Dementia Glossary of Terms

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 ).
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Absorb: 1. To take something in, as through the skin or the intestine.
2. To react with radiation and reduce it in intensity, as with a dose of radiation or transmitted light.
See also: Absorbed dose; Absorption; Malabsorption; Reabsorption.

Acetylcholine: A key chemical in neurons (nerve cells) that acts as a neurotransmitter and carries information across the synaptic cleft, the space between two nerve cells. Abbreviated ACh.

Acquired: Anything that is not present at birth but develops some time later. In medicine, the word "acquired" implies "new" or "added." An acquired condition is "new" in the sense that it is not genetic (inherited) and "added" in the sense that was not present at birth.
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Aging: The process of becoming older, a process that is genetically determined and environmentally modulated.
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Alcoholism: Physical dependence on alcohol to the extent that stopping alcohol use will bring on withdrawal symptoms. In popular and therapeutic parlance, the term may also be used to refer to ingrained drinking habits that cause health or social problems. Treatment requires first ending the physical dependence, then making lifestyle changes that help the individual avoid relapse . In some cases, medication or hospitalization are needed. Alcohol dependence can have many serious effects on the brain , liver , and other organs of the body.
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Alexander disease: A slowly progressive and ultimately fatal brain disorder that most commonly occurs in children. The infantile form of the disease is characterized by megalencephaly (an abnormally large head), seizures, spasticity and developmental retardation. It leads to death usually within the first decade. Patients with the juvenile and adult forms of Alexander disease typically experience ataxia and spasticity and a more slowly progressive course. The classic hallmark of all forms of Alexander disease is the presence of Rosenthal fibers, abnormal inclusions in astrocytes that contain the intermediate filament protein GFAP. Mutations in the gene for GFAP (glial fibrillary acidic protein) cause Alexander disease, the first known example of a primary genetic disorder of astrocytes, one of the major cell types in the vertebrate CNS . The disease was first described by W. Stewart Alexander, a New Zealand pathologist , in 1949.
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Alpha-synuclein: One in a family of structurally related proteins that are prominently expressed in the central nervous system. Aggregated alpha-synuclein proteins form brain lesions that are hallmarks of some neurodegenerative diseases (synucleinopathies). The gene for alpha-synuclein, which is called SNCA, is on chromosome 4q21. One form of hereditary Parkinson disease is due to mutations in SNCA. Another form of hereditary Parkinson disease is due to a triplication of SNCA. See also: Parkinson disease gene.

Alzheimer's disease: A progressive neurologic disease of the brain that leads to the irreversible loss of neurons and dementia . The clinical hallmarks of Alzheimer's disease are progressive impairment in memory, judgment, decision making, orientation to physical surroundings, and language. A working diagnosis of Alzheimer disease is usually made on the basis of the neurologic examination. A definitive diagnosis can be made only at autopsy. On a cellular level, Alzheimer's disease is characterized by unusual helical protein filaments in nerve cells (neurons) of the brain. These odd twisted filaments are called neurofibrillary tangles. On a functional level, there is degeneration of the cortical regions, especially the frontal and temporal lobes, of the brain.
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Amino acid: One of the 20 building blocks of protein . The sequence of amino acids in a protein and, hence, the function of that protein are determined by the genetic code in the DNA .
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Amyloid: Any of a number of complex proteins that are deposited in tissues and that share selected laboratory features such as a change in the fluorescence intensity of certain aromatic dyes like Congo Red.
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Analysis: A psychology term for processes used to gain understanding of complex emotional or behavioral issues.
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Anemia: The condition of having less than the normal number of red blood cells or less than the normal quantity of hemoglobin in the blood. The oxygen-carrying capacity of the blood is, therefore, decreased.
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Anesthesia: Loss of feeling or awareness. A general anesthetic puts the person to sleep. A local anesthetic causes loss of feeling in a part of the body such as a tooth or an area of skin without affecting consciousness. Regional anesthesia numbs a larger part of the body such as a leg or arm, also without affecting consciousness. The term "conduction anesthesia" encompasses both local and regional anesthetic techniques. Many surgical procedures can be done with conduction anesthesia without significant pain. In many situations, such as a C-section, conduction anesthesia is safer and therefore preferable to general anesthesia. However, there are also many types of surgery in which general anesthesia is clearly appropriate.

Angiopathy: Disease of the blood vessels (arteries, veins, and capillaries). There are two basic types of angiopathy: microangiopathy and macroangiopathy.
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Angioplasty: Procedure with a balloon-tipped catheter to enlarge a narrowing in a coronary artery. Also called Percutaneous Transluminal Coronary Angioplasty (PTCA).

Anoxia: 1. Strictly speaking, the absence of oxygen . 2. The near absence of oxygen. 3. Sometimes used loosely as a synonym for hypoxia .
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Antihypertensive: Something that reduces high blood pressure (hypertension).

Antipsychotic: A medication (or another measure) that is believed to be effective in the treatment of psychosis. For example, aripiprazole (Abilify) is an antipsychotic medication used to treat schizophrenia.

Anxiety: A feeling of apprehension and fear characterized by physical symptoms such as palpitations , sweating, and feelings of stress . Anxiety disorders are serious medical illnesses that affect approximately 19 million American adults. These disorders fill people's lives with overwhelming anxiety and fear. Unlike the relatively mild, brief anxiety caused by a stressful event such as a business presentation or a first date, anxiety disorders are chronic, relentless, and can grow progressively worse if not treated.
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Aphasia: One in a group of speech disorders in which there is a defect or loss of the power of expression by speech, writing, or signs, or a defect or loss of the power of comprehension of spoken or written language. See, for example, auditory aphasia .
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ApoE: Abbreviation for apolipoprotein E, a gene that codes for a protein component of lipoproteins (complexes of fat + protein) that are normal constituents of blood plasma -- namely, chylomicrons, HDL (high density lipoprotein), LDL (low density lipoprotein), and VLDL (very low density lipoprotein).
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Apolipoprotein E: A type of lipoprotein (a protein connected to a fat). Apolipoprotein E is abbreviated ApoE and the gene that encodes it is known as APOE. APOE is located on chromosome 19 in band 19q13.2.
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Apraxia: The inability to execute a voluntary motor movement despite being able to demonstrate normal muscle function. Apraxia is not related to a lack of understanding or to any kind of physical paralysis but is caused by a problem in the cortex of the brain.
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Artery: A vessel that carries blood high in oxygen content away from the heart to the farthest reaches of the body. Since blood in arteries is usually full of oxygen, the hemoglobin in the red blood cells is oxygenated. The resultant form of hemoglobin (oxyhemoglobin) is what makes arterial blood look bright red.
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Aspiration: Removal of a sample of fluid and cells through a needle. Aspiration also refers to the accidental sucking in of food particles or fluids into the lungs.

Aspirin: A good example of a tradename that entered into the language, Aspirin was once the Bayer trademark for acetylsalicylic acid .
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Asthma : A common disorder in which chronic inflammation of the bronchial tubes (bronchi) makes them swell, narrowing the airways. Asthma involves only the bronchial tubes and does not affect the air sacs ( alveoli ) or the lung tissue (the parenchyma of the lung) itself.
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Ataxia: Wobbliness. Incoordination and unsteadiness due to the brain's failure to regulate the body's posture and regulate the strength and direction of limb movements. Ataxia is usually a consequence of disease in the brain, specifically in the cerebellum which lies beneath the back part of the cerebrum.

Atherosclerosis: A process of progressive thickening and hardening of the walls of medium-sized and large arteries as a result of fat deposits on their inner lining.
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Atrophy: Wasting away or diminution. Muscle atrophy is wasting of muscle, decrease in muscle mass.
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Atypical: Not typical, not usual, not normal, abnormal. Atypical is often used to refer to the appearance of precancerous or cancerous cells.

Aura: A premonition. There is often an aura before a migraine or a grand mal seizure. The aura, a symptom of brain malfunction, may consist of flashing lights, a gleam of light, blurred vision, an odor, the feeling of a breeze, numbness, weakness, or difficulty speaking.

Autoimmune: Pertaining to autoimmunity, a misdirected immune response that occurs when the immune system goes awry and attacks the body itself.
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Autoimmune disease: An illness that occurs when the body tissues are attacked by its own immune system . The immune system is a complex organization within the body that is designed normally to "seek and destroy" invaders of the body, including infectious agents. Patients with autoimmune diseases frequently have unusual antibodies circulating in their blood that target their own body tissues.
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Autopsy : A postmortem examination. Also called a necropsy .
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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.

Bladder: Any pouch or other flexible enclosure that can hold liquids or gases but usually refers to the hollow organ in the lower abdomen that stores urine -- the urinary bladder. The kidneys filter waste from the blood and produce urine, which enters the bladder through two tubes called ureters. Urine leaves the bladder through another tube, the urethra . In women, the urethra is a short tube that opens just in front of the vagina . In men, it is longer, passing through the prostate gland and then the penis . Infection of the bladder is called cystitis .
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Blind: 1. Unable to see. Without part or all of the sense of sight.
2. In a clinical trial, not to know the treatment given or received. The participant is not told whether they are in the experimental or control arm of the study. Also called masked.
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Blood clot: Blood that has been converted from a liquid to a solid state. Also called a thrombus .
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Blood count: The calculated number of white or red blood cells (WBCs or RBCs) in a cubic millimeter of blood.

Blood pressure: The blood pressure is the pressure of the blood within the arteries. It is produced primarily by the contraction of the heart muscle. It's measurement is recorded by two numbers. The first (systolic pressure) is measured after the heart contracts and is highest. The second (diastolic pressure) is measured before the heart contracts and lowest. A blood pressure cuff is used to measure the pressure. Elevation of blood pressure is called "hypertension".

Bovine: Having to do with cows and cattle, as in bovine spongiform encephalopathy (mad cow disease), bovine tuberculosis, and bovine growth hormone.

Bowel: Another name for the intestine . The small bowel and the large bowel are the small intestine and large intestine , respectively.
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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."
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C-reactive protein: A plasma protein that rises in the blood with the inflammation from certain conditions.
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CADASIL: Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy. An inherited form of vascular dementia that strikes relatively young adults of both sexes and is characterized by multiple strokes, dementia, migraine-like headaches, and psychiatric disturbances. CADASIL is due to mutation of a gene called NOTCH3 located on chromosome 19. Also called hereditary multi-infarct dementia.

Calcium: A mineral found mainly in the hard part of bones, where it is stored. Calcium is added to bones by cells called osteoblasts and is removed from bones by cells called osteoclasts. Calcium is essential for healthy bones. It is also important for muscle contraction, heart action, nervous system maintenance, and normal blood clotting. Food sources of calcium include dairy foods, some leafy green vegetables such as broccoli and collards, canned salmon, clams, oysters, calcium-fortified foods, and tofu. According to the National Academy of Sciences, adequate intake of calcium is 1,200 milligrams a day (four glasses of milk) for men and women 51 and older, 1,000 milligrams a day for adults 19 through 50, and 1,300 milligrams a day for children 9 through 18. The upper limit for calcium intake is 2.5 grams daily.

Cardiovascular: The circulatory system comprising the heart and blood vessels which carries nutrients and oxygen to the tissues of the body and removes carbon dioxide and other wastes from them.
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Carotid: Pertaining to the carotid artery and the area near that key artery located in the front of the neck though which blood from the heart goes to the brain.
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Carotid endarterectomy: Endarterectomy (a surgical procedure designed to clean out material occluding an artery) done on the carotid artery (a major artery in the neck that supplies blood to the brain) to restore normal blood flow through it to the brain and prevent a stroke.

Cavities: Holes in the two outer layers of a tooth called the enamel and the dentin. The enamel is the outermost white hard surface and the dentin is the yellow layer just beneath enamel. Both layers serve to protect the inner living tooth tissue called the pulp, where blood vessels and nerves reside. Small cavities may not cause pain, and may be unnoticed by the patient. Larger cavities can collect food, and the inner pulp of the affected tooth can become irritated by bacterial toxins, foods that are cold, hot, sour, or sweet - causing toothache. Also referred to as caries.

Cell: The basic structural and functional unit in people and all living things. Each cell is a small container of chemicals and water wrapped in a membrane .
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Cerebral: Pertaining to the brain, the cerebrum or the intellect.
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Cerebral cortex: A thin mantle of gray matter about the size of a formal dinner napkin covering the surface of each cerebral hemisphere. The cerebral cortex is crumpled and folded, forming numerous convolutions ( gyri ) and crevices ( sulci ). It is made up of six layers of nerve cells and the nerve pathways that connect them. The cerebral cortex is responsible for the processes of thought, perception and memory and serves as the seat of advanced motor function, social abilities, language, and problem solving.
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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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Cerebrovascular: Pertaining to the blood vessels and, especially, the arteries that supply the brain. As in cerebrovascular accident or cerebrovascular disease.

Cerebrovascular disease: Disease of the blood vessels and, especially, the arteries that supply the brain. Cerebrovascular disease is usually caused by atherosclerosis and can lead to a stroke. See also atherosclerosis, stroke.

Cholesterol: The most common type of steroid in the body, cholesterol has gotten something of a bad name. However, cholesterol is a critically important molecule.
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Chorea: Ceaseless rapid complex body movements that look well coordinated and purposeful but are, in fact, involuntary.
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Chromosome: A visible carrier of the genetic information.
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Chronic: This important term in medicine comes from the Greek chronos, time and means lasting a long time.
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Clinical trial: See: Clinical trials. See also: Inconclusive clinical trial; Negative clinical trial; Non-inferior clinical trial; Positive clinical trial.

Clinical trials: Trials to evaluate the effectiveness and safety of medications or medical devices by monitoring their effects on large groups of people.
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Cognition: The process of knowing and, more precisely, the process of being aware, knowing, thinking, learning and judging. The study of cognition touches on the fields of psychology, linguistics, computer science, neuroscience, mathematics, ethology and philosophy.
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Cognitive: Pertaining to cognition , the process of knowing and, more precisely, the process of being aware, knowing, thinking, learning and judging. The study of cognition touches on the fields of psychology , linguistics, computer science, neuroscience , mathematics, ethology and philosophy.
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Coma: A state of deep unarousable unconsciousness.
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Complete blood count : A set values of the cellular (formed elements) of blood. These measurements are generally determined by specially designed machines that analyze the different components of blood in less than a minute.
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Computed tomography: An x-ray procedure that uses the help of a computer to produce a detailed picture of a cross section of the body. Also called a CT scan or CAT scan.

Contrast: Short for "contrast media." Contrast media are X-ray dyes used to provide contrast, for example, between blood vessels and other tissue.

Cortex: The outer portion of an organ.
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Cortical: Having to do with the cortex, the outer portion of an organ.
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CT scan: Computerized tomography scan. Pictures of structures within the body created by a computer that takes the data from multiple X-ray images and turns them into pictures on a screen. CT stands for computerized tomography.
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Cure: 1. To heal, to make well, to restore to good health. Cures are easy to claim and, all too often, difficult to confirm.
2. A time without recurrence of a disease so that the risk of recurrence is small, as in the 5-year cure rate for malignant melanoma .
3. Particularly in the past, a course of treatment. For example, take a cure at a spa.
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Dehydration : Excessive loss of body water. Diseases of the gastrointestinal tract that cause vomiting or diarrhea may, for example, lead to dehydration. There are a number of other causes of dehydration including heat exposure, prolonged vigorous exercise (e.g., in a marathon), kidney disease, and medications (diuretics).
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Delirium: A sudden state of severe confusion and rapid changes in brain function, sometimes associated with hallucinations and hyperactivity , in which the patient is inaccessible to normal contact. Symptoms may include inability to concentrate and disorganized thinking evidenced by rambling, irrelevant, or incoherent speech. There may be a reduced level of consciousness, sensory misperceptions and illusions, disturbances of sleep, drowsiness, disorientation to time, place, or person, and problems with memory.
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Dementia : Significant loss of intellectual abilities such as memory capacity, severe enough to interfere with social or occupational functioning.
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Depression : An illness that involves the body, mood, and thoughts, that affects the way a person eats and sleeps, the way one feels about oneself, and the way one thinks about things. A depressive disorder is not the same as a passing blue mood. It is not a sign of personal weakness or a condition that can be wished away. People with a depressive disease cannot merely "pull themselves together" and get better. Without treatment, symptoms can last for weeks, months, or years. Appropriate treatment, however, can help most people with depression.
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Diabetes: Refers to diabetes mellitus or, less often, to diabetes insipidus . Diabetes mellitus and diabetes insipidus share the name "diabetes" because they are both conditions characterized by excessive urination (polyuria).
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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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DNA: Deoxyribonucleic acid. One of two types of molecules that encode genetic information. (The other is RNA . In humans DNA is the genetic material; RNA is transcribed from it. In some other organisms, RNA is the genetic material and, in reverse fashion, the DNA is transcribed from it.)
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Down syndrome : A common chromosome disorder due to an extra chromosome number 21 (trisomy 21). Down syndrome causes mental retardation, a characteristic face, and multiple malformations. Down syndrome is a relatively common birth defect. The chromosome abnormality affects both the physical and intellectual development of the individual.
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Dura: The outermost, toughest, and most fibrous of the three membranes ( meninges ) covering the brain and the spinal cord . Dura is short for dura mater (from the Latin for hard mother). Also called the pachymeninx (singular) or pachymeniges (plural).
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Dysfunction: Difficult function or abnormal function.
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Dysphagia: Difficulty in swallowing, swallowing problems . Dysphagia is due to problems in nerve or muscle control. It is common, for example, after a stroke . Dysphagia compromises nutrition and hydration and may lead to aspiration pneumonia and dehydration .
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EEG: Electroencephalogram, e technique for studying the 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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Embolism: The obstruction of a blood vessel by a foreign substance or a blood clot blocking the vessel. Something travels through the bloodstream, lodges in a vessel and plugs it.
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Encephalitis: Inflammation of the brain. Encephalitis occurs, for example, in 1 in 1,000 cases of measles . It may start (up to 3 weeks) after onset of the measles rash and present with high fever , convulsions, and coma. It usually runs a blessedly short course with full recovery within a week. Or it may eventuate in central nervous system impairment or death.
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Endarterectomy: An operation to clean out an artery and restore normal blood flow through the artery. An endarterectomy is basically a "Rotorooter" procedure. It removes diseased material from the inside of an artery, and also removes any occluding atheromatous deposits, the aim being to leave a smooth lining within the vessel, so the blood can flow normally.
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Endocrine: Pertaining to hormones and the glands that make and secrete them into the bloodstream through which they travel to affect distant organs. The endocrine sites include the hypothalamus, pituitary gland, pineal gland, thyroid, parathyroids, heart (which makes atrial-natriuretic peptide), the stomach and intestines, islets of Langerhans in the pancreas, the adrenal glands, the kidney (which makes renin, erythropoietin, and calcitriol), fat cells (which make leptin). the testes, the ovarian follicle (estrogens) and the corpus luteum in the ovary). Endocrine is as opposed to exocrine. (The exocrine glands include the salivary glands, sweat glands and glands within the gastrointestinal tract.)

Enzyme: A protein (or protein-based molecule) that speeds up a chemical reaction in a living organism. An enzyme acts as catalyst for specific chemical reactions , converting a specific set of reactants (called substrates) into specific products. Without enzymes, life as we know it would not exist.
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Enzymes: Proteins that act as a catalysts in mediating and speeding a specific chemical reaction .
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Estrogen: Estrogen is a female hormone produced by the ovaries. Estrogen deficiency can lead to osteoporosis .
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Familial: A condition that is tends to occur more often in family members than expected by chance alone. A familial disease may be genetic (such as cystic fibrosis ) or environmental (such as tuberculosis ).
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Family history: The family structure and relationships within the family, including information about diseases in family members.
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Fatal familial insomnia: Abbreviated FFI. An hereditary prion disease characterized by disrupted sleep (insomnia), motor abnormalities (myoclonus, ataxia, dysarthria, dysphagia, and pyramidal signs), and hyperactivation of the autonomic nervous system. Due to a missense mutation at codon 178 of the prion protein gene on chromosome 20. A sporadic form of fatal insomnia is also known.

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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Fever : Although a fever technically is any body temperature above the normal of 98.6 degrees F. (37 degrees C.), in practice a person is usually not considered to have a significant fever until the temperature is above 100.4 degrees F (38 degrees C.).
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fMRI: Functional magnetic resonance imaging.

Folic acid: One of the B vitamins that is a key factor in the synthesis (the making) of nucleic acid (DNA and RNA).
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Food and Drug Administration: The FDA, 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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Frontal: In anatomy, pertaining to the forehead. As, for example, the frontal bone, frontal sinus, and frontal nerve. From the Latin "frons" meaning the forehead or brow.
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Frontal lobe: The part of each hemisphere of the brain located behind the forehead that serves to regulate and mediate the higher intellectual functions. The frontal lobes have intricate connections to other areas of the brain. In the frontal lobes, we meld emotions, cognition, error detection, volition, a sense of self, and more to create our social brain.
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Gait: A manner of walking. Observation of the gait can provide clues to a number of diagnoses including Parkinson disease, cerebral palsy, congenital dislocation of the hip, and stroke.

Gene: The basic biological unit of heredity . A segment of deoxyribonucleic acid (DNA) needed to contribute to a function.
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Genes: The basic biological units of heredity . Segments of deoxyribonucleic acid (DNA) needed to contribute to a function.
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Genetic: Having to do with genes and genetic information.

Genetic disease: A disease caused by an abnormality in an individual's genome .
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Genetics: The scientific study of heredity . Genetics pertains to humans and all other organisms. So, for example, there is human genetics, mouse genetics, fruitfly genetics, etc.
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Gerstmann-Straussler-Scheinker disease: See: Gerstmann-Sträussler-Scheinker syndrome.

Glaucoma : A common eye condition in which the fluid pressure inside the eyes rises because of slowed fluid drainage from the eye. If untreated, it may damage the optic nerve and other parts of the eye, causing the loss of vision or even blindness.
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Glucose: The simple sugar (monosaccharide) that serves as the chief source of energy in the body. Glucose is the principal sugar the body makes. The body makes glucose from proteins, fats and, in largest part, carbohydrates. Glucose is carried to each cell through the bloodstream. Cells, however, cannot use glucose without the help of insulin . Glucose is also known as dextrose.
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Glutamate: A form of glutamic acid. See: Glutamic acid.

Gyri: The plural of gyrus.

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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Heart attack: The death of heart muscle due to the loss of blood supply. The loss of blood supply is usually caused by a complete blockage of a coronary artery, one of the arteries that supplies blood to the heart muscle. Death of the heart muscle, in turn, causes chest pain and electrical instability of the heart muscle tissue.
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Heart disease: Any disorder that affects the heart. Sometimes the term "heart disease" is used narrowly and incorrectly as a synonym for coronary artery disease. Heart disease is synonymous with cardiac disease but not with cardiovascular disease which is any disease of the heart or blood vessels. Among the many types of heart disease, see, for example: Angina; Arrhythmia; Congenital heart disease; Coronary artery disease (CAD); Dilated cardiomyopathy; Heart attack (myocardial infarction); Heart failure; Hypertrophic cardiomyopathy; Mitral regurgitation; Mitral valve prolapse; and Pulmonary stenosis.

Heart valves: There are four heart valves. All are one-way valves. Blood entering the heart first passes through the tricuspid valve and then the pulmonary valve. After returning from the lungs, the blood passes through the mitral (bicuspid) valve and exits via the aortic valve.

Hemorrhage: Bleeding or the abnormal flow of blood.
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Hemorrhagic: Pertaining to bleeding or the abnormal flow of blood.
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High blood pressure : Also known as hypertension, high blood pressure is, by definition, a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140 with a diastolic pressure above 90.
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Hippocampus: An area buried deep in the forebrain that helps regulate emotion and memory. Functionally, the hippocampus is part of the olfactory cortex, that part of the cerebral cortex essential to the sense of smell. Certain antidepressants (such as fluoxetine, or Prozac) influence the birth of new neurons in the hippocampus. The hippocampus is so-called because its shape suggests that of a seahorse. From the Greek hippos (horse) = kampos (a sea monster).

HIV: Acronym for the Human Immunodeficiency Virus , the cause of AIDS (acquired immunodeficiency syndrome). HIV has also been called the human lymphotropic virus type III, the lymphadenopathy-associated virus and the lymphadenopathy virus . No matter what name is applied, it is a retrovirus. (A retrovirus has an RNA genome and a reverse transcriptase enzyme. Using the reverse transcriptase , the virus uses its RNA as a template for making complementary DNA which can integrate into the DNA of the host organism).
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Homocysteine : An amino acid produced by the body, usually as a byproduct of consuming meat. Homocysteine is made from another amino acid, methionine, and then in turn is converted into other amino acids.
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Hormone: A chemical substance produced in the body that controls and regulates the activity of certain cells or organs.
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Hospice: A program or facility that provides special care for people who are near the end of life and for their families. Hospice care can be provided at home, in a hospice or another freestanding facility, or within a hospital. See also: Hospice care.

Huntingtin: The name of the gene responsible for Huntington disease (HD) and of the protein encoded by that gene. The molecular basis of HD is an increase in the length of a CAG triplet repeat (or 'polyglutamine') within the huntingtin gene. The gene is on chromosome 4p16.3.
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Hydrocephalus : Hydrocephalus is an abnormal buildup of cerebrospinal fluid (CSF) in the ventricles of the brain. The fluid is often under increased pressure and can compress and damage the brain.
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Hydrogen: The most plentiful element in the universe and one present in all organic compounds. Hydrogen is a gas with an atomic number of 1 and the symbol H.
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Hypertension: High blood pressure , defined as a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140 with a diastolic pressure above 90.
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Hypoglycemia : Low blood sugar (glucose). When symptoms of hypoglycemia occur together with a documented blood glucose under 45 mg/dl, and the symptoms promptly resolve with the administration of glucose, the diagnosis of hypoglycemia can be made with some certainty. Hypoglycemia is only significant when it is associated with symptoms.
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Hypotension: Any blood pressure that is below the normal expected for an individual in a given environment. Hypotension is the opposite of hypertension (abnormally high blood pressure).
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Hypoxia: A subnormal concentration of oxygen. By contrast with normoxia (normal oxygen) and anoxia (the absence or near absence of oxygen). From hyp– (below) + -ox- (oxygen) + –ia.

Ibuprofen: A non-steroidal anti-inflammatory drug (NSAID) commonly used to treat pain, swelling, and fever. Common brand names for Ibuprofen include Advil, Motrin, and Nuprin.

Immune: Protected against infection. The Latin immunis means free, exempt.

Immunodeficiency: Inability to mount a normal immune response. Immunodeficiency can be due to a genetic disease or acquired as in AIDS due to HIV.
See the entire definition of Immunodeficiency

Incidence: The frequency with which something, such as a disease, appears in a particular population or area. In disease epidemiology, the incidence is the number of newly diagnosed cases during a specific time period. The incidence is distinct from the prevalence which refers to the number of cases alive on a certain date.
See the entire definition of Incidence

Incontinence: Inability to control excretions. Urinary incontinence is inability to keep urine in the bladder. Fecal incontinence is inability to retain feces in the rectum.

Indicate: In medicine, to make a treatment or procedure advisable because of a particular condition or circumstance. For example, certain medications are indicated for the treatment of hypertension during pregnancy while others are contraindicated.

Infarct: An area of tissue death due to a local lack of oxygen .
See the entire definition of Infarct

Infection: The growth of a parasitic organism within the body. (A parasitic organism is one that lives on or in another organism and draws its nourishment therefrom.) A person with an infection has another organism (a "germ") growing within him, drawing its nourishment from the person.
See the entire definition of Infection

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.

Insomnia: The perception or complaint of inadequate or poor-quality sleep because of one or more of the following: difficulty falling asleep; waking up frequently during the night with difficulty returning to sleep; waking up too early in the morning; or unrefreshing sleep. Insomnia is not defined by the number of hours of sleep a person gets or how long it takes to fall asleep. Individuals vary normally in their need for, and their satisfaction with, sleep. Insomnia may cause problems during the day, such as tiredness, a lack of energy, difficulty concentrating, and irritability.
See the entire definition of Insomnia

Insulin: A natural hormone made by the pancreas that controls the level of the sugar glucose in the blood. Insulin permits cells to use glucose for energy. Cells cannot utilize glucose without insulin.
See the entire definition of Insulin

Insulin resistance: The diminished ability of cells to respond to the action of insulin in transporting glucose (sugar) from the bloodstream into muscle and other tissues. Insulin resistance typically develops with obesity and heralds the onset of type 2 diabetes. It is as if insulin is "knocking" on the door of muscle. The muscle hears the knock, opens up, and lets glucose in. But with insulin resistance, the muscle cannot hear the knocking of the insulin (the muscle is "resistant"). The pancreas makes more insulin, which increases insulin levels in the blood and causes a louder "knock." Eventually, the pancreas produces far more insulin than normal and the muscles continue to be resistant to the knock. As long as one can produce enough insulin to overcome this resistance, blood glucose levels remain normal. Once the pancreas is no longer able to keep up, blood glucose starts to rise, initially after meals, eventually even in the fasting state. Type 2 diabetes is now overt.

Involuntary: Done other than in accordance with the conscious will of the individual. The opposite of voluntary.
See the entire definition of Involuntary

Iron: An essential mineral. Iron is necessary for the transport of oxygen (via hemoglobin in red blood cells) and for oxidation by cells (via cytochrome). Deficiency of iron is a common cause of anemia. Food sources of iron include meat, poultry, eggs, vegetables and cereals (especially those fortified with iron). According to the National Academy of Sciences, the Recommended Dietary Allowances of iron are 15 milligrams per day for women and 10 milligrams per day for men. Iron overload can damage the heart, liver, gonads and other organs. Iron overload is a particular risk in people who may have certain genetic conditions (hemochromatosis) sometimes without knowing it and also in people receiving recurrent blood transfusions. Iron supplements meant for adults (such as pregnant women) are a major cause of poisoning in children.

JC virus: (JCV) A virus that commonly causes infections of no consequence in children with a normal immune system but which is responsible for an infection of the brain and spinal cord called progressive multifocal leukoencephalopathy (PML) in people with AIDS and other forms of immune system impairment. JC virus is also the primary cause of nephropathy (kidney disease) in people who have received a kidney transplant and are on immunosuppressive therapy.
See the entire definition of JC virus

Joint: A joint is the area where two bones are attached for the purpose of motion of body parts. A joint is usually formed of fibrous connective tissue and cartilage. An articulation or an arthrosis is the same as a joint.
See the entire definition of Joint

Kidney: One of a pair of organs located in the right and left side of the abdomen which clear "poisons" from the blood, regulate acid concentration and maintain water balance in the body by excreting urine. The kidneys are part of the urinary tract. The urine then passes through connecting tubes called "ureters" into the bladder. The bladder stores the urine until it is released during urination.

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."
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Leukemia : Cancer of the blood cells. The growth and development of the blood cells are abnormal. Strictly speaking, leukemia should refer only to cancer of the white blood cells (the leukocytes) but in practice it can apply to malignancy of any cellular element in the blood or bone marrow, as in red cell leukemia (erythroleukemia).
See the entire definition of Leukemia

Leukodystrophy: A disorder of the white matter of the brain, the part of the brain that contains myelinated nerve fibers. The white matter is white because it is the color of myelin , the insulation covering the nerve fibers. (The white matter is as opposed to the gray matter , the cortex of the brain which contains the nerve cell bodies). The white matter is involved in the conduction of nerve impulses in the brain.
See the entire definition of Leukodystrophy

Lipids: Another word for "fats." (Please see the various meanings of Fat .) Lipids can be more formally defined as substances such as a fat, oil or wax that dissolves in alcohol but not in water. Lipids contain carbon, hydrogen and oxygen but have far less oxygen proportionally than carbohydrates .
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Lipoprotein: A complex of lipid and protein, the way lipids travel in the blood.
See the entire definition of Lipoprotein

Liver: An organ in the upper abdomen that aids in digestion and removes waste products and worn-out cells from the blood. The liver is the largest solid organ in the body. The liver weighs about three and a half pounds (1.6 kilograms). It measures about 8 inches (20 cm) horizontally (across) and 6.5 inches (17 cm) vertically (down) and is 4.5 inches (12 cm) thick.

Lobe: Part of an organ that appears to be separate in some way from the rest. A lobe may be demarcated from the rest of the organ by a fissure (crack), sulcus (groove), connective tissue or simply by its shape. For example, there are the frontal, parietal, temporal, and occipital lobes of the brain.
See the entire definition of Lobe

Long-term memory: A system for permanently storing, managing, and retrieving information for later use. Items of information stored as long-term memory may be available for a lifetime.
See the entire definition of Long-term memory

Low blood pressure : Any blood pressure that is below the normal expected for an individual in a given environment. Low blood pressure is also referred to as hypotension.
See the entire definition of Low blood pressure

Lungs: The lungs are a pair of breathing organs located with the chest which remove carbon dioxide from and bring oxygen to the blood. There is a right and left lung.

Lupus: A chronic inflammatory condition caused by an autoimmune disease. An autoimmune disease occurs when the body's tissues are attacked by its own immune system. Patients with lupus have unusual antibodies in their blood that are targeted against their own body tissues.
See the entire definition of Lupus

Lyme disease: Lyme disease is a bacterial illness caused by a bacterium called a "spirochete." Lyme disease is spread by ticks when they bite the skin. Lyme disease can cause abnormalities in the skin, joints, heart and nervous system.
See the entire definition of Lyme disease

Macular: Pertaining to the macula. A macula is a small spot. A macula on the skin is a small flat spot while the macula in the eye is a small spot where vision is keenest in the retina .

Macular degeneration : A disease that progressively destroys the macula , the central portion of the retina , impairing central vision . Macular degeneration rarely causes blindness because only the center of vision is affected. However, injury to the macula in the center of the retina can impair the ability to see straight ahead clearly and sometimes make it difficult to read, drive, or perform other daily activities that require fine central vision.
See the entire definition of Macular degeneration

Magnetic resonance imaging : A special radiology technique designed to image internal structures of the body using magnetism, radio waves, and a computer to produce the images of body structures. In magnetic resonance imaging (MRI), the scanner is a tube surrounded by a giant circular magnet. The patient is placed on a moveable bed that is inserted into the magnet. The magnet creates a strong magnetic field that aligns the protons of hydrogen atoms, which are then exposed to a beam of radio waves. This spins the various protons of the body, and they produce a faint signal that is detected by the receiver portion of the MRI scanner. A computer processes the receiver information, and an image is produced. The image and resolution is quite detailed and can detect tiny changes of structures within the body, particularly in the soft tissue, brain and spinal cord, abdomen and joints.
See the entire definition of Magnetic resonance imaging

Marker: A piece of DNA that lies on a chromosome so close to a gene that the marker and the gene are inherited together. A marker is thus an identifiable heritable spot on a chromosome. A marker can be an expressed region of DNA (a gene) or a segment of DNA with no known coding function. All that matters is that the marker can be detected and trailed.
See the entire definition of Marker

Medicare: The United States government's health insurance program for:

• "senior citizens" -- people 65 years of age or older,
• certain younger people with specific disabilities, and
• people with end-stage renal disease (ESRD) -- permanent kidney failure requiring dialysis or a transplant.

Membrane: A very thin layer of tissue that covers a surface.

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.
See the entire definition of Memory

Meningitis: Inflammation of the meninges, usually due to a bacterial infection but sometimes from viral, protozoan, or other causes (in some cases the cause cannot be determined).
See the entire definition of Meningitis

Metabolic: Relating to metabolism, the whole range of biochemical processes that occur within us (or any living organism). Metabolism consists of anabolism (the buildup of substances) and catabolism (the breakdown of substances).
See the entire definition of Metabolic

Metabolism: The whole range of biochemical processes that occur within us (or any living organism). Metabolism consists both of anabolism and catabolism (the buildup and breakdown of substances, respectively). The term is commonly used to refer specifically to the breakdown of food and its transformation into energy.

Microscope: An optical instrument that augments the power of the eye to see small objects. The name microscope was coined by Johannes Faber (1574-1629) who in 1628 borrowed from the Greek to combined micro-, small with skopein, to view. Although the first microscopes were simple microscopes, most (if not all) optical microscopes today are compound microscopes.

Microscopic: So small it cannot be seen without the aid of microscope. As opposed to macroscopic (large enough to be seen with naked eye). A tiny tumor is microscopic while a big tumor is macroscopic.
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Migraine: Usually, periodic attacks of headaches on one or both sides of the head. These may be accompanied by nausea, vomiting, increased sensitivity of the eyes to light (photophobia), increased sensitivity to sound (phonophobia), dizziness , blurred vision, cognitive disturbances, and other symptoms. Some migraines do not include headache, and migraines may or may not be preceded by an aura.
See the entire definition of Migraine

Mild cognitive impairment: Abbreviated MCI. A brain disorder in which thinking abilities are mildly impaired. Individuals with mild cognitive impairment are able to function in everyday activities but have difficulty with memory -- trouble remembering the names of people they met recently, remembering the flow of a conversation, and a tendency to misplace things. The individual may be aware of these difficulties and compensate with increased reliance on notes and calendars. The diagnosis of MCI relies on the fact that the individual is able to perform all their usual activities successfully, without more assistance from others than they previously needed. In this regard, MCI is different from dementia. In dementia, memory loss has progressed to such a point that normal independent function is impossible and the individual can no longer successfully manage their finances or provide for their own basic needs. Most (but not all) patients with MCI develop a progressive decline in their thinking abilities over time, and Alzheimer's disease is usually the underlying cause.

Mitochondrial: Referring to mitochondria. The mitochondria are normal structures called organelles in cells. They are located in the cell's cytoplasm outside the nucleus.
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Motor: In medicine, having to do with the movement of a part of the body. Something that produces motion or refers to motion. For example, a motor neuron is a nerve cell that conveys an impulse to a muscle causing it to contract. The term "motor" today is also applied to a nerve that signals a gland to secrete. Motor is as opposed to sensory.

Motor neuron: A neuron that sends electrical output signals to muscle neurons. Also called a motoneuron.

Motor neuron disease: A group of neurological diseases characterized by steadily progressive deterioration of the motor neurons in the brain, brainstem and spinal cord that send instructions in the form of electrical impulses to the muscles, leading to muscle weakness and wasting.
See the entire definition of Motor neuron disease

MRI: Abbreviation and nickname for magnetic resonance imaging. For more information, see: Magnetic Resonance Imaging; Paul C. Lauterbur; Peter Mansfield.

Mucopolysaccharidosis: One of a series of inherited metabolic disorders affecting a type of complex carbohydrate called a mucopolysaccharide that is deposited in body tissues because the person lacks the specific enzyme needed to metabolize it.
See the entire definition of Mucopolysaccharidosis

Multi-infarct dementia: Dementia brought on by a series of strokes. See Vascular dementia.

Multifocal: Having to do with two or more foci or arising from two or more places. For example, aortic aneurysm disease is often multifocal and needs total aortic screening for diagnosis.

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.

Mutation: A permanent change, a structural alteration, in the DNA or RNA . In humans and many other organisms, mutations occur in DNA. However, in retroviruses like HIV , mutations occur in RNA which is the genetic material of retroviruses.
See the entire definition of Mutation

Myelin: The fatty substance that covers and protects nerves. Myelin is a layered tissue that sheathes the axons (nerve fibers). This sheath around the axon acts like a conduit in an electrical system, ensuring that messages sent by axons are not lost en route. It allows efficient conduction of action potentials down the axon. Myelin consists of 70% lipids (cholesterol and phospholipid) and 30% proteins. It is produced by oligodendrocytes in the central nervous system.

Myoclonus: A condition of abnormal contraction of muscles or portions of muscles.

Naproxen : A non-steroidal anti-inflammatory drug (NSAID) used for the management of mild to moderate pain, fever, and inflammation . Naproxen blocks the enzyme cyclooxygenase that makes prostaglandins, resulting in lower concentrations of prostaglandins. As a consequence, inflammation, pain and fever are reduced. Brand names for naproxen include Anaprox, Naprelan, Naprosyn, and Aleve.
See the entire definition of Naproxen

Neck: The part of the body joining the head to the shoulders. Also, any narrow or constricted part of a bone or organ that joins its parts as, for example, the neck of the femur bone.
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Neprilysin: See: Metallomembrane endopeptidase.

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.

Nerve cell: See: Neuron.

Neuroleptic: A term that refers to the effects of antipsychotic drugs on a patient, especially on his or her cognition and behavior.
See the entire definition of Neuroleptic

Neurological: Having to do with the nerves or the 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.
See the entire definition of Neurology

Neuron: A nerve cell that sends and receives electrical signals over long distances within the body. A neuron may send electrical output signals to muscle neurons (called motor neurons or motoneurons) and to other neurons. A neuron may receive electrical input signals from sensory cells (called sensory neurons) and from other neurons. A neuron that simply signals another neuron is called an interneuron.
See the entire definition of Neuron

Neurotoxin: A substance that causes damage to nerves or nerve tissue. For example, lead is a neurotoxin.
See the entire definition of Neurotoxin

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.
See the entire definition of Neurotransmitter

Niemann-Pick disease: A biochemical disorder affecting a lipid (fat) called sphingomyelin, resulting usually in progressive enlargement of the liver and spleen (hepatosplenomegaly), "swollen glands" (lymphadenopathy), anemia and mental and physical deterioration. Niemann-Pick disease is hereditary and follows an autosomal recessive pattern.
See the entire definition of Niemann-Pick disease

NIH: The National Institutes of Health. The NIH is an important U.S. health agency. It is devoted to medical research. Administratively under the Department of Health and Human Services (HHS), the NIH consists of 20-some separate Institutes and Centers. NIH's program activities are represented by these Institutes and Centers.
See the entire definition of NIH

NIMH: Stands for the National Institute of Mental Health, one of the National Institutes of Health in the U.S., whose mission is to "provide national leadership dedicated to understanding, treating, and preventing mental illnesses through basic research on the brain and behavior, and through clinical, epidemiological, and services research."

NINDS: Stands for the National Institute of Neurological Disorders and Stroke, one of the National Institutes of Health in the U.S., whose mission is to "support and conduct research and research training on the normal structure and function of the nervous system and on the causes, prevention, diagnosis, and treatment of more than 600 nervous system disorders including stroke, epilepsy, multiple sclerosis, Parkinson's disease, head and spinal cord injury, Alzheimer's disease, and brain tumors."

NPH: Normal pressure hydrocephalus.

Nursing: 1) Profession concerned with the provision of services essential to the maintenance and restoration of health by attending the needs of sick persons. 2) Feeding a infant at the breast.

Nursing home: A residential facility for persons with chronic illness or disability, particularly older people who have mobility and eating problems. Also called a convalescent home, long-term care facility.

Olivopontocerebellar: Pertaining to three particular parts of the brain -- namely, the oliva, the pons, and the cortex of the cerebellum. The oliva (olive) is a rounded prominence on the surface of the medulla oblongata in the brain. The olivopontocerebellar pathway consists of nerve fibers that connect the olivary nucleus to the pons and cerebellum. Olivopontocerebellar atrophy is a disorder of this pathway.

Olivopontocerebellar atrophy: A group of genetic diseases in which there is progressive degeneration of the olivopontocerebellar pathway in the brain connecting the inferior olive, pons, and cerebellum. The cerebellum is the part of the brain that plays a role in maintaining balance and posture as well as coordinating voluntary movement. The pons is part of the brainstem and contains important neuronal pathways between the cerebrum, spinal cord, and cerebellum. The pons serves as a relay point for messages between these structures. The inferior olives are two round structures that contain nuclei that are involved with balance, coordination and motor activity.
See the entire definition of Olivopontocerebellar atrophy

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.
See the entire definition of Onset

OPCA: Olivopontocerebellar atrophy.

Opiate: A medication or illegal drug that is either derived from the opium poppy, or that mimics the effect of an opiate (a synthetic opiate). Opiate drugs are narcotic sedatives that depress activity of the central nervous system, reduce pain, and induce sleep . Side effects may include oversedation, nausea, and constipation . Long- term use of opiates can produce addiction, and overuse can cause overdose and potentially death.
See the entire definition of Opiate

Organic: 1. A chemical compound that contains carbon.
2. Related to an organ.
3. Grown or prepared without the use of chemicals or pesticides, as in organic food.
See the entire definition of Organic

Organic brain syndrome: Psychiatric or neurological symptoms, including problems with attention, concentration, and memory, confusion, anxiety, and depression, arising from damage to or disease in the brain. Also called organic mental disorder. See also: Neurobiological disorder.

Oxygen: A colorless, odorless and tasteless gas that makes up about 20% of the air we breathe (and at least half the weight of the entire solid crust of the earth) and which combines with most of the other elements to form oxides. Oxygen is essential to human, animal and plant life.
See the entire definition of Oxygen

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

Palliative care: 1) Medical or comfort care that reduces the severity of a disease or slows its progress rather than providing a cure. For incurable diseases, in cases where the cure is not recommended due to other health concerns, and when the patient does not wish to pursue a cure, palliative care becomes the focus of treatment. For example, if surgery cannot be performed to remove a tumor, radiation treatment might be tried to reduce its rate of growth, and pain management could help the patient manage physical symptoms. 2) In a negative sense, provision only of perfunctory health care when a cure is possible.

Palsy: Paralysis, generally partial, whereby a local body area is incapable of voluntary movement (motor function). For example, Bell's palsy is localized paralysis of the muscles on one side of the face. The word "palsy" is a corruption (and contracture) of the French word "paralysie" which means "paralysis."

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.

Parkinson's disease: See: Parkinson disease.

Parkinsonism: 1. Parkinson disease.
2. A syndrome similar to Parkinson disease, for example, as a side effect of an antipsychotic drug.

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.

Pellagra: A disease due to deficiency of niacin, a B-complex vitamin. Pellagra is the "disease of the four D's" --

• Diarrhea;
• Dermatitis: A scaly rash on skin exposed to light or trauma;
• Dementia: Mental disorientation, delusions and depression ; and
• Death.

Pernicious anemia : A blood disorder caused by inadequate vitamin B12 in the blood. Patients who have this disorder do not produce the substance in the stomach that allows the body to absorb vitamin B12. This substance is called intrinsic factor (IF).
See the entire definition of Pernicious anemia

Placebo: A "sugar pill" or any dummy medication or treatment.
See the entire definition of Placebo

Plaque: 1. An semi-hardened accumulation of substances from fluids that bathe an area. Examples include dental plaque and cholesterol plaque.
See the entire definition of Plaque

Plasma: The liquid part of the blood and lymphatic fluid, which makes up about half of its volume. Plasma is devoid of cells and, unlike serum, has not clotted. Blood plasma contains antibodies and other proteins. It is taken from donors and made into medications for a variety of blood-related conditions. Some blood plasma is also used in non-medical products.

PML: Stands for progressive multifocal leukoencephalopathy, a rapidly progressive, often fatal viral infection of the brain. Commonly abbreviated as PML.
See the entire definition of PML

Pneumonia: Inflammation of one or both lungs with consolidation. Pneumonia is frequently but not always due to infection. The infection may be bacterial, viral, fungal or parasitic. Symptoms may include fever, chills, cough with sputum production, chest pain, and shortness of breath.

Poisoning: Taking a substance that is injurious to health or can cause death. Poisoning is still a major hazard to children, despite child-resistant (and sometimes adult-resistant) packaging and dose-limits per container.
See the entire definition of Poisoning

Positron emission tomography: PET. A highly specialized imaging technique that uses short-lived radioactive substances to produce three-dimensional colored images of those substances functioning within the body. These images are called PET scans and the technique is termed PET scanning.
See the entire definition of Positron emission tomography

Postmenopausal: After the menopause . Postmenopausal is defined formally as the time after which a woman has experienced twelve (12) consecutive months of amenorrhea (lack of menstruation) without a period.
See the entire definition of Postmenopausal

Posture: The carriage of the body as a whole, the attitude of the body, or the position of the limbs (the arms and legs).
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Precursor: Forerunner. That which precedes or is derived from an available source.
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Prevalence: The proportion of individuals in a population having a disease. Prevalence is a statistical concept referring to the number of cases of a disease that are present in a particular population at a given time.
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Prion: A disease-causing agent that is neither bacterial nor fungal nor viral and contains no genetic material. A prion is a protein that occurs normally in a harmless form. By folding into an aberrant shape, the normal prion turns into a rogue agent. It then coopts other normal prions to become rogue prions.
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Progestin: Any one of a group of steroid hormones that have the effect of progesterone.

Progressive: Increasing in scope or severity. Advancing. Going forward. In medicine, a disease that is progressive is going from bad to worse.
See the entire definition of Progressive

Progressive multifocal leukoencephalopathy: A rapidly progressive, often fatal viral infection of the brain. Commonly abbreviated as PML.
See the entire definition of Progressive multifocal leukoencephalopathy

Protein: A large molecule composed of one or more chains of amino acids in a specific order determined by the base sequence of nucleotides in the DNA coding for the protein.
See the entire definition of Protein

Proteins: Large molecules composed of one or more chains of amino acids in a specific order determined by the base sequence of nucleotides in the DNA coding for the protein.
See the entire definition of Proteins

Psychiatric: Pertaining to or within the purview of psychiatry , the medical specialty concerned with the prevention, diagnosis , and treatment of mental illness.
See the entire definition of Psychiatric

Psychosis: In the general sense, a mental illness that markedly interferes with a person's capacity to meet life's everyday demands. In a specific sense, it refers to a thought disorder in which reality testing is grossly impaired.
See the entire definition of Psychosis

Public health: The approach to medicine that is concerned with the health of the community as a whole. Public health is community health. It has been said that: "Health care is vital to all of us some of the time, but public health is vital to all of us all of the time."
See the entire definition of Public health

Pulmonary: Having to do with the lungs. (The word comes from the Latin pulmo for lung).

Pulmonary embolism: The obstruction of the pulmonary artery or a branch of it leading to the lungs by a blood clot, usually from the leg, or foreign material causing sudden closure of the vessel. (Embolus is from the Greek "embolos" meaning plug.)
See the entire definition of Pulmonary embolism

Quality of life: An important consideration in medical care, quality of life refers to the patient's ability to enjoy normal life activities. Some medical treatments can seriously impair quality of life without providing appreciable benefit, while others greatly enhance quality of life.

Referral: The recommendation of a medical or paramedical professional. If you get a referral to ophthalmology, for example, you are being sent to the eye doctor. In HMOs and other managed care schemes, a referral is usually necessary to see any practitioner or specialist other than your primary care physician (PCP), if you want the service to be covered. The referral is obtained from your PCP, who may require a telephone or office consultation first.
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Resistance: Opposition to something, or the ability to withstand it. For example, some forms of staphylococcus are resistant to treatment with antibiotics.
See the entire definition of Resistance

Risk factor: Something that increases a person's chances of developing a disease.

Robust: In statistics, a term applied to a test or procedure that is not seriously disturbed by violations of the assumptions on which it is based. For example, it was an "unexpected and robust difference in the rate of events." (Dr. Harold J. Burstein, in The New England Journal of Medicine, Oct 9, 2003)

Rule out: A term much used in medicine, meaning to eliminate or exclude something from consideration. The ACB (albumin cobalt binding) test helps rule out a heart attack in the differential diagnosis of severe chest pain.

Sanfilippo syndrome: The most common disorder of mucopolysaccharide metabolism, a syndrome in which the onset of clinical abnormalities is between the ages of 2 and 6 with mild coarsening of the facial features (but normal clear corneas), mild stiffening of the joints, slowing of growth, and intellectual deterioration resulting in severe mental retardation.
See the entire definition of Sanfilippo syndrome

Scan: As a noun, the data or image obtained from the examination of organs or regions of the body by gathering information with a sensing device.
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Sclerosis: Localized hardening of skin.

Senile: 1. Pertaining to old age. 2. Pertaining to the physical decline associated with old age. 3. Pertaining to the mental decline once associated with old age but now known to be due to dementia , such as Alzheimer's disease or cerebral atherosclerosis . "The road to senility is paved with plaques." (Paul F. Wehrle, MD [1921-2004] pediatrician and vaccine researcher)
See the entire definition of Senile

Senility: 1. Originally, old age. 2. The physical decline associated with old age. 3. The mental decline once associated with old age but now known to be due to dementia , as for instance Alzheimer's disease and atherosclerosis. "The road to senility is paved with plaques." (Paul F. Wehrle, MD [1921-2004] pediatrician and vaccine researcher who helped eradicate smallpox)
See the entire definition of Senility

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.

Sensory: Relating to sensation , to the perception of a stimulus and the voyage made by incoming ( afferent ) nerve impulses from the sense organs to the nerve centers.
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Sepsis: Commonly called a "blood stream infection." The presence of bacteria (bacteremia) or other infectious organisms or their toxins in the blood (septicemia) or in other tissue of the body. Sepsis may be associated with clinical symptoms of systemic (bodywide) illness, such as fever , chills, malaise (generally feeling "rotten"), low blood pressure , and mental status changes. Sepsis can be a serious situation, a life threatening disease calling for urgent and comprehensive care.
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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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Sleeplessness: Insomnia. See also Fatal familial insomnia.

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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SPECT: An acronym that stands for Single Photon Emission Computed Tomography, a nuclear medicine procedure in which a gamma camera rotates around the patient and takes pictures from many angles, which a computer then uses to form a tomographic (cross-sectional) image.
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Speech therapy: The treatment of speech and communication disorders. The approach used depends on the disorder. It may include physical exercises to strengthen the muscles used in speech (oral-motor work), speech drills to improve clarity, or sound production practice to improve articulation.
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Spinal cord: The major column of nerve tissue that is connected to the brain and lies within the vertebral canal and from which the spinal nerves emerge. Thirty-one pairs of spinal nerves originate in the spinal cord: 8 cervical , 12 thoracic , 5 lumbar, 5 sacral, and 1 coccygeal. The spinal cord and the brain constitute the central nervous system ( CNS ). The spinal cord consists of nerve fibers that transmit impulses to and from the brain. Like the brain, the spinal cord is covered by three connective-tissue envelopes called the meninges . The space between the outer and middle envelopes is filled with cerebrospinal fluid ( CSF ), a clear colorless fluid that cushions the spinal cord against jarring shock. Also known simply as the cord.
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Spleen: An organ located in the upper left part of the abdomen near the stomach . The spleen produces lymphocytes ; it is the largest lymphatic organ in the body. The spleen also filters the blood, serves as a major reservoir for blood and destroys blood cells that are aged.
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Spongiform: Resembling a sponge in being soft and full of cavities, as in as in transmissible spongiform encephalopathy.

Sporadic: Occurring upon occasion or in a scattered, isolated or seemingly random way.
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Statins: A class of drugs that lower cholesterol .
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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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Stroke : The sudden death of some brain cells due to a lack of oxygen when the blood flow to the brain is impaired by blockage or rupture of an artery to the brain. A stroke is also called a cerebrovascular accident or, for short, a CVA.
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Subdural: Below the dura, the outermost, toughest, and most fibrous of the three membranes (meninges) covering the brain and the spinal cord. An subdural hematoma is a collection of blood beneath the dura.

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.

Substance abuse: The excessive use of a substance, especially alcohol or a drug. (There is no universally accepted definition of substance abuse.)
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Sulci: The plural of sulcus.

Supportive care: Treatment given to prevent, control, or relieve complications and side effects and to improve the patient's comfort and quality of life.

Surgery: The word "surgery" has multiple meanings. It is the branch of medicine concerned with diseases and conditions which require or are amenable to operative procedures. Surgery is the work done by a surgeon. By analogy, the work of an editor wielding his pen as a scalpel is s form of surgery. A surgery in England (and some other countries) is a physician's or dentist's office.
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Symptom: Any subjective evidence of disease. Anxiety, lower back pain, and fatigue are all symptoms. They are sensations only the patient can perceive. In contrast, a sign is objective evidence of disease. A bloody nose is a sign. It is evident to the patient, doctor, nurse and other observers.

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

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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Syphilis: A sexually transmitted disease caused by Treponema pallidum, a microscopic organism called a spirochete. This worm-like, spiral-shaped organism infects people by burrowing into the moist mucous membranes of the mouth or genitals. From there, the spirochete produces a non-painful ulcer known as a chancre. There are three stages of syphilis:
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Systolic: The blood pressure when the heart is contracting. It is specifically the maximum arterial pressure during contraction of the left ventricle of the heart. The time at which ventricular contraction occurs is called systole.
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Telomerase: An enzyme concerned with the formation, maintenance, and renovation of telomeres , the ends of chromosomes . Telomerase regulates the proliferative capacity of human cells. Telomerase activation plays a critical role in the progression of cancer as well as in normal somatic cells. Failure to activate sufficient telomerase promotes disease.
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Temporal: 1. Pertaining to time, limited in time, temporary, or transient.
2. Pertaining to the temple region of the head. The temporal lobe of the brain is located beneath the temple.
From the Latin tempus which means both time and the temple of the head.

Temporal arteritis: Also called giant cell arteritis or cranial arteritis, this is a serious disease characterized by inflammation of the walls of the blood vessels (vasculitis). The vessels affected by inflammation are the arteries (hence the name "arteritis"). The age of affected patients is usually over 50 years of age. Giant cell arteritis can lead to blindness and/or stroke. It is detected by a biopsy of an artery. It is treated with high dose cortisone-related medications.

Therapy: The treatment of disease .
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Thiamine: Vitamin B1. Thiamine (vitamin B1) acts as a coenzyme in the metabolism of the body. Deficiency of thiamine leads to beriberi, a syndrome characterized by inflammation of multiple nerves (polyneuritis), heart disease (cardiopathy), and edema (swelling).
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Thyroid: 1. The thyroid gland . Also, pertaining to the thyroid gland. 2. A preparation of the thyroid gland used to treat hypothyroidism . 3. Shaped like a shield. (The thyroid gland was so-named by Thomas Wharton in 1656 because it was shaped like an ancient Greek shield.)
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Tomography: The process for generating a tomogram , a two-dimensional image of a slice or section through a three-dimensional object. Tomography achieves this remarkable result by simply moving an x-ray source in one direction as the x-ray film is moved in the opposite direction during the exposure to sharpen structures in the focal plane, while structures in other planes appear blurred. The tomogram is the picture; the tomograph is the apparatus; and tomography is the process.
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Toxicology: The study of the nature, effects and detection of poisons and the treatment of poisoning.
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Trauma: Any injury , whether physically or emotionally inflicted. "Trauma" has both a medical and a psychiatric definition. Medically, "trauma" refers to a serious or critical bodily injury, wound, or shock . This definition is often associated with trauma medicine practiced in emergency rooms and represents a popular view of the term. In psychiatry , "trauma" has assumed a different meaning and refers to an experience that is emotionally painful, distressful, or shocking, which often results in lasting mental and physical effects.
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Traumatic brain injury: Brain damage from trauma. The three leading causes of death from traumatic brain injury relate to firearms, motor vehicles and falls. The leading causes of death differ by age group. Motor vehicles are the leading cause among youth from birth to 19 years of age. Firearms are the leading cause of death among persons aged 20 to 74 years. Falls are the leading cause of death among persons aged 75 and older.

Tremor: Any abnormal repetitive shaking movement of the body. Tremors have many causes and can be inherited, be related to illnesses such as thyroid disease, or caused by fever, hypothermia, drugs or fear.

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.

Urinalysis : A test that determines the content of the urine. Because urine removes toxins and excess liquids from the body, it can contain important clues. Urinalysis can be used to detect some types of disease, particularly in the case of metabolic disorders and kidney disease. It can also be used to uncover evidence of drug abuse .
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Urinary: Having to do with the kidneys, ureters, and bladder. The urinary system represents the functional and anatomic aspects of the kidneys, ureters, and bladder.

Urinary incontinence : The unintentional loss of urine. Inability to hold urine in the bladder due to loss of voluntary control over the urinary sphincters re