Guillain-Barré Syndrome (GBS)

What happens in Guillain-Barré syndrome

Peripheral nerves carry signals between the spinal cord and the muscles and skin. They are insulated by a fatty coating, myelin. In GBS, an infection prompts the immune system to make antibodies that, by mistake, also recognize parts of the nerves (molecular mimicry). The immune attack damages the myelin, the nerve fibers (axons), or both. Signals slow down or stop, causing weakness and sensory changes.

GBS affects about 1 to 2 people per 100,000 each year, at any age, slightly more often men and older adults.

Types of GBS

Causes and triggers

About two thirds of people have an infection in the weeks before symptoms:

• Campylobacter jejuni: a cause of diarrhea from undercooked poultry, the most common identified trigger
• respiratory infections and influenza
• cytomegalovirus and Epstein-Barr virus
• Zika virus and COVID-19
• hepatitis E and Mycoplasma

Rarely, GBS follows surgery or vaccination. Studies have found a very small increased risk after some vaccines, such as certain flu vaccines (about 1 to 2 extra cases per million doses) and some RSV vaccines in older adults. The risk of GBS after the infections themselves is generally higher than after vaccination.

Symptoms

• tingling, pins and needles or numbness in the toes and fingers
• weakness starting in the legs and rising to the arms, usually on both sides equally
• difficulty walking, climbing stairs or rising from a chair
• loss or reduction of reflexes
• deep, aching back or leg pain, sometimes the first symptom
• facial weakness, difficulty swallowing or speaking
• double vision and eye movement problems (especially Miller Fisher syndrome)
• breathing muscle weakness
• autonomic problems: fast or slow heart rate, blood pressure swings, sweating changes, bladder retention and constipation

Symptoms progress over days to 2 weeks, reach their worst by 4 weeks at most, plateau, and then slowly improve.

Diagnosis

GBS is diagnosed from the pattern of symptoms and examination, supported by tests:

• neurological examination: symmetric weakness and reduced or absent reflexes
• lumbar puncture: raised protein with a normal white cell count in the spinal fluid (albuminocytological dissociation), often after the first week
• nerve conduction studies and EMG: show slowing or blocked nerve signals and classify the type
• breathing tests: forced vital capacity and other measures, repeated regularly
• blood tests to exclude other causes, and antibody tests (such as anti-GQ1b in Miller Fisher)
• MRI of the spine in some cases, to rule out spinal cord compression

Conditions that can mimic GBS include spinal cord problems, botulism, myasthenia gravis, tick paralysis, low potassium and other neuropathies.

Treatment

Immunotherapy

• IV immunoglobulin (IVIG): antibodies from donated blood given over 5 days. It is the most commonly used treatment.
• Plasma exchange (plasmapheresis): the patient's blood plasma is removed and replaced, removing harmful antibodies, over several sessions.

Both are equally effective, especially when started within 2 weeks of onset. Combining them offers no extra benefit. Steroids do not help GBS.

Supportive care

• hospital monitoring of breathing, swallowing, heart rhythm and blood pressure, often in intensive care
• mechanical ventilation if breathing weakens
• prevention of blood clots with blood thinners and compression
• pain relief, often with nerve pain medicines
• feeding tubes if swallowing is unsafe
• pressure sore prevention, bladder and bowel care
• psychological support, as patients are often fully aware while paralyzed

Rehabilitation

Physical, occupational and speech therapy start early and continue for months. Braces, walkers and other aids help during recovery.

Recovery and outlook

• Most people start to improve within 2 to 4 weeks of the plateau.
• About 80% can walk independently by 6 months.
• Around 1 in 5 have significant lasting weakness after a year.
• Fatigue, pain and numbness can persist for years.
• About 3% to 7% die, mainly from breathing failure, blood clots, infections or heart rhythm problems.
• A small minority have a recurrence. Symptoms that continue to worsen beyond 8 weeks may indicate chronic inflammatory demyelinating polyneuropathy (CIDP).

Older age, rapid onset, severe weakness, needing a ventilator and preceding diarrhea are linked to slower recovery.

Frequently asked questions

What are the first signs of Guillain-Barré syndrome?

Early signs are tingling or pins and needles in the toes and fingers, weakness in the legs that makes walking or climbing stairs hard, and sometimes back or leg pain. Weakness spreads upward over days. Seek urgent care if this happens, especially after a recent infection.

What causes Guillain-Barré syndrome?

GBS is an autoimmune reaction, usually triggered by a recent infection. The most common trigger is Campylobacter gastroenteritis from undercooked poultry. Respiratory infections, flu, CMV, Epstein-Barr virus, Zika and COVID-19 can also trigger it. Rarely, it follows surgery or vaccination.

How is Guillain-Barré syndrome treated?

The main treatments are IV immunoglobulin or plasma exchange, which reduce the immune attack and speed recovery. Patients are monitored closely in hospital, and some need a ventilator. Rehabilitation with physical and occupational therapy is essential during recovery.

How long does it take to recover from Guillain-Barré?

Recovery usually begins a few weeks after symptoms peak. Many people walk again within months, and about 80% walk independently by 6 months. Full recovery can take a year or longer, and some people have lasting weakness, numbness, pain or fatigue.

Can Guillain-Barré syndrome come back?

It is uncommon. A small percentage of people have a second episode, sometimes years later. If symptoms keep worsening or relapse over more than 8 weeks, doctors consider CIDP, a related chronic condition that needs long-term treatment.