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February 10, 2012

Electromyogram (EMG) Glossary of Terms

The following are health and medical definitions of terms that appear in the Electromyogram (EMG) article.

Abnormal: Not normal. Deviating from the usual structure, position, condition, or behavior. In referring to a growth, abnormal may mean that it is cancerous or premalignant (likely to become cancer).

Arms: An appendage in anatomy and in clinical trials. See: Arm.

Carpal tunnel syndrome: A type of compression neuropathy (nerve damage) caused by compression and irritation of the median nerve in the wrist. The nerve is compressed within the carpal tunnel, a bony canal in the palm side of the wrist that provides passage for the median nerve to the hand. The irritation of the median nerve is specifically due to pressure from the transverse carpal ligament.
See the entire definition of Carpal tunnel syndrome

Disc: Shortened terminology for an intervertebral disc, a disk-shaped piece of specialized tissue that separates the bones of the spinal column.
See the entire definition of Disc

Electrocardiogram: A recording of the electrical activity of the heart. An electrocardiogram is a simple, non-invasive procedure. Electrodes are placed on the skin of the chest and connected in a specific order to a machine that, when turned on, measures electrical activity all overaround the heart. Output is usually in the form of a long scroll of paper displaying a printed graph of activity. Newer models output the data directly to a computer and screen, although a print-out may still be made.
See the entire definition of Electrocardiogram

Electromyogram: A test used to record the electrical activity of muscles. When muscles are active, they produce an electrical current that is usually proportional to the level of muscle activity. An electromyogram (EMG) is also called a myogram.
See the entire definition of Electromyogram

Fiber: The parts of plants that cannot be digested, namely complex carbohydrates. Also known as bulk or roughage.
See the entire definition of Fiber

Herniation: Abnormal protrusion of tissue through an opening. For example, a intervertebral disk (one situated between the vertebral bodies) can protrude and impinge on a nerve root.

Inflammation: A basic way in which the body reacts to infection, irritation or other injury, the key feature being redness, warmth, swelling and pain. Inflammation is now recognized as a type of nonspecific immune response.
See the entire definition of Inflammation

Injury: Harm or hurt. The term "injury" may be applied in medicine to damage inflicted upon oneself as in a hamstring injury or by an external agent on as in a cold injury. The injury may be accidental or deliberate, as with a needlestick injury. The term "injury" may be synonymous (depending on the context) with a wound or with trauma.

Isolate: A group in which mating is always between members of the group. For example, the Amish.

Lateral: 1. In anatomy, the side of the body or a body part that is farther from the middle or center of the body. Typically, lateral refers to the outer side of the body part, but it is also used to refer to the side of a body part. For example, when referring to the knee, lateral refers to the side of the knee farthest from the opposite knee. The opposite of lateral is medial.
2. In radiology, slang for a lateral X-ray.
See the entire definition of Lateral

Leg: In popular usage, the leg extends from the top of the thigh down to the foot. However, in medical terminology, the leg refers to the portion of the lower extremity from the knee to the ankle.
See the entire definition of Leg

Muscle: Muscle is the tissue of the body which primarily functions as a source of power. There are three types of muscle in the body. Muscle which is responsible for moving extremities and external areas of the body is called "skeletal muscle." Heart muscle is called "cardiac muscle." Muscle that is in the walls of arteries and bowel is called "smooth muscle."

Muscular: Having to do with the muscles. Also, endowed with above average muscle development. Muscular system refers to all of the muscles of the body collectively.

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Muscular dystrophy: One of a group of genetic diseases characterized by progressive weakness and degeneration of the skeletal or voluntary muscles which control movement. The muscles of the heart and some other involuntary muscles are also affected in some forms of muscular dystrophy, and a few forms involve other organs as well.
See the entire definition of Muscular dystrophy

Myasthenia gravis: An autoimmune neuromuscular disorder characterized by fatigue and exhaustion of muscles. Myasthenia gravis is caused by a mistaken immune response to the nicotinic acetylcholine receptors (AChR), which are found in junctions between muscles and the nervous system. The body produces antibodies that attack these AChR receptors, preventing signals from reaching the muscles. Proof that the anti-AChR antibodies are responsible for myasthenia comes from the effect these antibodies can have on the unborn and the newborn.
See the entire definition of Myasthenia gravis

Nerve: A bundle of fibers that uses chemical and electrical signals to transmit sensory and motor information from one body part to another. See: Nervous system.

Neuropathy: Any and all disease or malfunction of the nerves.

Pain: An unpleasant sensation that can range from mild, localized discomfort to agony. Pain has both physical and emotional components. The physical part of pain results from nerve stimulation. Pain may be contained to a discrete area, as in an injury, or it can be more diffuse, as in disorders like fibromyalgia. Pain is mediated by specific nerve fibers that carry the pain impulses to the brain where their conscious appreciation may be modified by many factors.
See the entire definition of Pain

Peripheral: Situated away from the center, as opposed to centrally located.
See the entire definition of Peripheral

Sclerosis: Localized hardening of skin.

Skeletal: Pertaining to the skeleton, the bones of the body which collectively provide the framework for the body.

Sore: 1. (adjective) A popular term for painful. I have sore fingers from typing dictionary terms. She has a sore throat. 2. (noun) A nondescript term for nearly any lesion of the skin or mucous membranes. He has a number of sores in his mouth.

See the entire definition of Sore

Syndrome: A set of signs and symptoms that tend to occur together and which reflect the presence of a particular disease or an increased chance of developing a particular disease.
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  • Related Diseases & Conditions

    • Sciatica
      • Sciatica pain, caused by irritation of the sciatic nerve, typically radiates from the low back to behind the thigh to below the knee. Disc herniation is usually the cause of sciatica. Medication to alleviate pain, physical therapy, and bed rest are treatments for sciatica.
    • Lower Back Pain
      • There are many causes of back pain. Pain in the low back can relate to the bony lumbar spine, discs between the vertebrae, ligaments around the spine and discs, spinal cord and nerves, muscles of the low back, internal organs of the pelvis and abdomen, and the skin covering the lumbar area.
    • Pinched Nerve
      • A pinched nerve can be caused of a variety of conditions, for example, carpal tunnel syndrome, herniated disc, sciatica, arthritis, spinal stenosis, trauma, and more. Common symptoms of a pinched nerve include pain, numbness, tingling, and weakness. Treatment of a pinched nerve depends on the cause of the pinched nerve.
    • Muscle Spasms
      • Muscle spasms are involuntary muscle contractions that come on suddenly and are usually quite painful. Dehydration, doing strenuous exercise in a hot environment, prolonged muscle use, and certain diseases of the nervous system may cause muscle spasms. Symptoms and signs of a muscle spasm include an acute onset of pain and a possible bulge seen or felt beneath the skin where the muscle is located. Gently stretching the muscle usually resolves a muscle spasm.
    • Neck Pain
      • Neck pain (cervical pain) may be caused by any number of disorders and diseases. Tenderness is another symptom of neck pain. Though treatment for neck pain really depends upon the cause, treatment typically may involve heat/ice application, traction, physical therapy, cortisone injection, topical anesthetic creams, and muscle relaxants.
    • Carpal Tunnel Syndrome And Tarsal Tunnel Syndrome
      • Carpal tunnel syndrome is a condition in which irritation of the wrist's median nerve causes tingling and numbness of the thumb, index, and the middle fingers. This condition is known as tarsal tunnel syndrome in the ankles and feet. Treatment of carpal tunnel syndrome depends on the severity of the symptoms and the nature of any disease that might be causing the symptoms.
    • Herniated Disc
      • A herniated disc may be caused by injury or degeneration from age. Symptoms depend on the location of the herniation and whether nerve tissue is being irritated. An MRI or CT scan is performed to diagnose a herniated disc. Treatment may involve physical therapy, cortisone injection, pain medications, antiinflammatory medications, muscle relaxants, and surgery.
    • Myasthenia Gravis
      • Myasthenia gravis, a chronic autoimmune neuromuscular disease. Varying degrees of weakness of the voluntary muscles of the body are the main characteristics. A defect in the transmission of nerve impulses ot the muscles is the cause of myasthenia gravis. Symptoms include weakness of th eye muscles, facial expression, and difficulty swallowing. Treatment of myasthenia gravis are medical therapies to control the symptoms of the disease.
    • Degenerative Disc Disease & Sciatica
      • Degenerative disc disease makes the disc more susceptible to herniation (rupture) which can lead to localized or radiating pain. The pain from degenerative disc or joint disease of the spine is usually treated conservatively with intermittent heat, rest, rehabilitative exercises and medications to relieve pain, muscle spasm and inflammation.
    • Botulism
      • Botulism is an illness caused by a neurotoxin produced by the bacterium Clostridium botulinum. There are three types of botulism: food-borne, wound, and infant. Symptoms include muscle paralysis, dry mouth, constipation, slurred speech, and blurred vision. If food-borne and wound botulism are detected early enough, they may be treated with an antitoxin. Infant botulism is treated intravenously with BabyBIG (Botulism Immune Globulin).
    • Radiculopathy
      • Radiculopathy, a condition in which a nerve or nerves along the spine are compressed causing pain, numbness, weakenss, and tingling along the nerve(s). Some causes of radiculopathy include bone spurs, disc hernation, osteoarthritis, tumors, infection, and neuropathy. Treatment depends on the are of nerve compression. Surgery is generally not required.
    • Polymyositis
      • Polymyositis is a disease of the muscle featuring inflammation of the muscle fibers. It results in weakness of the muscles which can be severe and when associated with skin rash, is referred to as dermatomyositis. Although the cause of this disease is unknown, diagnosis includes physical examination of muscle strength, blood tests for muscle enzymes, electrical tests of muscle and nerves, and conformation by a muscle biopsy. Treatment of Polymyositis and Dermatomyositis includes high doses of cortisone-related medications, immune suppression, and physical therapy.
    • Thoracic Outlet Syndrome
      • Thoracic Outlet Syndrome is a condition where symptoms are produced from compression of nerves or blood vessels because the passageway through the neck and armpit is inadequate. Symptoms of thoracic outlet syndrome include neck, shoulder and arm pain, and numbness or impaired circulation to the extremities.
    • Urinary Incontinence
      • There are many types of urinary incontinence (UI), which is the accidental leakage of urine. These types include stress incontinence, urge incontinence, and overflow incontinence. Urinary incontinence in men may be caused by prostate or nerve problems. Treatment depends upon the type and severity of the UI and the patient's lifestyle.
    • Amyotrophic Lateral Sclerosis (ALS)
      • Amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease) is a neurological disease that progresses rapidly. The disease attacks the nerve cells responsible for the control of voluntary muscles. Early symptoms include cramping, twitching, or stiffness of the muscles; slurred nasal speech; difficulty swallowing or chewing, and muscle weakness in an arm or leg. Currently, the cause of ALS is not known. ALS is a fatal disease. No cure has been found for ALS, however, the drug riluzole (Rilutek) is FDA approved, and this drug reduces the damage to motor neurons by decreasing the release of glutamate.
    • Dystonia
      • Dystonia disorders cause involuntary movements and prolonged muscle contraction, resulting in twisting body motions, tremor, and abnormal posture. There are many forms of dystonia. Some types of dystonia respond to dopamine, or can be controlled with dedative-type medications, or surgery.
    • Cauda Equina Syndrome
      • Cauda equina syndrome is a medical emergency condition that is caused by the uncommon compression of the nerves at the end of the spinal cord. Symptoms of cauda equina syndrome include lower back pain, tingling and/or numbness in the buttocks and lower extremities, bowel or bladder incontinence, and weakness in the legs. Causes of cauda equina syndrome include herniated discs, hematomas, or infection. Treatment is generally prompt surgery.
    • Charcot-Marie-Tooth-Disease
      • Charcot-Marie-Tooth disease is one of the most common inherited neurological disorders. Charcot-Marie-Tooth disease affects the peripheral nerves. Symptoms include weakness of the lower leg muscles and foot, foot drop, foot deformities, etc. There are several forms of Charcot-Marie-Tooth disease. Inherited gene mutations are the cause of Charcot-Marie-Tooth disease. There is no cure for Charcot-Marie-Tooth disease; however, therapeutical measures and mild exercise may help symptoms.
    • Nerve Disease and Bladder Control
      • A nerve problem might affect your bladder control if the nerves that are supposed to carry messages between the brain and the bladder do not work properly. Such problems include urine retention, poor control of sphincter muscles, and overactive bladder. Treatment depends upon the cause of the nerve damage and resulting type of bladder control problem.
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Electromyogram (EMG)

What are the dystonias?

The dystonias are movement disorders in which sustained muscle contractions cause twisting and repetitive movements or abnormal postures. The movements, which are involuntary and sometimes painful, may affect a single muscle; a group of muscles such as those in the arms, legs, or neck; or the entire body. Those with dystonia usually have normal intelligence and no associated psychiatric disorders.

What are the symptoms of dystonias?

Dystonia can affect many different parts of the body. Early symptoms may include a deterioration in handwriting after writing several lines, foot cramps, and/or a tendency of one foot to pull up or drag; this may occur "out of the blue" or may occur after running or walking some distance. The neck may turn or pull involuntarily, especially when the patient is tired or stressed. Sometimes both eyes will blink rapidly and uncontrollably, rendering a person functionally blind. Other po...

Read the Dystonia article »







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