Tremors Glossary of TermsThe following are health and medical definitions of terms that appear in the Tremors article.
Ablation: Removal or excision. Ablation is usually carried out surgically. For example, surgical removal of the thyroid gland (a total thyroidectomy) is ablation of the thyroid. The word ablation comes from the Latin ablatum meaning to carry away. 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). Acute: Of abrupt onset, in reference to a disease. Acute often also connotes an illness that is of short duration, rapidly progressive, and in need of urgent care. Addiction: A chronic relapsing condition characterized by compulsive drug-seeking and abuse and by long-lasting chemical changes in the brain. Addiction is the same irrespective of whether the drug is alcohol, amphetamines, cocaine, heroin, marijuana, or nicotine. Every addictive substance induces pleasant states or relieves distress. Continued use of the addictive substance induces adaptive changes in the brain that lead to tolerance, physical dependence, uncontrollable craving and, all too often, relapse. Dependence is at such a point that stopping is very difficult and causes severe physical and mental reactions from withdrawal. The risk of addiction is in part inherited. Genetic factors, for example, account for about 40% of the risk of alcoholism. The genetic factors predisposing to addiction are not yet fully understood. Amelioration: Not a word confined to medicine but a word used in medicine, amelioration is synonymous with improvement. Amitriptyline: An antidepressant medication. In some patients with depression, abnormal levels of brain chemicals called neurotransmitters may relate to the depression. Amitriptyline elevates mood by raising the level of neurotransmitters in brain tissue. Amitriptyline is also a sedative that is useful for depressed patients with insomnia, restlessness, and nervousness. It is sometimes used to treat fibromyalgia and symptoms related to chronic pain. Brand names are Elavil and Endep. A generic version is available. Anticonvulsant: A medication used to control (prevent) seizures (convulsions) or stop an ongoing series of seizures. There are a large number of anticonvulsant drugs today including, but not limited to: phenobarbital, phenytoin (Dilantin), carbamazepine, ethosuximide (Zarontin), clonazepam (Klonopin), diazepam (Valium), lorazepam (Ativan), and midazolam (Versed). Anticonvulsant drugs taken during pregnancy put the baby at risk of major birth defects -- growth retardation, microcephaly (a small head) and deformities of the face and fingers -- a condition known as anticonvulsant embryopathy. Antidepressants: Anything, and especially a drug, used to prevent or treat depression. 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. Arms: An appendage in anatomy and in clinical trials. See: Arm. Arsenic: A metallic element that forms a number of poisonous compounds, arsenic is found in nature at low levels mostly in compounds with oxygen, chlorine, and sulfur. These are called inorganic arsenic compounds. Arsenic in plants and animals combines with carbon and hydrogen. This is called organic arsenic. Organic arsenic is usually less harmful than inorganic arsenic. 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. Basal ganglia: A region consisting of 3 clusters of neurons (called the caudate nucleus, putamen, and the globus pallidus) located at the base of the brain that are responsible for involuntary movements such as tremors, athetosis, and chorea. The basal ganglia are abnormal in a number of important neurologic conditions including Parkinson disease and Huntington disease. The term "basal ganglia" refers to the fact that this region is in the "basement" of the brain. Benign: Not cancer. Not malignant. A benign tumor does not invade surrounding tissue or spread to other parts of the body. A benign tumor may grow but it stays put (in the same place). Bilateral: Having, or relating to, two sides. Bilateral is as opposed, for example, to unilateral (which means having, or relating to, one side). Blood count: The calculated number of white or red blood cells (WBCs or RBCs) in a cubic millimeter of blood. Botulinum toxin: A toxin produced by the bacterium Clostridium botulinum that is the most poisonous biological substance known. Botulinum toxin acts as a neurotoxin. It binds to the nerve ending at the point where the nerve joins a muscle, blocking the release by the nerve of the chemical acetylcholine (the principal neurotransmitter at the neuromuscular junction), preventing the muscle from contracting. The result is weakness and paralysis of the muscle. The muscle atrophies. The blockage of acetylcholine release is irreversible. Function can be recovered by the sprouting of nerve terminals and the formation of new synaptic contacts, which usually takes 2 to 3 months. 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." Caffeine: A stimulant found naturally in coffee beans, tea leaves, cocoa beans (chocolate) and kola nuts (cola) and added to soft drinks, foods, and medicines. A cup of coffee has 100-250 milligrams of caffeine. Black tea brewed for 4 minutes has 40-100 milligrams. Green tea has one-third as much caffeine as black tea. 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. Learn more about calcium with evidence-based information on RxList.CBC: A commonly used abbreviation in medicine that stands for 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. Cerebellar: Pertaining to the cerebellum, the part of the brain in the back of the head between the cerebrum and the brain stem. The cerebellum controls balance for walking and standing and other complex motor functions. Cerebellum: The portion of the brain in the back of the head between the cerebrum and the brain stem. The cerebellum controls balance for walking and standing and other complex motor functions. Chin: Medically, the mentum. The lower portion of the face below the lower lip including the prominence of the lower jaw and the line of fusion of the two separate halves of the jawbone (mandible). This line of fusion (called the symphysis menti) encloses a triangular area at tip of the chin (termed the mental protuberance). On each side, below the second premolar tooth, is the mental foramen, an opening for the passage of blood vessels and a nerve that supply the chin. Chronic: This important term in medicine comes from the Greek chronos, time and means lasting a long time. Cocaine: The most potent stimulant of natural origin, a bitter addictive anesthetic (pain blocker) which is extracted from the leaves of the coca scrub (Erythroxylon coca) indigenous to the Andean highlands of South America. 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. Contralateral: On the other side. The contralateral breast is the breast on the other breast. A stroke affecting the right side of the brain may cause contralateral paralysis, affecting the left arm and leg. The opposite of contralateral is ipsilateral which refers to the same side. Cortisol: The primary stress hormone. Cortisol is the major natural GLUCOCORTICOID (GC) in humans. 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. 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. Dementia: Significant loss of intellectual abilities such as memory capacity, severe enough to interfere with social or occupational functioning. 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. Distal: The more (or most) distant of two (or more) things. For example, the distal end of the femur (the thigh bone) is the end down by the knee; the end more distant from the torso. The distal bile duct is the far end of the cystic duct, the end away from the gallbladder. And the distal lymph node in a chain of nodes is the most distant one. The opposite of distal is proximal. Dopamine: An important neurotransmitter (messenger) in the brain. Encephalopathy: Disease, damage, or malfunction of the brain. In general, encephalopathy is manifested by an altered mental state that is sometimes accompanied by physical changes. Although numerous causes of encephalopathy are known, the majority of cases arise from infection, liver damage, anoxia, or kidney failure. The term encephalopathy is very broad and, in most cases, is preceded by various terms that describe the reason, cause, or special conditions of the patient that leads to brain malfunction. For example, anoxic encephalopathy means brain damage due to lack of oxygen, and hepatic encephalopathy means brain malfunction due to liver disease. Depending upon the cause and severity of the condition, symptoms may range from mild alterations in mental status to severe and potentially fatal manifestations such as dementia, seizures, and coma. Endep: See: Amitriptyline. Eskalith: See: Lithium. Essential: 1. Something that cannot be done without. Essential tremor: Uncontrollable shaking (tremor) of the hands and head and sometimes other parts of the body. Essential tremor is the most common of all movement disorders and is estimated to affect 3 to 4 million people in the US. In more than half of cases, essential tremor is inherited in an autosomal dominant manner. In 1997, the ETM1 gene (also called FET1) was mapped to chromosome 3 in a study of Icelandic families while another gene, called ETM2, was mapped to chromosome 2 in a large American family of Czech descent. That two genes for essential tremor have been found on two different chromosomes demonstrates that mutations in various genes may lead to essential tremor. The mainstays of treatment are drugs such as propranolol and primidone. Excise: To cut out. A laser beam may be used to excise a tumor, much as a scalpel does. The terms excise and resect are not synonymous. Excise implies total removal whereas resect does not. Eyelid: The lid or cover of the eye, a movable fold of skin and muscle that can be closed over the eyeball or opened at will. Each eye has an upper and a lower lid. An eyelid is also called a palpebra. 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). Flexion: The process of bending or the state of being bent. Flexion of the fingers results in a clenched fist. Flutter: Flutter is a rapid vibration or pulsation. The difference between flutter and fibrillation is that flutter is well organized while fibrillation is not. 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. Gamma knife: A type of radiosurgery (radiation therapy) machine that acts by focusing low-dosage gamma radiation from many sources on a precise target. Areas adjacent to the target receive only slight doses of radiation, while the target gets the full intensity. Gene: The basic biological unit of heredity. A segment of deoxyribonucleic acid (DNA) needed to contribute to a function. Genetic: Having to do with genes and genetic information. Horizontal: In anatomy, a plane passing through the standing body. A person lying on a bed is considered in a horizontal position. Hormone: A chemical substance produced in the body that controls and regulates the activity of certain cells or organs. 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. Hyperparathyroidism: Too much parathyroid hormone resulting in abnormally high levels of calcium in the blood (hypercalcemia). This can cause bone resorption and osteoporosis, calcium deposits in the kidneys, muscular weakness, nausea, vomiting, abdominal pains, and drowsiness. Hyperparathyroidism can be primary or secondary. Primary hyperparathyroidism is a disorder of the parathyroid glands in which one or more of the parathyroid glands are enlarged (hyperplastic), overactive, and secrete too much parathyroid hormone. In secondary hyperparathyroidism, the parathyroid glands themselves are normal but a problem such as kidney failure makes the body resistant to the action of parathyroid hormone. Hypocalcemia: Lower-than-normal blood calcium. Low blood calcium makes the nervous system highly irritable with tetany (spasms of the hands and feet, muscle cramps, abdominal cramps, and overly active reflexes). Chronic hypocalcemia contributes to poor mineralization of bones, soft bones (osteomalacia) and osteoporosis. In children, hypocalcemia leads to rickets and impaired growth. 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 gram daily for both men and women. The upper limit for calcium intake is 2.5 grams daily. 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. Hypomagnesemia: Too little magnesium. Magnesium deficiency can occur due to inadequate intake or impaired intestinal absorption of magnesium. Low magnesium (hypomagnesemia) is often associated with low calcium (hypocalcemia) and low potassium (hypokalemia). Deficiency of magnesium causes increased irritability of the nervous system with tetany (spasms of the hands and feet, muscular twitching and cramps, spasm of the larynx, etc.). According to the National Academy of Sciences, the Recommended Dietary Allowances of magnesium are 420 milligrams per day for men and 320 milligrams per day for women. The upper limit of magnesium as supplements is 350 milligrams daily, in addition to the magnesium from food and water. Hyponatremia: An abnormally low concentration of sodium in the blood. Too little sodium can cause cells to malfunction, and extremely low sodium can be fatal. Hyponatremia has many causes including medications such as diuretics and antidepressants, hypothyroidism, cortisone deficiency (such as in Addison's disease), dehydration, vomiting or diarrhea, severe burns, kidney or heart failure, and cirrhosis. 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. Impotence: A common problem among men characterized by the consistent inability to sustain an erection sufficient for sexual intercourse or the inability to achieve ejaculation, or both. Impotence can vary. It can involve a total inability to achieve an erection or ejaculation, an inconsistent ability to do so, or a tendency to sustain only very brief erections. 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. Jaw: The bones below the mouth (the mandible) and the bone above the mouth just above the mouth (the maxilla). The word jaw comes from the Anglo-Saxon ceowan meaning to chew. 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. 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. See the entire definition of Kidney Limb: The arm or leg. Lips: Aside from the lips of the mouth, there are two pairs of lips at the entrance to the vagina. They are the labia majora (the larger outside pair) and the labia minora (the smaller inside pair). Together they form part of the vulva (the female external genitalia). Lithium: Lithium carbonate (brand names: Eskalith; Lithobid), a drug used as a mood stabilizer for the treatment of manic/depressive (bipolar) disorder. It prevents or diminishes the intensity of episodes of mania in bipolar patients. Typical symptoms of mania include pressure of speech, motor hyperactivity, reduced need for sleep, flight of ideas, grandiosity, elation, poor judgment, aggressiveness and possibly hostility. Lithobid: See: Lithium. 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. See the entire definition of Liver Liver disease: Liver disease refers to any disorder of the liver. The liver is a large organ in the upper right abdomen that aids in digestion and removes waste products from the blood. Magnesium: A mineral involved in many processes in the body including nerve signaling, the building of healthy bones, and normal muscle contraction. About 350 enzymes are known to depend on magnesium. 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. 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). 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. Mouth: 1. The upper opening of the digestive tract, beginning with the lips and containing the teeth, gums, and tongue. Foodstuffs are broken down mechanically in the mouth by chewing and saliva is added as a lubricant. Saliva contains amylase, an enzyme that digests starch. 2. Any opening or aperture in the body. The mouth in both senses of the word is also called the os, the Latin word for an opening, or mouth. The o in os is pronounced as in hope. The genitive form of os is oris from which comes the word oral. MRI: Abbreviation and nickname for magnetic resonance imaging. For more information, see: Magnetic Resonance Imaging; Paul C. Lauterbur; Peter Mansfield. Multiple sclerosis: Abbreviated MS. A disease of the central nervous system (CNS) marked by numbness, weakness, loss of muscle coordination, and problems with vision, speech, and bladder control. MS is an autoimmune disease in which the body's immune system attacks myelin, a key substance that serves as a nerve insulator and helps in the transmission of nerve signals. The progress, severity and specific symptoms in MS are unpredictable. One never knows when attacks will occur, how long they will last, or how severe they will be. Most people with MS are between the ages of 20 and 40 at the time of diagnosis. The term "multiple" refers to the multiple places in the CNS that are affected and to the multiple relapses and remissions characteristic of MS. 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." 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. 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. Neuroleptic: A term that refers to the effects of antipsychotic drugs on a patient, especially on his or her cognition and behavior. 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. Neurosyphilis: Neurological complications in the third (tertiary) and final phase of syphilis, which involve the central nervous system and can include psychosis, pain, and loss of physical control over a variety of bodily functions. Nicotine: An alkaloid (a nitrogen-containing chemical) made by the tobacco plant or produced synthetically. In the plant kingdom, nicotine is not restricted to tobacco but is widespread. The tobacco plant, Nicotiana tabacum, belongs to the nightshade family, which also includes potatoes, tomatoes, eggplant and red peppers. All contain nicotine. However, the concentration of nicotine in those vegetables is far lower than the level in tobacco. Nicotine has powerful pharmacologic effects (including increased heart rate, heart stroke volume, and oxygen consumption by the heart muscle) as well as powerful psychodynamic effects (such as euphoria, increased alertness, and a sense of relaxation). As is now well known, nicotine is also powerfully addictive. When someone becomes habituated to nicotine and then stops using it, they experience the symptoms of withdrawal, including anxiety, irritability, restlessness, shortened attention span and an intense, sometimes irresistible, craving for nicotine. Nitrogen: Element number 7, a colorless, odorless, tasteless gas that is biologically important. Nitrogen is a constituent of protein and nucleic acids and is present in all living cells. Nitrogen does not support respiration and is fatal if breathed alone, because of the lack of oxygen. Nitrogen is soluble in the blood and body fluids and, when released as bubbles of gas, can have serious or even fatal consequences. Nose: The external midline projection from the face. Nuclei: The plural of nucleus. Nucleus: 1) In cell biology, the structure that houses the chromosomes. 2) In neuroanatomy, a group of nerve cells. 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. Operation: Although there are many meanings to the word "operation", in medicine it refers to a surgical procedure. 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. Pallidotomy: A surgical operation performed on the globus pallidus to destroy it. The purpose of this operation is to relieve involuntary movements or muscular rigidity, as, for example, in Parkinson's disease. 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." Parathyroid hormone: See Parathormone. Parkinson's disease: See: Parkinson disease. Parkinsonism: 1. Parkinson disease. 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. Physiologic: Something that is normal, neither due to anything pathologic nor significant in terms of causing illness. Postural: Pertaining to the posture or position of the body, the attitude or carriage of the body as a whole, or the position of the limbs (the arms and legs). Postural hypotension is a drop in blood pressure (hypotension) due to a change in body position (a change in posture). It occurs when a person, often an older person, moves to a more vertical position: from sitting to standing or from lying down to sitting or standing. The change in posture causes a temporary reduction in blood flow and therefore a shortage of oxygen to the brain, which leads to lightheadedness and, sometimes, a "black out" episode, a loss of consciousness. Posture: The carriage of the body as a whole, the attitude of the body, or the position of the limbs (the arms and legs). Primary care: The "medical home" for a patient, ideally providing continuity and integration of health care. All family physicians and most pediatricians and internists are in primary care. The aims of primary care are to provide the patient with a broad spectrum of care, both preventive and curative, over a period of time and to coordinate all of the care the patient receives. Progressive: Increasing in scope or severity. Advancing. Going forward. In medicine, a disease that is progressive is going from bad to worse. Progressive supranuclear palsy: A neurologic disorder of unknown origin that gradually destroys cells in many areas of the brain, leading to serious and permanent problems with the control of gait and balance. The most obvious sign of the disease is an inability to aim the eyes properly, which occurs because of damage in the area of the brain that coordinates eye movements. Some patients describe this effect as a blurring. Another common visual problem is an inability to maintain eye contact during a conversation. This can give the mistaken impression that the patient is hostile or uninterested. Patients also often show alterations of mood and behavior, including depression and apathy as well as progressive mild dementia. Psychiatrist: A physician (an M.D.) who specializes in the prevention, diagnosis, and treatment of mental illness. Psychiatrists must receive additional training and serve a supervised residency in their specialty. They may also have additional training in a psychiatric specialty, such as child psychiatry or neuropsychiatry. They can prescribe medication, which psychologists cannot do. Psychogenic: Caused by the mind or emotions. Radiation: 1. Rays of energy. Gamma rays and X-rays are two of the types of energy waves often used in medicine. 2. The use of energy waves to diagnose or treat disease. See also: Irradiation. Refractory: Not yielding (at least not yielding readily) to treatment. Risk factor: Something that increases a person's chances of developing a disease. 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. 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. Sclerosis: Localized hardening of skin. Serum: The clear liquid that can be separated from clotted blood. Serum differs from plasma, the liquid portion of normal unclotted blood containing the red and white cells and platelets. It is the clot that makes the difference between serum and plasma. Somatization: The process by which psychologic distress is expressed as physical symptoms. Somatization is an unconscious process. 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. Spinocerebellar: Pertaining to the spinal cord and the cerebellum, as in spinocerebellar ataxia (ataxia with cerebellar malfunction). Static posture: Any posture that is held for a long time. A static posture may result in fatigue and even injury over time. 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. 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. 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. 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. 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.) Thyroid hormone: A chemical substance made by the thyroid gland for export into the bloodstream. The thyroid gland needs iodine to make thyroid hormones. The two most important thyroid hormones are thyroxine (T4) and triiodothyronine (T3). Thyroid hormones: Chemical substances made by the thyroid gland, which is located in the front of the neck. This gland uses iodine to make thyroid hormones, which are essential for the function of every cell in the body. They help regulate growth and the rate of chemical reactions (metabolism), and are involved in the circadian rhythms that govern sleep, among other essential functions. Tongue: The tongue is a strong muscle anchored to the floor of the mouth. It is covered by the lingual membrane which has special areas to detect tastes. Toxin: One of a number of poisons produced by certain plants, animals, and bacteria. 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. Unilateral: Having, or relating to, one side. Unilateral is as opposed, for example, to bilateral (which means having, or relating to, two sides). Urea: A nitrogen-containing substance normally cleared from the blood by the kidney into the urine. Diseases that compromise the function of the kidney often lead to increased blood levels of urea, as measured by the blood urea nitrogen (BUN) test. Urine: Liquid waste. The urine is a clear, transparent fluid. It normally has an amber color. The average amount of urine excreted in 24 hours is from 40 to 60 ounces (about 1,200 cubic centimeters). Chemically, the urine is mainly an aqueous (watery) solution of salt (sodium chloride) and substances called urea and uric acid. Normally, it contains about 960 parts of water to 40 parts of solid matter. Abnormally, it may contain sugar (in diabetes), albumen (a protein) (as in some forms of kidney disease), bile pigments (as in jaundice), or abnormal quantities of one or another of its normal components. Vascular: Relating to the blood vessels of the body. The blood vessels of the body, as a group, are referred to as the vascular system. Ventral: Pertaining to the front or anterior of any structure. The ventral surfaces of the body include the chest, abdomen, shins, palms, and soles. Ventral is as opposed to dorsal. From the Latin "venter" meaning belly. Vertical: In anatomy, upright. As opposed to horizontal. Wrist: The proximal segment (the near part) of the hand consisting of the carpal bones and the associated soft parts.
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Tremors
Topic Overview
Tremor is an involuntary shaking movement that is repeated over and over. Although it may affect any part of the body, tremor most often affects the hands and head. Your voice may also shake. Sometimes the feet or torso may also shake.
Essential tremor, which sometimes runs in families, is one of the most common types of tremor. It is shaking that is most noticeable when you are doing something like lifting a cup or pointing at an object. The shaking does not occur when you are not moving. Medicine can help reduce the shaking. Brain surgery can be helpful in some cases.
Tremors can also be caused by conditions or medicines that affect the nervous system, including Parkinson's disease, liver failure, alcoholism, mercury or arsenic poisoning, lithium, and certain antidepressants. Side effects from other medicines can also cause tremors.
If you notice a tremor, observe it carefully and note what seems to make it better or worse before calling ...
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