• Specialty
  • Cardiology
  • Dentistry
  • Dermatology
  • General Medicine
  • GI/GU
  • Hematology
  • Immunology
  • Lab Medicine & Pathology
  • Neuro-Psych
  • OB-Gyn
  • Oncology
  • Ophthalmology
  • Orthopaedic
  • Otolaryngology - ENT
  • Radiology
  • Surgery

• Neuro-Psych
  • Lots of Neuro-Psych Terms
  • Alzheimer�s Disease Terms
  • Brain Injury Terms
  • Consciousness Levels
  • Cranial Nerves (I-XII)
  • Depression Related Terms
  • Glasgow Coma Scale
  • Mental Health Related Terms
  • Neuro/Psych Medications
  • Phobias
  • Psychiatric Interviews & Examinations
  • Sleep Related Abbreviations
  • Sleep Related Terms
  • Suicide Related Terms
  • Tumors - Neuro
  • Sample Reports - Neurosurgery
  • Sample Reports - Sleep Medicine
  • Sample Reports - Psychiatry / Psychology
  • Sample Reports - Neurology

• Sleep Related Terms

- S -

• Sedatives

Compounds tending to calm, and reduce nervousness or excitement and foster sleep



• Sedentary Situation

Not requiring physical activity, e.g. working at a desk, sitting in a meeting or in a theater, watching television.



• Septoplasty

Surgery on the nasal septum (dividing the nasal passage)



• Serotonin

Neurotransmitter in the brain that modulates mood, appetite, sexual activity, aggression, body temperature and sleep



• Shiftwork

Working hours outside of the conventional daytime hours of 9:00 a.m. to 5:00 p.m.



• Sleep

A state marked by lessened consciousness, lessened movement of the skeletal muscles, and slowed-down metabolism



• Sleep Apnea

Cessation of breathing for 10 or more seconds during sleep



• Sleep architecture

NREM/REM stage and cycle infrastructure of sleep understood from the vantage point of the quantitative relationship of these components to each other



• Sleep cycle

Synonymous with NREM-REM cycle



• Sleep Debt

Result of recurrent sleep deprivation which occurs over time when an individual does not experience a sufficient amount of the restorative daily sleep that is required to maintain a sense of feeling rested and refreshed. .



• Sleep Deprivation

Acute or chronic lack of sufficient sleep.



• Sleep Disorders

Broad range of illnesses arising from many causes, including, dysfunctional sleep mechanisms, abnormalities in physiological functions during sleep, abnormalities of the biological clock, and sleep disturbances that are induced by factors extrinsic to the sleep process



• Sleep efficiency (SE)

Proportion of sleep in the period potentially filled by sleep--ratio of total sleep time to time in bed



• Sleep Episode

Interval of sleep that may be voluntary or involuntary



• Sleep Extension

Extending sleep time by increasing the time in bed



• Sleep Fragmentation

Brief arousals occurring throughout the night, reducing the total amount of time spent in the deeper levels of sleep.



• Sleep hygiene

Conditions and practices that promote continuous and effective sleep, including regularity of bedtime and arise time; conforming time spent in bed to the time necessary for sustained and individually adequate sleep (i.e., the total sleep time sufficient to avoid sleepiness when awake); restriction of alcohol and caffeine beverages in the period prior to bedtime; employment of exercise, nutrition, and environmental factors so that they enhance, not disturb, restful sleep



• Sleep Hyperhydrosis

Excessive sweating during sleep.



• Sleep Inertia

Feelings of grogginess and/or sleepiness that persist longer than 10 to 20 minutes after waking up



• Sleep interruption

Breaks in the sleep architecture resulting in arousal and wakefulness



• Sleep latency

Time period measured from "lights out," or bedtime, to the beginning of sleep



• Sleep log (-diary)

Daily, written record of an individual's sleep-wake pattern containing such information as time of retiring and arising, time in bed, estimated total sleep period, number and duration of sleep interruptions, quality of sleep, daytime naps, use of medications or caffeine beverages, nature of waking activities, and other data



• Sleep Mentation

Thoughts, feelings, images, perceptions, hallucinations, and active dreams taking place during sleep



• Sleep onset

Transition from wake to sleep, normally into NREM stage 1 (but in certain conditions, such as infancy and narcolepsy, into stage REMS)



• Sleep Onset Imagery

Images and experiences during the moments following the transition from wake to sleep



• Sleep paralysis

Waking and not being able to move for a short period of time, usually occurs out of REM (dream) sleep.



• Sleep pattern (24 hour sleep-wake pattern)

Individual's clock hour schedule of bedtimes and rise times as well as nap behavior: may also include time and duration of sleep interruptions



• Sleep Related Accidents

Accidents caused by individuals who were sleep deprived and who, as a result, had impaired judgment



• Sleep Restriction

Limitation of the number of hours in bed



• Sleep spindle

Episodically appearing, spindle-shaped aggregate of 12-14 Hz waves with a duration of 0.5-1.5 seconds, one of the identifying EEG phenomena of NREM stage 2 sleep



• Sleep stage 1

A stage of NREM sleep occurring after wake. Its criteria consist of a low-voltage EEG with slowing to theta frequencies, alpha activity less than 50%, EEG vertex spikes, and slow rolling eye movements; no sleep spindles, K-complexes, or REMS. Stage 1 normally assumes 4-5% of total sleep.



• Sleep stage 2

A stage of NREM sleep characterized by sleep spindles and K complexes against a relatively low-voltage, mixed-frequency EEG background; high-voltage delta waves may comprise up to 20% of stage 2 epochs; usually accounts for 45-55% of total sleep time.



• Sleep stage 3

A stage of NREM sleep defined by at least 20 and not more than 50% of the period (30 second epoch) consisting of EEG waves less than 2 Hz and more than 75 uV (high -amplitude delta waves); a "delta" sleep stage; with stage 4, it constitutes "deep "NREM sleep; appears usually only in the first third of the sleep period; usually comprises 4-6% of total sleep time.



• Sleep stage 4

All statements concerning NREM stage 3 apply to stage 4 except that high-voltage, slow EEG waves, cover 50% or more of the record; NREM stage 4 usually takes up 12-15% of total sleep time. Somnambulism, sleep terror, and sleep-related enuresis episodes generally start in stage 4 or during arousals from this stage



• Sleep Stage Demarcation

Significant polysomnographic characteristics that distinguish the boundaries of the sleep stages.



• Sleep stage NREM

Major sleep state apart from REMS; comprises sleep stages 1-4



• Sleep stage REM

The stage of sleep found in all mammal studies, including man, in which brain activity is extensive, brain metabolism is increased, and vivid hallucinatory imagery, or dreaming occurs (in humans). Also called "paradoxical sleep" because, in the face of this intense excitation of the CNS and presence of spontaneous rapid eye movements, resting muscle activity is suppressed. The EEG is a low-voltage, fast-frequency, non alpha record. Stage REMS is usually 20-25% of total sleep time.



• Sleep structure

Similar to sleep architecture. Sleep structure, in addition to encompassing sleep stage and cycle relationships, assesses the within-stage qualities of the EEG and other physiological attributes.



• Sleep talking

Talking in sleep takes place during stage REMS, representing a motor breakthrough of dream speech, or in the course of transitory arousals from NREMS and other stages. Full consciousness is not achieved and no memory of the event remains.



• Sleepiness (somnolence, drowsiness)

Difficulty in maintaining the wakeful state so that the individual falls asleep if not actively kept aroused; not simply a feeling of physical tiredness or listlessness



• Sleeping Pills

Compounds that have a sedative effect, used to produce sleepiness



• Sleep-maintenance DIMS or insomnia

Disturbance in maintaining sleep once achieved; persistently interrupted sleep without difficulty falling asleep



• Sleep-onset REM period

Atypical beginning of sleep by entrance directly into stage REM



• Sleep-wake shift (-change, -reversal)

Sleep wholly or partially moved to a time of customary waking activity, and the latter is moved to the habitual sleep period; common in jet lag and shift work.



• Sleep-Wake Transition Disorder

Disorder occuring during the transition from wakefulness to sleep or from one sleep stage to another; a form of parasomnia



• Sleep-wake, 24 hour cycle

The clock hour relationships of the major sleep and wake phases in the 24 hour cycle: similar to sleep pattern.



• Sleepwalker or Sleepwalking

Individual subject to somnambulism (one who walks while sleeping). Sleepwalking typically occurs in the first third of the night during deep NREM sleep (stages 3 and 4).



• Slow wave sleep (SWS)

Sleep stages 3 and 4



• SmartPAP (Smart CPAP)

(Smart [Continuous] Positive Airway Pressure) Medical device used in the treatment of obstructive sleep apnea providing preset levels of continuous airflow, and automatically adjusting to keep the breathing passages open by sensing changes in airway integrity. The air flows from the device through a tube that connects to a nose or face mask.



• Snoring

Noise produced primarily with inspiratory respiration during sleep owing to vibration of the soft palate and the pillars of the oropharyngeal inlet. Many snorers have incomplete obstruction of the upper airway, and may develop obstructive sleep apnea.



• Soft Palate

Membranous and muscular fold suspended from the posterior margin of the hard palate and partially separating the oral cavity from the pharynx



• Somatic Complaints

Awareness of pain or problems in the body



• Somnambulism

Walking while asleep



• Somnifacient

Inducing sleep; hypnotic, as in a drug



• Somnolence

Prolonged drowsiness or sleepiness.



• Somnoplasty

Commercial name for radiofrequency treatment of certain sleep disorders



• Soporific

Causing or tending to cause sleep



• Spindle REMS

Condition in which sleep spindles persist atypically in REMS; seen in chronic DIMS conditions



• Stanford Sleepiness Scale (SSS)

7-point rating scale consisting of seven numbered statements describing subjective levels of sleepiness/alertness



• Subjective Sleepiness

Feelings of sleepiness



• Substance Abuse

Excessive use of alcohol or drug; substances can cause sleep disturbances



• Subwakefulness syndrome

Syndrome defined as a defect in the CNS support system for waking. The few individuals reported with subwakefulness syndrome have daytime drowsiness and daytime sleep episodes that are always composed of NREMS stages 1 or 2. The naps occur repetitively



• Sudden Infant Death Syndrome (SIDS)

Sudden and unexpected death of an apparently healthy infant, whose death remains unexplained after the performance of an adequate postmortem investigation. Death usually occurs during sleep. SIDS is a classification that is used to describe a deceased infant. It is not a disease, nor can it be a diagnosis for a living baby.



• Synchronization

Chronobiological term used to indicate that two or more rhythms recur with the same phase relationship. In an EEG tracing, the term is used to indicate an increased amplitude with an occasional decreased frequency of the dominant activities.



• Synchrony

Scheduling sleep to synchronize with the biological clock