Glossary of Major Terms
Acoustic reflectometry A technique that allows for noninvasive measurement of human airways to quantify anatomical obstruction of the upper airway.
Actigraph A movement detector coupled with software that uses movement patterns to diagnose sleep disorders.
Adenoid An enlarged mass of lymphoid tissue at the back of the nasopharynx that, when enlarged, can obstruct the nasal and ear passages, forcing respiration through the mouth and inducing nasality, postnasal discharge, and dullness of facial expression.
Adenotonsillectomy The surgical removal of tonsils and adenoids.
African trypanosomiasis A category of disease caused by infection with the Trypanosoma brucei (Tb) parasite and resulting in sleeping sickness.
Antihypertensive A class of drugs that are used to reduce high blood pressure.
Antipsychotic A powerful tranquilizer typically used to treat psychosis.
Apnea Transient stop of respiration due to either normal or abnormal causes.
Apnea-hypopnea index The total number of episodes of apnea and hypopnea per hour of sleep. A value of 5 or greater is abnormal and may be associated with excessive daytime sleepiness.
Atonia Lack of physiological muscle tone.
Attention-deficit/hyperactivity disorder (ADHD) A syndrome of disordered learning and disruptive behavior, with no known cause, and characterized by one or all of the following symptoms: inattentiveness,
hyperactivity, and impulsive behavior. Also known as attention deficit disorder (ADD).
Autoimmune Referring to or caused by autoantibodies or white blood cells that attack molecules, cells, or tissues of the organism producing them.
BEARS A 5-step pediatric sleep screening form to identify sleep problems (B = bedtime issues, E = excessive daytime sleepiness, A = night awakenings, R = regularity and duration of sleep, S = snoring).
Body mass index (BMI) A measure of body fat that is the ratio of the weight of the body in kilograms to the square of its height in meters.
Carotid body A small body of vascular tissue that is able to sense changes in the partial pressures of oxygen and carbon dioxide in the blood and to mediate reflex changes in respiration.
Cataplexy A symptom of narcolepsy, characterized by a sudden loss of muscle control with retention of clear consciousness in response to a strong emotional stimulus.
Catecholamine An amine (such as norepinephrine or dopamine), derived from tyrosine, that functions as a neurotransmitter, hormone, or both.
Central sleep apnea Cessation of breathing during sleep that is caused a disturbance in the brain’s respiratory center.
Cerebral cortex The surface layer of the brain’s gray matter, which coordinates sensory and motor information.
Cerebrospinal fluid (CSF) A liquid that is secreted from the blood into the internal cavities in each cerebral hemisphere of the brain and circulates through the cavities to the spaces formed between the brain or spinal cord and the surrounding membranes; serves chiefly to maintain uniform pressure within the brain and spinal cord.
Chemoreflex A physiological reflex initiated in a chemoreceptor or in response to a chemical stimulus.
CHQ-PF50 A parent report measure of children’s physical, emotional, and social functional status and well-being.
Chronobiology The science of biological rhythms.
Circadian rhythms 24-hour periods or cycles of biological activity or function.
Cognitive therapy Psychotherapeutic method aimed at changing faulty beliefs and attitudes about sleep, insomnia, and the next-day consequences. Other cognitive strategies are used to control intrusive thoughts at bed-time and prevent excessive monitoring of the daytime consequences of insomnia.
Confusional arousal One type of disorder of arousal associated with NREM sleep. Individuals display mental confusion or confusional behavior during or following arousal, typically from slow-wave sleep.
Corticosteroids Any of various adrenal-cortex steroids used medically, especially as anti-inflammatory agents.
Dementia A condition characterized by the progressive development of multiple cognitive deficits, such as memory impairment, difficulty in speech comprehension and production, and inability to plan and initiate complex behavior.
Dialysis A category of medical procedures to remove wastes or toxins from the blood and adjust fluid and electrolyte imbalances.
Diurnal Occurring in the daytime.
Dysesthesia The impairment of tactile sensitivity.
Electroencephalograph (EEG) Machine used to monitor and categorize sleep stages by measuring changes in brain wave activity.
Electro-oculogram A record of the standing voltage between the front and back of the eye that is correlated with eyeball movement (as in REM sleep) and obtained by electrodes suitably placed on the skin near the eye.
Electrophysiology The study of the electrical activity related to physiological function of living tissue.
Epilepsy A category of disorders characterized by abnormal electrical activity in the brain and featuring symptoms such as sudden brief episodes of altered or diminished consciousness, involuntary movements, or convulsions.
Epworth sleepiness scale A series of questions used to determine whether an individual is sleepy or not.
Excessive daytime sleepiness Background of constant sleepiness with sleep attacks leading to unintended napping during the day; a characteristic symptom of narcolepsy.
Exploding head syndrome Characterized by a sudden, loud noise or explosion in the head, this is an imagined, painless noise.
F30 fellowship Individual Predoctoral National Research Service Award for M.D./Ph.D. degrees. Fellowship award that provides combined medical school and predoctoral Ph.D. support for a maximum of 6 years.
F31 fellowship Predoctoral Individual National Research Service Award. Fellowship award that provides up to 5 years of support for research training leading to the Ph.D. or equivalent research.
F32 fellowship Postdoctoral Individual National Research Service Award. Fellowship award that provides postdoctoral research training to broaden scientific background.
F33 fellowship National Research Service Award for Senior Fellow. Fellowship award that provides opportunities for experienced scientists to broaden scientific background.
Gene A DNA sequence that encodes a protein.
Gene loci The term used to describe the locations of genes on a chromosome.
Generalized anxiety disorder An anxiety disorder characterized by chronic excessive anxiety and worry that is difficult to control, and it consequently impairs daily functioning and causes stress. Primary symptoms include: restlessness, irritability, poor concentration, and sleep disturbances.
Hemodialysis The removal and purification of blood from an artery, followed by the addition of vital substances and reintroduction into the circulatory system through a vein.
Hypersomnia Periods of normal duration of sleep and waking are interspersed with excessive periods of sleep.
Hypersomnolence Excessive drowsiness.
Hypertension Abnormally high arterial blood pressure that typically results in a thickening and inelasticity of arterial walls and left heart ventricle hypertrophy. A risk factor for various pathological conditions or events such as heart attack, heart failure, stroke, end-stage renal disease, or retinal hemorrhage.
Hypnagogic Relating to or occurring in the drowsiness stage that immediately precedes the onset of sleep.
Hypnagogic hallucinations A characteristic symptom of narcolepsy that is marked by frightening dreamlike REM sleep experiences when falling asleep.
Hypnopompic Referring to the semiconsciousness period that precedes waking.
Hypnopompic hallucinations A characteristic symptom of narcolepsy that is marked by frightening dreamlike REM sleep experiences when waking up from sleep.
Hypnotic An agent that induces sleep.
Hypocretin-1 One of a pair of highly excititory neuropeptide hormones (the other being hypocretin-2) that are biosynthesized in the hypothalamus and are involved in the cause of narcolepsy-cataplexy. Also known as orexin-A.
Hypopnea Extremely shallow or abnormally slow respiration.
Hypoxia Impaired oxygenation of the tissues of the body.
Insomnia A prolonged and usually abnormal inability to obtain adequate sleep that may result in sleepiness, fatigue, difficulty concentrating, and irritability.
Interleukin Compounds of low molecular weight that chiefly function in immune system regulation and cell-mediated immunity.
K award Career development awards offered by the NIH to assist new investigators at stages beyond postdoctoral training in order to become independent scientists. Support for the awards is limited to one 3- to 5-year term and is usually restricted to one mentored career award per individual.
K01 award Mentored Research Scientist Development Award. Provides salary and fringe benefits for awardees for career development experience.
K02 award Independent Scientist Award. Provides up to 5 years of salary and fringe benefit support for newly independent scientists.
K05 award Senior Scientist Award. Provides salary and fringe benefit support for outstanding scientists to enhance skills in their research field.
K07 award Academic Career Award. Provides up to 5 years of funding to develop or improve curricula changes that emphasize development and leadership skills of scientists.
K08 award Mentored Clinical Scientist Development Award. Provides salary and fringe benefit support for the development of clinician research scientists.
K12 award Mentored Clinical Scientist Development Program Award. Provides support to an educational institution for career development experiences for clinicians leading to research independence.
K23 award Mentored Patient-Oriented Research Career Development Award. Provides salary and fringe benefit support for the development of patient-oriented research scientists.
K24 award Midcareer Investigator Award in Patient-Oriented Research. Provides salary and fringe benefit support to allow protected time for patient-oriented research and time to act as mentors for beginning clinical investigators.
K25 award Mentored Quantitative Research Career Development Award. Provides salary and fringe benefit support for career development for scientists with quantitative and engineering backgrounds to foster interdisciplinary collaboration in biomedical research.
K-complex Negative sharp waves followed immediately by slower positive component; sleep spindles may ride on K-complexes. May occur in response to sound or spontaneously but may be distinguished from background activity on the EEG.
Kleine-Levin syndrome Characterized by recurrent episodes of dramatic hypersomnia lasting from 2 days to several weeks. These episodes are associated with behavioral and cognitive abnormalities, binge eating or hypersexuality, and alternate with long asymptomatic periods that last months to years.
Leptin A peptide hormone produced by fat cells and involved in the regulation of body weight by acting on the hypothalamus to suppress appetite and burn fat stored in connective tissue.
Magnetic resonance imaging (MRI) A type of diagnostic imaging technique that relies on the interactions of magnetic fields and radio-frequency radiation with body tissues.
Melatonin A vertebrate hormone that has been linked to circadian rhythm regulation, is derived from serotonin, and is secreted by the pineal gland especially in response to darkness.
Multiple Sleep Latency Test (MSLT) A test that objectively quantifies daytime sleepiness.
Myoclonic epilepsy Epilepsy characterized by myoclonic seizures, which involve brief and involuntary contractions of a muscle.
Narcolepsy A chronic neurological condition marked by transient attacks of deep sleep, with symptoms of cataplexy, hypnagogic hallucinations, sleep disruption, and sleep paralysis.
Nares The pair of openings of the nose.
Nightmare disorder Recurrent nightmares that are coherent dream sequences and manifest as disturbing mental experiences, generally occurring during REM sleep.
Night terrors One type of disorder of arousal associated with NREM sleep. Typically initiated by a loud scream associated with panic, followed by intense motor activity, which can result in injury.
Nocturnal groaning Characterized by disruptive groaning that occurs during expiration, particularly during the second half of night. Also known as catathrenia.
Non-rapid eye movement sleep (NREM) A state of deep, usually dreamless, sleep that occurs regularly during a normal period of sleep with intervening periods of REM sleep and is characterized by delta waves and a low level of autonomic physiological activity—called also non-REM sleep or slow-wave sleep.
Obstructive sleep apnea (OSA) Obstructive sleep apnea is caused by recurrent interruption of breathing during sleep due to upper airway obstruction caused by sleep-related loss of upper airway muscle tone or anatomical obstruction of the upper airway. Also called obstructive sleep apnea syndrome.
P01 grant Federally supported research program project grant that is sponsored by the National Institutes of Health and that funds as many as
three separate, multidisciplinary research projects that are based on a central research theme. Funding is limited to about $1 million each year in direct costs.
P20 grant Federally supported research program project grant that is sponsored by the National Institutes of Health and that funds exploratory grants. Provides support for the development of new or interdisciplinary programs or the expansion of existing resources.
P30 grant Federally supported center core grant that is sponsored by the National Institutes of Health and that provides funds to develop an infrastructure that supports centralized research, facilities, and resources. Core grants provide resources to investigators to help them achieve a higher level of productivity. Awards are limited to 5 years and about $500,000 in direct costs per year.
P50 grant Federally supported specialized center grant that is sponsored by the National Institutes of Health and that provides funds for multi-investigator, multidisciplinary research. Funding is limited to about $1 million each year in direct costs.
Parasomnia Unpleasant or undesirable behaviors or experiences that occur during entry into sleep, during sleep, or during arousals from sleep.
Pharyngeal Relating to or located in the pharynx area.
Polysomnogram A sleep test that continuously acquires physiological data obtained during sleep, including brain wave activity, eye movements, muscle activity (chin and legs), heart rate, body position, and respiratory variables, including oxygen saturation.
Polysomnography Use of a polygraph to record multiple physiological variables during sleep.
Prader-Willi syndrome A genetic disorder marked by mental retardation, below average height, hypotonia, abnormally small hands and feet, gonadal incompetence, and excessive appetite resulting in extreme obesity.
R01 award Federal research project grant that supports specific health-based research for 1 to 5 years. It can be investigator initiated or submitted in response to a request for application or program announcement.
R03 award Federal grant that supports small research projects for a limited period of time and with limited resources. Grants are awarded for up to 2 years with direct costs limited to $50,000 per year.
R13 award Federal grant that supports conference grants. Provides support for a symposium, seminar, workshop, or other formal conference assembled to exchange and disseminate information or to explore a subject, problem, or field of knowledge.
R21 award Federally supported exploratory or developmental research grant that supports the early development of an innovative project. Grants are awarded for up to 2 years, with total direct costs not to exceed $275,000 for the length of the project.
R25 award Federal grant that supports education project grants. Provides support to develop a program in education, information, training, technical assistance, or evaluation.
Rapid eye movement (REM) Rapid and simultaneous movement of both eyes, and associated with REM sleep.
Rapid eye movement sleep A state of sleep that is experienced in several cycles during a normal period of sleep and is marked by increased forebrain and midbrain neuronal activity and by reduced muscle tone. Humans experience dreams, rapid eye movements, and vascular congestion of the sex organs during REM sleep.
Rapid eye movement sleep behavior disorder A complex set of behaviors, including mild to harmful body movements associated with dreams and nightmares and loss of muscle atonia.
Restless legs syndrome (RLS) A neurological condition characterized by an irresistible urge to move that occurs or worsens at rest and is relieved by activity. It is also sometimes characterized by worsening in the evening and night.
Sleep apnea A condition marked by transient cessation of breathing during sleep, as a result of either airway obstruction or a disturbance in the brain’s respiratory center. Especially associated with excessive daytime sleepiness.
Sleep drunkenness Difficulty waking up and being foggy for long periods of time after wake onset. Also known as sleep inertia.
Sleep hygiene Describes the practice of maintaining proper sleep health.
Sleep medicine A branch of clinical medicine devoted to the diagnosis and treatment of individuals suffering from chronic sleep loss or sleep disorders.
Sleep paralysis Muscle paralysis akin to REM sleep atonia while awake, when falling asleep, or waking up.
Sleep-related dissociative disorder A dissociative episode that can occur in the period from wakefulness to sleep or from awakening from stages 1 or 2 or from REM sleep.
Sleep-related eating disorder Marked by repeated episodes of involuntary eating and drinking during arousals from sleep.
Sleep-related hallucination Hallucinatory images that occur at sleep onset or on awakening from sleep.
Sleep restriction therapy A method to curtail time in bed to the actual sleep time, thereby creating mild sleep deprivation, which results in more consolidated and more efficient sleep.
Sleep spindle Waxing and waning electrical brain activity at 7 to 14 Hz, grouped in sequences that last 1 to 2 seconds and recur periodically with a slow rhythm of 0.1 to 0.4 Hz. Typically appear during sleep stage 2.
Sleepwalking One type of disorder of arousal associated with NREM sleep. Involves a series of behaviors initiated during arousals from slow-wave sleep that culminate in walking around in an altered state of consciousness.
Slow-wave sleep (SWS) Term used to describe sleep stages 3 and 4 together due to characteristic slow waves.
Somnology The branch of science devoted to the study of the physiology of sleep, the behavioral dimensions of sleep, and the consequences of sleep loss and sleep disorders on an individual’s and the general population’s health, performance, safety, and quality of life.
Spasticity A state of increased muscular tone in which abnormal stretch reflexes intensify muscle resistance to passive movements.
Stage 1 sleep First stage of NREM sleep characterized by low-voltage, mixed frequency waves on the EEG; small eye movements; and tonic muscles.
Stage 2 sleep Second stage of NREM sleep characterized by low-voltage, mixed frequency waves on the EEG, sleep spindles, and K-complexes; occasional small eye movements near sleep onset; and tonic muscles.
Stage 3 sleep Third stage of NREM sleep characterized by high-voltage, slow-wave activity on EEG; no eye movements; and tonic muscles.
Stage 4 sleep Fourth stage of NREM sleep characterized by high-voltage, slow-wave activity on EEG; no eye movements; and tonic muscles.
Sudden Infant Death Syndrome (SIDS) The death of an apparently healthy infant usually before 1 year of age that is of unknown cause and occurs especially during sleep.
Suprachiasmatic nucleus (SCN) Either of a pair of neuron clusters in the hypothalamus that receive visual information from the retina via the optic nerve and that regulate the body’s circadian rhythms.
T32 training grant National Research Service Award Institutional Research Training Grants. Provides support to institutions to develop or enhance research training opportunities for predoctoral and post-doctoral students.
T34 training grant National Research Service Award Institutional Undergraduate Research Training Grant. Provides support to institutions to promote undergraduate research training to underrepresented groups in the biomedical and behavioral sciences.
T35 training grant Short-Term Institutional Research Training Grant. Provides support to institutions for predoctoral and postdoctoral training focused on biomedical and behavioral research.
Type 2 diabetes mellitus Diabetes that develops especially in adults and especially in obese individuals. Marked by high blood sugar that is a consequence of impaired insulin utilization and a physiological inability to compensate with increased insulin production. Also called adult-onset diabetes, late-onset diabetes.
U Cooperative Agreements Provided to support any part of the full range of research and development activities composing a multidisciplinary attack on a specific disease entity or biomedical problem area.