Narcolepsy Glossary of Terms

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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).

Analysis: A psychology term for processes used to gain understanding of complex emotional or behavioral issues.

Antidepressants: Anything, and especially a drug, used to prevent or treat depression.
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Autosomal: Pertaining to a chromosome that is not a sex chromosome; relating to any one of the chromosomes save the sex chromosomes.
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Autosomal dominant: A pattern of inheritance in which an affected individual has one copy of a mutant gene and one normal gene on a pair of autosomal chromosomes. (In contrast, autosomal recessive diseases require that the individual have two copies of the mutant gene.) Individuals with autosomal dominant diseases have a 50-50 chance of passing the mutant gene and therefore the disorder onto each of their children. Examples of autosomal dominant diseases include Huntington disease, neurofibromatosis, and polycystic kidney disease.

Autosomal recessive: A genetic condition that appears only in individuals who have received two copies of an autosomal gene, one copy from each parent. The gene is on an autosome, a nonsex chromosome. The parents are carriers who have only one copy of the gene and do not exhibit the trait because the gene is recessive to its normal counterpart gene.
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Brain: That part of the central nervous system that is located within the cranium (skull). The brain functions as the primary receiver, organizer and distributor of information for the body. It has two (right and left) halves called "hemispheres."

Cataplexy: A debilitating medical condition in which a person suddenly feels weak and collapses at moments of strong emotion such as laughter, anger, fear or surprise. In so collapsing, people with cataplexy may injure themselves.
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Cerebrospinal fluid: CSF. A watery fluid, continuously produced and absorbed, which flows in the ventricles (cavities) within the brain and around the surface of the brain and spinal cord.
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Diagnosis: 1 The nature of a disease; the identification of an illness. 2 A conclusion or decision reached by diagnosis. The diagnosis is rabies. 3 The identification of any problem. The diagnosis was a plugged IV.
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Double-blind: Term used to described a study in which both the investigator or the participant are blind to (unaware of) the nature of the treatment the participant is receiving. Double-blind trials are thought to produce objective results, since the expectations of the researcher and the participant about the experimental treatment such as a drug do not affect the outcome. Also called double-masked. See also: Double-blinded study.

Dysfunction: Difficult function or abnormal function.
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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.
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Electroencephalogram: A study of electrical current within the brain. Electrodes are attached to the scalp. Wires attach these electrodes to a machine which records the electrical impulses. The results are either printed out or displayed on a computer screen. Electroencephalogram is abbreviated EEG.
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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.
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Epilepsy (seizure disorder): When nerve cells in the brain fire electrical impulses at a rate of up to four times higher than normal, this causes a sort of electrical storm in the brain, known as a seizure. A pattern of repeated seizures is referred to as epilepsy. Known causes include head injuries, brain tumors, lead poisoning, maldevelopment of the brain, genetic and infectious illnesses. But in fully half of cases, no cause can be found. Medication controls seizures for the majority of patients.

Excessive daytime sleepiness: A neurological disorder in which there is a sudden recurrent uncontrollable compulsion to sleep. Excessive daytime sleepiness is also known as narcolepsy.
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FDA: The Food and Drug Administration, an agency within the U.S. Public Health Service, which is a part of the Department of Health and Human Services.
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Gastrointestinal: Adjective referring collectively to the stomach and small and large intestines.
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Genetic: Having to do with genes and genetic information.

Headache: A pain in the head with the pain being above the eyes or the ears, behind the head (occipital), or in the back of the upper neck. Headache, like chest pain or back ache, has many causes.
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Heart: The muscle that pumps blood received from veins into arteries throughout the body. It is positioned in the chest behind the sternum (breastbone; in front of the trachea, esophagus, and aorta; and above the diaphragm muscle that separates the chest and abdominal cavities. The normal heart is about the size of a closed fist, and weighs about 10.5 ounces. It is cone-shaped, with the point of the cone pointing down to the left. Two-thirds of the heart lies in the left side of the chest with the balance in the right chest.
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Hygiene: The science of preventive medicine and the preservation of health. From the name of Hygeia, the daughter of Asklepios, the Greek god of medicine (whose staff with entwined snake is the symbol of medicine). Asklepios (known to the Romans as Aesculapius) had a number of children including not only Hygeia but also Panaceia, the patroness of clinical medicine. Hygeia also followed her father into medicine. As the patroness of health, Hygeia was charged with providing a healthy environment to prevent illness. In Greek, "hygieia" means health.

Hypnagogic: Concerning the drowsiness one commonly feels before sleep, the transitional state preceding sleep, and also the hallucinations that may occur at that time.
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Hypothalamus: The area of the brain that controls body temperature, hunger, and thirst.

Idiopathic: Of unknown cause. Any disease that is of uncertain or unknown origin may be termed idiopathic. For example, acute idiopathic polyneuritis, diffuse idiopathic skeletal hyperostosis, idiopathic pulmonary fibrosis, idiopathic scoliosis, etc.
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Internal medicine: A medical specialty dedicated to the diagnosis and medical treatment of adults. A physician who specializes in internal medicine is referred to as an internist. A minimum of seven years of medical school and postgraduate training are focused on learning the prevention, diagnosis, and treatment of diseases of adults. Subspecialties of internal medicine include allergy and immunology, cardiology (heart), endocrinology (hormone disorders), hematology (blood disorders), infectious diseases, gastroenterology (diseases of the gut), nephrology (kidney diseases), oncology (cancer), pulmonology (lung disorders), and rheumatology (arthritis and musculoskeletal disorders).

Laboratory: A place for doing tests and research procedures and preparing chemicals, etc. Although "laboratory" looks very like the Latin "laboratorium" (a place to labor, a work place), the word "laboratory" came from the Latin "elaborare" (to work out, as a problem, and with great pains), as evidenced by the Old English spelling "elaboratory" designating "a place where learned effort was applied to the solution of scientific problems."

Lumbar: Referring to the 5 lumbar vertebrae which are situated below the thoracic vertebrae and above the sacral vertebrae in the spinal column. The 5 lumbar vertebrae are represented by the symbols L1 through L5. There are correspondingly 5 lumbar nerves.

Lumbar puncture: A lumbar puncture or "LP" is a procedure whereby spinal fluid is removed from the spinal canal for the purpose of diagnostic testing. It is particularly helpful in the diagnosis of inflammatory diseases of the central nervous system, especially infections, such as meningitis. It can also provide clues to the diagnosis of stroke, spinal cord tumor and cancer in the central nervous system.
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Medical school: A school with a curriculum leading to a medical degree. The mission of every medical school includes medical teaching, research, and patient care. All medical schools share the goal of preparing students in the art and science of medicine, and providing them with the background necessary to enter the period of graduate medical education. The years of medical school preceding graduate medical education are typically divided into a preclinical phase and a clinical phase.
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Memory: 1. The ability to recover information about past events or knowledge. 2. The process of recovering information about past events or knowledge. 3. Cognitive reconstruction. The brain engages in a remarkable reshuffling process in an attempt to extract what is general and what is particular about each passing moment.
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Modafinil: An oral drug first approved by the FDA in 1998 for the treatment of narcolepsy, a condition in which there is an uncontrollable desire to sleep. Modafinil promotes wakefulness. In 2004 the FDA also approved modafinil for the treatment of obstructive sleep apnea and sleeping problems caused by shift work.
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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."

Narcolepsy: A neurological disorder marked by a sudden recurrent uncontrollable compulsion to sleep. Narcolepsy is often associated with cataplexy (a sudden loss of muscle tone and paralysis of voluntary muscles associated with a strong emotion), sleep paralysis (immobility of the body that occurs in the transition from sleep to wakefulness), what are called hypnagogic hallucinations (pre-sleep dreams) and automatic behaviors (such as doing something "automatically" and not remembering afterwards how one did it).
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Nasal: Having to do with the nose. Nasal drops are intended for the nose, not (for example) the eyes. The word "nasal" came from the Latin "nasus" meaning the nose or snout.

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.

Neurology: The medical specialty concerned with the diagnosis and treatment of disorders of the nervous system -- the brain, the spinal cord, and the nerves.
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Neurotransmitter: A chemical that is released from a nerve cell which thereby transmits an impulse from a nerve cell to another nerve, muscle, organ, or other tissue. A neurotransmitter is a messenger of neurologic information from one cell to another.

Objective: In a microscope, the objective (also called the objective lens) is the lens nearest to the object being examined whereas the lens closest to the eye is termed the ocular (the eyepiece).
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Onset: In medicine, the first appearance of the signs or symptoms of an illness as, for example, the onset of rheumatoid arthritis. There is always an onset to a disease but never to the return to good health. The default setting is good health.
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Paralysis: Loss of voluntary movement (motor function). Paralysis that affects only one muscle or limb is partial paralysis, also known as palsy; paralysis of all muscles is total paralysis, as may occur in cases of botulism.

Pathologic: 1. Indicative of or caused by disease, as in a pathologic fracture, pathologic tissue, or pathologic process. 2. Pertaining to pathology, the branch of medicine that studies disease and especially the essential nature of disease.

Pharmacy: A location where prescription drugs are sold. A pharmacy is, by law, constantly supervised by a licensed pharmacist.

Placebo-controlled: A term used to describe a method of research in which an inactive substance (a placebo) is given to one group of participants, while the treatment (usually a drug or vaccine) being tested is given to another group. The results obtained in the two groups are then compared to see if the investigational treatment is more effective than the placebo.

Polysomnography: Continuous recording of specific physiologic variables during sleep. Polysomnography typically records brain wave changes (electroencephalogram), eye movements (electrooculogram), muscle tone (electromyogram), respiration, electrocardiogram (EKG), and leg movements.

Provigil: Brand name of the drug modafinil. See: Modafinil.

Recessive: A condition that appears only in individuals who have received two copies of a mutant gene, one copy from each parent. The individuals with a double dose of the mutated gene are called homozygotes. Their parents, each with a single dose of the mutated gene, appear normal and are called heterozygotes, or gene carriers.
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REM sleep: REM sleep is the portion of sleep when there are rapid eye movements (REMs).
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Reuptake: The reabsorption of a secreted substance by the cell that originally produced and secreted it. The process of reuptake, for example, affects serotonin.
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Selective serotonin reuptake inhibitor: A selective serotonin reuptake inhibitor (SSRI) is one of the commonly prescribed drugs for treating depression.
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Sensitivity: 1. In psychology, the quality of being sensitive. As, for example, sensitivity training, training in small groups to develop a sensitive awareness and understanding of oneself and of ones relationships with others. 2. In disease epidemiology, the ability of a system to detect epidemics and other changes in disease occurrence. 3. In screening for a disease, the proportion of persons with the disease who are correctly identified by a screening test. 4. In the definition of a disease, the proportion of persons with the disease who are correctly identified by defined criteria.

Serotonin: A hormone, also called 5-hydroxytryptamine, in the pineal gland, blood platelets, the digestive tract, and the brain. Serotonin acts both as a chemical messenger that transmits nerve signals between nerve cells and that causes blood vessels to narrow.
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Sleep: The body's rest cycle.
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Sleep disorders: Any disorder that affects, disrupts, or involves sleep. The most common sleep disorder is probably snoring, although it is usually not medically significant. Insomnia, sleep apnea, restless leg syndrome, and sleepwalking are also sleep disorders. Most large medical centers have diagnostic and treatment facilities dedicated to sleep disorders.
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Sleep hygiene: A series of practices and non-medical treatments for insomnia. Sleep hygiene includes simple steps that may improve initiation and maintenance of sleep, such as maintaining a regular sleep schedule, making the bedroom an inviting place to sleep, avoiding alcohol or smoking prior to going to bed, and exercising regularly (but not in the 4-5 hours prior to bedtime).

Sleep paralysis: A frightening form of paralysis that occurs when a person suddenly finds himself or herself unable to move for a few minutes, most often upon falling asleep or waking up. Sleep paralysis is due to an irregularity in passing between the stages of sleep and wakefulness.
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Sodium: The major positive ion (cation) in fluid outside of cells. The chemical notation for sodium is Na⁺. When combined with chloride, the resulting substance is table salt.
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Specificity: 1. The quality of being specific as, for example, she showed the use of specificity in her diagnosis. 2. The proportion of persons without a disease who are correctly identified by a test. The specificity is the number of true negative results divided by the sum of the numbers of true negative plus false positive results.

Stress: Forces from the outside world impinging on the individual. Stress is a normal part of life that can help us learn and grow. Conversely, stress can cause us significant problems.
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Substance: 1. Material with particular features, as a pressor substance.
2. The material that makes up an organ or structure. Also known in medicine as the substantia.
3. A psychoactive drug as, for example, in substance abuse.

Symptomatic: 1 With symptoms, as a symptomatic infection. 2 Characteristic, as behavior symptomatic of Huntington disease. 3 Directed at the symptoms, as symptomatic treatment.

Transducer: An instrument that converts electrical energy into mechanical energy. A transducer can also act as a transmitter and receiver of ultrasound information.

Tricyclic antidepressants (TCAs): One of a class of medications used to treat depression. The tricyclic antidepressants (TCAs) are also used for some forms of anxiety, fibromyalgia, and the control of chronic pain.
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Trigger: Something that either sets off a disease in people who are genetically predisposed to developing the disease, or that causes a certain symptom to occur in a person who has a disease. For example, sunlight can trigger rashes in people with lupus.