Introduction
Miller Fisher syndrome (MFS), also called Fisher’s syndrome, is a neurological disorder characterized by sudden facial weakness, loss of reflexes, and poor coordination. Miller Fisher syndrome (MFS) is a rare, autoimmune nerve disease. It is a less severe or mild form of Guillain-Barré syndrome.
Read the article below to get an overview of Miller Fisher syndrome, including its cause, symptoms, diagnosis, and treatment.
What Is Miller Fisher Syndrome?
MFS is a sudden-onset neurological disorder that results in problems related to the peripheral nervous system, including:
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Loss of reflexes.
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Facial droopiness.
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Coordination and balance.
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Problems controlling the eyelids.
MFS often occurs following a viral infection, so many people have symptoms of a cold, diarrhea, mono, or other diseases before the appearance of MFS. MFS is a milder or less severe variant of Guillain-Barré syndrome (GBS). Both are considered autoimmune disorders that develop when the body’s immune system starts attacking the nervous system.GBS can lead to weakness, tiredness, tingling sensation, and paralysis in the limbs. More severe forms of GBS can lead to difficulty in breathing. Approximately 5 to 10 percent of people with GBS experience respiratory paralysis that requires a breathing tube or ventilator. The outlook of MFS is usually good as most people start recovering within 2 to 4 weeks. However, a few people may have lasting effects, and the condition may relapse. Alternatively, the symptoms of MFS could signify the beginning of GBS. Since GBS can result in breathing issues, healthcare providers may hospitalize people with MFS symptoms.
What Are the Signs and Symptoms of Miller Fisher Syndrome?
The symptoms of MFS typically develop rapidly, distinguishing it from other gradual-onset nerve conditions. The three primary defining symptoms of MFS are:
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Ataxia - loss of controlled body movements, including weakness or incoordination of the limbs.
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Areflexia - loss of tendon reflexes, particularly in the knees and ankles
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Ophthalmoplegia - weakness of the eye muscles leading to impaired eye movements and double vision.
For most people, the symptoms start to appear in the eyes. However, some people may also experience other neurological symptoms, such as trouble urinating.
What Causes Miller Fisher Syndrome?
The MFS symptoms are caused due to a specific type of nerve damage. Nerves are enclosed and protected by a substance known as myelin, and when this myelin gets damaged, the nerves are unable to function normally. This process is known as demyelination. Researchers are of the opinion that something, usually an infection, stimulates the body to produce an antibody that causes MFS. This antibody results in damage to the peripheral nerves that affect the muscles, eyes, and sometimes the bladder. Certain viruses, such as Herpes simplex, Campylobacter jejuni, and Mycoplasma, are some of the common triggers for GBS. Though MFS is usually caused by an infection, it is unclear why this syndrome occurs in some people and not in others.
MFS or GBS also develops in some people following vaccination or surgery. The antibody is found in the blood of approx 80 percent of people with MFS and can be used to confirm the diagnosis. MFS does not affect more than one person in the family. There are rare reports of siblings or identical twins involved. There may be a hereditary predisposition to develop the disease.
How Is Miller Fisher Syndrome Diagnosed?
MFS is often difficult to diagnose since it can mimic other neurologic disorders such as myasthenia gravis, diphtheria, botulism, brain stem encephalitis, brain stem stroke, and basal meningitis. Therefore, physicians should have a high index of suspension, rule out similar diseases, and support testing for anti-GQ1b antibodies to help diagnose Miller Fisher syndrome. Doctors typically diagnose GBS or MFS based on a physical examination and assessment of a person's symptoms and how quickly the symptoms appeared.
It is crucial that a doctor must rule out other conditions, particularly those that may be life-threatening or medical emergencies, such as a brain injury or stroke. Therefore, doctors may order imaging scans such as an MRI (magnetic resonance imaging) on the brain to test for such conditions and may also inquire about medical history, recent illnesses, and lifestyle. A blood test may also be performed for the identification of the specific antibody known as the anti-GQ1b antibody, typically found in people with MFS or GBS. In addition, a nerve test known as the nerve conduction velocity test or a spinal tap that removes a tiny bit of cerebrospinal fluid may also help with the diagnosis.
What Is the Treatment of Miller Fisher Syndrome?
Since MFS is similar and a milder version of GBS and may progress into GBS, the two conditions' management is identical. According to the National Institute of Neurological Disorders and Stroke (NINDS), two primary treatment options are available for MFS. The first option involves injecting specific proteins known as immunoglobulins into the veins intravenously (IV). The alternative treatment option is a process known as plasma exchange, a procedure for cleansing blood. Plasma exchange is a process that involves the removal of some blood plasma, cleaning it, and then putting it back into the body. This procedure can take several hours and is more complicated than immunoglobulin therapy. Therefore most doctors prefer IV treatment with immunoglobulin proteins.
Some people with MFS may need additional treatments to maintain their bodies. For example, people with MFS, which later progresses into GBS, may require a ventilator or heart monitor and will likely need continual hospital monitoring. Treatment does not permanently cure the condition but may shorten the recovery time. Supportive therapy can also prevent severe complications of GBS. It has been observed that immunoglobulin therapy had an impact on the reduction in the length of time that some people experienced movement issues and eye problems. However, only a little difference was noted in recovery times between those who had plasma exchange, IV treatment, and no treatment. Therefore, the study concluded that neither immunoglobulin therapy nor plasma exchange had an effect on the overall outcomes.
Conclusion
Miller fisher syndrome is a rare and poorly understood neurological disorder. Doctors find it hard to know why MFS develops in some people following an illness but not in most people. Providing comprehensive information about the symptoms and health history to the doctor can ensure an appropriate diagnosis. It may also prove helpful for medical providers to understand this puzzling syndrome better.
