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

At the age of 32 Sigmund Freud developed a new problem. Pricking and other unpleasant sensations had overtaken the skin on the outer side of his right thigh. Walking made his symptoms worse. The affected skin was exquisitely sensitive to touch and even the usual rubbing of his underclothes irritated the area.

Seven years later in 1895, when Freud wrote up his self-observations for a German medical journal, the abnormal sensations were still present, but had migrated. At first, the area of disturbance had been more noticeable near the top of the thigh, but gradually the abnormal sensations moved downward to a palm-sized area a hands breadth above the side of his knee.

When Freud squeezed a fold of skin in this area, it hurt more than it did in his left thigh. Although he could feel a pinprick as such, it also burned. Even so, individual spots within the zone of abnormal skin were insensitive to ordinarily painful maneuvers. He also noticed that temperature sense was impaired. Warm objects placed against the affected skin felt cooler than in unaffected areas. And although the original pricking sensations improved over time, his outer thigh had become generally less sensitive to usual stimulations.

Freuds physician, Josef Breuer, found that the affected skin was in the territory of the lateral femoral cutaneous nerve, a nerve that concerns itself with sensation only and has no muscular connections. Dr. Breuer concluded that Freuds symptoms were caused by damage to this nerve. Dr. Breuer also suspected that the nerve might be particularly vulnerable to injury in the groin near the front of the hip where it passes between strands of a ligament. As a result, he thought that wearing tight clothing might aggravate the condition.

Our understanding of this disorder has changed little in the 110 years since Freud wrote his report for Berlins Neurologisches Centralblatt, or in the 20 years since Francis Schiller, M.D., translated it into English for the American journal Neurology.

To set the record straight, Freud and Breuer were not the first to recognize this condition. Max Bernhardt of Germany first wrote about it in 1878 and in 1895 Vladimir Roth of Moscow named the condition meralgia paresthetica, a term still in use. This name is the sum of its three parts. Meros is Greek for thigh, algos is Greek for pain and paresthetica means unprovoked sensations. This entrapment neuropathy pinched nerve condition was one of the first to be recognized as such.

The lateral femoral cutaneous nerve is formed in the lower back from branches of the second and third lumbar spinal nerves which combine to form a single nerve on each side soon after emerging from the spinal column. The nerve passes through the interior of the pelvis and exits the pelvis near the outer border of the inguinal groin ligament before making a downward turn to run beneath the skin of the outer thigh.

The course of the nerve can vary from person to person and even from side to side in the same person. In about 25 of people the nerve splits into branches before reaching the inguinal ligament, and there can be up to 5 branches. This variability might make some people more vulnerable to nerve-injury than others.

Pressure within the pelvis, as from pregnancy, obesity and rarely tumors, can injure the portion of the nerve within the pelvis. And as Freud’s physician surmised, the nerve is particularly vulnerable to injury from external pressure at the inguinal ligament, as from corsets, wide belts and tight pants. However, a cause for meralgia paresthetica is not always found, as was apparently the case when Freud had it.

The nerve can also be injured during a wide variety of surgical procedures, including orthopedic, vascular, gynecological, abdominal, hernia and even stomach-stapling operations. In a recent series of spinal surgery cases in Taiwan, 60 out of 252 patients experienced meralgia paresthetica as a complication of the surgery. Fortunately, in all cases it resolved within two months.

Diagnosis of this condition is usually made from the history and the physical examination, with the key features being numbness and unpleasant sensations on the side of the thigh. Other conditions can mimic meralgia paresthetica, for example, a pinched spinal nerve in the lower back, or impairment in the nearby femoral nerve that also emerges from the pelvis at the inguinal ligament. Tests of muscle and nerve electricity–electromyography and nerve conduction studies–can help resolve ambiguous cases.

Treatment of meralgia paresthetica has not been studied by the gold-standard method of randomized, controlled trials involving a comparison group of untreated patients. So in choosing appropriate treatment all we have to go on are collections of cases published in medical journals. Because many cases turn out well without drastic treatments, conservative approaches are tried first. Weight loss, removal of tight garments, completion of pregnancy and simple watchful waiting can all be effective.

While awaiting a favorable outcome, symptoms can be managed with skin-patches containing a local anesthetic drug, anti-inflammatory medications, certain epilepsy and antidepressant drugs known to relieve nerve-pain, and local injections with steroids. Surgery to relieve the pinch is usually reserved as a last resort.

C 2005 by Gary Cordingley

So here’s the scenario. It’s Saturday night and I’ve had a long week. I hit the bars and tip back one or two too many. Stumbling out of the last bar, I find I can’t make it past the city park without landing on my nose, so I plop onto a park bench. Slinging an arm over the back of the bench to stabilize myself, I fall into a deep slumber.

Now it’s Sunday morning and the sun is shining, the birds are singing and I’ve got a splitting headache. My arm is where I left it last night, slung over the back of the bench. I haul it back in front of me, but something is wrong. When I try to extend cock up my wrist, it doesn’t go anywhere. In fact, it droops downward. Moreover, I can’t straighten my drooping fingers, either. As I investigate further, I find that the skin on the back of my hand is numb. What gives?

The problem is that I have injured the arm’s radial nerve. As a result, the muscles it controls and the skin-sensation it manages are out of commission. On its course from the spinal cord in the neck to the forearm and hand, the radial nerve–a bundle containing many individual nerve-fibers–spirals around the humerus-bone of the upper arm. The nerve is particularly vulnerable to injury near the mid-portion of the humerus, in this case by allowing the hard edge of the park-bench to compress it against the bone all night. The weakness produced by this condition is usually more impairing than the numbness that is also present. With “palsy” as another word for weakness, this kind of injury to the radial nerve is called “Saturday night palsy.”

Of course, injury to the radial nerve injury can occur on any other night of the week, as well, and the setting does not have to be a park-bench. The usual common denominators are that alcohol or other drugs are involved, and because of the deep, drug-induced slumber, the arm is kept in the same position all night long.

This part of the radial nerve can also be injured by off-course injection-needles intended for the shoulder muscle above it the deltoid muscle. When this occurs, the pattern of weakness and numbness is the same, but instead of going by the name of “Saturday night palsy,” the nerve-injury is sometimes called “law suit.”

In either case, the nerve and its functions usually recover over a time-frame that can vary from days to longer than a year. The faster recoveries mean that the nerve-fibers within the nerve-bundle were sick but not dead. In more severe injuries, the nerve-fibers at the site of the injury and beyond have actually died, and their surviving stumps need to send out sprouts to replace the missing parts. This is a slow process. The growing sprouts reach the upper forearm where the wrist-straightening muscles are located before reaching the mid-forearm where the finger-straightening muscles are located. As a result, the muscles that straighten the wrist usually recover before those that straighten the fingers.

People with Saturday night palsy often exercise their arms by squeezing rubber balls or similar objects. Unfortunately, this activity exercises the wrong muscles. The radial nerve and its muscles have nothing to do with flexing the hand muscles. These functions are instead served by the arm’s median and ulnar nerves which were not injured in the first place. In order to be useful, an exercise would need to focus on cocking up the wrist and straightening the fingers.

But this, too, might be futile because the paralyzed muscles have no incoming nerve-messages to activate them. Until the damaged nerve-fibers reconnect with the muscle-fibers, the most useful exercise is a passive one in which the other hand does the work by stretching out the weak muscles at least daily. Using passive “range-of-motion” exercises, people with nerve-injury can avoid shortening of tendons and freezing of joints that might otherwise occur as complications while waiting for the nerve to recover.

What else can be done? Unfortunately, there is a dearth of scientific evidence in the form of randomized, controlled trials–the gold-standard for judging a treatment–to go by. All we have to go on is collective “clinical experience” and common sense. In order to properly heal and grow, nerve-fibers need a good supply of nutrients, so healthy eating–perhaps supplemented by a multiple vitamin or two each day–can give the nerve the building-blocks it needs to properly recover. Avoidance of alcohol might prevent a second injury. Because alcohol can also produce a direct toxic effect on the body’s peripheral nerves, abstinence would additionally prevent this barrier to recovery. In cases of prolonged weakness, electrical stimulation of the affected muscles via probes applied to the skin might keep the muscle-tissue healthier until they can receive more normal activation through their nerves.

While waiting for the nerve to heal, the wrist can be splinted in a neutral position with a device that leaves the fingers free to move. The fingers are more functional when the wrist is straight. One can prove this to himself or herself by flexing the wrist and trying to do something useful with the fingers, like write a sentence or pick up a coin. However, use of a splint does not preclude the need for at least daily, passive, range-of-motion exercises.

C 2005 by Gary Cordingley