OVERVIEW

What is Miller Fisher syndrome?

Miller Fisher syndrome (MFS), also known as Miller Fisher syndrome, is a variant of Guillain-Barré syndrome, an acute autoimmune peripheral nervous system disease. Typical symptoms may include the triad of ophthalmoplegia, ataxia, and areflexia.

The disease is rare and is currently thought to be associated with GQ1b antibodies.

Is Miller Fisher syndrome common?

No, it is uncommon.

Is there a gender difference in the incidence of Miller Fisher syndrome?

Studies have shown that the male-to-female ratio of Miller Fisher syndrome is 2:1, with an average age of onset of 43.6 years.

SYMPTOMS

What are the symptoms and manifestations of Miller Fisher syndrome?

• Patients with Miller Fisher syndrome often have a history of preceding infections, including respiratory infections, diarrhea, and Campylobacter jejuni infection. The onset can be acute, with symptoms peaking within days to weeks.

• Patients with Miller Fisher syndrome typically exhibit the triad of ophthalmoplegia, ataxia, and hyporeflexia. Ophthalmoplegia may present as impaired eye movements in all directions, diplopia, ptosis, and sometimes pupillary abnormalities.

• Ataxia may manifest as unsteady gait, dizziness, inability to walk in a straight line, and uncoordinated movements. Unlike other common subtypes of Guillain-Barré syndrome, this condition usually does not significantly affect limb muscle strength or cause impaired consciousness.

• Incomplete forms of MFS include acute ophthalmoplegia without ataxia and acute ataxic neuropathy without ophthalmoplegia. Some MFS patients may exhibit fixed and dilated pupils.

What conditions should Miller Fisher syndrome be differentiated from?

Miller Fisher syndrome should be distinguished from other conditions that cause ophthalmoplegia and unsteady gait, such as brainstem infarction, myasthenia gravis, Wernicke encephalopathy, botulism, and tick bites.

CAUSES

What is the cause of Miller Fisher syndrome?

The pathogenesis of this disease is not yet fully understood. Current research suggests it may be related to autoimmune reactions following infections such as Campylobacter jejuni, which produce autoantibodies (e.g., GQ1b antibodies) that attack self-antigens, leading to cranial nerve damage.

However, due to the low incidence of Miller Fisher syndrome, its exact pathological mechanisms and specific sites of injury remain incompletely understood.

DIAGNOSIS

How is Miller Fisher Syndrome diagnosed?

Based on the patient's acute onset, progressively worsening course, symptoms such as diplopia, nystagmus, ophthalmoplegia, and unsteady gait, along with physical examination findings of diminished tendon reflexes, this condition should be highly suspected. Diagnosis can be confirmed after ruling out other diseases through lumbar puncture and other tests.

The current diagnostic criteria for Miller Fisher Syndrome are:

• Acute onset, with symptoms peaking within days or weeks.
• Primary clinical manifestations include ophthalmoplegia, ataxia, and diminished tendon reflexes, with normal or mildly weakened limb muscle strength.
• Cerebrospinal fluid shows albuminocytologic dissociation or tests positive for GQ1b antibodies.
• The disease course is self-limiting.

What tests do patients with Miller Fisher Syndrome need? Why are these tests necessary?

• Lumbar puncture: Patients suspected of having Miller Fisher Syndrome should undergo lumbar puncture for cerebrospinal fluid analysis. This helps detect albuminocytologic dissociation (though not all patients present with it, and it often appears after 2 weeks of onset) and allows for specific antibody testing. It also aids in differential diagnosis.

• Brain MRI: To rule out brainstem lesions.

• Serum Campylobacter jejuni antibody testing: If available, testing for Campylobacter jejuni antibodies can support the diagnosis.

• Neurophysiological studies: Electrophysiological tests in MFS patients show reduced or absent sensory responses without slowing of sensory nerve conduction velocity.

TREATMENT

Which department should I visit for Miller Fisher syndrome?

Neurology.

Can Miller Fisher syndrome heal on its own?

The disease may be self-limiting, but the likelihood of sequelae increases without active treatment, so aggressive therapy is still recommended.

Does Miller Fisher syndrome require hospitalization?

Yes.

How is Miller Fisher syndrome treated?

The goal of treatment is to suppress abnormal immune responses, eliminate pathogenic factors causing nerve damage, and promote nerve regeneration. The specific treatment plan is similar to other Guillain-Barré syndromes, primarily focusing on immunotherapy:

• Intravenous immunoglobulin (IVIG): Can halt disease progression, shorten the course, and improve short- and long-term outcomes. It has no severe side effects, is convenient to use, and is widely applied.

• Plasma exchange (PE): Can shorten the disease course and stop progression, recommended for moderate or severe cases within 4 weeks of onset. Due to limited PE equipment availability in only a few hospitals and high costs, its use is somewhat restricted. Contraindications include severe infections, arrhythmias, heart failure, and coagulation disorders.

• Corticosteroids: Their efficacy is uncertain and may be considered for patients unable to undergo the first two treatments.

DIET & LIFESTYLE

What should Miller Fisher syndrome patients pay attention to in their diet?

No special precautions are required; maintaining a healthy diet is sufficient.

What should Miller Fisher syndrome patients pay attention to in daily life?

Due to blurred vision and unsteady walking, patients with Miller Fisher syndrome are prone to falls, so family members should provide close supervision.

Does Miller Fisher syndrome require follow-up examinations? How are they conducted?

This disease follows an acute course. If complete recovery is achieved after treatment, regular follow-ups are unnecessary. However, if residual symptoms persist, periodic outpatient reviews are needed to develop a rehabilitation training plan.

Can Miller Fisher syndrome patients fly, engage in strenuous exercise, or travel to high-altitude areas?

It is not recommended before the disease is effectively treated.

PREVENTION

Can Miller Fisher Syndrome Be Prevented?

The pathogenesis of this disease is not fully understood, but it is mostly related to infections. Avoiding cold exposure, infections, staying up late, and maintaining a healthy, regular routine with consistent exercise can help strengthen the body and prevent the disease.