Looking on helplessly while a wave of weakness climbs one’s body from the ankles upward can cause dismay. This is what happens in Guillain Barre pronounced GHEE-on bah-RAY syndrome, known more formally as acute inflammatory demyelinating polyradiculoneuropathy. Occurring in just one or two people per year in a population of 100,000, Guillain Barre syndrome makes up for its rarity by taking people by surprise and quickly disabling them.

Acute inflammatory demyelinating polyradiculoneuropathy is about as bulky and awkward a name as there is, but the terminology has the endearing feature of encoding the disease’s essential features. Starting from the back end and working forwards, “-pathy” means illness; “neuro” says that the peripheral nerves are involved; “radiculo” means that the spinal nerves emanating from the spinal cord are also affected; “poly” means it’s a widespread process; “demyelinating” means that the nerve-fibers are stripped of their sheath-like myelin coverings; “inflammatory” means a local tissue reaction to biochemical or physical irritation; and “acute” means that the disease develops rapidly over a matter of days. Despite the lesson in medical terminology provided by the full name, it’s easy to see why the condition often goes by the shorter names of AIDP or Guillain Barre Syndrome GBS.

Georges Guillain and Jean-Alexandre Barre described cases of this condition among French soldiers in the First World War. It is noteworthy that the condition is labeled a “syndrome,” rather than a disease, because it is likely that multiple disease-processes can produce the same pattern of clinical illness syndrome.

Diagnosing GBS involves recognizing the typical pattern of progressing symptoms in which a loss of strength works its way up the legs and often even into the arms and breathing muscles. The symptoms quickly worsen over a matter of days, even hours, and the weakness typically peaks within 2-3 weeks of the onset of symptoms. Although the affected peripheral nerves and spinal nerves also conduct messages concerning bodily sensation, sensory loss in GBS is typically a minor component, while weakness — caused by disruption of nerves carrying messages to muscles — predominates.

The physical exam confirms the muscular weakness and, when present, the associated numbness. Another classic finding on examination is a loss of rubber-hammer-type tendon reflexes. Supplemental tests that help confirm the diagnosis — or, depending on their outcome, point in another direction — are nerve conduction studies and cerebrospinal fluid analysis. Nerve conduction studies check the electrical characteristics of the peripheral nerves. In GBS the nerve impulses are often slowed or blocked on their way from one part of the nerve to another. Cerebrospinal fluid is the watery liquid bathing the outside of the brain, spinal cord and spinal nerves. It is obtained for analysis by means of a lumbar puncture, also known as spinal tap. In GBS the protein content of the fluid is increased without any corresponding increase in the numbers of red or white blood cells in the fluid.

The cause of GBS is unknown, but because it often follows an infection or other challenge to the body’s immune system and also involves inflammation, it seems likely that GBS is the result of an overactive immune system. If so, GBS is one of several so-called autoimmune diseases in which the body’s own immune system mistakenly attacks a component of the body, in this case the myelin coverings of individual nerve-fibers. Other examples of autoimmune disease are rheumatoid arthritis, in which the immune system attacks the joints, and psoriasis, in which the immune system attacks the skin.

A case series refers to a collection of consecutive cases sharing agreed-upon features. Analyzing a case series provides insight into how variable the illness can be as well as which features are more constant.

Between 1995 and 2003 researchers at the Aga Khan University Hospital in Karachi, Pakistan, collected a case series of 34 patients with GBS. The ages of the patients ranged from 3 to 70, and 62 were male. In 35 of the cases there was a preceding gastrointestinal infection and in another 26 of the cases there was a preceding respiratory infection. Breathing failed in 56 of the cases, requiring mechanical ventilation. One patient died.

Despite the frequently devastating nature of GBS, most patients improve, albeit slowly. Compiling a separate case series, investigators at the Centre for Rehabilitation Research in Orebro, Sweden, tracked the progress of 42 patients with this illness. Mechanical ventilation was necessary in just 21 of their cases. At 2 weeks, 1 year and 2 years after the onset of symptoms, 0, 38 and 45 of patients had completely normal strength. At the same time points, 38, 90 and 93 were able to walk 30 feet without assistance.

Treatment is available for patients with GBS. Of course, when patients can’t breathe on their own, using a mechanical ventilator to support respiration is a form of treatment and is usually life-saving. Two other treatments have been shown by randomized, controlled trials — the gold standard method for evaluating a treatment — to hasten recovery in GBS.

One is plasmapheresis, also known as plasma exchange, in which the liquid portion of the blood plasma is separated from the blood cells. The blood cells are then returned to the patient’s body, and the body produces more plasma on its own to replace the plasma that was removed. The reason plasmapheresis works is uncertain, but it probably removes damaging antibodies from the bloodstream.

Infusing immunoglobulin into the patient’s bloodstream is the other treatment of proven effectiveness. The immunoglobulin preparation contains antibodies pooled from a large number of healthy donors. These healthy antibodies presumably counteract the injurious antibodies produced in the GBS patient.

One might think that two treatments — plasmapheresis and immunoglobulin infusion — administered together or in succession would be better than just one, but that is not the case. A study showed that the two treatments in combination were no better in hastening recovery than one treatment.

C 2006 by Gary Cordingley

The peripheral nerves are bundles containing many individual nerve-fibers, and are similar to telephone cables carrying many individual wires. There are two basic types of nerve-fibers–motor and sensory. The motor fibers carry electrical impulses outward from the spinal cord to the muscles, causing them to contract. The sensory fibers carry electrical impulses inward from the skin, joints and other structures to the spinal cord, providing the nervous system with inputs, among others, concerning the senses of touch, pain and temperature.

Peripheral nerves can be pinched or injured in specific locations. When this occurs, the problem is called a “mononeuropathy,” meaning that a single peripheral nerve is affected. Examples of mononeuropathy include carpal tunnel syndrome in which the median nerve is pinched at the wrist, and peroneal neuropathy in which the peroneal nerve is injured near the knee. Because the median and peroneal nerves contain both motor and sensory fibers, people with these conditions can experience both weakness and numbness.

In carpal tunnel syndrome, certain muscles of the thumb can become weak, while numbness affects the thumb, index finger, middle finger and part of the ring finger–but not the little finger. In peroneal neuropathy muscles that lift the front and outer edges of the foot can become weak, while numbness affects the outer surface of the calf and the top of the foot–but not its bottom. In cases of mononeuropathy only the structures connected to that one nerve’s fibers are affected.

In contrast, “polyneuropathy” produces a pattern of weakness and numbness completely different from that seen in mononeuropathies. Instead of affecting the fibers of just a single peripheral nerve, polyneuropathy simultaneously impacts fibers traveling in numerous peripheral nerves.

In usual cases of polyneuropathy it is the longest nerve-fibers that are most at risk, while the shorter nerve-fibers are less affected. In brief, polyneuropathy is a “length-dependent” neuropathy. Because the longest nerve-fibers in the body are those that run from the lower back to the feet, in typical cases of polyneuropathy the first part of the body to become weak or numb is the feet.

In polyneuropathy muscles ordinarily served by more than one peripheral nerve can become weak, and the numbness extends beyond the territory of any single nerve. If a person with polyneuropathy pulled on stockings, he or she could cover the parts of the legs affected by weakness and numbness. Thus, the weakness and numbness affecting the legs are described as showing a “stocking” pattern of loss.

When the medical condition responsible for the polyneuropathy causes worsening damage to the peripheral nerves, the stockings climb ever higher as the next-longest nerve-fibers become involved. By the time a person’s stockings climb as high the knees, he or she might also notice symptoms in the fingers. This is because the nerve-fibers running from the neck to the fingers are about as long as those running from the lower back to the knees.

If a person with polyneuropathy affecting the hands and arms pulled on gloves, he or she could cover the parts of the arms affected by weakness and numbness. Thus, the weakness and numbness affecting the arms are described as showing a “glove” pattern of loss, and when legs and arms are simultaneously impacted, it is called a “stocking-glove” pattern.

Medical doctors are usually able to detect polyneuropathy from patients’ histories of symptoms and their physical examinations, but tests of muscle and nerve electricity–called electromyography and nerve conduction studies–are often helpful in characterizing the extent and pattern of nerve impairment.

Polyneuropathy is more of a category of nerve impairment than a final diagnosis, and numerous diseases can produce the same end-result of stocking-glove loss.

Diabetes is the most common cause of polyneuropathy in both the U.S. and the rest of the world. Blood sugars are elevated in people with diabetes, but the extent of polyneuropathy is not strictly related to how bad the blood sugars are, or for how long they have been elevated. For example, one person with severe, long-term elevations of blood sugars might have very little polyneuropathy, while another person might have polyneuropathy as the very first symptom of their diabetes. At present there is no good treatment for the polyneuropathy of diabetes apart from best-achievable control of blood sugars, but when annoying sensations like burning or tingling are present, these can be managed with topical or oral medications.

Ingestion of toxic chemicals can also produce polyneuropathy, and alcohol is the chemical most frequently involved. And while people with heavy and prolonged use of alcohol are more likely than light drinkers to develop this complication, here, too, some people seem more susceptible to this problem than others. Abstinence can keep the polyneuropathy from worsening, but the already damaged nerve-fibers might not fully recover. Because people with alcoholic polyneuropathy often lack sufficient quantities of thiamine, a vitamin important to the nerves, supplementing well-rounded, nutritious meals with this vitamin is usually helpful.

Inherited polyneuropathy can be transmitted in families in either a dominant or recessive form. In families with dominant transmission a bad gene from just one parent is sufficient to produce the disease in a child. In families with recessive transmission defective genes from both parents are required in order to produce the disease.

As a final illustration of the range of disease processes that can cause polyneuropathy let’s consider Guillain-Barr pronounced GEE-on bah-RAY syndrome, also known by the more cumbersome term of acute inflammatory demyelinating polyradiculoneuropathy. In contrast to the diabetic, alcoholic and genetic forms of polyneuropathy that typically worsen at a pace measured in months or years, Guillain-Barr develops in a matter of days. The affected patient usually notices weakness about the ankles, followed rapidly by weakness about the knees, hips, arms and even of the muscles controlling breathing. Symptoms usually peak within two weeks during which time a patient should be monitored in a hospital in case a ventilator is needed to support breathing. Subsequent recovery of strength occurs over a course of weeks to months.

Guillain-Barr syndrome involves inflammation of nerves and nerve-roots spinal cord connections caused by an overactive immune system. This is a so-called auto-immune disease in which a person’s immune system attacks a tissue within their own bodies, in this case the nerves. Certain treatments that temporarily suppress the action of the immune system have been shown by randomized, controlled trials–the gold-standard of medical proof–to improve outcome in this condition.

C 2005 by Gary Cordingley