Guillain-Barre Syndrome

Picture of a nerve showing the myelin sheath (5). Source: Wikimedia Commons

Guillain-Barré syndrome (GBS) is a disorder in which the body's immune system attacks part of the peripheral nervous system. GBS is characterised by weakness and numbness which generally begin in the legs. The symptoms usually ascend to the arms and face over a period of several days to weeks. The syndrome may lead to paralysis of the muscles used in breathing. There is no cure for Guillain-Barre syndrome, but most people recover completely, even from severe cases.

Types

• AIDP - acute inflammatory demyelinating polyneuropathy (most common)
• AMAN - acute motor axonal neuropathy
• ASAN - acute sensory ascending neuropathy
• AMSAN - acute motor and sensory axonal neuropathy
• CIDP - Chronic inflammatory demyelinating polyneuropathy (this is the chronic version of Guillain-Barre syndrome).

Symptoms

The primary group of symptoms refer to AIDP. Each subtype has slight differences. The symptoms include:

• Muscle weakness or loss of muscle function (paralysis)
  • Weakness begins in the feet and legs and may move up to the arms and head
  • May get worse over 24 to 72 hours
  • May start in the arms and move downward
  • May begin in the arms and legs at the same time
  • May occur in the nerves of the head only
  • In mild cases, weakness or paralysis may not occur
• Uncoordinated movement
• Changes in sensation
• Numbness or decreased sensation
• Tenderness or pain

The weakness may cause clumsiness or frequent falls.

Other symptoms may include:

• Blurred vision
• Difficulty swallowing
• Drooling
• Difficulty breathing
• Fainting

Causes

Usually, Guillain-Barré occurs a few days or weeks after the patient has had symptoms of a respiratory or gastrointestinal viral infection. This most commonly includes:

• Food poisonings, such as campylobacteror salmonella infections
• HIV/AIDS
• Epstein-Barr virus and
• Mycoplasma

Occasionally, surgery or vaccinations will trigger the syndrome. 2/3 of cases report having had an illness within 2 months of the start of symptoms. There is evidence to support both viral and bacterial infection causes.

No one yet knows why Guillain-Barré strikes some people and not others or what sets the disease in motion. What scientists do know is that the body's immune system begins to attack the body itself, specifically the peripheral neurvous system (auto-immune response).

The primary theory is that the body is triggered to attack itself in response to infection of some type. In Guillain-Barre, the body begins to attack the protective sheath that covers our peripheral nerves called myelin. As this myelin is attacked, it them begins to expose more of the nerve and slow its ability to transport nerve impulses. Much like a wire whose plastic coating is worn away and the wire then shorts out. In some cases, it is also thought that a degree of permanent damage is caused to the very ends of the nerves called the axon.

Diagnosis

Guillain-Barré is a syndrome rather than a disease because it is not clear that a specific disease-causing agent is involved. Carefull examination and laboratory tests are used to rule out other diseases or conditions:

History

A careful medical history should include questions about the character, severity and location of symptoms, as well as any history of recent illness, surgery or vaccinations.

Physical Examination

Should evaluate muscle strength, reflexes, any atrophy of muscles as well as ruling out any other cause for the symptoms.

Tests

Commonly administered tests include:

• Nerve conduction velocity (NCV), which tests the speed in which a signal travels throug a nerve.
• Electromyelography (EMG) evaluates the electrical activity in muscles. It may shows that nerves do not react properly to stimulation.
• Lumbar puncture may show the CSF (cerebrospinal fluid) to have increased levels of protein without an increase in white blood cells.
• Electrocardiogram (ECG) may show heart problems in some cases.

Treatment

There is no known cure for Guillain-Barre syndrome. The goal of treatment is to lessen the severity of the illness and accelerate the recovery. There are also a number of ways to treat the complications of the disease:

Plasmapheresis

Plasmapheresis, or plasma exchange, seems to reduce the severity and duration of a Guillain-Barré episode. Plasmapheresis is a process of mechanically removing autoantibodies from the blood. The blood is passed through a cell separator which either spins the blood at high speed or "filters" the blood through a membrane. The cells are returned to the body while the plasma (fluid), which contains the offending antibodies, is discarded. The plasma is replaced with other fluids.

High-dose immunoglobulin therapy

In high-dose immunoglobulin therapy, doctors give intravenous injections of the proteins that, in small quantities, the immune system uses naturally to attack invading organisms. Investigators have found that giving high doses of these immunoglobulins, derived from a pool of thousands of normal donors, to Guillain-Barré patients, can lessen the immune attack on the nervous system.

Respiratory Support

The most critical part of the treatment for this syndrome consists of keeping the patient's body functioning during recovery of the nervous system. This can sometimes require placing the patient on a respirator, a heart monitor, or other machines that assist body function.

Physical Therapy

There is a great possibility that physical therapy will be started soon after the patient becomes medically stable. This treatment can range from having the physical therapist perform stretching for the patient while they are unable to move to starting to get the patient out of bed and walking again. It is important to maintain joint range of motion in the early stages to maintain flexibility and prevent bed sores. Aquatic therapy will often be started early on in recovery as well to help intiate movement. Currently it is thought that too much exercise while still in the recovery phase can be damaging to the patient. The physical therapist will be sure to monitor the intensity and keep it to a tolerable level. As able, therapy will then be transfered to the land; working on walking, functional tasks, balance, and much more.

Living with Guillain-Barré syndrome

Guillain-Barré syndrome can be a devastating disorder because of its sudden and unexpected onset. Most people reach the stage of greatest weakness within the first 2 weeks after symptoms appear, and by the third week of the illness 90 percent of all patients are at their weakest. The recovery period may be as little as a few weeks or as long as a few years. About 30 percent of those with Guillain-Barré still have a residual weakness after 3 years. About 3 percent may suffer a relapse of muscle weakness and tingling sensations many years after the initial attack.

Chances of Developing Guillain-Barré syndrome

According to the National Institute of Allergy and Infections Diseases (NIAID) Guillain-Barre affects approximately 1 in 100,000 people. It is more common in Japan and China then in North America and Europe. It affects men and women equally.

Clinical Trials

Current Clinical Trials

A list of clinical trials is available at Guillain-Barre clinical trials

Controversy

The association between vaccine administration and Guillain-Barre syndrome is unclear. There has been evidence of a relationship betwen the influenza vaccine and the syndrome. ^[1] Research is ongoing regarding a possible link between the meningicoccal vaccine and GBS.

Research

Recent discoveries

• A recent study was done to determine whether early mechanical ventilation can prevent hospital acquired pneumonia in adults with Guillain Barré Syndrome. The study showed that delaying intubation did increase the risk of pheumonia. ^[2]
• An adolescent boy recently developed the first known case of Guillain-Barre after Legionella infection. ^[3]

Future reseearch

• A study is underway regarding the incidence of Guillain-Barre syndrome after the administration of the tetravalent meningococcal conjugate vaccine (Menactra). The vaccine is recommended for all adolescents. The study was requested by CDC and FDA because of an unexpected number of case reports to the CDC's Vaccine Adverse Event Reporting System (VAERS). ^[4]
• A study was recently completed which looked at the use of 4-aminopyridine (4-AP), a calcium channel blocker which may improve nerve conduction, in patients with chronic residual symptoms of GBS. ^[5]
• Scientists are concentrating on finding new treatments and refining existing ones. Scientists are also looking at the workings of the immune system to find which cells are responsible for beginning and carrying out the attack on the nervous system. The fact that so many cases of Guillain-Barré begin after a viral or bacterial infection suggests that certain characteristics of some viruses and bacteria may activate the immune system inappropriately. Investigators are searching for those characteristics. Neurological scientists, immunologists, virologists, and pharmacologists are all working collaboratively to learn how to prevent this disorder and to make better therapies available when it strikes.

References

1. ↑ Juurlink DN, Stukel TA, Kwong J, et al. Guillain-Barré syndrome after influenza vaccination in adults: a population-based study. Arch Intern Med. 2006 Nov 13;166(20):2217-21. Abstract
2. ↑ Orlikowski D, Sharshar T, Porcher R, Annane D, Raphael JC, Clair B. Prognosis and risk factors of early onset pneumonia in ventilated patients with Guillain-Barré syndrome. Intensive Care Med. 2006 Dec;32(12):1962-9. Epub 2006 Sep 21. Abstract
3. ↑ Akyildiz B, Gümüs H, Kumandas S, et al. Guillain-Barre Syndrome Associated with Legionnella Infection. J Trop Pediatr. 2008 Mar 28. (Epub ahead of print) Abstract
4. ↑ ClinicalTrials.gov: Safety Study of GBS Following Menactra Meningococcal Vaccination
5. ↑ ClinicalTrials.gov: Assessment of Chronic Guillain-Barre Syndrome Improvement With Use of 4-Aminopyridine

• Hund EF, Borel CO, Cornblath DR et al. Intensive management and treatment of severe Guillain-Barre syndrome. Crit Care Med. 1993; 21: 435.

External Links

Muscular Dystrophy Association: Facts About Plasmapheresis

Neurology Channel: Guillain-Barre Online Forum

GBS/CIDP Foundation International