Multiple sclerosis (MS) and Guillain-Barré syndrome (GBS) are autoimmune diseases that affect the nervous system. In both conditions, the immune system damages the myelin sheath, the protective covering around nerves. This process, called demyelination, can cause symptoms such as tingling, muscle weakness, or other nerve problems.

Because both GBS and MS involve demyelination, it can be hard to tell them apart. In this article, we’ll cover how to tell the difference between MS and GBS.

GBS develops in men and women at about the same rate. It’s most commonly seen in older adults, people over the age of 50. GBS is very rare, affecting about 3,000 people in the United States each year.

By contrast, MS affects about 1 million Americans and is much more common in women. People usually start showing signs of MS between the ages of 20 and 40.

There are two parts to your body’s nervous system. The central nervous system, or CNS, consists of your brain and your spinal cord. The peripheral nervous system includes all the rest of the nerves in your body that branch out from your brain and spine. Both parts are important to the sensations you feel and the way your body moves.

GBS affects the myelin covering nerves in the peripheral nervous system, which is the network of nerves connecting the brain and the spinal cord to the rest of the body. GBS most often targets a type of nerve cell called a Schwann cell. When GBS interferes with your nerves, it may become difficult to move effectively or feel sensations.

MS, on the other hand, affects the myelin covering of nerves in the CNS. MS mostly targets a type of nerve cell called an oligodendrocyte. When the myelin in your brain or spinal cord is damaged, it can disrupt the signals your body sends from the brain to the rest of the body. This can get worse over time, leading to problems with thinking, moving, and fatigue.

GBS symptoms may seem like they come on out of nowhere. Once you have symptoms, they may get worse quickly, over hours or days. Most people recover from GBS, although it can take time. Some may continue to have muscle weakness.

Most people living with MS have relapses, when symptoms such as vision problems, bladder problems, or numbness and tingling get worse. These relapses are followed by longer periods of remission, when symptoms improve partly or fully.

However, MS is also progressive. It can become worse and eventually cause disability. Disease-modifying therapies reduce relapses and slow progression, but MS is a chronic (long-term) condition.

A lumbar puncture can help doctors look for clues that point to GBS or MS. In GBS, spinal fluid often shows high protein levels with a normal white blood cell count. This pattern can support a GBS diagnosis, especially along with symptoms and nerve conduction testing.

In MS, spinal fluid may show oligoclonal bands or a high IgG index. These findings suggest immune activity in the CNS, which includes the brain and spinal cord.

Spinal fluid results are only one part of making a diagnosis. Doctors also use symptoms, a neurological exam, MRI scans, and nerve tests to tell GBS and MS apart.

GBS usually develops days or weeks after a person has a bacterial or viral illness. For instance, Campylobacter jejuni, which causes an upset stomach, nausea, diarrhea, and vomiting, is an infection that can lead to GBS. Other viruses, like the flu and COVID-19, may also arise before GBS develops.

GBS rarely shows up after a person has surgery or gets a vaccine. HIV, AIDS, and Hodgkin disease may also happen before GBS develops.

On the other hand, MS seems to be caused by a combination of your genes and environmental factors. Genes alone don’t seem to cause MS, but inherited genes may make you more likely to develop it.

The development of MS is associated with certain environmental risk factors. These include not having enough vitamin D, smoking, and some viruses that cause the myelin around your nerves to become inflamed. Viruses associated with MS risk include measles, some herpes viruses, and the Epstein-Barr virus. However, MS does not typically develop shortly after viral infection, unlike GBS. Instead, the disease may develop years after the infection, likely as a result of a mix of genetic and environmental factors.

GBS symptoms can spread quickly. In some cases, the condition can become life-threatening if it affects the heart or breathing muscles, or if it leads to a serious infection. Overall, about 5 percent of GBS cases are fatal, often because of complications.

Most people with MS will have a normal lifespan. Although rare, severe MS can increase the risk of death.

Talk to Your Doctor

If you're having any unusual symptoms that seem to be connected to a neurological disorder, talk to your healthcare team right away. For both GBS and MS, getting a timely diagnosis and starting treatment as soon as possible can help you have a better outcome.

If you’ve already been diagnosed with MS or GBS, let your neurology team know if you notice new or worsening symptoms of your autoimmune disorder.

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