Carsten Kolberg is an athletic man. As a pool attendant and life guard he was until recently easily able to swim 100 meters in just over a minute. He is also a SCUBA diver, diving in ice-cold water to depths that are beyond the imagination of most other people.

In his profession, Kolberg needs to be immunized against infectious diseases. As a first responder at an open-air pool, he can easily come into contact with blood or feces.

"The company doctor found out that I needed to refresh my hepatitis B vaccination," Kolberg recalled. "I had this done before, and never had a problem with it."

Carsten Kolberg before the infection - full of energy, sawing a hole into the ice for winter diving

After Kolberg got his shot, he showed symptoms of a cold: sneezing, coughing, a sore throat. One week later the symptoms had turned flu-like, with fever, fatigue and a headache. Then his feet started hurting when he walked. The doctor prescribed antibiotics and told him to stay in bed.

Not a simple flu

"The doctor said it would be over in five days. But the very next day I was unable to get out of bed", Kolberg said. "That was when I got scared. Since my mobile phone wasn't on my nightstand, I couldn't reach it. I had to roll out of bed and crawl into the living room, where I was able to reach the phone and call my girlfriend for help."

When he arrived at the emergency room at Bonn University hospital, Kolberg was already in a wheelchair. He could not feel his legs and one of his arms was also paralyzed.

"The ER waiting room was packed" he recalled. "I was glad to have a wheelchair. Two patients to my left and right had been in a car accident and looked really bad. Then a young doctor came in and said: 'We have someone here who needs urgent attention.' I looked at the others and thought: 'They really don't look good'. But then the doctor looked at me and said: 'No, we mean you!' Only then I realized how bad it really was."

An inflammation of the nerve roots blocks the passage of impulses

Immunologist Julian Zimmerman (left) and neurologist Ullrich Wüllner (right)

The doctors diagnosed Guillain-Barré syndrome, or GBS for short. It's an inflammation of the nervous system, or more precisely of the myelin sheath - a fatty insulation layer around the nerve cells. If the myelin sheath is inflamed, our nerves are unable to pass on electric impulses.

The doctors took Kolberg into the neurology department. That's where Professor Ullrich Wüllner heads the section for movement disorders. He says two to three GBS Patients present each month. The inflammatory disease is rather rare.

"Such an immune system reaction can either occur following diarrhea or an infection of the upper respiratory system," he said. "There are also several microbes that can trigger such a reaction of the immune system. Those include Campylobacter bacteria, for example."

Only one in several hundreds of thousands of people will suffer GBS. It occurs even more rarely as a result of a vaccination.

"It is possible that ingredients in the vaccine can trigger such a reaction," Wüllner said. "It could be aluminum ingredients or gelatin from cartilage."

An autoimmune disease

But why is it that the immune system attacks the body's own nerve cells all of a sudden?

"The immune system is highly specialized," said immunologist Dr. Julian Zimmermann, a colleague of Wüllner's. "It's trained to detect exogenous substances, like viruses, bacteria or fungus, and then develops a specific defense against them."

In the case of an autoimmune disease like GBS, the intruders camouflage themselves with surface structures that are similar to those of the healthy body.

"The surface structures of the campylobacter bacteria, for example, look similar to those of the myelin sheath," Zimmermann explained. "And all of a sudden, the immune systems starts attacking the myelin sheath and even destroying nerve cells."

There are different ways doctors can determine someone has GBS. One involves an electrophysiological test to measure the speed in which the nerves transport electric signals. Also imaging technology can help doctors.

"An MRI of the spinal cord will show us the inflammation of the nerve roots," Wüllner said. "And we can detect that inflammation in the cerebrospinal fluid as well."

The fluid will be extracted from the spinal cord. If the protein content exceeds a certain concentration as compared to the defense cells, doctors know they are dealing with GBS.

After the treatment Kolberg had to work his way back from wheelchair and walker

Life threatening, but not incurable

Guillain-Barré-Syndrome can be fatal - if the paralysis hits vital parts of the nervous system, like those that control breathing, blood pressure or the heart. To prevent that from happening, doctors constantly monitor the patient's vital functions.

They furthermore support the healing process either through specialized hemodialysis or infusions of immunoglobulins. In Kolberg's case, the doctors opted for that second option.

"Those are pooled antibodies from blood donors," immunologist Zimmermann explained. "We were able to show that GBS heals faster and the symptoms are milder when the patient is given immunoglobulins at a high concentration."

Kolberg (left) still loves scuba diving - even in cold waters - and hopes to fully return to it

Excercising is of the essence

When Kolberg was released from hospital after 2 weeks, he'd lost 11 kilograms, mostly muscle. From there he went to a rehabilitation clinic. He could only walk a few meters, using a walker. And he had to re-learn almost everything else.

"I had to re-learn my writing grip," Kolberg said. "I was in a writin -school and had to learn how to hold and move a pencil - just like in elementary school. I had to learn how to feel, how to figure out whether a surface is rough or smooth."

In the beginning Kolberg was wondering why the water faucets in the rehabilitation clinic were marked with a warning sign, saying 'Caution, hot!'

"Then I realized that one of my arms couldn't feel the difference between hot and cold."

Three months later, Kolberg is on the mend. He did a lot of work in rehab to rebuild his nervous system and muscles.

"It really did me well," he said. "I'm almost as fit as I used to be before the disease - I stand at about 90 percent."

Carsten is now back to swimming and has also been diving again. He will still continue going to a local rehabilitation clinic for another 6 months. When that is over, he's optimistic he will once again be able to swim 100 meters in a minute.