Peripheral neuropathy

Answer 1

Definition

Peripheral neuropathy is a problem with the nerves that carry information to and from the brain and spinal cord. This can produce pain, loss of sensation, and an inability to control muscles.

• "Peripheral" means nerves further out from the center of the body, distant from the brain and spinal cord.
• "Neuro" means nerves.
• "Pathy" means abnormal.

Alternative Names

Peripheral neuritis; Neuropathy - peripheral; Neuritis - peripheral

Causes, incidence, and risk factors

One set of peripheral nerves relay information from your central nervous system (brain and spinal cord) to muscles and other organs. A second set relays information from your skin, joints, and other organs back to your brain.

Peripheral neuropathy occurs when these nerves don't work properly, resulting in pain, loss of sensation, inability to control muscles, and other possible problems.

In some cases, the failure of nerves that control blood vessels, intestines, and other organs results in abnormal blood pressure, digestion problems, and loss of other basic body processes. Peripheral neuropathy may involve damage to a single nerve or nerve group (mononeuropathy) or may affect multiple nerves (polyneuropathy).

There are numerous reasons for nerves to malfunction. In many cases, no cause can be identified. Damage to nerves can result from:

• Diseases that run in families (hereditary disorders) such as:
  • Charcot-Marie-Tooth disease
  • Friedreich's ataxia
• Diseases that affect the whole body (systemic or metabolic disorders) such as:
  • Diabetes(diabetic neuropathy)
  • Dietary deficiencies (especially vitamin B-12)
  • Excessive alcohol use (alcoholic neuropathy)
  • Uremia (from kidney failure)
  • Cancer
• Infections or inflammation, including:
  • AIDS
  • Hepatitis
  • Colorado tick fever
  • Diphtheria
  • Guillain-Barre syndrome
  • HIV infectionwithout development of AIDS
  • Leprosy
  • Lyme disease
  • Polyarteritis nodosa
  • Rheumatoid arthritis
  • Sarcoidosis
  • Sjogren syndrome
  • Syphilis
  • Systemic lupus erythematosus
  • Amyloidosis
• Exposure to poisonous substances such as:
  • Sniffing glue or other toxic compounds
  • Nitrous oxide
  • Industrial chemicals -- especially solvents
  • Heavy metals (lead, arsenic, mercury, etc.)
• Neuropathy secondary to drugs (many drugs, including some used for chemotherapy, can cause neuropathy)
• Miscellaneous causes
  • Compression of a nerve by casts, splints, braces, crutches, or other devices
  • Decreased oxygen and blood flow (ischemia)
  • Direct injury of the nerve either by hitting the nerve
  • Prolonged exposure to cold temperature
  • Prolonged pressure on the nerve (such as a long surgery or lengthy illness)

Peripheral neuropathy is very common. Because there are numerous types and causes of neuropathy and scientists don't always agree on the same definition of neuropathy, the exact incidence cannot be determined precisely.

Some people have a hereditary predisposition for neuropathy.

Symptoms

The symptoms depend on which type of nerve is affected. The three main types of nerves are:

• Those that carry sensations (sensory)
• Those that control muscles (motor)
• Those that carry information to organs and glands (autonomic)

Neuropathy can affect any one or a combination of all three types of nerves. Symptoms also depend on whether the condition affects the whole body or just one nerve (as from an injury).

Longer nerves are more easily injured than shorter ones, so it is common for you to have worse symptoms in the legs and feet than in the hands and arms.

SENSATION CHANGES

Damage to sensory fibers results in changes in sensation, burning sensations, nerve pain, tingling or numbness, or an inability to determine joint position, which causes incoordination.

For many neuropathies, sensation changes often begin in the feet and progress toward the center of the body with involvement of other areas as the condition worsens. Diabetes is a common cause for sensory neuropathy.

MOVEMENT DIFFICULTIES

Damage to the motor fibers interferes with muscle control and can cause weakness, loss of muscle bulk, and loss of dexterity. Sometimes, cramps are a sign of motor nerve involvement.

Other muscle-related symptoms include:

• Difficulty breathing or swallowing
• Difficulty or inability to move a part of the body (paralysis)
• Falling (from legs buckling or tripping over toes)
• Lack of dexterity (such as being unable to button a shirt)
• Lack of muscle control
• Loss of muscle tissue (muscle atrophy)
• Muscle twitching or cramping

AUTONOMIC SYMPTOMS

The autonomic nerves control involuntary or semivoluntary functions, such as control of internal organs and blood pressure. Damage to autonomic nerves can cause:

• Abdominal bloating
• Blurred vision
• Constipation
• Decreased ability to sweat
• Diarrhea
• Difficulty beginning to urinate (urinary hesitancy)
• Dizziness that occurs when standing up or fainting associated with a fall in blood pressure
• Feeling full after eating a small amount (early satiety)
• Feeling of incomplete bladder emptying
• Heat intolerance with exertion
• Male impotence
• Nausea or vomiting after meals
• Unintentional weight loss (more than 5% of body weight)
• Urinary incontinence

Signs and tests

A detailed history will be needed to determine the cause of the neuropathy. A neurological exam may reveal problems with movement, sensation, or organ function. Changes in reflexes and muscle bulk may also be present.

Blood tests may be done to screen for medical conditions such as diabetes and vitamin deficiencies.

Tests that reveal neuropathy may include:

• EMG (a recording of electrical activity in muscles)
• Nerve conduction tests
• Nerve biopsy

Tests for neuropathy are guided by the suspected cause of the disorder, as suggested by the history, symptoms, and pattern of symptom development. They may include various blood tests, x-rays, scans, or other tests and procedures.

Treatment

Treatment involves:

• Identifying and treating any underlying medical problem (such as diabetes) or removing the cause (such as alcohol)
• Controlling symptoms
• Curing the disorder, if possible
• Helping the patient gain maximum independence and self-care ability

Physical therapy, occupational therapy, and orthopedic interventions may be recommended. For example, exercises and retraining may be used to increase muscle strength and control. Wheelchairs, braces, and splints may improve mobility or the ability to use an affected arm or leg.

Safety is an important consideration for people with neuropathy. Lack of muscle control and reduced sensation increase the risk of falls and other injuries. The person may not notice a potential source of injury because he or she can't feel it. For example, one may not notice if water in a bathtub is too hot. For this reason, people with decreased sensation should check their feet or other affected areas frequently for bruises, open skin areas, or other injuries, which may go unnoticed and become severely infected. Often, a podiatrist can determine if special orthotic devices are needed.

Safety measures for people experiencing difficulty with movement may include:

• Installing railings
• Removing obstacles on floors such as loose rugs

Safety measures for people having difficulty with sensation include:

• Adequate lighting (including night lights)
• Testing water temperature before bathing
• Use of protective shoes (no open toes, no high heels)

Shoes should be checked often for grit or rough spots that may cause injury to the feet.

Persons with neuropathy (especially those with polyneuropathy or mononeuropathy multiplex) are prone to new nerve injury at pressure points such as knees and elbows. They should avoid prolonged pressure on these areas from leaning on the elbows, crossing the knees, or assuming similar positions.

Prescription pain medications may be needed to control nerve pain. Anticonvulsants (phenytoin, carbamazepine, gabapentin, and pregabalin), tricyclic antidepressants (duloxetine), or other medications may be used to reduce the stabbing pains. Use the lowest dose possible to avoid side effects.

Adjusting position, using frames to keep bedclothes off tender body parts, or other measures may also be helpful to reduce pain.

The symptoms of autonomic changes may be difficult to treat or respond poorly to treatment.

• Use of elastic stockings and sleeping with the head elevated may help treat low blood pressure that occurs when standing up (postural hypotension). Fludrocortisone or similar medications may also be helpful.
• Medications that increase gastric motility (such as metoclopramide), eating small frequent meals, sleeping with the head elevated, or other measures may help.
• Manual expression of urine (pressing over the bladder with the hands), intermittent catheterization, or medications such as bethanechol may be necessary for those with bladder dysfunction.
• Impotence, diarrhea, constipation, or other symptoms are treated as appropriate.

Support Groups

Additional information can be obtained from The Neuropathy Association - www.neuropathy.org

Expectations (prognosis)

The outcome greatly depends on the cause of the neuropathy. In cases where a medical condition can be identified and treated, the outlook may be excellent. However, in severe neuropathy, nerve damage can be permanent, even if the cause is treated appropriately.

For most hereditary neuropathies, there is no cure. Some of these conditions are harmless, while others progress more rapidly and may lead to permanent, severe complications.

Complications

The inability to feel or notice injuries can lead to infection or structural damage. Changes include poor healing, loss of tissue mass, tissue erosions, scarring, and deformity. Other complications include:

• Decreased self-esteem
• Difficulty breathing
• Difficulty swallowing
• Irregular heart rhythms (arrhythmias)
• Need for amputation
• Partial or complete loss of movement or control of movement
• Partial or complete loss of sensation
• Relationship problems related to impotence
• Recurrent or unnoticed injury to any part of the body

Calling your health care provider

Call your health care provider if symptoms of peripheral neuropathy are present. In all cases, early diagnosis and treatment increases the possibility that symptoms can be controlled.

Nerve pain, such as that caused by peripheral neuropathy, can be difficult to control. If pain is severe, a pain specialist may be able to suggest different approaches.

Emergency symptoms include irregular or rapid heartbeats, difficulty breathing, difficulty swallowing, and fainting.

Prevention

If a prolonged procedure or immobility is expected, appropriate measures (such as padding vulnerable areas) can be taken beforehand to reduce the risk of nerve problems.

Persons with a hereditary predisposition for neuropathy need to be especially careful to limit alcohol and manage other medical problems closely.

All people can reduce the risk of neuropathy by following a balanced diet, drinking alcohol in moderation, and maintaining good control of diabetes and other medical problems, if present.

References

Shy ME. Peripheral neuropathies. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 446.

Answer 2

One of the most common complications of long term diabetes is peripheral neuropathy. It gets its name because it affects the peripheral nerves. These are the nerves that are outside the central nervous system of the spinal cord and the brain. Other causes of neuropathy can be Guillain-Barre syndrome, Alcoholism, cancer treatment, autoimmune diseases like lupus, infections or injury. In some cases people inherit peripheral neuropathy. Sometimes the condition can effect deeper organs of the body and can lead to cardiac disorders, alternating diarrhea and constipation, impotence and an inability to empty the bladder.

Symptoms of Peripheral Neuropathy

Neuropathy causes the nerves to eventually lose function, which leads to pain, tingling sensations, muscle weakness and numbness. These sensations often occur in the hands or feet. Diabetic neuropathy is one of the biggest factors in the development of foot ulcers in diabetics. The risk of diabetics developing ulcers in their feet is twenty times greater than the general population. This is because with the loss of sensation in the feet, diabetics are less likely to take care of an injury or an infection. Anyone who suffers from peripheral neuropathy is more likely to overlook injuries, as they can't feel them.

The best way to avoid peripheral neuropathy and other complications of diabetes is to keep the blood sugar under control. Vitamin B6 supplementation also seems to help against the patient developing neuropathy. Interestingly, a deficiency in Vitamin B6 in and of itself often mimics the symptoms of peripheral neuropathy.

In other types of peripheral neuropathy the onset is rapid, then the patient gets better as the nerves repair themselves. Other people have episodes where they suffer from the condition, followed by long periods in between where they feel normal. Some patients endure symptoms that neither worsen nor get better for years.

Treatment of Peripheral Neuropathy

A person who suspects that they're suffering from peripheral neuropathy, or has unexplained numbness or tingling in the extremities should visit their physician. The physician in turn might recommend a neurologist, a Doctor Who specializes in nerve disorders. The patient will probably undergo tests like MRIs or CT scans, electromyography, blood tests and even nerve biopsies to see what's wrong. A doctor might also prescribe medications to deal with the pain of peripheral neuropathy.

Answer 3

Definition

Peripheral nerves carry information to and from the brain. They also carry signals to and from the spinal cord to the rest of the body.

Peripheral neuropathy means these nerves don't work properly. Peripheral neuropathy may be damage to a single nerve. It may be damage to a nerve group. It may also affect nerves in the whole body.

Alternative Names

Peripheral neuritis; Neuropathy - peripheral; Neuritis - peripheral

Causes, incidence, and risk factors

Nerve damage is very common. There are many types and causes. Often, no cause can be found. Some nerves diseases run in families.

Diabetes is the most common cause of this type of nerve problem. It happens when you have high blood sugar levels over a long time.

Other medical problems that may cause neuropathy are:

• Autoimmune disorders rheumatoid Arthritis or lupus
• Chronic kidney disease
• Infections such as HIV and liver infections
• Low levels of vitamin B12 or other problems with your diet
• Poor blood flow to the legs
• Underactive thyroid gland

Drugs and toxins may damage nerves. One example is heavy alcohol use. Glue, lead, mercury, and solvents may damage nerves. Drugs that treat infections, cancer, seizures, and high blood pressure may cause nerve damage.

Pressure on a nerve near a body part may be a cause. An example is carpal tunnel syndrome.

A bone fracture or other trauma may damage a nerve. Being exposed to cold temperatures for a long period of time may too. Pressure from bad-fitting casts, splints, a brace, or crutches can damage a nerve.

Symptoms

Symptoms depend on the nerve that is damaged. Symptoms also depend on whether the damage affects one nerve, several nerves, or the whole body.

PAIN AND NUMBNESS

Tingling or burning in the arms and legs may be an early sign of nerve damage. These feelings often start in your toes and feet. You may have deep pain. This often happens in the feet and legs.

You may lose feeling in your legs and arms. Because of this, you may not notice when you step on something sharp. You may not notice when touch something that is too hot or cold. You may not know when you have a small blister or sore on your feet.

MUSCLE PROBLEMS

Damage to the nerves can make it harder to control muscles. It can also cause weakness. You may notice problems moving a part of your body. You may fall because your legs buckle. You may trip over your toes.

Doing tasks such as buttoning a shirt may be harder. You may also notice your muscles twitch or cramp. Your muscles may become smaller.

PROBLEMS WITH BODY ORGANS

People with nerve damage may have problems digesting food. You may feel full or bloated and have heartburn after eating only a little food. Sometimes you may vomit food that has not been digested well. You may have either loose stools are hard stools. Some people have problems swallowing.

Damage to the nerves to your heart may cause you to feel lightheaded, or faint, when you stand up.

Angina is the warning chest pain for Heart disease and heart attack. Nerve damage may "hide" this warning sign. You should learn other warning signs of a heart attack. They are sudden fatigue, sweating, shortness of breath, nausea, and vomiting.

OTHER SYMPTOMS OF NERVE DAMAGE

Sexual problems. Men may have problems with erections. Women may have trouble with vaginal dryness or orgasm.

Some people may not be able to tell when their blood sugar gets too low.

Bladder problems. You may leak urine. You may not be able to tell when your bladder is full. Some people are not able to empty their bladder.

You may sweat too much. This may happen when the temperature is cool, when you are at rest, or at other unusual times.

Signs and tests

Your doctor will do a careful history of you. You will also have a physical exam.

You may have blood tests to look for causes of your nerve damage.

You may also have tests to: check activity in muscles, see how fast signals travel along nerves, and look at a sample of a nerve under a microscope.

Treatment

Treating the cause of nerve damage, if it is known, may improve your symptoms. People with diabetes should learn to control their blood sugar.

If you use alcohol, stop. Your medicines may need to be changed. Replacing a vitamin or making other changes in your diet may help.

You may need surgery to stop injury to a nerve.

You may have therapy to learn exercises to get better muscle strength and control. Wheelchairs, braces, and splints may improve movement or the ability to use an arm or leg with nerve damage.

SETTING UP YOUR HOME

Safety is very important for people with nerve damage. Nerve damage can increase the risk of falls and other injuries.

Remove loose wires and rugs from areas you walk through. Do not keep small pets in your home. Fix uneven flooring in doorways.

Have good lighting. Put handrails in the bathtub or shower and next to the toilet. Place a slip-proof mat in the bathtub or shower.

WATCHING YOUR SKIN

Wear shoes at all times to protect your feet from injury. Before you put them on, always check inside your shoes for stones, nails, or rough areas that may hurt your feet.

Check your feet every day. Look at the top, sides, soles, heels, and between the toes. Wash your feet every day with lukewarm water and mild soap. Use lotion, petroleum jelly, lanolin, or oil on dry skin.

Check bathwater temperature with your elbow before putting your feet in the water.

Avoid putting pressure on areas with nerve damage for too long.

TREATING PAIN

Medicines may help reduce pain in the feet, legs, and arms. They usually do not bring back loss of feeling.

You may take pain pills. Medicines used to treat other medical problems, such as seizures or depression, can also help manage the pain. Use the lowest dose possible to avoid side effects.

Your doctor may refer you to a pain specialist. Talk therapy may help you better understand how your pain is affecting your life. It can also help you learn ways to better cope with pain.

TREATING OTHER SYMPTOMS

Wearing elastic stockings may help treat low blood pressure and fainting. So can sleeping with your head elevated. Some medicines may also help.

Your health care provider may give you medicines to help with problems going to the bathroom. Eating small frequent meals may help.

There are ways to help bladder problems. You can learn exercises to strengthen your pelvic floor muscles. You may need to use a thin tube that is inserted into your bladder (urinary catheter). You may take medicines.

Medicines can often help with erection problems.

Support Groups

You can find support group information from The Neuropathy Association - www.neuropathy.org

Expectations (prognosis)

The outcome depends on the cause of nerve damage. When a medical condition can be found and treated, your outlook may be excellent. But, in severe neuropathy, nerve damage can be permanent, even if the cause is treated.

Chronic pain can be a major problem for some patients. Those with numbness in the feet can get skin sores that do not heal. They are also at risk for joint deformities. Rarely, numbness in the feet may lead to amputation.

For most neuropathies passed down in families, there is no cure. Some of these problems do not interfere with daily life. Others get worse quickly and may lead to long-term, severe symptoms and problems.

Calling your health care provider

Call your health care provider if you have symptoms of nerve damage. Early treatment increases the chance of controlling symptoms and preventing more problems.

Prevention

You can prevent some causes of nerve damage.

Drink alcohol in moderation. Follow a balanced diet. Keep good control over diabetes and other medical problems. Learn about chemicals used at your workplace.

References

Shy ME. Peripheral neuropathies. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 446.

Reviewed By

Review Date: 04/26/2011

A.D.A.M. Editorial Team: David Zieve, MD, MHA, and David R. Eltz. Previously reviewed by David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Daniel B. Hoch, PhD, MD, Assistant Professor of Neurology, Harvard Medical School, Department of Neurology, Massachusetts General Hospital (8/27/2010).