Nerve conduction study (NCS)
Nerve conduction studies are preformed first. The goal of the test is to study your nerves. This is done by taping small metal disks to the skin over the nerve area to be tested. A small electrical current is then used to stimulate the nerve. This process will be repeated over several areas and may also be done at different sites along the nerve. It should be noted that the electrical current produces a tingling sensation that may be slightly uncomfortable to some.
Nerve conduction studies are used mainly for evaluation of paresthesias (numbness, tingling, burning) and/or weakness of the arms and legs. The type of study required is dependent in part by the symptoms presented. A physical exam and thorough history also help to direct the investigation. Some of the common disorders which can be diagnosed by nerve conduction studies are:
The nerve conduction study consists of the following components:
- Motor NCS
- Sensory NCS
- F-wave study
- H-reflex study
The second part of the test is an EMG designed to study your muscles. First, a small metal disc (about the size of a fifty-cent piece) will be taped to your skin. The EMG doctor will then insert a small needle into your muscle in order to record your muscle’s electrical activity. EMG testing may be done on several different muscles (but each muscle will be tested on its own). During the test, you will hear a crackling speaker sound. This is the electrical activity from your muscles, changed into sound waves. You do not receive any electrical stimulation for this part of the test. The EMG can be somewhat uncomfortable because of the needle used. For a day or two after the test, you may feel some tenderness or notice a small bruise around the sites where the needle was inserted.
EMG/NCS Can Help Diagnose:
- Pinched Nerves
- Carpal Tunnel Syndrome
- Muscle Weakness
- Arm or Leg Numbness/Pain
- Muscular Dystrophy
- Myasthenia Gravis
- Amyotrophic Lateral Sclerosis (ALS) or
- Lou Gehrig’s Disease
- Foot Numbness/Weakness
- Peripheral Neuropathy
- Ulnar neuropathy
- Guillain-Barré syndrome
When are NCSs/EMGs used?
A doctor may recommend that you undergo this test. There are a wide variety of conditions that are assessed with this technique. Quite frequently, the examination is requested because the patient is experiencing symptoms that suggest some problem with the nerves (numbness, tingling, weakness or pain) or muscles (weakness or pain), even though the physical examination is normal. Indeed, in many cases, there is no abnormality seen and the test can then be reassuring, but it cannot detect all conditions. In general terms, the test is useful for detecting if there is a significant abnormality, but this is also often easier when there is a definite clinical abnormality. In such cases, the test can help clarify what the problem is, although usually, unless the nerve problem is a common entrapment (site of compression), other tests may be required to ascertain the exact nature of the problem.
What does an NCS/EMG detect?
There are several types of nerves but generally speaking, the two major types aremotor and sensory nerves. Motor nerves carry signals from the brain to the muscle to enable contraction and movement, and sensory nerves relay information to the brain. When the nerve is stimulated with metal electrodes (metallic patch/es that can conduct signals), a response can be measured by surface (on the skin) electrodes some distance away in sensory nerves overlying the nerve itself. For the motor nerves, the response is usually detected over the muscle that is activated by that nerve. In this fashion, results can reveal information about the size and speed of the electrically conducted impulse. The size usually reveals the number of nerve fibres present and the speed, the integrity of the myelin (insulating membrane around the nerve ‘axon’ or cable). This is why the word ‘conduction’ is used.
This can pick up electrical signals in the muscle either in its resting state or with activation of the muscle. As mentioned earlier, it is useful for looking at both the nerve and the muscle but this portion of the test, being invasive, is not always employed.
Preparing for an NCS/EMG
You will be given instructions on how to prepare for the test. You should not use creams or emollients on your hands and feet (the most common sites of your nerve tests) on the day of the test, and preferably since your last shower or bath. Generally speaking, there are no other preparations of note.
Please advise the neurologist performing the test if you have a pacemaker or other similar devices. If you are taking warfarin, heparin or some other medication to thin your blood, and if you are having a needle EMG test, you should advise both your GP and the neurologist. A measurement of how thin your blood is may be important before that test can be performed.
The NCS procedure is usually very safe and is non-invasive. Firstly, you will be told how to position yourself and the skin area will be prepared. Then some electrodes will be attached to your skin and you will be forewarned when to expect the stimulation. Many people are understandably anxious about the intensities of the small safe electrical pulses that are passed via the skin, but usually relax quickly when they know what to expect. It is faily important that you remain relaxed for the recordings to minimise the ‘noise’ (interference) in the recordings from excessive muscular activity.
Here, a small needle is inserted through the skin into a muscle belly. Sterilisation of the skin and a local anaesthetic is not generally required. Usually the consultation and procedure takes about 30-45 minutes in all. More complicated assessments may demand more time.
What happens after an NSC/EMG?
Following the test, you will be allowed to put on your garments and shoes. It should be noted that the final interpretation of the clinical meaning of the test rests with the clinician who ordered the test. This is because they can put together the whole picture. For this reason, the neurologist performing the test can only give you limited information about the meaning of the results, and may not even be able to provide any information on the next step or any possible treatments because they are unaware of all the other clinical information.
Few common Neuropathies:
1. Carpal tunnel syndrome:
Carpal tunnel syndrome occurs when the median nerve, which runs from the forearm into the hand, becomes pressed or squeezed at the wrist. The median nerve controls sensations to the palm side of the thumb and fingers (although not the little finger), as well as impulses to some small muscles in the hand that allow the fingers and thumb to move. The carpal tunnel – a narrow, rigid passageway of ligament and bones at the base of the hand – houses the median nerve and tendons. Sometimes, thickening from irritated tendons or other swelling narrows the tunnel and causes the median nerve to be compressed. The result may be pain, weakness, or numbness in the hand and wrist, radiating up the arm. Although painful sensations may indicate other conditions, carpal tunnel syndrome is the most common and widely known of the entrapment neuropathies in which the body’s peripheral nerves are compressed or traumatized.
What are the symptoms of carpal tunnel syndrome?
Symptoms usually start gradually, with frequent burning, tingling, or itching numbness in the palm of the hand and the fingers, especially the thumb and the index and middle fingers. Some carpal tunnel sufferers say their fingers feel useless and swollen, even though little or no swelling is apparent. The symptoms often first appear in one or both hands during the night, since many people sleep with flexed wrists. A person with carpal tunnel syndrome may wake up feeling the need to “shake out” the hand or wrist. As symptoms worsen, people might feel tingling during the day. Decreased grip strength may make it difficult to form a fist, grasp small objects, or perform other manual tasks. In chronic and/or untreated cases, the muscles at the base of the thumb may waste away. Some people are unable to tell between hot and cold by touch.
What are the causes of carpal tunnel syndrome?
Carpal tunnel syndrome is often the result of a combination of factors that increase pressure on the median nerve and tendons in the carpal tunnel, rather than a problem with the nerve itself. Most likely the disorder is due to a congenital predisposition – the carpal tunnel is simply smaller in some people than in others. Other contributing factors include trauma or injury to the wrist that cause swelling, such as sprain or fracture; overactivity of the pituitary gland; hypothyroidism; rheumatoid arthritis; mechanical problems in the wrist joint; work stress; repeated use of vibrating hand tools; fluid retention during pregnancy or menopause; or the development of a cyst or tumor in the canal. In some cases no cause can be identified.
There is little clinical data to prove whether repetitive and forceful movements of the hand and wrist during work or leisure activities can cause carpal tunnel syndrome. Repeated motions performed in the course of normal work or other daily activities can result in repetitive motion disorders such as bursitis and tendonitis. Writer’s cramp – a condition in which a lack of fine motor skill coordination and ache and pressure in the fingers, wrist, or forearm is brought on by repetitive activity – is not a symptom of carpal tunnel syndrome.
Who is at risk of developing carpal tunnel syndrome?
Women are three times more likely than men to develop carpal tunnel syndrome, perhaps because the carpal tunnel itself may be smaller in women than in men. The dominant hand is usually affected first and produces the most severe pain. Persons with diabetes or other metabolic disorders that directly affect the body’s nerves and make them more susceptible to compression are also at high risk. Carpal tunnel syndrome usually occurs only in adults.
The risk of developing carpal tunnel syndrome is not confined to people in a single industry or job, but is especially common in those performing assembly line work – manufacturing, sewing, finishing, cleaning, and meat, poultry, or fish packing. In fact, carpal tunnel syndrome is three times more common among assemblers than among data-entry personnel. A 2001 study by the Mayo Clinic found heavy computer use (up to 7 hours a day) did not increase a person’s risk of developing carpal tunnel syndrome.
How is carpal tunnel syndrome diagnosed?
Early diagnosis and treatment are important to avoid permanent damage to the median nerve. A physical examination of the hands, arms, shoulders, and neck can help determine if the patient’s complaints are related to daily activities or to an underlying disorder, and can rule out other painful conditions that mimic carpal tunnel syndrome. The wrist is examined for tenderness, swelling, warmth, and discoloration. Each finger should be tested for sensation, and the muscles at the base of the hand should be examined for strength and signs of atrophy. Routine laboratory tests and X-rays can reveal diabetes, arthritis, and fractures.
Physicians can use specific tests to try to produce the symptoms of carpal tunnel syndrome. In the Tinel test, the doctor taps on or presses on the median nerve in the patient’s wrist. The test is positive when tingling in the fingers or a resultant shock-like sensation occurs. The Phalen, or wrist-flexion, test involves having the patient hold his or her forearms upright by pointing the fingers down and pressing the backs of the hands together. The presence of carpal tunnel syndrome is suggested if one or more symptoms, such as tingling or increasing numbness, is felt in the fingers within 1 minute. Doctors may also ask patients to try to make a movement that brings on symptoms.
Often it is necessary to confirm the diagnosis by use of electrodiagnostic tests. In a nerve conduction study, electrodes are placed on the hand and wrist. Small electric shocks are applied and the speed with which nerves transmit impulses is measured. In electromyography, a fine needle is inserted into a muscle; electrical activity viewed on a screen can determine the severity of damage to the median nerve. Ultrasound imaging can show impaired movement of the median nerve. Magnetic resonance imaging (MRI) can show the anatomy of the wrist but to date has not been especially useful in diagnosing carpal tunnel syndrome.
How is carpal tunnel syndrome treated?
Treatments for carpal tunnel syndrome should begin as early as possible, under a doctor’s direction. Underlying causes such as diabetes or arthritis should be treated first. Initial treatment generally involves resting the affected hand and wrist for at least 2 weeks, avoiding activities that may worsen symptoms, and immobilizing the wrist in a splint to avoid further damage from twisting or bending. If there is inflammation, applying cool packs can help reduce swelling.
Drugs – In special circumstances, various drugs can ease the pain and swelling associated with carpal tunnel syndrome. Nonsteroidal anti-inflammatory drugs, such as aspirin, ibuprofen, and other nonprescription pain relievers, may ease symptoms that have been present for a short time or have been caused by strenuous activity. Orally administered diuretics (“water pills”) can decrease swelling. Corticosteroids (such as prednisone) or the drug lidocaine can be injected directly into the wrist or taken by mouth (in the case of prednisone) to relieve pressure on the median nerve and provide immediate, temporary relief to persons with mild or intermittent symptoms. (Caution: persons with diabetes and those who may be predisposed to diabetes should note that prolonged use of corticosteroids can make it difficult to regulate insulin levels. Corticosterioids should not be taken without a doctor’s prescription.) Additionally, some studies show that vitamin B6 (pyridoxine) supplements may ease the symptoms of carpal tunnel syndrome.
Exercise – Stretching and strengthening exercises can be helpful in people whose symptoms have abated. These exercises may be supervised by a physical therapist, who is trained to use exercises to treat physical impairments, or an occupational therapist, who is trained in evaluating people with physical impairments and helping them build skills to improve their health and well-being.
Alternative therapies – Acupuncture and chiropractic care have benefited some patients but their effectiveness remains unproved. An exception is yoga, which has been shown to reduce pain and improve grip strength among patients with carpal tunnel syndrome.
Carpal tunnel release is one of the most common surgical procedures in the United States. Generally recommended if symptoms last for 6 months, surgery involves severing the band of tissue around the wrist to reduce pressure on the median nerve. Surgery is done under local anesthesia and does not require an overnight hospital stay. Many patients require surgery on both hands. The following are types of carpal tunnel release surgery:
Open release surgery, the traditional procedure used to correct carpal tunnel syndrome, consists of making an incision up to 2 inches in the wrist and then cutting the carpal ligament to enlarge the carpal tunnel. The procedure is generally done under local anesthesia on an outpatient basis, unless there are unusual medical considerations.
Endoscopic surgery may allow faster functional recovery and less postoperative discomfort than traditional open release surgery. The surgeon makes two incisions (about ½” each) in the wrist and palm, inserts a camera attached to a tube, observes the tissue on a screen, and cuts the carpal ligament (the tissue that holds joints together). This two-portal endoscopic surgery, generally performed under local anesthesia, is effective and minimizes scarring and scar tenderness, if any. One-portal endoscopic surgery for carpal tunnel syndrome is also available.
Although symptoms may be relieved immediately after surgery, full recovery from carpal tunnel surgery can take months. Some patients may have infection, nerve damage, stiffness, and pain at the scar. Occasionally the wrist loses strength because the carpal ligament is cut. Patients should undergo physical therapy after surgery to restore wrist strength. Some patients may need to adjust job duties or even change jobs after recovery from surgery.
Recurrence of carpal tunnel syndrome following treatment is rare. The majority of patients recover completely.
How can carpal tunnel syndrome be prevented?
At the workplace, workers can do on-the-job conditioning, perform stretching exercises, take frequent rest breaks, wear splints to keep wrists straight, and use correct posture and wrist position. Wearing fingerless gloves can help keep hands warm and flexible. Workstations, tools and tool handles, and tasks can be redesigned to enable the worker’s wrist to maintain a natural position during work. Jobs can be rotated among workers. Employers can develop programs in ergonomics, the process of adapting workplace conditions and job demands to the capabilities of workers. However, research has not conclusively shown that these workplace changes prevent the occurrence of carpal tunnel syndrome.
2. Ulnar Neuropathies:
Ulnar neuropathy is an inflammation or compression of the ulnar nerve, resulting in paresthesia (numbness, tingling, and pain) in the outer side of the arm and hand near the little finger.
The ulnar nerve transmits impulses to muscles in the forearm and hand. The nerve is responsible for the proper sensing of touch, texture, and temperature throughout the fourth and fifth digits of the hand, the palm, and the underside of the forearm. Ulnar neuropathy arises most commonly because of damage to the nerve as it passes through the wrist. The elbow is also a frequent site of nerve damage. Ulnar neuropathy is variously known as bicycler’s neuropathy, cubital tunnel syndrome, Guyon or Guyon’s canal syndrome, and tardy ulnar palsy.
Ulnar neuropathy that originates at the elbow is very common. Estimates are that 40% of Americans experience some form of this neuropathy at some point in their lives. While the ulnar nerve is structurally identical in men and women, men tend to develop ulnar neuropathy more than women. This is because men generally do not have as much fat overlaying the elbow, and so the underlying nerve can be more susceptible to irritationand damage.
The onset of ulnar neuropathy can occur slowly. As a result, many of those who are affected are middle-aged or older adults. Demographic risk factors include a family history of diabetes, alcoholism, and presence of human immunodeficiency virus. Because leaning on the elbows can trigger ulnar neuropathy, people such as telephone operators, receptionists, and those who operate computers for extended periods of time are at risk for developing the disorder.
Causes and symptoms
Ulnar neuropathy is caused by nerve damage. The nature of the nerve damage is varied, and can result from inflammation or compression. Nerve damage at the elbow can result from compression of the nerve when sensation is obliterated during general anesthesia. As well, a blow to the elbow or even too much leaning on the elbow can be damaging, as can diseases (rheumatoid arthritis) and metabolic disturbances (diabetes). Even malnutrition can be a factor, as protective fatty deposits and muscle mass waste away. Damage to the nerve at the wrist can be caused by a blow, tumors, and impinging of an artery.
The nerve damage that results in ulnar neuropathy can involve the main body of the nerve, the branching region at the end of the nerve known as the axon (which is involved in the movement of the nerve impulse to the adjacent nerve), and the protective myelin coating around the nerve. When the main body of the nerve is involved, the problem is usually a block in the passage of the impulse down the nerve. Axon damage typically decreases the movement of the nerve impulse away from the nerve or the wavelength of the impulse. As a result, the impulse may not reach the adjacent nerve, or may not be recognized by the receptors of that adjacent nerve. Finally, damage to the myelin sheath (demyelination) also impedes the movement of signal down the body of the nerve.
Depending on the site of the neuropathy and whether the neuropathy arises suddenly (acute) or has been present for a long time (chronic), various symptoms can arise. Acute and chronic ulnar neuropathy of the elbow is always associated with numbness and weakness. Pain is present almost 40% of the time in the acute form of the disorder and almost 80% of the time in the chronic disorder. When the ulnar neuropathy involves the wrist, weakness is ever-present in a main muscle controlling wrist movement, generalized weakness in the absence of pain in 50% of those afflicted, and finger numbness occurs in about 25% of cases.
Other physical signs include the adoption of a clawed shape by the hand and the inability of the entire thumb to move to the forefinger in a single motion.
Typically, the development of weakness in the elbow or wrist is the sign that alerts aclinician to the possibility of ulnar neuropathy. Follow-up tests can include ultrasound or magnetic resonance imaging to visualize cysts or structural abnormalities. The functioning of the nerve can be assessed in a nerve conduction EMG/NCS test. Laboratory analyses of blood can be done to detect the presence of diabetes or infections that can damage nerves (such as Lyme disease, human immunodeficiencyvirus, or hepatitis viruses).
3. Diabetic Neuropathies:
What are diabetic neuropathies?
Diabetic neuropathies are a family of nerve disorders caused by diabetes. People with diabetes can, over time, develop nerve damage throughout the body. Some people with nerve damage have no symptoms. Others may have symptoms such as pain, tingling, or numbness—loss of feeling—in the hands, arms, feet, and legs. Nerve problems can occur in every organ system, including the digestive tract, heart, and sex organs.
About 60 to 70 percent of people with diabetes have some form of neuropathy. People with diabetes can develop nerve problems at any time, but risk rises with age and longer duration of diabetes. The highest rates of neuropathy are among people who have had diabetes for at least 25 years. Diabetic neuropathies also appear to be more common in people who have problems controlling their blood glucose, also called blood sugar, as well as those with high levels of blood fat and blood pressure and those who are overweight.
What causes diabetic neuropathies?
The causes are probably different for different types of diabetic neuropathy. Researchers are studying how prolonged exposure to high blood glucose causes nerve damage. Nerve damage is likely due to a combination of factors:
- metabolic factors, such as high blood glucose, long duration of diabetes, abnormal blood fat levels, and possibly low levels of insulin
- neurovascular factors, leading to damage to the blood vessels that carry oxygen and nutrients to nerves
- autoimmune factors that cause inflammation in nerves
- mechanical injury to nerves, such as carpal tunnel syndrome
- inherited traits that increase susceptibility to nerve disease
- lifestyle factors, such as smoking or alcohol use
What are the symptoms of diabetic neuropathies?
Symptoms depend on the type of neuropathy and which nerves are affected. Some people with nerve damage have no symptoms at all. For others, the first symptom is often numbness, tingling, or pain in the feet. Symptoms are often minor at first, and because most nerve damage occurs over several years, mild cases may go unnoticed for a long time. Symptoms can involve the sensory, motor, and autonomic—or involuntary—nervous systems. In some people, mainly those with focal neuropathy, the onset of pain may be sudden and severe.
Symptoms of nerve damage may include
- numbness, tingling, or pain in the toes, feet, legs, hands, arms, and fingers
- wasting of the muscles of the feet or hands
- indigestion, nausea, or vomiting
- diarrhea or constipation
- dizziness or faintness due to a drop in blood pressure after standing or sitting up
- problems with urination
- erectile dysfunction in men or vaginal dryness in women
Symptoms that are not due to neuropathy, but often accompany it, include weight loss and depression.
What are the types of diabetic neuropathy?
Diabetic neuropathy can be classified as peripheral, autonomic, proximal, or focal. Each affects different parts of the body in various ways.
- Peripheral neuropathy, the most common type of diabetic neuropathy, causes pain or loss of feeling in the toes, feet, legs, hands, and arms.
- Autonomic neuropathy causes changes in digestion, bowel and bladder function, sexual response, and perspiration. It can also affect the nerves that serve the heart and control blood pressure, as well as nerves in the lungs and eyes. Autonomic neuropathy can also cause hypoglycemia unawareness, a condition in which people no longer experience the warning symptoms of low blood glucose levels.
- Proximal neuropathy causes pain in the thighs, hips, or buttocks and leads to weakness in the legs.
Focal neuropathy results in the sudden weakness of one nerve or a group of nerves, causing muscle weakness or pain. Any nerve in the body can be affected. Neuropathy Affects Nerves Throughout the Body
Peripheral neuropathy affects
Autonomic neuropathy affects
- heart and blood vessels
- digestive system
- urinary tract
- sex organs
- sweat glands
Proximal neuropathy affects
Focal neuropathy affects
- facial muscles
- pelvis and lower back
What is peripheral neuropathy?
Peripheral neuropathy, also called distal symmetric neuropathy or sensorimotor neuropathy, is nerve damage in the arms and legs. Your feet and legs are likely to be affected before your hands and arms. Many people with diabetes have signs of neuropathy that a doctor could note but feel no symptoms themselves. Symptoms of peripheral neuropathy may include
- numbness or insensitivity to pain or temperature
- a tingling, burning, or prickling sensation
- sharp pains or cramps
- extreme sensitivity to touch, even light touch
- loss of balance and coordination
These symptoms are often worse at night.
Peripheral neuropathy affects the nerves in your toes, feet, legs, hands, and arms.
Peripheral neuropathy may also cause muscle weakness and loss of reflexes, especially at the ankle, leading to changes in the way a person walks. Foot deformities, such as hammertoes and the collapse of the midfoot, may occur. Blisters and sores may appear on numb areas of the foot because pressure or injury goes unnoticed. If foot injuries are not treated promptly, the infection may spread to the bone, and the foot may then have to be amputated. Some experts estimate that half of all such amputations are preventable if minor problems are caught and treated in time.
What is autonomic neuropathy?
Autonomic neuropathy affects the nerves that control the heart, regulate blood pressure, and control blood glucose levels. Autonomic neuropathy also affects other internal organs, causing problems with digestion, respiratory function, urination, sexual response, and vision. In addition, the system that restores blood glucose levels to normal after a hypoglycemic episode may be affected, resulting in loss of the warning symptoms of hypoglycemia.
Autonomic neuropathy affects the nerves in your heart, stomach, intestines, bladder, sex organs, sweat glands, eyes, and lungs.
Normally, symptoms such as shakiness, sweating, and palpitations occur when blood glucose levels drop below 70 mg/dL. In people with autonomic neuropathy, symptoms may not occur, making hypoglycemia difficult to recognize. Problems other than neuropathy can also cause hypoglycemia unawareness. For more information about hypoglycemia, see the fact sheet Hypoglycemia at
Heart and Blood Vessels
The heart and blood vessels are part of the cardiovascular system, which controls blood circulation. Damage to nerves in the cardiovascular system interferes with the body’s ability to adjust blood pressure and heart rate. As a result, blood pressure may drop sharply after sitting or standing, causing a person to feel light-headed or even to faint. Damage to the nerves that control heart rate can mean that your heart rate stays high, instead of rising and falling in response to normal body functions and physical activity.
Nerve damage to the digestive system most commonly causes constipation. Damage can also cause the stomach to empty too slowly, a condition called gastroparesis. Severe gastroparesis can lead to persistent nausea and vomiting, bloating, and loss of appetite. Gastroparesis can also make blood glucose levels fluctuate widely, due to abnormal food digestion
Nerve damage to the esophagus may make swallowing difficult, while nerve damage to the bowels can cause constipation alternating with frequent, uncontrolled diarrhea, especially at night. Problems with the digestive system can lead to weight loss.
Urinary Tract and Sex Organs
Autonomic neuropathy often affects the organs that control urination and sexual function. Nerve damage can prevent the bladder from emptying completely, allowing bacteria to grow in the bladder and kidneys and causing urinary tract infections. When the nerves of the bladder are damaged, urinary incontinence may result because a person may not be able to sense when the bladder is full or control the muscles that release urine.
Autonomic neuropathy can also gradually decrease sexual response in men and women, although the sex drive may be unchanged. A man may be unable to have erections or may reach sexual climax without ejaculating normally. A woman may have difficulty with arousal, lubrication, or orgasm.
For more information, see the fact sheets Nerve Disease and Bladder Control and Sexual and Urologic Problems of Diabetes at www.kidney.niddk.nih.gov.
Autonomic neuropathy can affect the nerves that control sweating. When nerve damage prevents the sweat glands from working properly, the body cannot regulate its temperature as it should. Nerve damage can also cause profuse sweating at night or while eating.
Finally, autonomic neuropathy can affect the pupils of the eyes, making them less responsive to changes in light. As a result, a person may not be able to see well when a light is turned on in a dark room or may have trouble driving at night.
What is proximal neuropathy?
Proximal neuropathy, sometimes called lumbosacral plexus neuropathy, femoral neuropathy, or diabetic amyotrophy, starts with pain in the thighs, hips, buttocks, or legs, usually on one side of the body. This type of neuropathy is more common in those with type 2 diabetes and in older adults with diabetes. Proximal neuropathy causes weakness in the legs and the inability to go from a sitting to a standing position without help. Treatment for weakness or pain is usually needed. The length of the recovery period varies, depending on the type of nerve damage.
What is focal neuropathy?
Focal neuropathy appears suddenly and affects specific nerves, most often in the head, torso, or leg. Focal neuropathy may cause
- inability to focus the eye
- double vision
- aching behind one eye
- paralysis on one side of the face, called Bell’s palsy
- severe pain in the lower back or pelvis
- pain in the front of a thigh
- pain in the chest, stomach, or side
- pain on the outside of the shin or inside of the foot
- chest or abdominal pain that is sometimes mistaken for heart disease, a heart attack, or appendicitis
Focal neuropathy is painful and unpredictable and occurs most often in older adults with diabetes. However, it tends to improve by itself over weeks or months and does not cause long-term damage.
People with diabetes also tend to develop nerve compressions, also called entrapment syndromes. One of the most common is carpal tunnel syndrome, which causes numbness and tingling of the hand and sometimes muscle weakness or pain. Other nerves susceptible to entrapment may cause pain on the outside of the shin or the inside of the foot.
How can I prevent diabetic neuropathies?
The best way to prevent neuropathy is to keep your blood glucose levels as close to the normal range as possible. Maintaining safe blood glucose levels protects nerves throughout your body.
For additional information about preventing diabetes complications, including neuropathy, see the Prevent Diabetes Problems Series atwww.diabetes.niddk.nih.gov/dm/pubs/complications.
How are diabetic neuropathies diagnosed?
Doctors diagnose neuropathy on the basis of symptoms and a physical exam. During the exam, your doctor may check blood pressure, heart rate, muscle strength, reflexes, and sensitivity to position changes, vibration, temperature, or light touch.
Experts recommend that people with diabetes have a comprehensive foot exam each year to check for peripheral neuropathy. People diagnosed with peripheral neuropathy need more frequent foot exams. A comprehensive foot exam assesses the skin, muscles, bones, circulation, and sensation of the feet. Your doctor may assess protective sensation or feeling in your feet by touching your foot with a nylon monofilament—similar to a bristle on a hairbrush—attached to a wand or by pricking your foot with a pin. People who cannot sense pressure from a pinprick or monofilament have lost protective sensation and are at risk for developing foot sores that may not heal properly. The doctor may also check temperature perception or use a tuning fork, which is more sensitive than touch pressure, to assess vibration perception.
The doctor may perform other tests as part of your diagnosis.
- Nerve conduction studies or electromyography are sometimes used to help determine the type and extent of nerve damage. Nerve conduction studies check the transmission of electrical current through a nerve. Electromyography shows how well muscles respond to electrical signals transmitted by nearby nerves. These tests are rarely needed to diagnose neuropathy.
- A check of heart rate variability shows how the heart responds to deep breathing and to changes in blood pressure and posture.
- Ultrasound uses sound waves to produce an image of internal organs. An ultrasound of the bladder and other parts of the urinary tract, for example, can show how these organs preserve a normal structure and whether the bladder empties completely after urination.
How are diabetic neuropathies treated?
The first treatment step is to bring blood glucose levels within the normal range to help prevent further nerve damage. Blood glucose monitoring, meal planning, physical activity, and diabetes medicines or insulin will help control blood glucose levels. Symptoms may get worse when blood glucose is first brought under control, but over time, maintaining lower blood glucose levels helps lessen symptoms. Good blood glucose control may also help prevent or delay the onset of further problems. As scientists learn more about the underlying causes of neuropathy, new treatments may become available to help slow, prevent, or even reverse nerve damage.
As described in the following sections, additional treatment depends on the type of nerve problem and symptom. If you have problems with your feet, your doctor may refer you to a foot care specialist.
Doctors usually treat painful diabetic neuropathy with oral medications, although other types of treatments may help some people. People with severe nerve pain may benefit from a combination of medications or treatments. Talk with your health care provider about options for treating your neuropathy.
Medications used to help relieve diabetic nerve pain include
- tricyclic antidepressants, such as amitriptyline, imipramine, and desipramine (Norpramin, Pertofrane)
- other types of antidepressants, such as duloxetine (Cymbalta), venlafaxine, bupropion (Wellbutrin), paroxetine (Paxil), and citalopram (Celexa)
- anticonvulsants, such as pregabalin (Lyrica), gabapentin (Gabarone, Neurontin), carbamazepine, and lamotrigine (Lamictal)
- opioids and opioid-like drugs, such as controlled-release oxycodone, an opioid; and tramadol (Ultram), an opioid that also acts as an antidepressant
Duloxetine and pregabalin are approved by the U.S. Food and Drug Administration specifically for treating painful diabetic peripheral neuropathy.
You do not have to be depressed for an antidepressant to help relieve your nerve pain. All medications have side effects, and some are not recommended for use in older adults or those with heart disease. Because over-the-counter pain medicines such as acetaminophen and ibuprofen may not work well for treating most nerve pain and can have serious side effects, some experts recommend avoiding these medications.
Treatments that are applied to the skin—typically to the feet—include capsaicin cream and lidocaine patches (Lidoderm, Lidopain). Studies suggest that nitrate sprays or patches for the feet may relieve pain. Studies of alpha-lipoic acid, an antioxidant, and evening primrose oil have shown that they can help relieve symptoms and may improve nerve function.
A device called a bed cradle can keep sheets and blankets from touching sensitive feet and legs. Acupuncture, biofeedback, or physical therapy may help relieve pain in some people. Treatments that involve electrical nerve stimulation, magnetic therapy, and laser or light therapy may be helpful but need further study. Researchers are also studying several new therapies in clinical trials.
To relieve mild symptoms of gastroparesis—indigestion, belching, nausea, or vomiting—doctors suggest eating small, frequent meals; avoiding fats; and eating less fiber. When symptoms are severe, doctors may prescribe erythromycin to speed digestion, metoclopramide to speed digestion and help relieve nausea, or other medications to help regulate digestion or reduce stomach acid secretion.
To relieve diarrhea or other bowel problems, doctors may prescribe an antibiotic such as tetracycline, or other medications as appropriate.
Dizziness and Weakness
Sitting or standing slowly may help prevent the light-headedness, dizziness, or fainting associated with blood pressure and circulation problems. Raising the head of the bed or wearing elastic stockings may also help. Some people benefit from increased salt in the diet and treatment with salt-retaining hormones. Others benefit from high blood pressure medications. Physical therapy can help when muscle weakness or loss of coordination is a problem.
Urinary and Sexual Problems
To clear up a urinary tract infection, the doctor will probably prescribe an antibiotic. Drinking plenty of fluids will help prevent another infection. People who have incontinence should try to urinate at regular intervals—every 3 hours, for example—since they may not be able to tell when the bladder is full.
To treat erectile dysfunction in men, the doctor will first do tests to rule out a hormonal cause. Several methods are available to treat erectile dysfunction caused by neuropathy. Medicines are available to help men have and maintain erections by increasing blood flow to the penis. Some are oral medications and others are injected into the penis or inserted into the urethra at the tip of the penis. Mechanical vacuum devices can also increase blood flow to the penis. Another option is to surgically implant an inflatable or semirigid device in the penis.
Vaginal lubricants may be useful for women when neuropathy causes vaginal dryness. To treat problems with arousal and orgasm, the doctor may refer women to a gynecologist.
People with neuropathy need to take special care of their feet. The nerves to the feet are the longest in the body and are the ones most often affected by neuropathy. Loss of sensation in the feet means that sores or injuries may not be noticed and may become ulcerated or infected. Circulation problems also increase the risk of foot ulcers.
More than half of all lower-limb amputations in the United States occur in people with diabetes—86,000 amputations per year. Doctors estimate that nearly half of the amputations caused by neuropathy and poor circulation could have been prevented by careful foot care.
Follow these steps to take care of your feet:
- Clean your feet daily, using warm—not hot—water and a mild soap. Avoid soaking your feet. Dry them with a soft towel and dry carefully between your toes.
- Inspect your feet and toes every day for cuts, blisters, redness, swelling, calluses, or other problems. Use a mirror—laying a mirror on the floor works well—or get help from someone else if you cannot see the bottoms of your feet. Notify your health care provider of any problems.
- Moisturize your feet with lotion, but avoid getting the lotion between your toes.
- After a bath or shower, file corns and calluses gently with a pumice stone.
- Each week or when needed, cut your toenails to the shape of your toes and file the edges with an emery board.
- Always wear shoes or slippers to protect your feet from injuries. Prevent skin irritation by wearing thick, soft, seamless socks.
- Wear shoes that fit well and allow your toes to move. Break in new shoes gradually by first wearing them for only an hour at a time.
- Before putting your shoes on, look them over carefully and feel the insides with your hand to make sure they have no tears, sharp edges, or objects in them that might injure your feet.
- If you need help taking care of your feet, make an appointment to see a foot doctor, also called a podiatrist.