Синдром Гієна-Барре (СГБ)

Although the cause of Guillain-Barré syndrome is not fully understood, it is thought to be autoimmune.

In about two thirds of patients, Guillain-Barré syndrome begins 5 days to 3 weeks after a banal infectious disorder, surgery, or vaccination. Infection is the trigger in > 50% of patients (1); common pathogens include

• Campylobacter jejuni

• Enteric viruses

• Herpesviruses (including cytomegalovirus and Epstein-Barr virus)

• Mycoplasma species (2)

A cluster of cases followed the swine flu vaccination program in 1976, but the association was later shown to be spurious, due to ascertainment bias. In some patients, Guillain-Barré syndrome has developed after a Zika virus infection or after COVID-19.

Adverse effects of immune checkpoint inhibitors include a syndrome that resembles Guillain-Barré syndrome.

If weakness progresses for > 2 months, chronic inflammatory demyelinating polyneuropathy is diagnosed.

Flaccid weakness predominates in most patients with Guillain-Barré syndrome; it is always more prominent than sensory abnormalities and may be most prominent proximally. Relatively symmetric weakness with paresthesias usually begins in the legs and progresses to the arms, but it occasionally begins in the arms or head. In 90% of patients, weakness is usually maximal at 3 to 4 weeks (1). Deep tendon reflexes are lost. Sphincters are usually spared. Weakness remains the same for a variable period of time, typically for a few weeks, then resolves.

Facial and oropharyngeal muscles are weak in > 50% of patients with severe disease. Dehydration and undernutrition may result. Respiratory paralysis severe enough to require endotracheal intubation and mechanical ventilation occurs 20% (2).

A few patients (possibly with a variant form) have significant, life-threatening autonomic dysfunction causing blood pressure fluctuations, inappropriate antidiuretic hormone secretion, cardiac arrhythmias, gastrointestinal stasis, urinary retention, and pupillary changes.

An unusual variant (Fisher variant, or Miller-Fisher syndrome) may cause only ophthalmoparesis, ataxia, and areflexia.

• Clinical evaluation

• Electrodiagnostic testing

• Cerebrospinal fluid (CSF) analysis

Diagnosis of Guillain-Barré syndrome is primarily clinical.

• Intensive supportive care

• IV immune globulin (IVIG) or plasma exchange

Guillain-Barré syndrome is a medical emergency, requiring constant monitoring and support of vital functions, typically in an intensive care unit. Forced vital capacity should be measured frequently so that respiration can be assisted if necessary; if vital capacity is < 15 mL/kg, endotracheal intubation is indicated. Inability to lift the head off the pillow by flexing the neck is another danger sign; it frequently develops simultaneously with phrenic nerve (diaphragm) weakness.

If oral fluid intake is difficult, IV fluids are given as needed to maintain a urine volume of at least 1 to 1.5 L/day. Extremities should be protected from trauma and from the pressure of bed rest.

Heat therapy helps relieve pain, making early physical therapy possible. Immobilization, which may cause ankylosis and contractures, should be avoided. Passive full-range joint movement should be started immediately, and active exercises should be initiated when acute symptoms subside. Low molecular weight heparin (LMWH) helps prevent deep venous thrombosis in bedbound patients.

Given early, IVIG is the treatment of choice (1, 2, 3). It can be given in one the following ways:

• IVIG 2 g/kg over 1 to 2 days, with acetaminophen 650 mg and diphenhydramine 25 mg given orally 30 minutes before

• IVIG given more slowly, as 400 mg/kg IV once a day for 5 consecutive days

IVIG has some benefit up to 1 month from disease onset.

Plasma exchange helps when done early; it is used if IVIG is ineffective. Plasma exchange shortens the disease course and hospital stay, and reduces mortality risk and incidence of permanent paralysis (4). However, it may cause hypotension due to large fluid shifts, and IV access may be difficult or cause complications. Plasma exchange removes any previously administered IVIG, negating its benefits, and so should never be done during or soon after use of IVIG. Waiting at least 2 to 3 days after stopping IVIG is recommended.

Corticosteroids do not improve and may worsen the outcome. Eculizumab may be beneficial, but further study is needed before it can be recommended (5).

Guillain-Barré syndrome is fatal in < 4% (1). Most patients improve considerably over a period of months, but a substantial number of adults and even more children have some residual weakness at 3 years. Patients with residual defects may require retraining, orthopedic appliances, or surgery.

After initial improvement, approximately 5% of patients develop chronic inflammatory demyelinating polyneuropathy (2).