Miller Fisher Syndrome


What is Miller Fisher syndrome?

Miller Fisher syndrome (MFS) is a rare disorder that causes your immune system to attack nerves, usually starting in your face. It can affect the nerves that control your eye muscles, so you may have trouble moving your eyes. MFS also can cause problems with your coordination and reflexes. Symptoms usually follow a viral or bacterial infection.

Who gets Miller Fisher syndrome?

Anyone can get Miller Fisher syndrome, but it’s more common in:

  • People of Asian descent.
  • Men and people assigned male at birth (AMAB). MFS affects people AMAB twice as often as women and people assigned female at birth.
  • Adults over the age of 55.

What’s the difference between Miller Fisher syndrome and Guillain-Barré syndrome?

Miller Fisher syndrome is a form of Guillain-Barré syndrome (GBS). Like MFS, GBS is an autoimmune disease triggered by an infection. But MFS tends to affect your upper body first, whereas GBS typically affects your lower body and then spreads upward. Common symptoms of GBS include back pain, breathing problems and muscle weakness in your feet, legs and hands. GBS is also more common than MFS.

Is Miller Fisher syndrome contagious?

Miller Fisher Syndrome isn’t contagious, so it doesn’t spread from person to person.

How common is Miller Fisher syndrome?

Miller Fisher syndrome is very rare. It affects about 1 to 2 people per 1,000,000 people worldwide.

Symptoms and Causes

What are the symptoms of Miller Fisher syndrome?

The symptoms of Miller Fisher syndrome tend to come on suddenly and develop over a few days. Symptoms usually start about 10 days after a viral or bacterial infection. Sometimes, your symptoms may not appear for several weeks.

The most common symptoms of MFS include:

You may also develop:

  • Breathing problems.
  • Muscle weakness in your arms and legs.
  • Swallowing problems.
  • Tongue weakness.

What causes Miller Fisher syndrome?

MFS can develop if your immune system reacts to an infection and mistakenly attacks nerves while it’s trying to fight the infection. Viral and bacterial infections that may trigger MFS include:

Is Miller Fisher Syndrome hereditary?

MFS may be inherited (passed down from parents to children), but it’s rare for two people in the same family to have the disorder.

Diagnosis and Tests

How is Miller Fisher syndrome diagnosed?

There isn’t a test that can confirm a diagnosis of MFS. Your healthcare provider will perform a physical exam, evaluate your symptoms and review your medical history. Be sure to tell your provider if you’ve had a viral or bacterial infection in the last several months.

If your provider suspects you have MFS, they may perform the following tests:

  • Blood tests: Blood tests can detect high levels of certain antibodies in your blood. Antibodies are proteins your immune system produces to fight infections.
  • Electromyography: An electromyogram is a test that measures how well your muscles are responding to signals from nerves.
  • Nerve conduction study: This test measures how quickly an electrical signal moves through your nerves.
  • Spinal tap: During a spinal tap (lumbar puncture), your provider removes a sample from the fluid surrounding your spine and examines the fluid for certain antibodies.

Management and Treatment

How is Miller Fisher syndrome treated?

There isn’t a cure for Miller Fisher Syndrome, but some therapies can stop your immune system from attacking healthy nerves. The most common treatments include:

  • Intravenous immunoglobulin (IVIG) therapy: IVIG therapy uses purified plasma (the liquid portion of your blood) and healthy antibodies from donors. It can help prevent your immune system from attacking healthy tissue.
  • Plasma exchange (plasmapheresis): Plasmapheresis is a procedure to filter your blood of plasma that may contain harmful antibodies.
  • Physical rehabilitation: You may work with a physical therapist or occupational therapist to regain muscle strength, flexibility and coordination. Therapists can help you improve your balance and gait (walking) and show you techniques for performing daily activities.


How can I prevent Miler Fisher syndrome?

There’s no way to prevent Miller Fisher syndrome. But you can take steps to reduce your risk of getting a viral or bacterial infection. Be sure to:

  • Avoid contact with people who are sick.
  • Cover coughs and sneezes.
  • Disinfect surfaces that you touch often.
  • Don’t touch your face unless your hands are clean.
  • Wash your hands often and use hand sanitizer.

Outlook / Prognosis

What’s the outlook for someone with Miller Fisher syndrome?

The outlook for people who receive treatment for Miller Fisher syndrome is good. It’s rarely fatal and usually doesn’t cause any serious or long-term health complications. Most people recover within two to six months.

Living With

When should I see my healthcare provider about Miller Fisher syndrome?

See your healthcare provider immediately if you experience any issues with your reflexes, coordination or muscle movements. The symptoms of Miller Fisher syndrome can be similar to those of other disorders that affect your nerves and muscles.

A note from Cleveland Clinic

Noticing problems with your eyes, muscles or balance can be scary. In most cases, these symptoms don’t mean you have Miller Fisher syndrome (MFS) because the disease is so rare. But they’re signs that something isn’t right, so it’s important to talk to your healthcare provider right away if you experience any of these issues. Your provider can do tests to check your muscles, nerves and overall health before designing a treatment plan that best fits your needs.

Last reviewed by a Cleveland Clinic medical professional on 09/12/2022.


  • Cabrero FR, Morrison EH. Miller Fisher Syndrome. ( [Updated 2021 July 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Accessed 9/12/2022.
  • National Organization for Rare Disorders. Miller Fisher Syndrome. ( Accessed 9/12/2022.

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy