Arthritis Glossary – I, J, L, M, N, & O

Idiopathic scoliosis

A type of scoliosis that has no specific identifiable cause. Scoliosis is a condition causing a lateral (toward the side) curvature in the normally straight vertical line of the spine. Idiopathic scoliosis is the most common type of scoliosis.

Immune system

The body’s defense system against diseases

Impingement syndrome

A common condition of the shoulder often seen in aging adults. It typically results in difficulty reaching up behind the back, pain with overhead use of the arm, and weakness of shoulder muscles. It may be a precursor to rotator cuff tear.

Imuran

An immunosuppressive drug originally used to prevent graft rejection in patients receiving kidney transplants. Imuran also is used to suppress the abnormal immune response in some patients with vasculitis, systemic lupus erythematosus, and rheumatoid arthritis.

Inflammation

A process by which the body's white blood cells and chemicals protect the body against infection and foreign substances such as bacteria and viruses. Inflammation is characterized by redness, warmth, swelling, and pain.

Informed consent

A process in which a patient is given all available information necessary to understand the risks and benefits of proposed treatments. He or she can then give or withhold informed consent.

Intravenous

Through a vein, a route by which medications can be given

Isometrics

A group of exercises that help strengthen muscles without bending painful joints. Isometrics strengthen muscle groups by using an alternating series of isolated muscle flexes and periods of relaxation.

Isotonics

A group of exercises that involve joint mobility. Isotonic exercises achieve strength development through increased repetitions or by introducing light resistance with small dumbbells or stretch bands.

Joint

The area where two bones meet. All synovial joints have a cavity containing a small amount of synovial fluid that allows for movement.

Joint aspiration

The removal of some fluid from a joint to examine under a microscope, or subject to other testing such as culture, protein determination, etc.

Joint replacement surgery

A surgical procedure in which natural joints are replaced with synthetic ones to restore function in the affected area

Lumbar sympathetic block

An injection (shot) of numbing medication placed in the nerve tissue in the lumbar, or lower, back to provide pain relief

Lupus (systemic lupus erythematosus)

A disease in which the immune system inappropriately attacks tissues in various parts of the body, leading to tissue damage and illness

Lyme disease

A specific bacterial infection transmitted by a tick. Lyme disease can cause arthritic problems, as well as heart, brain, and nerve complications.

Magnetic resonance imaging (MRI)

A test that produces images of the human body without the use of X-rays. MRI uses a large magnet, electromagnetic energy waves, and a computer to produce these images.

Methotrexate (Rheumatrex)

A chemotherapy drug that sometimes is used to treat autoimmune disorders.

Methylsulfonylmethane (MSM)

A naturally occurring sulfur-containing chemical that is taken as a dietary supplement. Some people take MSM for arthritis, but there is little medical evidence showing its benefits.

Myositis

Inflammation of muscle

Neurotransmitters

Body chemicals that cause nerve impulses between nerve fibers

Nonsteroidal anti-inflammatory drugs (NSAIDs)

Medicines that reduce inflammation and relieve pain. Inflammation is the body's response to irritation or injury, and is characterized by redness, warmth, swelling, and pain. NSAIDs work by blocking the production of certain chemicals in the body that cause inflammation.

Neuromuscular scoliosis

A type of scoliosis that is a result of abnormal muscles or nerves. It frequently is seen in people with spina bifida or cerebral palsy, or those with various conditions that are accompanied by, or result in, paralysis. Scoliosis is a condition causing a lateral (toward the side) curvature in the normally straight vertical line of the spine.

Neutropenia

A low white blood cell count. This condition may cause decreased resistance to infection. Also called leukopenia.

Occlusion

A blockage, as of a blood vessel

Occupational therapy

A form of therapy that teaches how to reduce strain on joints while doing everyday activities. Also can recommend and show the patient how to use assistive devices, suggest ways to make everyday and work activities easier, and teach how to reduce strain on joints and conserve energy.

Osteoarthritis

The most common type of arthritis. It is associated with a breakdown of cartilage in joints and can occur in almost any joint in the body. It most commonly occurs in the fingers, hips, knees, and spine. Osteoarthritis also is called degenerative joint disease.