364
edits
Changes
→G, H, I
== A , B, C ==
'''Abdominal Movement''' - Movement of the abdomen, which reflects breathing effort and movement of the diaphragm. This is typically measured by the placement of a sensor band around the chest. Abdominal movement is recorded in diagnostic sleep studies. This measurement is used in differentiating the type of sleep apnea.
'''Basic Sleep Cycle''' - See Sleep Cycle.
'''Benzodiazepines''' - Class of sedative medication commonly used to treat anxiety and insomnia.
'''Beta Activity ''' - Brain waves seen in alert wakefulness which have a frequency greater than 13 Hz (Hertz).
'''Bi-Level Positive Airway Pressure (Bi-level or BiPAP)''' - See CPAP. A CPAP device providing two measured pressure levels of continuous airflow: one level for inhalation and a lower level for exhalation.
'''Brain Waves''' - Spontaneous electrical activity of the brain studied by method of electroencephalography (EEG).
'''Brick''' - Slang term for CPAP machines that record limited data. "Power brick" may be used for the external power supply that goes between the CPAP machine and the electrical outlet.
'''Bruxism (Toothgrinding)''' - Grinding one's teeth while asleep. This occurs at some time in approximately 70% of people; most have no noticeable side effects. However, 5% of victims develop symptoms such as tooth wear, jaw pain and headaches. Episodes of grinding are more severe after stressful days.
'''C'''
'''Cardiovascular''' - Pertaining to the heart and blood vessels.
'''Central Nervous System (CNS)''' - The brain and spinal cord.
'''Central Sleep Apnea''' - A period of at least 10 seconds without airflow, during which no respiratory effort is evident.[[Central sleep apnea (CSA)]]
'''Chronotherapy''' - Treatment of a circadian rhythm sleep disorder by systemically changing sleeping and waking times to reset the patient's biological clock.
'''CPAP Pressure''' - Amount of pressure needed to maintain an open airway in a sleep apnea patient being treated with CPAP, expressed in centimeters of water (cm H20). The positive pressure may range from 5 to 20 cm H20. Different patients will require different pressures. This value is determined in a CPAP titration study.
'''Deep Sleep (Delta Sleep) (Slow Wave Sleep)''' - In sleep studies, refers to combined non-REM sleep stages 3 and 4.
'''Delayed Sleep Phase Syndrome''' - A circadian rhythm disorder, which in the daily sleep/wake cycle, is delayed with respect to clock time. Accordingly, the sleep phase occurs well after the conventional bedtime. Usually associated with difficulty getting up in the morning.
'''Delta Sleep (Deep Sleep) (Slow Wave Sleep)''' - Sleep stages 3 and 4 in which EEG delta waves are prevalent.
'''Diagnostic Sleep Study''' - Continuous monitoring of several physiological activities in a sleeping individual. Usually carried out to determine the absence or presence of a specific sleep disorder. A diagnostic sleep study can be performed in a sleep disorders center or in a patient's home with portable recording equipment.
'''Diaphragm''' - The large, concave muscle attached to the rib cage at bottom of the chest (top of the abdomen). Inhalation occurs when the diaphragm contracts. Exhalation is usually passive as the muscle relaxes.
'''Diurnal''' - Active and wakeful in the daytime, as opposed to active in the nighttime.
'''Electrocardiography (EKG) (ECG)''' - Method of measuring the electrical activity of the heart. EKG is continuously recorded in both diagnostic sleep studies and CPAP titration sleep studies.
'''Electrooculogram (EOG)''' - A recording of the movements of the eyes. If rapid eye movements are detected during sleep, the subject is in REM sleep, which is the state in which vivid dreaming takes place. EOG is recorded in both diagnostic and CPAP titration sleep studies.
'''EPAP - (Expiratory Positive Airway Pressure)''' - The pressure prescribed for the expiratory (breathing out) phase of an individual on Bi-level CPAP therapy for OSA (obstructive sleep apnea).
'''Epidemiology''' - The scientific discipline that studies the incidence, distribution, and control of disease in a population. Includes the study of factors that affect the progress of an illness, and, in the case of many chronic diseases, their natural history.
'''Excessive Daytime Sleepiness (EDS, Somnolence, Hypersomnia)''' - A subjective report of difficulty in maintaining the awake state, accompanied by a ready entrance into sleep when the individual is sedentary; may be quantitatively measured by use of subjectively defined rating scales of sleepiness.
'''Expiratory Phase''' - The phase of the breathing cycle in which air is expelled.
'''Fatigue''' - A feeling of tiredness or weariness usually associated with performance decrements.
'''Fragmentation (pertaining to Sleep Architecture)''' - The interruption of a sleep stage due to the transition to a lighter stage, or to wakefulness, leading to disrupted sleep cycles.
'''GABA (Gamma-Amniobutyric Acid)''' - A major inhibiting compound (neurotransmitter) in the brain, which is considered to be involved in muscle relaxation, sleep, diminished emotional reaction and sedation. GABA is released in the greatest amount from the cerebral cortex during slow wave sleep.
'''Habitual Snorers''' - Individuals who snore nearly every night.
'''Heart Rate or beats per minute (bpm)''' - Pace or speed of the heart measured in beats per minute; 60-80 is generally considered normal. Heart rate is continuously monitored in both diagnostic sleep studies and CPAP titration studies.
'''Hertz (Hz)''' - A unit of frequency measuring cycles per second (cps). A measurement used in describing sleep EEG brain waves.
'''Histogram''' - A graph showing frequency distributions.
'''Hypopharynx''' - The lowermost portion of the pharynx leading to the larynx and esophagus.
'''Hypopnea''' - An episode of diminished breathing during sleep, caused by a partial airway obstruction, and resulting in arousal. Usually accompanied by oxygen desaturation. Hypopneas may be just as serious as apneas and have the same troublesome effects.[[Hypopnea]]
'''Hypoventilation''' - Reduced rate and depth of breathing.
'''Imidazopyridines''' - Newest class of medications that induce sleepiness. They are short acting and few side effects have been found with this class of hypnotics. (Zolpidem, trade name Ambien, is in this class).
'''Inappropriate Sleep Episodes''' - Periods of sleep that are not planned and often occur in an unsafe situation (i.e., while driving). These episodes are always due to sleep deprivation.
'''Insomnia''' - Difficulty with falling asleep or staying asleep.
'''IPAP''' - Inspiratory Positive Airway Pressure. The pressure prescribed by a physician for the inspiratory phase on a Bi-level CPAP device, used in the treatment of OSA.
'''Jet Lag''' - A disturbance induced by a major rapid shift in environmental time during travel to a new time zone. Symptoms include fatigue, sleep and impaired alertness.
'''K-Alpha''' - A type of micro-arousal where a K complex is followed by several seconds of alpha rhythm.
'''Laser Assisted Uvuloplasty (LAUP)''' - Surgical treatment usually used for simple snoring or mild obstructive sleep apnea. This procedure is designed to open the airway behind the palate. It requires multiple procedures where the laser reduces tissue of the palate and the area heals by scarring. It is an outpatient procedure performed under local anesthesia.
== M , N, O ==
'''Macroglossia''' - Large tongue; usually a congenital disorder (present at birth). May result from other medical conditions such as acromegaly.
'''Nap''' - A short period of sleep generally obtained at a time separate from the daily major sleep period.
'''Narcolepsy''' - A sleep disorder characterized by excessive sleepiness, cataplexy, sleep paralysis, hypnagogic hallucinations, and an abnormal tendency to pass directly into REM sleep from wakefulness. It was recently found to be caused by an abnormal gene in the brain.
'''Nasal Airflow/Nasal Ventilation''' - A recording of the respiratory cycle by measuring inspiratory and expiratory airflow. In diagnostic sleep studies it is referred to as nasal ventilation or respiratory airflow. It is measured through heat or pressure changes at the nares. This value is usually recorded in both diagnostic sleep studies and CPAP titration sleep studies.
'''National Commission on Sleep Disorders Research''' - Created by the U.S. Congress in 1990, the commission conducted a comprehensive study of the social and economic impact of sleep disorders in America, and made recommendations based on its findings to Congress in January of 1993.
'''Nocturnal Enuresis (Bedwetting)''' - The release of urine while asleep.
'''Non-Invasive ''' - Medical procedure that does not penetrate the skin or a body cavity.
'''NREM Sleep (Non-Rapid Eye Movement, Non-Rem)''' - All sleep stages other than REM sleep; made up of sleep stages 1 through 4. Characterized by a slowing of brain waves and some physiological functions. A state that lacks the visible motility of rapid eye movements and twitches. See Sleep Stages.
'''NREM Sleep''' - Consists of sleep stages 1 through 4, and characterized by a decrease of mental activity. A state that lacks the visible motility of rapid eye movements and twitches, and exhibits a different EEG pattern than REM sleep. See Sleep Stages.
'''Obesity-Hypoventilation Syndrome''' - A term applied to obese individuals who have abnormally slow and shallow respiration (hypoventilation) during wakefulness, resulting in an increased level of carbon dioxide in the blood.
'''Obstructive Hypopnea''' - Periodic, partial closure of the throat during sleep resulting in reduced air exchange. The medical consequences of this partial closure can be as severe as sleep apnea (full closure of throat) Usually characterized by snoring, excessive daytime sleepiness, and other symptoms of fatigue
'''Obstructive Sleep Apnea (OSA)''' - Repetitive cessation of breathing during sleep for 10 seconds or more due to complete closure (collapse) of the throat. Usually characterized by snoring, excessive daytime sleepiness, and other symptoms of fatigue.[[Obstructive sleep apnea (OSA)]] '''Ondine's Curse''' - Condition in which the respiratory center in the brain is unable to stimulate breathing in response to an increased amount of carbon dioxide in the blood. Ondine's Curse is synonymous with central alveolar hypoventilation and typically worsens during sleep.
'''Optimum Sleep''' - The average amount of sleep needed every night by any given individual. Most adults require about 7 to 8.5 hours per night, although this number is subjective, and may vary from person to person.
'''
== P, Q, R ==
'''Pressure Support''' - Pressure support (PS) in positive air pressure therapy, is the difference between inspiratory positive air pressure (IPAP) and expiratory positive pressure (EPAP). For example if IPAP is set at 12 and EPAP is set at 8 the PS is 12 - 8 = 4.0.
'''Pulse Oximetry''' - Pulse oximetry is a non-invasive method allowing the monitoring of the oxygenation of a patient's hemoglobin at the fingertip or earlobe.
'''Radiofrequency''' - Electromagnetic radiation in the frequency range 3 kilohertz (kHz) to 300 gigahertz (GHz). It is generally considered to include microwaves and radio waves. Microwaves occupy the spectral region between 300 GHz and 300 MHz, while RF or radio waves include 300 MHz to 3 kHz. The primary health effects of radiofrequency energy are considered to be thermal. The absorption of radiofrequency energy varies with frequency.
'''REM Sleep (Rapid Eye Movement Sleep)''' - The sleep stage in which vivid dreaming occurs; identified by the occurrence of rapid eye movements under closed eyelids, motor atonia and low voltage EEG patterns. Also associated with bursts of muscular twitching, irregular breathing, irregular heart rate, and increased autonomic activity.
'''REM Sleep Behavior Disorder''' - A disorder in which REM motor atonia is partially or completely absent. People with this disorder are able to move their muscles and act out their dreams. The behaviors may include punching, kicking, leaping and running from the bed.
'''REM Sleep Episode''' - The REM sleep portion of a NREM-REM sleep cycle. There are typically 4-6 REM sleep episodes during an entire sleep period. Early episodes may be only several minutes in duration. Later REM episodes are usually longer, lasting 20 to 60 minutes.
'''REM Sleep Latency''' - The interval from sleep onset to the first appearance of REM sleep.
'''REM Sleep Onset''' - The designation for the first epoch of a REM sleep episode.
'''REM Sleep Percent''' - The proportion of total sleep time occupied by REM sleep.
'''Respiratory Disturbance Index (RDI)(Apnea/Hypopnea Index)''' - The frequency of abnormal respiratory events per hour of sleep. These events are classified as Apneas or Hypopneas. Apnea is when breathing (airflow) stops for 10 seconds or more. Hypopnea is a partial blockage of airflow resulting in arousal and a possible drop in oxygen level. An RDI of 45 would indicate that the patient is experiencing complete or partial airflow blockage 45 times per hour.
'''Restless Legs Syndrome''' - The sleep disorder characterized by tingling, creeping, crawling, or aching sensation in the legs that tends to occur when an individual is not moving. There is an almost irresistible urge to move the legs that relieve the sensations. Inability to remain at rest can result in severe sleep disturbance.
== S , T, U ==
'''Seasonal Affective Disorder (SAD)''' - A mood disorder occurring in the winter months characterized by diminished energy, hypersomnia, overeating and depressed mood. Exposure to bright light in the morning hours may be effective in alleviating or decreasing symptoms.
'''Sleeping Pills (hypnotics)''' - Compounds that have a sedative effect are often used to produce sleepiness. If taken frequently, development of tolerance to the medication is common.
'''Sleep Inertia''' - Feelings of grogginess and sleepiness that persist up to 20 minutes after waking up. This results in poor performance upon awakening. '''Sleep Latency''' - The length of time it takes to go from full wakefulness to the moment of sleep.
'''Sleep Log (Diary)''' - A daily, written record of a person's sleep-wake pattern containing such information as time of retiring and arising, time in bed, estimated total sleep time, number and duration of sleep interruptions, quality of sleep, daytime naps, use of medications or caffeine beverages, and nature of waking activities.
'''Sleep Related Accidents''' - Accidents caused by individuals who were sleep deprived and had impaired judgment.
'''Sleep Restriction''' - A limitation of the number of hours in bed.
'''Sleep Spindle''' - A synchronized, rhythmic EEG waveform, with a duration of about ½ second and a frequency of 12 to 14 Hz. Sleep spindles are observed most frequently during stage 2 sleep.
'''Sleep Stage 3 (NREM Stage 3)''' - A stage of NREM sleep defined by at least 20% and not more than 50% of the period consisting of EEG waves of 2 cps or slower, with amplitudes of more than 75 mV (high-amplitude delta waves). It constitutes "deep" NREM sleep, or, so-called slow wave sleep (SWS), and is often combined with stage 4 NREM sleep because of the lack of documented physiological differences between the two. It normally appears usually only in the first third of the sleep episode, and usually compromises 4-6% of total sleep time.
'''Sleep Stage 4 (NREM Stage 4)''' - All statements concerning NREM sleep stage 3 apply to stage 4 except that high-voltage, slow EEG waves cover 50% or more of the record. NREM sleep stage 4 usually represents 12-15% of total sleep time. Sleepwalking, sleep terrors, and sleep-related enuresis episodes generally start in stage 4 or during arousals from this stage. '''Sleep Starts''' - See Hypnic jerks.
'''Sleep talking''' - Talking in sleep that usually occurs in the course of transitory arousals from NREM sleep. Can occur during REM sleep, at which time it represents a motor breakthrough of dream speech. Full consciousness is not achieved and no memory of the event remains. Sleep talking probably carries no psychological or psychiatric significance, and the content should be taken very lightly.
'''Sleep-Wake Cycle''' - The clock hour relationships of the major sleep and wake episodes in the 24-hour cycle. See Phase Transition, Circadian Rhythm.
'''Sleep-Wake-Junk''' - Clusters of apnea and hypopnea events concentrated mainly around periods of sleep-wake transition. In general Sleep-wake-junk (SWJ) is not regarded as "real" since they do not occur during periods of sleep, but may be during semi-awake periods or "dozing". [http://www.apneaboard.com/forums/Thread-Classic-example-of-Sleep-Wake-Junk-breathing?pid=184112#pid184112 Example of SWJ]
'''Sleep-Wake Shift (Change, Reversal)''' - When sleep as a whole or in part is moved to a time of customary waking activity, and wakefulness is moved to the time of the major sleep episode. This is common in jet lag and shift work.
'''Stage 2 (NREM Stage 2)''' - Stage of NREM sleep characterized by the advent of sleep spindles and K complexes against a low-voltage, mixed frequency EEG background similar to stage 1. Stage 2 sleep is usually free of slow rolling eye movements. A more intense stimulus is required to wake someone from stage 2 than from stage 1. In adults, stage 2 typically accounts for 45-55% of total sleep time.
'''Stage 3 (NREM Stage 3, Delta Sleep, Slow Wave Sleep)''' - Stage 3, along with stage 4 sleep is often called Delta Sleep or Slow Wave sleep. The Stage 3 EEG record consists of 20% to 50% delta EEG waves. These delta waves have a slow frequency of 2 cps or slower, and amplitudes of more than 75 mV (high amplitude delta waves). Stage 3 sleep is deeper than stages 1 or 2; it takes a more intense stimulus to awaken someone in this sleep state. Stage 3 primarily appears in the first half of the sleep episode in adults.
'''Stage 4 (NREM Stage 4, Delta Sleep, Slow Wave Sleep)''' - Stage 4 has similar attributes to stage 3, except there are a greater proportion of EEG delta waves. These high-voltage, slow EEG waves make up 50% or more of the record. This is the deepest stage of sleep; a more intense stimulus is needed to wake someone from stage 4 sleep than any other stage of NREM sleep. Young children have more stage 4 sleep and are much more difficult to arouse than adults. Both stages 3 and 4 decline with age and many older people report that their sleep is lighter than when they were young. Children typically spend 20-25% of sleep in stages 3 and 4 slow wave sleep; this decreases to less than 10% by age 60. Sleepwalking, sleep terrors, and sleep-related enuresis episodes generally occur in stages 3 or 4, or during arousals from this stage.
'''Subjective Sleepiness''' - Feelings of sleepiness.
'''Substance Abuse''' - The excessive use of alcohol or drugs. These substances can cause sleep disturbances.
'''Sudden Infant Death Syndrome (SIDS, Crib Death)''' - The sudden and unexpected death of an apparently healthy infant, whose death remains unexplained after an adequate postmortem investigation. Death usually occurs during sleep. SIDS is the leading cause of death in infants in their first year of life, with the peak occurrence at 2 - 4 months. Although the majority of SIDS victims do not have identifiable risk factors, groups of infants at a somewhat higher risk include siblings of SIDS victims and infants born to substance-abusing mothers.
'''Tachycardia''' - Rapid heart rate. In adults, usually defined by a heart rate of over 100 beats per minute (bpm).
'''Thermoregulation''' - The regulation of body temperature in mammals.
'''Theta Activity''' - EEG brain wave activity with a frequency of 4-8 Hz. It is most prominent over the central and temporal cortex.
'''Thoracic Excursion''' - Thoracic (chest) movement, which indicates respiratory effort. This is recorded in diagnostic sleep studies, and is typically measured by the placement of a sensor band around the chest. The sensor band records chest wall movement associated with respiration. This measurement is used in differentiating the type of sleep apnea.
'''Tidal Volume''' - The amount of air that passes in and out of the lungs in an ordinary breath. Usually expressed in liters.
'''Titration''' - A method of determining optimal CPAP (continuous positive airway pressure) treatment parameters for sleep apnea. This involves automatic or manual adjustment of the CPAP device to a level that eliminates airway blockage.
'''Total Recording Time''' - The duration of time from the beginning of a sleep recording ("lights out") to final awakening. In addition to total sleep time, it is comprised of the time taken up by wakeful periods.
'''Total Sleep Time''' - The amount of actual sleep time in a sleep episode. This is equal to the total sleep episode less the awake time. Total sleep time is the total of all REM and NREM sleep in a sleep episode.
'''Tracheotomy''' - Surgical procedure to create an opening in the trachea (windpipe) through which breathing can occur. Occasionally used to treat severe obstructive sleep apnea that is non-responsive to other treatment.
'''Transient Insomnia''' - Difficulty sleeping for only a few nights.
'''Tricyclic Antidepressants (Antidepressants)''' - A class of medications most commonly used in the treatment of depression. Tricyclic refers to the three-ring chemical structure. Most tricyclic antidepressants also reduce REM sleep. In sleep disorders, they are used to control cataplexy, hypnagogic hallucinations, and sleep paralysis.
'''Turbinate''' - Small, shelf-like, cartilaginous structures covered by mucous membranes, which protrude into the nasal airway to help warm, humidify, and cleanse inhaled air on its way to the lungs.
'''Unattended CPAP Titration Study''' - An automatic calibration test performed with a CPAP machine that measures the patient's airway pressure requirements during sleep. This is performed after determining that a patient has a sleep related breathing disorder such as OSA or Upper Airway Resistance Syndrome, and is likely to benefit from CPAP therapy. These findings are then used to prescribe the appropriate pressure the patient will use with their CPAP therapy.
'''Unintended Sleep Episode''' - A sleep episode that is not planned and may happen during an activity in which such an episode is hazardous, such as when driving a car or working with machinery.
'''Upper Airway''' - The part of the respiratory anatomy that includes the nose, nostrils, sinus passages, septum, turbinates, tongue, jaw, and palate. '''Upper Airway Resistance Syndrome''' - Part of the spectrum of obstructive sleep-related breathing disorders in which repetitive increases in resistance to airflow in the upper airway lead to brief arousals and daytime fatigue. Usually associated with loud snoring. Apneas and hypopneas (see RDI) may be totally absent. Blood oxygen levels can be in the normal range.
'''Uvula''' - Small soft structure hanging from the bottom of the soft palate in the midline above the back of the tongue. It is composed of connective tissue and mucous membrane.
'''Uvulopalatopharyngoplasty (UPPP)''' - Surgical treatment for obstructive sleep apnea and snoring. This procedure is designed to open the airway behind the palate. The uvula, tonsils, and excess palatal tissue are removed. The incision is closed with sutures. The procedure is performed under general anesthesia and usually requires a one or two day hospital stay.
'''V'''
'''Wake Time''' - The total time scored as wakefulness in a polysomnogram occurring between "lights out" and final awakening.
'''Zeitgeber''' - An environmental time cue that entrain biological rhythms to a specific periodicity. Known Zeitgebers are light, melatonin and physical activity. To be effective, these signals must occur when the biological clock is in a responsive phase.
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