist or fingers. You also may notice your grip is weaker than it used to be.

A hand pouring hot water depicts how MMN can affect the ability to hold on to the everyday item.

MMN can affect your ability to hold onto everyday items such as a tea kettle or pitcher.

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How does MMN affect daily life?

MMN may affect your daily life in one or more of the following ways due to limited dexterity:

  • Dropping things you’re trying to hold
  • Trouble gripping a fork, spoon, or knife while eating
  • Difficulty turning a key in a lock
  • Struggling to button a shirt or coat
  • Difficulty tying shoelaces
  • Trouble texting or scrolling on smartphones

If this sounds like you, it’s time to talk to your doctor about your symptoms. It may help to fill out the symptom tracker tool and bring a copy to your medical appointment.

These are not MMN symptoms

Unlike some other disorders, MMN does not present with the following symptoms:

Numbness in the affected limbs
Trouble swallowing or breathing

The reason MMN does not cause these symptoms is that it rarely affects the or neurons in your body. are the nerve cells that make you aware of pressure, heat, cold, or pain. So, when it comes to MMN, it helps to remember the expression "motor without sensory." That's because MMN usually only affects .

MMN and misdiagnosis

MMN can be difficult to diagnose. This is partly because MMN symptoms may get mistaken for more well-known conditions. For example, it may be mistaken for amyotrophic lateral sclerosis (ALS), also called Lou Gehrig's disease.

MMN vs other conditions that can look like MMN

Key signs and symptoms
Body distribution
Disease course
Key signs & symptoms
Body distribution & disease course
  • Muscle weakness in hands or feet
  • Muscle cramping, twitching, or spasms
  • Symptoms usually start in one hand or foot
  • No sensory issues like numbness, tingling, or pain
  • Blood tests report anti-GM1 antibodies
A red and grey body icon depicts the asymmetric symptom of MMN. Asymmetric
  • Weakness in hands, legs, feet, or ankles
  • Muscle cramps and/or twitches
  • Slurred speech or trouble swallowing
  • Tripping, falling, and difficulty walking
  • Changes in behavior
A red and grey body icon depicts the asymmetric symptom of MMN. Asymmetric
  • Numbness or tingling in fingers
  • Sometimes pain in hand and wrist
  • Fingers feel useless and swollen
A red and grey body icon depicts the asymmetric symptom of MMN. Asymmetric
  • Tingling, weakness, and loss of feeling in arms and legs
  • Loss of reflexes
  • Loss of balance and difficulty walking
A red body icon depicts how COPD is symmetric. Symmetric
progresses, and
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A video thumbnail of Jen, a MMN patient walking on the beach.
Now that I look back, I think symptoms started before I even started recognizing them.
Living with MMN


THAT MMN is manageable

Did you know there are treatment options that can help slow the progression of MMN in your body? If you are diagnosed with MMN, consider talking to your doctor about developing a management plan specifically for you and your needs.