Guillain-Barre Syndrome (GBS) or ‘acute idiopathic polyneuritis’ is an rapidly progressing autoimmune disorder (condition the individual’s immune system attacks the tissues) of the peripheral nerve tissues, usually following an infection (bacterial or viral) (about 60 to 70 % of all cases), and resulting in tiredness, muscle weakness, abnormal sensations in the lower limbs (and upper limbs), paralysis, respiratory difficulties, etc (NINDS, 2007). In rare cases, portions of the brain and the spinal nerves may be involved with the disease (Griffin, 2000, pp. 2192 and Mayo Clinic, 2006). Very rarely does GBS occur after surgery or vaccination (Cull, 1996, pp. 1106).
The disorder can occur in both sexes, and individuals of all age and ethnic groups. The condition is very rare and can occur once in every 100, 000 individuals in the US every year (Mayo Clinic, 2006). The infection usually follows a infection of the digestive tract or the respiratory system. The condition usually progresses gradually over the next few days or weeks (NINDS, 2007). Acute versions of the disease are more common in all regions of the World, other than the US and Europe (Griffin, 2000, pp. 2192).
The exact cause of GBS is not understood, but studies suggest that is basically due to defect in the immune system that may be initiated by a viral or bacterial infection. The body’s defense mechanism may begin to attack the myelin sheath that covers the nerve resulting in its degeneration. These myelin sheaths helps transmit nerve signals. The point at which myelin is absent at the nerve is known as ‘node of Ranvier’, and the nerve signals jump from one node of Ranvier to another, enabling speedy transmission of the nerve signals. When the myelin sheath is degenerated, the nerve signals cannot be transmitted resulting in inability of the muscles to respond efficiently to the signals generated from the brain. The nerves that carry sensory information from the sense organs to the brain also get demyelinated, resulting in improper decoding of sensory information. Several sensory abnormalities such a loss of sensations, abnormal sensations, stinging, etc, are experienced by the individual (NINDS, 2007).
GBS may occur following a viral infection or a bacterial infection. Some of the common infections in which GBS can occur include C. Jejuni infection, infectious mononucleosis, Cytomegalovirus infection, Epstein Bar Virus infection, Herpes infection and Myoplasma infection. The C. jejuni infection usually tends to be the most severe type (Griffin, 2000, pp. 2193). A study conducted demonstrated that about 1.17 individuals out of every 1000 affected with the bacteria would develop GBS, every year, and the incidence was about 77 more than the normal incidence rates. About 2 in every 10, 000 individuals who have suffered from the bacterial infection would develop GBS within the next two months (Tam, 2006). Once the cells are affected with the virus, a defective immune mechanism begins to act. Several defense cells of the body such as the lymphocytes and the macrophages tend to attack cells present in the nervous system resulting in the degeneration of the myelin sheath. Antibodies are produced by the B-lymphocytes against the myelin on stimulation by the T-lymphocytes (NINDS, 2007). The spinal nerve roots and the peripheral nerves are pathologically invaded with lymphocytes resulting in inflammation. The macrophages cause degeneration of the myelin sheath and secondary degeneration of the axon (Griffin, 2000, pp. 2193).
The individual initially experiences paraesthesia and weakness in the muscles of the lower limbs. The muscle weakness progresses from the distal end to the proximal end, whereas the paraesthesia progress from the proximal end to the distal end (Cull, 1996, pp. 1106). Frequently, the upper limbs are also involved. The individual may lose reflexes in various parts of the body. Gradually the symptoms worsen, until the individual is unable to move the limbs resulting in paralysis. About half the number of individuals has facial weakness on either side of the body (Cull, 1996, pp. 1106). Eye movements, mastication, speaking, swallowing, etc, may get involved with the disease process. Bladder and bowel functions are also affected (Mayo Clinic, 2006). In certain cases, the breathing, heart beat and the blood pressure may become abnormal (with the disease process) resulting in life-threatening conditions and requiring emergency care (NINDS, 2007). Some individuals may experience the symptoms for a certain amount of time, and slowly regain the lost muscle strength and the sensations. The process of recovery takes longer (several years) and requires active rehabilitation programs (Mayo Clinic, 2006).
The diagnosis of GBS may be difficult as the presentation of the symptoms and signs are varied and depend on several factors. The diagnosis is usually made based on the history, symptoms, signs, nerve conduction velocity tests, lumbar puncture, electromyography, blood tests, etc. The symptoms such as muscle weakness, absence of knee reflexes, paraesthesia, etc, should be observed on either side of the body. Blood tests are performed to determine a rise in the lymphocyte count. Electromyography (EMG) is performed to study the electrical activity of the muscles on nerve stimulation, and the rate at which it conducts the nerve signal (Mayo Clinic, 2006). Nerve conduction tests are performed to determine the rate at which nerve signals are transmitted (usually reduced in GBS). Lumbar puncture is utilized to determine the protein level in the CSF (usually raised in GBS) (NINDS, 2007). The proteins levels in the CSF are usually normal in the first week of the disorder (Cull, 1996, pp. 1106).
Currently, no specific treatment is available for GBS. Symptomatic relief is provided to ensure that the individuals are comfortable. However, techniques have been developed to reduce the severity of complications. GBS patients should be continuously monitored for lung functions (especially vital capacity), swallowing activity, autonomic functions, etc. Some of the measures that may help include plasmapheresis, corticosteroids, immunoglobulin, and rehabilitation therapy (NINDS, 2007). Corticosteroids are not effective when administered in GBS, independently (Griffin, 2000, pp. 2193).
Usually plasmapheresis (plasma exchange) is performed along with immunoglobulin therapy. The exact mechanism by which plasmapheresis works in GBS is still not understood, properly. But it is suggested that certain immune-mediated substances may be present in the plasma which brings about the symptoms of GBS. The blood is passed through the machine which helps to separate out the blood cells. The plasma is filtered out. The blood cells are reconstituted with an appropriate substitute which is injected back into the individual. Immunoglobulins help to attack microorganisms that stimulate GBS. Studies have also shown that they destroy antibodies that enable the GBS pathological process (Mayo Clinic, 2006). Corticosteroid therapy may be useful in treating the symptoms of GBS, but studies have demonstrated that it is usually not very effective (NINDS, 2007).
If the individual develops episodes of unproductive cough, an acute respiratory problem could exist, requiring immediate respiratory assistance (as respiratory failure can develop within a very short period). The condition may be fatal if immediate ventilation is not provided (Griffin, 2000, pp. 2193). Individuals may have to be admitted to the hospital to treat emergency conditions. The condition of the heart and the lungs has to be closely monitored.
After an attack occurs, the individual may require physical therapy and hydrotherapy to aid reducing the effect of muscle weakness (NINDS, 2007 and Mayo Clinic, 2006). Individuals admitted to intensive care units require constant monitoring of blood pressure, breathing, formation of the clots, etc. Usually, the individual is able to recover from this condition, but some amount of weakness in the muscles may continue to exist (NINDS, 2007).
The outcome of GBS differs depending on several factors such age of the individual, severity and the extent of demyelination. The individual may have involvement of the respiratory system with the disease (resulting in respiratory paralysis) (Griffin, 2000, pp. 2193). It takes about 3 months to recover from such an episodes (if plasmapheresis is performed) and 6 months in case plasmapheresis is not conducted. About 80 % of individuals treated are able to recover (Cull, 1996, pp. 1106). Some individual are able to recover faster than the others. About 10 % arrive at fatal outcomes, and another 10 % develop severe neurological disabilities (Cull, 1996, pp. 1106). Recurrences are usually treated with the help of plasmapheresis and immunoglobulin therapy. Education and motivation plays a very important role in improving the outcome of GBS. It helps to prevent rapid degeneration of the motor and the sensory functions. The individual is taught the manner in which communication is possible during a respiratory emergency situation (Griffin, 2000, pp. 2193). There are no known ways of preventing the disorder (Mayo Clinic, 2006).
Some of the different types of GBS include Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP), multifocal motor neuropathy and Miller Fisher Syndrome.
Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP) is an acute version of GBS. The pathology, clinical features, etc are similar to that of GBS. The course of the disease and certain episodes that occur in CIDP may be dissimilar compared to GBS. The immunological mechanism that results in CIPD is different. CIPD can occur in individuals of any age group. There is a slow muscle weakens in the legs, areflexia (absence of reflex actions), etc. Several parts of the body may be involved. The large nerve fibers are usually involved first. CIDP usually progresses at a much slower rate compared to GBS. Nerve conduction studies help to demonstrate the slow nerve conduction rate (suggesting demyelination) and lumbar puncture suggest increased proteins in the CSF. CIPD is usually treated with corticosteroids as they are effective. Sometimes, plasmapheresis and immunoglobulin therapy seems to be useful in the condition. Corticosteroids are administered in lower doses first. The plasmapheresis should be repeated every few weeks (Griffin, 2000, pp. 2193).
Another variant similar to CIPD is multifocal motor neuropathy. It is a pure neuropathy as no sensory nerves are involved with the condition. The individual experiences a drop in the wrist and the foot due to the involvement of the radial nerve and the peroneal nerve, respectively. The tendon reflexes are also lost. The nerves tend to be involved in a stepwise fashion. The pathological features of multifocal motor neuropathy are similar to that of CIPD. However, this condition tends to remain highly localized, and does not involve the sensory nerve. The diagnosis is usually made by the nerve conduction tests that demonstrate decreased nerve condition (due to focal demyelination). The CSF is normal, and usually blood tests demonstrate an increase in the IgM and the anti-ganglioside antibodies in the blood. The condition is usually treated by administering immunoglobulin and chemotherapeutic agents. Corticosteroids and plasmapheresis are usually not very effective in treating multifocal motor neuropathy (Griffin, 2000, pp. 2193).
Miller Fisher Syndrome (MFS) is a rare variant of GBS in which the individual develops poor coordination of the muscles (ataxia), paralysis of the muscles of the eye (ophthalmoplegia), and loss of the tendon reflexes (areflexia). It is a type of acute polyneuropathy. Besides, respiratory problem and muscle weakness also exist. The condition is usually associated with a viral infection. Blood tests performed usually demonstrate the presence of a specific antibody. Immunoglobulin therapy and plasmapheresis help in treating MFS. Supportive care may be required to aid in respiration. The outcome of MFS is usually better than GBS, as the individual recover within a few weeks after the disease has actually begun. The chances of recurrences are usually very minimal (NINDS, 2007).
References:
Cull, R. E., and Will, R. G. (1996). Diseases of the Nervous System, In. Edwards, C. R. A., Bouchier, I. A. D., & Haslett, C. (Ed), Davidson’s Principles and Practice of Medicine, (17th Ed), Edinburgh: Churchill Livingstone.
Griffin, J. W. (2000). Immune-mediated Neuropathies, Goldman, L. and Bennett. J. C. (Ed) Cecil Textbook of Medicine, (21st ed, Vol. 2), Philadelphia: W. B. Saunders.
Mayo Clinic staff (2006). Guillain-Barre Syndrome. Retrieved on April 11, 2007, from Mayo Clinic Web site: http://www.mayoclinic.com/health/guillain-barre-syndrome/DS00413/DSECTION=1
National Institute of Neurological Disorders and Stroke (2007). Guillain-Barre Syndrome Fact Sheet. Retrieved on April 11, 2007, from NINDS Web site: http://www.ninds.nih.gov/disorders/gbs/detail_gbs.htm
National Institute of Neurological Disorders and Stroke (2007). NINDS Miller Fisher Syndrome Information Page. Retrieved on April 11, 2007, from NINDS Web site: http://www.ninds.nih.gov/disorders/miller_fisher/miller_fisher.htm
Tam, C. C., Rodrigues, L. C., Petersen, I. Et al (2006). ”Incidence of Guillain-Barre syndrome among patients with Campylobacter infection: a general practice research database study.” J Infect Dis, 194(1), 95-97. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Abstract&list_uids=16741887
