What is Guillain-Barré syndrome?

Somebody has just used the words Guillain-Barré. Probably for the first time in your life, and probably in a ten-minute conversation you only half remember. This page is what should have been in that conversation.

The short answer

In Guillain-Barré syndrome your own immune system attacks your own nerves. Not the nerves in your brain or spinal cord, but the ones outside it: the cables carrying signals from your spinal cord to your muscles and skin.

Those cables have an insulating layer called myelin. That layer is what lets a signal travel quickly and without loss from one end to the other.

In GBS it is that insulation that gets damaged. And here is the part that often gets explained wrongly: the nerve itself is still fine, and the signal it sends is correct. Things are simply lost along the way. What arrives at the far end is only part of what was sent, or it arrives late, or it does not arrive at all.

That accounts for what you notice:

• Weakness. The instruction to your muscle arrives incomplete or too late. The muscle is not broken, it is not getting the message.
• Numbness. Information from your skin does not make it to the other end, so you feel less, or nothing.
• Tingling and pain. At the damaged spot the nerve can also fire off signals of its own, with nothing asking for them.

If the damage goes deeper, the nerve fibre itself can fail too. That distinction sets your recovery pace: myelin repairs relatively quickly, while a nerve fibre regrows at only about a millimetre a day.

It is rare. Roughly one to two people per hundred thousand per year. That explains a lot of what you are about to experience: most of the clinicians you meet have little or no first-hand experience of it.

Where does it come from?

For most people it starts with an ordinary infection, one to four weeks before the first weakness. Often a stomach bug or a respiratory infection.

The best-known trigger is the bacterium Campylobacter jejuni, usually picked up from contaminated food. Cytomegalovirus, Epstein-Barr virus, mycoplasma and Zika virus can also set it off.

What happens next is called molecular mimicry. Your immune system makes antibodies against the invader, but the surface of that invader happens to resemble the surface of your own nerves. The antibodies cannot tell the difference and attack both.

Which also means: you did nothing wrong. It is not hereditary, you cannot pass it to anyone, and there was nothing you could have done to prevent it.

Very rarely GBS follows a vaccination. In absolute numbers this is roughly one to two cases per million doses, while the infections being vaccinated against carry a higher risk of GBS themselves. We mention it because you will meet it when you search, and because you deserve the actual figure rather than having it either dismissed or inflated.

How fast does it move?

This is the part most often underestimated, including by clinicians.

GBS is fast by definition. Weakness increases over days to at most four weeks, and for most people the low point arrives within two weeks. Then comes a plateau, and then recovery begins.

It usually starts in the legs and climbs to the arms, and it is roughly equal on both sides. In about a quarter of people the breathing muscles weaken too, and then ventilation is needed.

The variants

Guillain-Barré is an umbrella term. Which variant you have shapes how your recovery goes.

AIDP is the most common form in Europe and North America. Here the insulating myelin is attacked. Myelin repairs relatively well.

AMAN and AMSAN attack the nerve fibre itself, not just the insulation. More common in Asia and after campylobacter infection. Recovery takes longer, because a nerve fibre regrows at about a millimetre a day.

Miller Fisher syndrome starts differently: with double vision, an unsteady gait and loss of reflexes. It is identified by a specific antibody, anti-GQ1b.

Ask which variant you have been diagnosed with and what that is based on. The answer changes what you should expect from your recovery.

How is it treated?

There are two treatments that work, and they work about equally well.

Immunoglobulin (IVIg) is an infusion of antibodies pooled from thousands of donors, usually 2 grams per kilogram of body weight spread over five days.

Plasma exchange filters your blood and removes the harmful antibodies.

Giving both together is no better than giving one.

Full detail on treatment.

And if it gets worse again?

In some people things improve after treatment and then deteriorate again. That is neither imagined nor rare.

There are two possibilities, and the difference between them decides your entire subsequent treatment. It may be a temporary fluctuation after the treatment wore off. Or it may mean you do not have ordinary GBS but a condition that needs maintenance treatment.

This is where most time is lost in practice, and it is where I lost years of my own. It is set out in full on relapse and CIDP. If you read one other page on this site, read that one.

What should you expect?

The honest version, with numbers:

• About 80 percent of people walk independently again after six months.
• About a quarter need mechanical ventilation at some point.
• Between 3 and 7 percent die of complications, usually in the acute phase and usually in intensive care.
• A great many people are left with lasting symptoms. Fatigue is by far the most common, and the most ignored.

Recovery continues well into the second and third year. That is longer than most people are told at discharge, and it is the difference between accepting a ceiling and training past it. See recovery.

What you can do now

1. Find out your score on the disability scale, a number clinicians use among themselves and that you are entitled to use too.
2. Start a daily log today. Writing down what you can and cannot do each day is the most powerful thing you have. Without those notes, deterioration is a feeling. With them, it is a fact.
3. Take the questions for your neurologist into your next appointment.