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Medical Terminology

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  • a

  • actigraphy
    Actigraphy is used to noninvasively measure body movement. An actigraph, which looks like an oversized watch, is typically worn on the nondominant wrist (that is, if you are right-handed, you would wear it on your left wrist). It contains an accelerometer and records movements that are then downloaded from the device and analyzed off line. When combined with a sleep diary or sleep log, actigraphy can be used to measure sleep patterns and circadian rhythms.
  • agonist
    An agonist is a chemical that binds to and activates a receptor. The result is a biologic response—an action.
  • allele
    An allele is one member of a pair of genes that is located at a specific position on a specific chromosome.
  • allosteric modulator
    Allosteric modulators are substances that indirectly influence or modulate the effects of an agonist at a receptor. GABAA receptor positive allosteric modulators increase the activity of the GABAA receptor protein in the central nervous system of mammals. Examples of positive allosteric modulators include alcohol, benzodiazepines (such as Valium), benzodiazepine-receptor agonists (such as Ambien or Lunesta), anesthetic gases, and propofol. Negative allosteric modulators inhibit or decrease the activity of the GABAA receptor protein. Examples of negative allosteric modulators or inhibitors of GABAA activity are flumazenil, bicuculline, pentylenetetrazol, and gabazine.
  • apathy
    Apathy refers to a lack of feeling, emotion, interest, or concern for self or others.
  • autonomic nervous system
    The autonomic nervous system (ANS) is made up of three parts: the sympathetic nervous system, the parasympathetic nervous system, and the enteric nervous system. The ANS regulates functions that are involuntary or reflexes, things that we are usually not aware of, such as heart rate and blood pressure. The ANS is most well known for regulating our flight-or-fight response when we encounter a frightening or dangerous situation.
  • b

  • Beck Depression Inventory
    The Beck Depression Inventory is a widely used 21-item questionnaire for measuring severity of depression.
  • biomarker
    A biomarker (which is a short for biological marker) is a substance that is found in blood, other body fluids, or tissues that indicates a normal or abnormal process, a condition or disease, or the effects of treatment.
  • c

  • carnitine
    Carnitine is a substance that our bodies make in our liver and kidneys. It is then stored in our skeletal muscles, heart, brain, and sperm. Carnitine helps to turn fat into energy. Our bodies usually make enough carnitine to satisfy all of their needs, but some people don't have enough carnitine because their bodies either can’t make enough or can’t transport the carnitine into tissues so it can be used.
  • cataplexy
    Cataplexy is a sudden and temporary episode of muscle weakness that is typically triggered by emotions (for example, laughing, crying, terror) in which the person remains fully conscious and aware.
  • CCR1/CCR3
    The CCR1 and CCR3 genes are involved in regulating the body’s response to bacteria, viruses, and other substances that the body perceives to be harmful or not a part of itself (that is, “foreign”).
  • cerebrospinal fluid
    Cerebrospinal fluid (CSF) is a clear, colorless liquid that bathes the brain and spinal cord. Its primary purpose is to protect the brain and spinal cord, acting as a barrier and shock absorber. This fluid also circulates nutrients and chemicals that are filtered from the blood and removes waste products, antibodies, chemicals, and disease-causing substances away from the brain and spinal-cord tissue into the bloodstream.
  • chemokine receptor 1 and 3
    The CCR1 and CCR3 genes are involved in regulating the body’s response to bacteria, viruses, and other substances that the body perceives to be harmful or not a part of itself (that is, “foreign”).
  • Clinical Global Impression-Improvement scale
    The Clinical Global Impression-Improvement scale (CGI-I) is a 7-point scale that requires the clinician to assess how much the patient's illness has improved or worsened relative to a baseline state at the beginning of an intervention. Responses include 1, very much improved; 2, much improved; 3, minimally improved; 4, no change; 5, minimally worse; 6, much worse; or 7, very much worse.
  • Clinical Global Impression-Severity scale
    The Clinical Global Impression-Severity scale (CGI-S) is a 7-point scale that healthcare professionals or researchers (clinicians) use to rate the patient’s severity of illness at the time of assessment, as compared with the clinician's past experience with patients who have the same diagnosis.
  • control subject
    In an experiment or clinical trial, control subjects make up a group of participants who have characteristics similar to those of the treatment group, but they do not receive the treatment being studied. In observational studies, the control subjects have similar characteristics as those participants being studied, except that they do not have the symptom, disease, syndrome, or disorder being studied.
  • Crossover study
    In a crossover study, each participant receives both the placebo and active drug for a defined period of time. The order in which people receive the different treatments is determined randomly, and the responses participants have to each of the different treatments are compared.
  • CSF
    Cerebrospinal fluid (CSF) is a clear, colorless liquid that bathes the brain and spinal cord. Its primary purpose is to protect the brain and spinal cord, acting as a barrier and shock absorber. This fluid also circulates nutrients and chemicals that are filtered from the blood and removes waste products, antibodies, chemicals, and disease-causing substances away from the brain and spinal-cord tissue into the bloodstream.
  • d

  • derealization
    Derealization is the repeated sense of feeling as if you are observing yourself from outside your body or that things around you aren't real, or both.
  • differential diagnosis
    In medicine, the process of considering other diagnoses which have similar symptoms or signs.
  • double-blind
    A double-blind trial or study is one in which neither the people who are doing the experiment nor the people who are the subjects of the experiments know which of the groups being studied is receiving the substance under investigation (active group) or is receiving placebo (control group).
  • dysautonomia
    Dystautonomia, or autonomic dysfunction, is a broad term that refers to any of a number of conditions that result from a problem or disturbance in the autonomic nervous system.
  • e

  • EDS
    Excessive daytime sleepiness refers to persistent sleepiness that occurs even with adequate or even prolonged nighttime sleep.
  • effector cell
    An effector cell is a muscle, gland or organ cell that is capable of responding to a stimulus.
  • electroencephalography
    Electroencephalography is the measurement and recording of the brain's electrical activity.
  • EMA
    The European Medicines Agency (EMA), which began in 1995, is a decentralized agency of the European Union located in London. The Agency is responsible for the scientific evaluation of medicines developed by pharmaceutical companies for use in the European Union.
  • encoding
    Our genes provide the blueprint or code to arrange amino acids to make proteins in our bodies.
  • endogenous
    An endogenous substance originates from or is produced within an organism (such as the human body), tissue or cell.
  • Epworth Sleepiness Scale
    The Epworth Sleepiness Scale (ESS) is a set of questions that measures how likely you are to fall asleep in each of 8 situations. You respond with 0 (would never doze), 1 (slight chance of dozing), 2 (moderate chance of dozing), or 3 (high chance of dozing). Your responses are added to make a final score, which can range between 0 and 24 and indicates your level of sleepiness. Higher scores indicate higher levels of daytime sleepiness. Most doctors and scientists consider scores of 10 or higher to indicate abnormal sleepiness.
  • etiology
    Etiology refers to the cause or basis of something.
  • European Medicines Agency
    The European Medicines Agency (EMA), which began in 1995, is a decentralized agency of the European Union located in London. The Agency is responsible for the scientific evaluation of medicines developed by pharmaceutical companies for use in the European Union.
  • excessive daytime sleepiness
    Excessive daytime sleepiness refers to persistent sleepiness that occurs even with adequate or even prolonged nighttime sleep.
  • exogenous
    An exogenous substance originates from or is produced outside an organism (such as the human body), tissue or cell.
  • f

  • FDA
    The United States Food and Drug Administration (FDA) is an agency within the U.S. Department of Health and Human Services. It is responsible for protecting the public health by ensuring the safety, effectiveness, quality, and security of human and veterinary drugs, vaccines, and other biologic products and medical devices. The FDA is also responsible for the safety and security of most of our nation’s food supply.
  • Food and Drug Administration
    The United States Food and Drug Administration (FDA) is an agency within the U.S. Department of Health and Human Services. It is responsible for protecting the public health by ensuring the safety, effectiveness, quality, and security of human and veterinary drugs, vaccines, and other biologic products and medical devices. The FDA is also responsible for the safety and security of most of our nation’s food supply.
  • functional outcomes of sleep questionnaire
    The Functional Outcomes of Sleep Questionnaire (FOSQ) was developed in 1997 as a means to measure the impact of excessive daytime sleepiness on a person’s daily ability to function. The 30 questions are divided into five subscales.
  • g

  • GABA
    γ-Aminobutyric acid or GABA is the main inhibitory neurotransmitter in the central nervous system (brain and spinal cord) of mammals. Its primary role is to reduce the excitability or dampen the actions of cells throughout the nervous system. In humans, GABA is also directly responsible for regulating muscle tone.
  • GABA-related hypersomnia
    GABA-related hypersomnia occurs in people who have one of the central disorders of hypersomnolence (idiopathic hypersomnia, Kleine-Levin syndrome, or narcolepsy) and the somnogen in their cerebrospinal fluid.
  • genome-wide association study
    A GWAS is a study that looks at people’s complete genetic material to identify DNA markers. It then compares the markers from people with a disease or trait to people without the disease or trait.
  • GWAS
    A GWAS is a study that looks at people’s complete genetic material to identify DNA markers. It then compares the markers from people with a disease or trait to people without the disease or trait.
  • h

  • histamine
    Histamine is a substance produced in the body that acts as a neurotransmitter. It is an important part of the reticular activating system (the part of the brain that wakes people up). Histamine may serve as a biomarker for problems or dysfunction in the hypothalamus. It is also involved in a number of activities, including the body’s immune and inflammatory responses and regulating the function of the gut.
  • HLA DQB1*0602 positive
    The HLA, or human leukocyte antigen, system is the location of genes that encode for proteins on the surface of white blood cells that are responsible for regulating our immune systems, our ability to fight infection. Most people with Type 1 narcolepsy carry the HLA-DQB1*0602 gene.
  • HLA typing
    The human leukocyte antigen (HLA) system is the location of a set of genes that encode for specific proteins (also called antigens). These inherited proteins are located on the surface of the white blood cells and other tissues in your body and are responsible for regulating your immune system.
  • humoral
    A humoral substance is a body fluid or related to a body fluid.
  • hypersexuality
    Hypersexuality refers to increased sexual urges or behavior.
  • hypersomnolence
    Hypersomnolence can refer to either excessive daytime sleepiness or prolonged nighttime sleep.
  • hypnagogic
    Hypnagogic is the transition from wakefulness to falling asleep.
  • hypnopompic
    Hypnopompic refers to the transition from sleep to wakefulness.
  • Hypocretin
    Hypocretin, also known as orexin, is a neurotransmitter that regulates alertness, mood, and appetite. Hypocretin/orexin was discovered almost at the same time by two different groups of researchers in the late 1990s. One of the groups, headed by Yanagasawa at University of Texas Southwestern in Dallas, was working on obesity and named the neurotransmitter orexin (orexis is Greek for appetite). The other group, based at Harvard named it hypocretin, because it is produced in thehypothalamus and somewhat resembles secretin, a hormone found in the gut. For now, the naming controversy continues—both camps are firmly entrenched in their terminology and neither will budge. Whatever its name, high levels of this neurotransmitter are associated with increased appetite, improved mood, and enhanced wakefulness. Low or nonexistent levels of hypocretin are found in the cerebrospinal fluid of people with Type 1 narcolepsy.
  • hypothalamus
    The hypothalamus is a very small part of the brain that has a number of very important functions: it controls the autonomic nervous system and processes and secretes neurohormones. These hormones regulate body temperature, hunger, thirst, sleep, fatigue, sex drive, mood, sleep, alertness, and circadian rhythms.
  • Hypothesis
    In science, a hypothesis is an idea or explanation that researchers then test in an experiment.
  • i

  • idiopathic hypersomnia
    Idiopathic hypersomnia (IH) is a sleep disorder in which people are excessively sleepy during the day independent of sleep duration. People with IH often wake feeling unrefreshed even after sleeping for long periods of time. They also have difficulty waking to alarms or external stimuli and may experience sleep inertia (difficulty moving and thinking after abrupt awakening) or confusional arousal.
  • IH
    Idiopathic hypersomnia (IH) is a sleep disorder in which people are excessively sleepy during the day independent of sleep duration. People with IH often wake feeling unrefreshed even after sleeping for long periods of time. They also have difficulty waking to alarms or external stimuli and may experience sleep inertia (difficulty moving and thinking after abrupt awakening) or confusional arousal.
  • In vitro
    In vitro means that something—in this circumstance, an experiment—takes place outside the body in an artificial environment.
  • inhibitory
    Inhibitory neurotransmitters, such as GABA and serotonin, decrease the likelihood that a nerve cell will send its chemical message on to the next nerve cell.
  • k

  • Kleine-Levin syndrome
    Kleine-Levin syndrome (KLS) is a rare disorder in which affected people experience episodes at least once per year during which they sleep for at least 11 hours out of every day (but often for days at a time), eat excessively (megaphagia), have abnormal thinking and behavior, and hypersexuality. Between episodes, their alertness, behavior, and thinking are normal
  • knockout mouse
    A knockout mouse is one in which researchers have inactivated, or "knocked out," an existing gene in the animal by replacing the gene or disrupting it with a different piece of DNA.
  • l

  • liquid chromatography mass spectrometry(LC/MS)
    LC/MS is a technique used to separate, identify, measure, and analyze substances in a mixture.
  • longitudinal
    In a longitudinal study, researchers observe the same subjects and repeatedly gather data, or information, over a period of time.
  • lumbar puncture
    A lumbar puncture is a medical procedure in which a needle is inserted through the skin of the lower back between two vertebrae, or bones of the spinal column, into the spinal canal. A sample of the cerebrospinal fluid is then removed and sent to a laboratory for testing.
  • m

  • magnetic resonance imaging
    MRI uses strong magnets and radio waves housed inside a specialized machine or scanner to make detailed 3-D pictures or images of organs and tissues within the body.
  • Maintenance of Wakefulness Test
    The purpose of the Maintenance of Wakefulness Test (MWT) is to see if you are able to stay awake during the daytime. The MWT takes place in a darkened, quiet, comfortable room. A technician places sensors on your head, face, and neck that can measure sleep. You recline in bed and try to stay awake during each of four measurement periods. The four measurement periods start about 9 or 10 am and last 40 minutes each. If you fall asleep, you are allowed to sleep for 90 seconds and are then awakened and kept awake until the next measurement period. If you don’t fall asleep within 40 minutes, that measurement period is ended. The measurement periods typically take place every two hours. This test is similar to the Multiple Sleep Latency Test (MSLT), but the MWT measures your likelihood of falling asleep when you are trying to stay awake. This is a subtle but important difference. Most people without sleep problems are able to stay awake for at least the first 8 minutes of each measurement period.
  • megaphagia
    Megaphagia, also referred to as polyphagia or hyperphagia, is an excessive appetite or hunger and abnormally large intake of solid food.
  • messenger RNA
    After being produced during transcription, mRNA carries information to the ribosome (the site in the cell where proteins are made).
  • metabolite
    A metabolite is any substance produced during digestion or other chemical processes that occur in the body. Metabolite may also refer to the product that remains after a drug is broken down by the body.
  • modafinil
    Modafinil is a wake-promoting drug that is approved by the United States' Food and Drug Administration (FDA) to improve wakefulness in adult patients with excessive sleepiness associated with narcolepsy, obstructive sleep apnea, and shift work disorder. In English-speaking countries, it is sold under the brand names Alertec (Canada), Modavigil (Australia, New Zealand), and Provigil (Ireland, South Africa, United Kingdom, United States).
  • MRI
    MRI uses strong magnets and radio waves housed inside a specialized machine or scanner to make detailed 3-D pictures or images of organs and tissues within the body.
  • mRNA
    After being produced during transcription, mRNA carries information to the ribosome (the site in the cell where proteins are made).
  • MSLT
    The multiple sleep latency test (MSLT) measures how quickly you fall asleep in a quiet environment during the day. The MSLT typically consists of five scheduled naps, each nap opportunity lasting 20 minutes, separated by two-hour breaks. During each of the nap opportunities, you lie in bed in a darkened quiet room and try to go to sleep. The time that it takes you to fall asleep is called the sleep latency. You will be allowed to sleep for a maximum of 15 minutes during each opportunity (You will be awakened if you don’t wake up on your own). If you do not fall asleep within 20 minutes, the nap trial will end.
  • Multiple Sleep Latency Test
    The multiple sleep latency test (MSLT) measures how quickly you fall asleep in a quiet environment during the day. The MSLT typically consists of five scheduled naps, each nap opportunity lasting 20 minutes, separated by two-hour breaks. During each of the nap opportunities, you lie in bed in a darkened quiet room and try to go to sleep. The time that it takes you to fall asleep is called the sleep latency. You will be allowed to sleep for a maximum of 15 minutes during each opportunity (You will be awakened if you don’t wake up on your own). If you do not fall asleep within 20 minutes, the nap trial will end.
  • MWT
    The purpose of the Maintenance of Wakefulness Test (MWT) is to see if you are able to stay awake during the daytime. The MWT takes place in a darkened, quiet, comfortable room. A technician places sensors on your head, face, and neck that can measure sleep. You recline in bed and try to stay awake during each of four measurement periods. The four measurement periods start about 9 or 10 am and last 40 minutes each. If you fall asleep, you are allowed to sleep for 90 seconds and are then awakened and kept awake until the next measurement period. If you don’t fall asleep within 40 minutes, that measurement period is ended. The measurement periods typically take place every two hours. This test is similar to the Multiple Sleep Latency Test (MSLT), but the MWT measures your likelihood of falling asleep when you are trying to stay awake. This is a subtle but important difference. Most people without sleep problems are able to stay awake for at least the first 8 minutes of each measurement period.
  • n

  • narcolepsy
    Narcolepsy is a neurologic disorder that affects the control of sleep and wakefulness.
  • neocortex
    If you look at a human or mammal’s brain from the top or the sides, what you see is the neocortex. In humans, this part of the brain. which is about 2-4 mm thick (a thickness somewhere between the size of the point of a crayon and the eraser end of a pencil) forms ridges or deep grooves called sulci. The neocortex in humans controls sensory perception, generation of motor commands, spatial reasoning, conscious thought, and language.
  • neuroendocrine
    Neuroendocrine cells receive input from neurotransmitters released by nerve cells and, as a result, release hormones into the bloodstream.
  • neuromodulator
    A neuromodulator is a chemical messenger released from a neuron in the central nervous system (the brain or spinal cord), or in the periphery, that affects not a single cell but groups of neurons or effector cells that have the appropriate receptors. Unlike a neurotransmitter, it may not be released at synaptic sites, it often acts through second messengers, and it can produce long-lasting effects. The release may be local, so that only nearby neurons or effectors are influenced, or it may be more widespread.
  • neuron
    A neuron is simply a nerve cell, which is a specialized cell that sends and receives messages.
  • neurons
    Nerve cells
  • neurotransmitter
    A neurotransmitter is a chemical messenger that allows nerve cells to “talk” with other nerve cells and with muscles, organs, or other tissue. This chemical is released from one nerve cell, or neuron, at a specialized location (synaptic site), or junction. It then spreads, or diffuses, across a narrow gap, or cleft, to affect one or sometimes two other neurons on the other side of the cleft (postsynaptic), a muscle cell, or another effector cell.
  • nucleotide
    The building block of DNA.
  • o

  • oxidation
    Oxidation is the process by which oxygen combines with an element and changes the appearance of the element. A simple example of slow oxidation is when iron reacts with oxygen and changes the iron to rust. An example of quick oxidation is when fire burns a log.
  • p

  • PET
    A PET scan creates computerized images of chemical changes that take place in tissue. In this test, various radioactive materials (tracers) and substances are injected into patients’ veins. The patient is then scanned in a special machine or scanner. Radiologists can then identify activity in certain parts of the brain by measuring blood flow and oxygen and glucose metabolism in the tissues of the working brain.
  • placebo
    A placebo is an inactive (or sham) substance that is designed to look like the substance or drug that is being studied. The placebo is used as a control in clinical trials and does not contain any active materials.
  • placebo-controlled trial
    placebo-controlled trial or study is one in which the effect of a drug is compared with the effect of a placebo. In placebo-controlled trials, participants receive either the drug being studied or a placebo. The results of the drug and placebo groups are then compared to see if the drug is more effective in treating the condition than is the placebo.
  • polysomnography
    Polysomnography, also called a sleep study, uses multiple electrodes and devices (multi-channel) to gather information about a patient during sleep. A standard in-laboratory study records brain waves, eye movements, oxygen levels in the blood, jaw movement, heart rate, breathing rate, airflow, respiratory effort, sound, and limb movements. Taken as a total picture, the results of these recordings allow a calculation of sleep stage and disorders of sleep. Limited-channel sleep studies can take place outside of the sleep laboratory.
  • positron emission tomography
    A PET scan creates computerized images of chemical changes that take place in tissue. In this test, various radioactive materials (tracers) and substances are injected into patients’ veins. The patient is then scanned in a special machine or scanner. Radiologists can then identify activity in certain parts of the brain by measuring blood flow and oxygen and glucose metabolism in the tissues of the working brain.
  • psychomotor vigilance task
    The Psychomotor Vigilance Task (PVT) measures sustained attention. In this simple task, a light on a handheld device turns on randomly every few seconds, and the person presses a button in response to the light appearing.
  • r

  • Randomized trial
    In a randomized controlled clinical trial, participants or subjects are randomly assigned (by chance) to one of two or more groups.
  • ribosome
    The site in the cell where proteins are made.
  • s

  • SF-36
    The SF-36 (or Short-Form Health Survey) is a questionnaire in which people answer 36 health-related and quality-of-life questions. The SF-36 is made up of eight scales that are summed to reach the total score. These scales include vitality, physical functioning, bodily pain, general health perceptions, physical role functioning, emotional role functioning, social role functioning, mental health. The SF-36 does not include a scale to assess sleep.
  • single nucleotide polymorphism
    A SNP is a DNA variation in which one nucleotide (the building block of DNA) differs from what is generally observed in the population. SNPs happen normally throughout a person’s DNA—usually about once in every 300 nucleotides. These variations are typically found in the DNA between genes. They can act as markers, helping scientists locate genes that are associated with a specific disease. When SNPs appear within a gene or in a regulatory region near a gene, they may play a more direct role in disease by affecting the function of a gene.
  • single-photon emission computed tomography
    SPECT is similar to positron emission tomography (PET) in that it uses a radioactive substance (tracer) and a special camera to create 3-D pictures of an internal organ of the body. Like PET, SPECT is particularly useful for looking at blood flow to an organ, such as the heart or brain. The primary difference between the two tests is that the tracers used in SPECT last longer than those used in PET, allowing for a longer time to view the organ working.
  • Sleep diary
    A sleep diary is a method of recording your sleep patterns, including the time you go to sleep and wake up, over an extended period of time.
  • sleep efficiency
    Sleep efficiency is the percentage of time spent asleep while in bed. It is calculated by dividing the amount of time spent asleep (in minutes) by the total amount of time in bed (in minutes). A normal sleep efficiency is considered to be 85% or higher.
  • sleep latency
    The sleep latency is the time it takes to fall asleep once a person attempts to go to sleep.
  • sleep log
    A sleep diary or sleep log is used to record a person’s waking and sleeping times over a period of time, typically at least two weeks.
  • Sleep paralysis
    Sleep paralysis is a phenomenon in which you are unable to move or speak during the transition from sleep to wake or from wake to sleep.
  • sleep stages
    Sleep is made up of four stages. These four stages can be subdivided into non-rapid-eye-movement (NREM, which typically makes up about 75% of your time asleep; Stages 1, 2, and 3) and rapid eye movement (REM, which makes up the other 25% of sleep). As you progress from wakefulness to deep sleep, you usually pass through progressively deeper stages, from stage 1 (the lightest) to stage 3 or slow wave sleep, (the deepest stage, in which critical substances such as growth hormone are released), and finally into REM sleep (during which the body doesn’t move and dreaming occurs). It is not uncommon for a person to move back and forth between stages 2 and 3 before moving into REM sleep. A typical sleep cycle lasts about 90 minutes, with more stage 3 sleep occurring earlier in the sleep period and more REM sleep later in the sleep period.
  • SNP
    A SNP is a DNA variation in which one nucleotide (the building block of DNA) differs from what is generally observed in the population. SNPs happen normally throughout a person’s DNA—usually about once in every 300 nucleotides. These variations are typically found in the DNA between genes. They can act as markers, helping scientists locate genes that are associated with a specific disease. When SNPs appear within a gene or in a regulatory region near a gene, they may play a more direct role in disease by affecting the function of a gene.
  • somnogen
    A somnogen is simply a substance that causes or induces sleepiness.
  • SPECT
    SPECT is similar to positron emission tomography (PET) in that it uses a radioactive substance (tracer) and a special camera to create 3-D pictures of an internal organ of the body. Like PET, SPECT is particularly useful for looking at blood flow to an organ, such as the heart or brain. The primary difference between the two tests is that the tracers used in SPECT last longer than those used in PET, allowing for a longer time to view the organ working.
  • striatum
    The striatum (which looks as if it has grey and white stripes and thus the name striae or stripe) is a section of the brain that lies beneath the front part of the cortex. This area of the brain has a number of functions, including planning and executing movement and controlling the reward system.
  • susceptibility gene
    A susceptibility gene is a permanent change in a gene (mutation) that increases a person’s susceptibility to or likelihood of developing a certain disease or disorder. When such a mutation is passed from a biologic parent to a child, symptoms of the disease or disorder are more likely to happen, but it is not certain that the symptoms will occur.
  • t

  • T1N
    The International Classification of Sleep Disorders, third edition, divides narcolepsy into Type 1 and Type 2 (the previous edition included narcolepsy with and without cataplexy). The new criteria for T1N require a combination of hypersomnolence and either low hypocretin levels in the cerebrospinal fluid or cataplexy plus short average sleep latency (≤ 8 minutes) and 2 or more sleep-onset REM periods (SOREMPs) on the Multiple Sleep Latency Test (MSLT). A SOREMP (within 15 minutes) of sleep onset on polysomnography may replace one of the SOREMPs on the MSLT.
  • transcription
    Transcription is the process in which when RNA is made from DNA.
  • type 1 narcolepsy
    The International Classification of Sleep Disorders, third edition, divides narcolepsy into Type 1 and Type 2 (the previous edition included narcolepsy with and without cataplexy). The new criteria for T1N require a combination of hypersomnolence and either low hypocretin levels in the cerebrospinal fluid or cataplexy plus short average sleep latency (≤ 8 minutes) and 2 or more sleep-onset REM periods (SOREMPs) on the Multiple Sleep Latency Test (MSLT). A SOREMP (within 15 minutes) of sleep onset on polysomnography may replace one of the SOREMPs on the MSLT.
  • v

  • vigilance
    Vigilance refers to the state of being alert and attentive.

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