Guillain-Barré Syndrome, Zika's other dark side

The results of the study, conducted in French Polynesia, suggest GBS sand Zika are linked, and they come amid increasing incidence of the syndrome in such territories where Zika is prevalent.

What is GBS?

Guillian-Barré Syndrome is an uncommon nervous system disorder that ultimately results in weakness of the muscles and is caused by an autoimmune response whereby the body's immune system mistakenly attacks its own nerve cells, inducing nerve damage and a delayed signal response.

The peripheral nervous system, which connects the brain with the body, is the main affected area, and this leads to weakness in the arms and legs and interference with primary motions such as eye movement and swallowing. In the worst cases, this muscle weakness can reach the respiratory tract, hindering breathing or even the ability to talk.

Under treatment, symptoms can last for several weeks to months before complete recovery. In some cases, the symptoms can lead to permanent damage.

When was it first discovered?

French physician Jean Landry described it in 1859, using the name "ascending paralysis." The syndrome was first diagnosed some 50 years later, when in 1916 Georges Guillain and Jean Alexadre Barré observed it in some First World War soldiers. This is how the syndrome received its name.

What are the causes?

According to Jan Felix Drexler, of Bonn University's virology institute: “There are many types of viruses that can lead to GBS: Hepatitis E, Dengue, Chikungunya etc.”

As a matter of fact, 30 percent of cases related to the GBS outbreak came after digestive tract infections caused by the bacteria Campylobacter jejuni.

Scientists say the syndrome is not completely understood, and that the risk factors have not been assessed yet. However, what is known is that GBS is the first non-traumatic paralysis, with a rate of one to four cases per 100,000 persons per year, worldwide.

How can it be treated?

Because the syndrome is not completely defined, the main treatments focus on alleviating the symptoms. This refers to physical and occupational rehabilitation - or even in severe cases the use of supportive measures, e.g., assisted breathing via mechanical ventilation.

However, there are two main initial treatment options to deal with the autoimmune response: intravenous immunoglobulin and plasma exchange. In any case, the hospitalization may be essential to monitor the patients and diagnose personally depending on individual symptoms.

Where is the syndrome most prevalent?

There are several different types of GBS, all of which are classified by the specific part of the peripheral nerve that is affected.

All of these variations are found all over the world, showing different patterns depending on the geographical location. In North America and Europe, the primary type results in a progressive weakness, while in Asia the sensory nerve damage leads to an acute paralysis.

The syndrome has now been related to Zika virus, leading to a screening of the regions that have an increasing incidence of both illnesses. The overlap is increasingly clear now in South America and French Polynesia.

Furthermore, the recent confirmation of the first Zika case in Europe (France) raised alarms about the possibility of the virus to cross the Atlantic. Zika is thus a pathogen with mild symptoms that now has two subsequent dark sides: microcephaly and GBS.