Sleep Flashcards
NREM stages
see screen shot of chart in folder
Sleep Latency
- Time from full wakefulness to sleep
- Interval is related to sleepiness, the quicker people fall asleep, the shorter the interval
- Once asleep, normal individuals enter NREM sleep and pass in success throughout the four stages.
- Typically NREM is 90-12 minutes, then enter initial REM period
- Interval between falling asleep to the first REM period is REM latency
- 90 minute NREM-REM cycles, 4-5 times per night
NREM, ANS activity
decrease
- progressively greater depths of unconsciousness
- slower, higher-voltage EEG patterns
- Eye rolling slowly
- Repositioning movements of the body, relative normal muscle town, and preserved deep tendon reflexes
REM, ANS activity
increase (increased pulse, elevated BP, raised intracranial pressure, increased cerebral blood flow, greater muscle metabolism and in men, erections)
-Except for eye movements and normal breathing, people in REM sleep remain immobile with paretic, areflexic and flaccid
- EMG : no electrical activity from muscles
- EEG: intense activity, similar to EEK during wakefulness
Why REM sleep is called as activated or paradoxical sleep.
discrepancy between intense ANS activity and the immobile body
REM-induced ANS activity has been implicated
increased incidence of myocardial infarctions and ischemic strokes that strike between 6 am and 11 am.
Light and dark cycles regulate the sleep-wake cycle in large part through their effect on the pineal gland’s synthesis and release of _______
melatonin
-melatonin regulates the suprachiasmatic nucleus, which has melatonin receptors on its surface
Darkness promotes synthesis of
melatonin and its release into the plasma. Melatonin concentration rise at night. Both natural/artificial light suppresses melatonin synthesis and release
Given it’s reaction to light/dark, altered melatonin concentration may play a role in _______
seasonal affective disorder
Melatonin, as medication increases ____________
sleepiness and REM sleep. It aids in the treatment of insomnia, jet lag, and possibly the delayed sleep phase syndrome
_________ occupies a greater portion of sleep time
REM sleep
REM induced paralysis
Sometimes REM is so abundant and forceful that its final period briefly spills into wakefulness.
In those cases, REM induced paralysis leaves people momentarily unable to move
Neonatal sleep pattern
Neonates sleep 16-20 hours per day with a 50% spent in REM sleep
Elderly sleep pattern
night time sleep is relatively short and fragmented by multiple brief awakening, especially early morning, have decreased total REM time, NREM sleep shrinks
Dyssomnias
Either impair initiating or maintaining sleep (falling asleep or staying asleep) or cause excessive daytime sleepiness.
Intrinsic Sleep Disorders –
Narcolepsy, Sleep Apnea Syndrome, Periodic Limb Movement, Restless Leg Syndrome, Kleine – Levin Syndrome
Extrinsic Sleep Disorder –
inadequate sleep hygiene, hypnotics, stimulants, alcohol and toxin dependency
Circadian Rhythm Disorders –
Time Zone Change (Jet Lag), shift work, delayed sleep phase
Narcoleptic tetrad
- Excessive daytime sleepiness
- Cataplexy (transient muscle weakness accompanied by full conscious awareness, typically triggered by emotions such as laughing, crying, or terror)
- Sleep paralysis
- Sleep hallucinations
Narcolepsy criteria
1 of the following, 3x/week for the past 3 months:
(episodes of cataplexy)
1. In individuals with long-standing disease, brief (seconds to minutes) episodes of sudden bilateral loss of muscle tone with maintained consciousness that are precipitated by laughter or joking.
2. In children or in individuals within 6 months of onset, spontaneous grimaces or jaw-opening episodes with tongue thrusting or a global hypotonia, without any obvious emotional triggers.
Narcolepsy, could be from what deficiency?
Hypocretin deficiency
Sleep Apnea criteria
Either one of these:
- polysomnography showed at least five obstructive apneas or hypopneas per hour of sleep and either of the following sleep symptoms: Nocturnal breathing disturbances: snoring, snorting/gasping, or breathing pauses during sleep.
Daytime sleepiness, fatigue, or unrefreshing sleep despite sufficient opportunities to sleep that is not better explained by another mental disorder (including a sleep disorder) and is not attributable to another medical condition. - polysomnography showed at least 15 or more obstructive apneas and/or hypopneas per hour of sleep regardless of accompanying symptoms.
Levels of sleep apnea
- Mild: Apnea hypopnea index is less than 15.
- Moderate: Apnea hypopnea index is 15–30.
- Severe: Apnea hypopnea index is greater than 30
Periodic Limb Movement Disorder
- Episodes movements of the limbs (predominately legs) during sleep.
- primarily during 1 and 2 of NREM sleep
- > 55 years old
- Can occur with restless leg syndrome and apnea
**Treatment – benzodiazepines and dopaminergic agents can suppress movements