A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Acute: Short duration of effect. It often refers to symptoms, which can appear or resolve suddenly.
Acute myelitis: An acute (short in duration) inflammation of the spinal cord. Along with optic neuritis (inflammation of the optic nerve), acute myelitis is one of the main symptoms of neuromyelitis optica (aka Devic’s disease).
Adaptive immunity: Involves cells that respond to specific antigens. T cells, B cells, and antibodies are part of adaptive immunity.
Adherence to therapy: Taking medications in the prescribed dose and at the correct time.
Akinesia: The inability to move, also called freezing. It can occur in people with Parkinson’s disease.
Alzheimer’s disease: A condition where the brain develops abnormal protein deposits and tissues, which leads to problems with memory and thought processes.
Americans With Disabilities Act: US law that prohibits discrimination against people with disabilities and requires reasonable accommodations for them. This applies to the fields of employment, government, and public and commercial facilities.
Antibodies: The proteins produced by B cells in response to an infection or vaccine. Also called immunoglobulins, antibodies bind to specific antigens.
Antigen: The term for a substance or molecule recognized by the immune system—either from a pathogen such as a virus or, in error, from the body’s own cells (“self”). In MS, the myelin that surrounds nerves is mistaken as an antigen.
Aquaporin-4: A protein that is expressed in astrocytes (cells that support the body’s blood brain barrier). Aquaporin-4 is responsible for maintaining a critical balance of water within and outside the astrocytes. Aquaporin-4 is implicated in the disease process of neuromyelitis optica.
Assistive devices: Tools designed or adapted to help people perform a particular task, such as walking, buttoning a shirt, or picking up food.
Aura: A sensory disturbance that may precede a neurological episode, such as a migraine; also called a prodrome. It may consist of visual disturbances or hallucinatory sounds, odors, tastes, or touch sensations.
Autoantibody: An antibody (a type of protein) manufactured by the immune system that targets one or more of an individual's own proteins. Many autoimmune diseases (such as MS and neuromyelitis optica) are caused by autoantibodies.
Autoimmune disease: A disease that results from the body’s reaction to itself, instead of to infection. Examples include lupus, multiple sclerosis, and rheumatoid arthritis.
Autoimmunity: A condition in which the body’s immune system malfunctions and attacks the body's own cells and tissues. It is the basis of the disease process in MS as well as other diseases.
Axons: The long, slender part of a nerve cell (or neuron) that transmits impulses from the body of the nerve. Axonal damage caused by MS is now known to occur early in the disease process, along with loss of the myelin covering of the axon.
B cells: Cells that produce antibodies to attack foreign substances in the body.
Bilateral: Involving both sides. Neuromyelitis optica (aka Devic’s disease) often presents with bilateral optic neuritis; that is, inflammation in the optic nerves of both eyes.
Binding antibodies: Molecules (antibodies) that attach to a foreign substance (antigen) in an effort to neutralize the effect of the antigen.
Bioequivalence: Bioequivalent means that a biosimilar drug releases its active ingredient into the blood at virtually the same rate and in virtually the same amount as the original drug it is modeled after. In order to be considered bioequivalent, a drug cannot just be demonstrated as safe and effective, it must also affect the body in a similar manner, over a similar period of time, as its branded counterpart.
Biologic: Biologic drugs are derived, not from chemicals, but from a living system or organism. The molecules that make up a biologic drug are much larger and more complicated in shape—typically a protein made up of hundreds of amino acids—than those that make up a chemical drug. This complexity of structure has several implications. First, biologics cannot be analyzed for their effectiveness in the same way as chemical drugs, by studying their individual components. Biologics must be carefully tested in the human body to monitor for an immune response to these large foreign molecules. Also because of their size, biologics cannot be administered in pill form, but must usually be administered by injection.
Biologics Price Competition and Innovations Act (or Biosimilars Act): The Biosimilars Act is part of the Patient Protection and Affordable Care Act, which was passed as part of the healthcare reform bill. The purpose of the Biosimilars Act is manifold. It creates a pathway for the approval of biosimilar drugs, but also creates and preserves incentives for the development of novel biologic therapies.
Biomarkers: Characteristics that indicate a normal biological process, a disease, or a specific response to a drug.
Biosimilars: Biosimilar is a term used to refer to the generic version of a biologic drug. Like other generic drugs, biosimilars may only be developed once the patent has expired on their biologic counterparts. As for all generic drugs, manufacturers must prove that they are as safe and effective as their branded counterparts. Because biologics are far more complex than chemical drugs, the biosimilar may not be an identical copy of the original drug.
Black holes: Areas of irreversibly damaged tissue in the brain of patients with multiple sclerosis.
Blood-brain barrier: Protects the brain from the entry of many substances. In MS, it fails to keep out activated T cells.
Bradykinesia: The uncontrollable delay in initiating and then performing a movement. It can occur in people with Parkinson’s disease.
Brand-name drug: A brand-name drug is a drug that is sold under a trade name and is protected by a patent. For example, Tylenol® is a brand-name drug for acetaminophen.
Central lesion: A lesion found toward the center of the spinal cord on MRI scans. Central lesions are associated more often with neuromyelitis optica (aka Devic’s disease) than with MS.
Central nervous system: Portion of the body that includes that brain and spinal cord.
Cerebrospinal fluid (CSF): A clear bodily fluid that occupies parts of the central nervous system—in and around the spinal cord and the brain. CSF provides basic mechanical and immunological protection to the brain.
Clinical trial: An organized test put together to show if a treatment works. It usually is made up of patients who are divided into 2 groups: a test group and a control group. At the end of the trial, the groups are compared to see if there was any difference in their outcomes. A randomized clinical trial is when patients are randomly selected to be included in the trial. This is done so that as broad a group of patients as possible can participate.
Cognitive function: The process a person uses to think. Good cognitive function allows a person to transform a thought into an action. Examples of cognitive function are identifying situations, coordinating actions, making decisions, and planning. Sometimes people with MS experience a loss in cognitive function, either occasionally or on an ongoing basis.
Coinsurance: A percentage a person pays for a service is called a coinsurance. For example, a person may pay a 25% coinsurance for drugs under a standard Medicare Part D plan, and the plan pays 75%.
Co-payment: A flat, pre-set amount a person pays for a service is called a co-payment. For a prescription plan, a person may pay the same co-payment for any generic drug and another co-payment for any brand-name drug.
Corticosteroids: Drugs that can reduce inflammation. They work by blocking a chemical in the body called prostaglandin that causes inflammation.
Cytokines: Proteins manufactured by leukocytes that reduce inflammation in the body and aid healing.
Deductible: The money a person pays before the insurance plan starts to pay. In Medicare Part D, the 2006 deductible is no more than $250.
Deep brain stimulation: A surgical procedure that involves implanting a device into the brain that blocks the brain signals that cause tremor.
Demyelination: A process in which the myelin around nerve cells gets stripped away, leaving the nerve cell bare and susceptible to temporary and permanent damage.
Disease-modifying therapy: Targets harmful immune responses in MS. It can change the course of MS by slowing it down. Studies show that disease-modifying therapy is most helpful when taken early in the course of MS.
Dopamine: A substance in the brain that helps nerve cells signal one another and tell the body’s muscles what to do. In Parkinson’s disease, the body does not produce enough of it to keep the muscles working properly.
Dysarthria: Is difficulty in articulating words.
Dysesthesia: An impairment or distortion of any sense. MS-related dysesthesia is caused by abnormalities in the sensory pathways in the central nervous system (CNS). It produces sensations such as burning, prickling, and aching, and it may make a soft touch painful.
Dyskinesia: An impairment of normal movement that may include uncontrollable twitching, nodding, or jerking movement, usually of the limbs or head. It can occur in people with Parkinson’s disease.
Dysfunction: Body parts or body systems that either don’t function the way they should if they were healthy or have difficulty doing what they are supposed to do.
Embolism: Blockage of an artery by a blood clot that is carried to the site through the bloodstream. When a clot lodges in an artery of the brain or neck, it can cause ischemic stroke.
Estrogen: A female sex hormone that modulates immune system activity in a way that appears to quiet MS activity.
Evoked potential tests: Tests used in neurology to measure the brain’s electrical responses. Three kinds of tests used are visual (eyes), auditory (hearing), and somatosensory (spinal).
Exacerbation: Becoming more severe, especially with regard to symptoms. It is another word for Relapse.
Follow-on drugs: Follow-on drugs are very similar, but not identical, to existing drugs, which may be already on the market, known as “first-in-class drugs.” The term is sometimes used interchangeably with biosimilars but can also refer to chemical drugs that mimic the action of an already existing medication.
Foreign: Not from one’s own body; often introduced from the outside.
Generic drug: A generic drug is a drug that is chemically equivalent to a brand-name drug that has an expired patent. Generic drugs usually cost less than a brand-name drug and meet the same FDA standards of safety, purity, strength, and effectiveness.
Helper T cells: T cells that recognize foreign substances in the body and initiate a response against them.
Hemorrhagic stroke: A stroke that results from the bursting of a blood vessel that bleeds into the brain.
HIPAA: The Health Insurance Portability & Accountability Act of 1996, which includes privacy regulations that affect how medical information is handled and disclosed.
Hypesthesia: A neuropathic syndrome that produces numbness, or the absence of sensation. This condition can make hands and feet feel strange. It can also cause other body sensations.
Immunoglobulin (see Antibodies)
Immunomodulating drugs: Drugs that act on the body’s immune system to interfere with a disease process. They are also referred to as immunomodulatory drugs and immunomodulators.
Innate immunity: Is the first line of defense against a pathogen. Skin, tears, mucus, and macrophages are the major players in innate immunity.
"Innovator" prescription drugs: "Innovator" prescription drugs, also known as branded prescription drugs, are manufactured and sold by a specific pharmaceutical company under a "trade name," which may often be simpler or "catchier" than the generic name. These drugs are protected by a patent and cannot be produced or sold by any other company. They must also be reviewed and approved by the US Food and Drug Administration.
Intramuscular injection: Injection of a drug directly into a muscle.
Intention tremor: Occurs when a person makes a movement.
Ischemic stroke: A stroke that results from blockage in an artery supplying the brain.
Lassitude: Weakness characterized by a lack of interest, vitality, and energy. Its cause in MS is unknown. It doesn’t seem to be related to exertion or time of day, and sleep does not always help.
Leukocyte: A type of white blood cell that manufactures proteins to reduce inflammation in the body and aid healing.
Lipoatrophy: The loss of the fatty tissue under the skin.
Lymphocyte: A type of white blood cell. Both T cells and B cells are types of lymphocytes.
Macrophages: Immune cells that patrol the body for nonspecific invaders, engulfing them for destruction or for presentation to specialized immune cells.
Magnetic resonance imaging (MRI): A noninvasive test that uses powerful magnets and radio waves to create pictures of the inside of the body. MRI does not use x-rays; MRI imaging is based on the magnetic properties of atoms.
Medicaid: Government-funded healthcare coverage for US citizens who are not able to afford healthcare services.
Medicare: Government-funded healthcare coverage for US citizens aged 65 years and older.
Migraine: A type of recurring headache that lasts for hours or days, is characterized by throbbing or pulsing pain, worsens with physical activity, and is usually confined to one side of the head, although not always on the same side. The pain is usually accompanied by sensitivity to light and by nausea or even vomiting.
Molecular target: A biochemical feature of a cell or its surroundings that can be disrupted; this can potentially inhibit the autoimmune responses found in diseases such as MS and neuromyelitis optica.
Monophasic: Having a single phase, without recurrence or relapse.
Multiple sclerosis: An autoimmune disease of the central nervous system in which the body’s cells attack its own myelin, the coating of a part of healthy nerve cells.
Myelin: A fatty substance that coats the outside of axons (myelin sheath), structures of healthy nerve cells.
Neurologists: Physicians who specialize in the diagnosis and treatment of illnesses of the central nervous system.
Neuromyelitis optica (NMO): Also called Devic’s disease, NMO is an inflammatory disorder in which a person’s own immune system attacks the optic nerves and spinal cord, producing inflammation in the optic nerve (optic neuritis) and the spinal cord. Though often mistaken for MS, NMO and MS can be distinguished with a blood test.
Neutralizing antibodies (NAbs): A set of antibodies produced by the body's immune system as a reaction to some drugs that are made of protein.
Neutrophil: A type of white blood cell found in the body’s blood stream. Elevated levels of neutrophils in spinal fluid is associated with neuromyelitis optica (aka Devic’s disease).
NMO immunoglobulin G (NMO-IgG): A protein created by the immune system to target aquaporin-4 (a protein that is responsible for maintaining the integrity of the body’s blood brain barrier). NMO-IgG is often found in people with neuromyelitis optica (aka Devic’s disease), but is not found in people with MS.
Nystagmus: A rapid, involuntary movement of the eye. It is a type of tremor that people with MS may experience.
Oligoclonal bands (OBs): Bands of immunoglobulins (aka antibodies) that are seen when a patient’s cerebrospinal fluid is analyzed. The presence of OBs in cerebrospinal fluid is associated with MS.
On–off effect: The abrupt and unpredictable onset of symptoms that results from the wearing-off effect in levodopa-treated patients with Parkinson’s disease.
Ordinal: Refers to ranking of scores along a continuum based on the perceptions of the person taking the test. Numbers are assigned to indicate the relative extent to which a characteristic is experienced. The differences between scores are relative, and the same score doesn’t always mean exactly the same thing. The Expanded Disability Status Scale (EDSS) is an ordinal scale used in MS. There may be small differences between people with a score of 0.0 (normal neurological exam) and 1.0-1.5 (no disability, but some abnormal signs on exam). There may be large differences between people with a score of 2.0-5.5 (disability, but able to walk without assistance).
Paraplegia: Impairment in motor and/or sensory function of the lower extremities, such as the legs and the feet.
Paresthesia: An abnormal neuropathic pain sensation that feels like prickling, tingling, or pins and needles. In MS, it sometimes feels like abdominal tightness.
Parkinson’s disease: A disease caused by the brain’s inability to make enough dopamine. It is characterized by uncontrolled muscle actions.
Patent: A patent grants intellectual property rights to the inventor of a product. In field of pharmaceutics, the patent is frequently granted to a pharmaceutical company for the intellectual property rights to a specific drug or manufacturing process. A patent prevents other pharmaceutical companies from developing, manufacturing, or selling their own version of a drug for a period of time after the patent is granted. Once a patent has expired, however, those other companies may manufacture a generic version of the drug, although they cannot sell it under the branded name.
Pathogens: Anything that can cause disease. Common pathogens include bacteria, viruses, and parasites.
Patient registries: Patient registries are databases that keep track of patients with specific medical conditions, or who have undergone specific medical tests. These registries can contain a variety of secondary information about patients, including information about treatments and medical costs. Patient or disease registries are often compared to electronic medical records, but unlike electronic medical records, monitor only a subset of the patient population. An example of a registry of MS patients is North American Research Committee on Multiple Sclerosis (NARCOMS)/Global Patient Registry, which was developed by the Consortium of MS Centers.
Peripheral lesion: A lesion found toward the sides (and away from the center) of the spinal cord. Short peripheral lesions are associated more often with MS than with neuromyelitis optica (aka Devic’s disease).
Plaques: In Alzheimer’s disease, patches of built-up material in the brain that cause cognition problems.
Plasmapheresis (aka plasma exchange): A therapy that cleans the blood of antibodies by circulating the blood through a machine.
Postural tremor: Occurs when a person is erect and being supported by gravity (ie, during standing and/or sitting).
Premium: The money you pay to be part of an insurance plan. In Medicare Part D, this is usually a monthly fee.
Primary fatigue: A type of fatigue that is directly relatable to multiple sclerosis and that is not related to gender, age, level of physical disability, or the presence of a sleep disturbance.
Primary-progressive multiple sclerosis (PPMS): A type of multiple sclerosis characterized by progressive worsening of disease, with no relapses or periods of recovery.
Prion: An abnormally shaped protein in the central nervous system that causes a family of infectious diseases that affect the brain.
Prion diseases: A related group of illnesses (eg, bovine spongiform encephalopathy—“mad cow disease,” Creutzfeld-Jakob disease) of the central nervous system, caused by a prion, which causes changes in the brain’s tissue.
Progressive-relapsing multiple sclerosis (PRMS): A type of multiple sclerosis that is characterized by both progressive worsening of disease and acute relapses that may or may not be followed by periods of recovery. The disease continues to progress between relapses.
Pseudoexacerbation: A temporary aggravation of MS symptoms that may result from factors such as infection or hot weather. Unlike true exacerbations (relapses), pseudoexacerbations are unrelated to new disease activity, and they disappear once the cause is removed.
Pseudorelapse: A relapse in patients with multiple sclerosis that occurs in association with infection or fever. It is a transient effect that is caused by disturbed conduction of electrical impulses and that disappears when the infection or fever is controlled.
Rebound headache: A headache caused by the use of pain medication for headache for more than 2 days a week.
Relapse: The onset of new or recurrent symptoms; also called an attack or exacerbation. In multiple sclerosis, it refers to the onset of new neurological symptoms persisting at least 24 hours, or to the recurrence or worsening of symptoms persisting longer than 48 hours, after a period of stability of 1 month or longer.
Relapsing-remitting multiple sclerosis (RRMS): The form of multiple sclerosis where there is a period of time with symptoms (eg, vision problems, muscle weakness), which go away for a while, but then return; it can be either the same symptoms as before or new symptoms.
Rigidity: The inability of muscles to relax; stiffness. It can occur in people with Parkinson’s disease.
Sclerosis: A hardening of tissue. May be associated with a disease state and result from inflammation or an overgrowth in other tissue.
Secondary fatigue: A type of fatigue that is not directly related to multiple sclerosis and that may be caused by lack of exercise (called deconditioning) or increased energy requirements related to physical limitations, sleep disturbances, or side effects of medications.
Secondary-progressive multiple sclerosis (SPMS): A type of multiple sclerosis that is characterized by relapsing- remitting disease at the outset but progressively worsens. Occasional relapses and periods of mild recovery may occur.
Spasticity: Muscle stiffness.
Statins: A class of drugs that reduce cholesterol levels in the blood. They include Crestor (rosuvastatin), Lipitor (atorvastatin), lovastatin, Pravachol (pravastatin), and Zocor (simvastatin). Preliminary research indicates that statins may act as a disease-modifying therapy in MS, a possibility that is being tested in larger trials.
Stenosis: A narrowing of a vessel in the body. When occurring in an artery in the brain or neck, it can cause ischemic stroke.
Subcutaneous injection: Injection of a drug just under the skin.
Substantia nigra: The part of the brain, dark in color, that produces dopamine.
Suppressor T cells: T cells that keep the response to foreign substances in the body in check.
T cells: Cells that orchestrate immune activity by means of specific receptors for antigens, commands to other immune cells, and the production of cytokines. A form of T cell called the Th1 cell predominates in MS autoimmunity, causing the inflammation that leads to nerve damage and symptoms in MS.
Thalamotomy: A procedure that interrupts brain signals. It involves destroying certain parts of the thalamus, which is part of the brain.
Th1 cells: Helper T cells that enhance the body’s inflammatory response.
Th2 cells: Helper T cells that suppress abnormal immune reactions in the body.
Thrombosis: A blood clot that forms inside a blood vessel. When it occurs in a neck or brain artery, it can cause ischemic stroke.
Thymus: A gland located at the base of the neck. T cells mature in the thymus, making it a critical part of a normally-functioning immune system.
Transient ischemic attack (TIA): A temporary blockage of blood to the brain that indicates that a more severe episode or stroke may occur in the future.
Tremor: An involuntary rhythmic shaking, usually of the hands. It can occur in people with Parkinson’s disease.
Triptans: A class of prescription drugs used to treat severe migraine.
Wearing-off effect: The waning of effect of doses of levodopa after the drug is taken for long periods by patients with Parkinson’s disease.
West Nile virus: a mosquito-carried illness that causes fever and headache and sometimes inflammations of parts of the brain (ie, encephalitis or meningitis). |
