carpal tunnel syndrome

What is carpal tunnel syndrome?

Carpus is a word derived from the Greek word karpos, which means "wrist." The wrist is surrounded by a band of fibrous tissue that normally functions as a support for the joint. The tight space between this fibrous band and the wrist bone is called the carpal tunnel. The median nerve passes through the carpal tunnel to receive sensations from the thumb, index, and middle fingers of the hand. Any condition that causes swelling or a change in position of the tissue within the carpal tunnel can squeeze and irritate the median nerve. Irritation of the median nerve in this manner causes tingling and numbness of the thumb, index, and the middle fingers -- a condition known as "carpal tunnel syndrome."

Causes

Carpal tunnel syndrome occurs as a result of compression of the median nerve. The median nerve runs from your forearm through a passageway in your wrist (carpal tunnel) to your hand. It provides sensation to the palm side of your thumb and fingers, with the exception of your little finger. It also provides nerve signals to move the muscles around the base of your thumb (motor function).

In general, anything that crowds, irritates or compresses the median nerve in the carpal tunnel space can lead to carpal tunnel syndrome. For example, a wrist fracture can narrow the carpal tunnel and irritate the nerve, as can the swelling and inflammation resulting from rheumatoid arthritis.

In many cases, no single cause can be identified. It may be that a combination of risk factors contributes to the development of the condition.

Tests and diagnosis

Your doctor may conduct one or more of the following tests to determine whether you have carpal tunnel syndrome:

• History of symptoms. The pattern of your signs and symptoms may offer clues to their cause. For example, since the median nerve doesn't provide sensation to your little finger, symptoms in that finger may indicate a problem other than carpal tunnel syndrome. Another clue is the timing of the symptoms. Typical times when you might experience symptoms due to carpal tunnel syndrome include while holding a phone or a newspaper, gripping a steering wheel, or waking up during the night.
• Physical exam. Your doctor will want to test the feeling in your fingers and the strength of the muscles in your hand, because these can be affected by carpal tunnel syndrome. Pressure on the median nerve at the wrist, produced by bending the wrist, tapping on the nerve or simply pressing on the nerve, can bring on the symptoms in many people.
• X-ray. Some doctors may recommend an X-ray of the affected wrist to exclude other causes of wrist pain, such as arthritis or a fracture.
• Electromyogram. Electromyography measures the tiny electrical discharges produced in muscles. A thin-needle electrode is inserted into the muscles your doctor wants to study. An instrument records the electrical activity in your muscle at rest and as you contract the muscle. This test can help determine if muscle damage has occurred.
• Nerve conduction study. In a variation of electromyography, two electrodes are taped to your skin. A small shock is passed through the median nerve to see if electrical impulses are slowed in the carpal tunnel.

The electromyogram and nerve conduction study tests are also useful in checking for other conditions that might mimic carpal tunnel syndrome, such as a pinched nerve in your neck.

Your doctor may recommend that you see a rheumatologist, neurologist, hand surgeon or neurosurgeon if your signs or symptoms indicate other medical disorders or a need for specialized treatment.

Treatments and drugs

Some people with mild symptoms of carpal tunnel syndrome can ease their discomfort by taking more-frequent breaks to rest their hands and applying cold packs to reduce occasional swelling. If these techniques don't offer relief within a few weeks, additional treatment options include wrist splinting, medications and surgery. Splinting and other conservative treatments are more likely to help you if you've had only mild to moderate symptoms for less than 10 months.

Nonsurgical therapy
If the condition is diagnosed early, nonsurgical methods may help improve carpal tunnel syndrome. Methods may include:

• Wrist splinting. A splint that holds your wrist still while you sleep can help relieve nighttime symptoms of tingling and numbness. Nocturnal splinting may be a good option if you are pregnant and have carpal tunnel syndrome.
• Nonsteroidal anti-inflammatory drugs (NSAIDs). NSAIDs may help relieve pain from carpal tunnel syndrome in the short term. There's no evidence, though, that these drugs can actually improve the carpal tunnel syndrome itself.
• Corticosteroids. Your doctor may inject your carpal tunnel with a corticosteroid, such as cortisone, to relieve your pain. Corticosteroids decrease inflammation and swelling, which relieves pressure on the median nerve. Oral corticosteroids aren't considered as effective as corticosteroid injections for treating carpal tunnel syndrome.

If carpal tunnel syndrome results from an inflammatory arthritis, such as rheumatoid arthritis, then treating the underlying condition may reduce symptoms of carpal tunnel syndrome, but this hasn't been proved.

Surgery
If your symptoms are severe or persist after trying nonsurgical therapy, surgery may be the best option.

The goal of carpal tunnel surgery is to relieve pressure on your median nerve by cutting the ligament pressing on the nerve. During the healing process after the surgery, the ligament tissues gradually grow back together while allowing more room for the nerve than existed before. The surgery may be done a couple of different ways. Either technique has risks and benefits that are important to discuss with your surgeon before surgery.

• Endoscopic surgery. Carpal tunnel surgery can be done using an endoscope, a telescope-like device with a tiny camera attached to it that allows your doctor to see inside your carpal tunnel and perform the surgery through small incisions in your hand or wrist.
• Open surgery. In other cases, surgery involves making a larger incision in the palm of your hand over the carpal tunnel and cutting through the ligament to free the nerve.

In general, your doctor will encourage you to use your hand after surgery, gradually working back to normal use of your hand while avoiding forceful hand motions or extreme positions of your wrist. Soreness or weakness may take from several weeks to as long as a few months to resolve after surgery. If your symptoms were very severe before surgery, symptoms may not go away completely after surgery.

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Posted in: carpal tunnel syndrome,Neurology

Guillain-Barré Syndrome

What is Guillain-Barré Syndrome?

Guillain-Barré syndrome is a disorder in which the body's immune system attacks part of the peripheral nervous system. The first symptoms of this disorder include varying degrees of weakness or tingling sensations in the legs. In many instances, the weakness and abnormal sensations spread to the arms and upper body. These symptoms can increase in intensity until the muscles cannot be used at all and the patient is almost totally paralyzed. In these cases, the disorder is life-threatening and is considered a medical emergency. The patient is often put on a respirator to assist with breathing. Most patients, however, recover from even the most severe cases of Guillain-Barré syndrome, although some continue to have some degree of weakness. Guillain-Barré syndrome is rare. Usually Guillain-Barré occurs a few days or weeks after the patient has had symptoms of a respiratory or gastrointestinal viral infection. Occasionally, surgery or vaccinations will trigger the syndrome. The disorder can develop over the course of hours or days, or it may take up to 3 to 4 weeks. 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, causing what is known as an autoimmune disease. Guillain-Barré is called a syndrome rather than a disease because it is not clear that a specific disease-causing agent is involved. Reflexes such as knee jerks are usually lost. Because the signals traveling along the nerve are slower, a nerve conduction velocity (NCV) test can give a doctor clues to aid the diagnosis. The cerebrospinal fluid that bathes the spinal cord and brain contains more protein than usual, so a physician may decide to perform a spinal tap.

Symptoms

Guillain-Barre syndrome often begins with weakness, tingling or loss of sensation starting in your feet and legs and spreading to your upper body and arms. These symptoms may begin — often not causing much notice — in your fingers and toes. In some people, symptoms begin in the arms or even the face. As the disorder progresses, muscle weakness can evolve into paralysis.

Signs and symptoms of Guillain-Barre syndrome may include:

• Prickling, "pins and needles" sensations in your fingers, toes or both
• Weakness or tingling sensations in your legs that spread to your upper body
• Unsteady walking or inability to walk
• Difficulty with eye movement, facial movement, speaking, chewing or swallowing
• Severe pain in your lower back
• Difficulty with bladder control or intestinal functions
• Very slow heart rate or low blood pressure
• Difficulty breathing

Most people with Guillain-Barre syndrome experience their most significant weakness within three weeks after symptoms begin. In some cases, signs and symptoms may progress very rapidly with complete paralysis of legs, arms and breathing muscles over the course of a few hours.

When to see a doctor
Call your doctor if you have mild tingling in your toes or fingers that doesn't seem to be spreading or getting worse.

Seek emergency medical help if you have any of the following severe signs or symptoms:

• Tingling that started in your feet or toes and is now ascending upward through your body
• Tingling or weakness that's spreading rapidly
• Tingling that involves both your hands and feet
• Difficulty catching your breath
• Choking on saliva

Guillain-Barre syndrome is a serious disease that requires immediate hospitalization because of the rapid rate at which it worsens. The sooner appropriate treatment is started, the better the chance of a good outcome.

Causes

The exact cause of Guillain-Barre syndrome is unknown. In about 60 percent of cases, an infection affecting either the lungs or the digestive tract precedes the disorder. But scientists don't know why such an infection can lead to Guillain-Barre syndrome for some people and not for others. Many cases appear to occur without any triggers.

In Guillain-Barre syndrome, your immune system — which usually only attacks foreign material and invading organisms — begins attacking the nerves that carry signals between your body and your brain. Specifically, the nerves' protective covering (myelin sheath) is damaged and this interferes with the signaling process, causing weakness, numbness or paralysis.

Diagnostic criteria

• Progressive, relatively symmetrical weakness of two or more limbs due to neuropathy
• Areflexia
• Disorder course < 4 weeks
• Exclusion of other causes (see below)

Supportive

• relatively symmetric weakness accompanied by numbness and/or tingling
• mild sensory involvement
• facial nerve or other cranial nerve involvement
• absence of fever
• typical CSF findings obtained from lumbar puncture
• electrophysiologic evidence of demyelination from electromyogram

Differential diagnosis:

• acute myelopathies with chronic back pain and sphincter dysfunction
• botulism with early loss of pupillary reactivity and descending paralysis
• diphtheria with early oropharyngeal dysfunction
• Lyme disease polyradiculitis and other tick-borne paralyses
porphyria with abdominal pain, seizures, psychosisvasculitis neuro
• pathy
• poliomyelitis with fever and meningeal signs
• CMV polyradiculitis in immunocompromised patients
• critical illness neuropathy
• myasthenia gravis
• poisonings with organophosphate, poison hemlock, thallium, or arsenic
• intoxication with Karwinskia humboldtiana leaves or seeds
• paresis caused by West Nile virus
• spinal astrocytoma
• motor neurone disease
• West Nile virus can cause severe, potentially fatal neurological illnesses, which include encephalitis, meningitis, Guillain-Barré syndrome, and anterior myelitis.

Treatments

Although some people can take months and even years to recover, most cases of Guillain-Barre syndrome follow this general timeline:

• Following the first symptoms, the condition tends to progressively worsen for about two weeks.
• Symptoms reach a plateau and remain steady for two to four weeks.
• Recovery begins, usually lasting six to 12 months.

There's no cure for Guillain-Barre syndrome. But two types of treatments speed recovery and reduce the severity of Guillain-Barre syndrome:

• Plasmapheresis. This treatment — also known as plasma exchange — is a type of "blood cleansing" in which damaging antibodies are removed from your blood. Plasmapheresis consists of removing the liquid portion of your blood (plasma) and separating it from the actual blood cells. The blood cells are then put back into your body, which manufactures more plasma to make up for what was removed. It's not clear why this treatment works, but scientists believe that plasmapheresis rids plasma of certain antibodies that contribute to the immune system attack on the peripheral nerves.
• Intravenous immunoglobulin. Immunoglobulin contains healthy antibodies from blood donors. High doses of immunoglobulin can block the damaging antibodies that may contribute to Guillain-Barre syndrome.

Each of these treatments is equally effective. Mixing the treatments or administering one after the other is no more effective than using either method alone.

Often before recovery begins, caregivers may need to manually move your arms and legs to help keep your muscles flexible and strong. After recovery has begun, you'll likely need physical therapy to help regain strength and proper movement so that you'll be able to function on your own. You may need training with adaptive devices, such as a wheelchair or braces, to give you mobility and self-care skills.

Prognosis

Most of the time recovery starts after the fourth week from the onset of the disorder. Approximately 80% of patients have a complete recovery within a few months to a year, although minor findings may persist, such as areflexia. About 5–10% recover with severe disability, with most of such cases involving severe proximal motor and sensory axonal damage with inability of axonal regeneration. However, this is a grave disorder and despite all improvements in treatment and supportive care, the death rate among patients with this disorder is still about 2–3% even in the best intensive care units. Worldwide, the death rate runs slightly higher (4%), mostly from a lack of availability of life support equipment during the lengthy plateau lasting four to six weeks, and in some cases up to one year, when a ventilator is needed in the worst cases. About 5–10% of patients have one or more late relapses, in which case they are then classified as having chronic inflammatory demyelinating polyneuropathy (CIDP).

Poor prognostic factors include: 1) age, over 40 years, 2) history of preceding diarrheal illness, 3) requiring ventilator support, 4) high anti-GM1 titre and 5) poor upper limb muscle strength

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Posted in: Guillain-Barré Syndrome,Neurology