8B- circadian rhythm sleep disorders Flashcards
circadian rhythm sleep disorders
a category of sleep disorders in which sleep is disrupted because the circadian rhythm and a person’s sleep wake schedule are misaligned
bright light therapy
a therapy to treat a sleep disorder in which the person is exposed to a bright light to reset the sleep wake cycle
delayed sleep phase syndrome
a circadian rhythm sleep disorder characterised by a delay in the timing of sleep onset and awakening compared with the timing that is desired
advanced sleep phase disorder
a circadian rhythm sleep disorder characterised by an advance in the timing of sleep onset and awakening compared to the timing that is desired
shift work
work that regularly takes place outside of normal business hours particularly at night and the very early morning, can cause a circadian rhythm sleep disorder
what is a circadian phase disorder?
Circadian phase disorder refers to sleep disorders that involve disruptions to a person’s sleep-wake cycle as there is a mismatch between a person’s normal sleep-wake pattern (reality) and the sleep-wake pattern that is required of them (expectation).
what can circadian rhythm disorders cause?
distress/dysfunction
excessive sleepiness/insomnia/ impairment in functioning
harder to function day to day
what are 3 circadian phase disorders?
advanced sleep phase disorder
delayed sleep phase syndrome
shift work
what can circadian rhythm sleep disorders be treated with?
bright light therapy which involves exposing a person to light for a specific amount of time to reset the sleep wake cycle. strategic exposure to light prompts the wake inducing biological mechanisms involving the circadian rhythm and suprachiasmatic nucleus and delays melatonin release, promoting wakefulness
what are some light sources for BLT
safe but artificial source from a specifically designed light box, desk lamp, floor lamp, visor hat with attached light or dawn simulator light
or may be natural sunlight if deemed reliable
ideal length and timing of light exposure is dependent on the type of disorder being treated
what is DSPS
delayed sleep phase syndrome is a sleep disorder characterised by a delay in timing of sleep onset and awakening compared to the desired timing
delay is usually 2 or more hours, with a person falling asleep later than required or conventionally accepted, causing a delay in awakening
what does the delay in sleep onset contribute to?
a sleep disorder when a person is unable to achieve the recommended amount of sleep because they have to wake up for work/school
how does DSPS occur
because the internal body clock doesn’t match the external cues like light and darkness. this delays sleep and wake times
give an example of DSPS
instead of sleeping at 10 and waking at 8, they may sleep at 1 and wake up at 11
when is DSPS seen throughout the lifespan
adolescent sleep-wake cycle shift
in order to be diagnosed what are the conditions?
must experience symptoms for more than 3 months
oftentimes, this also implies symptoms are not getting better, or are worsening.
what are some predisposing factors for DSPS?
age
longer than average circadian rhythm
delayed night time signal to the SCN, which delays melatonin release
less sensitive to morning light, would have a lack of light cues to the SCN to signal a reduction in melatonin release
how can bright light therapy be used as a treatment for DSPS?
exposed to the bright light source in the morning at an appropriate awakening time.
external cue to the SCN, promoting wakefulness by sending signals to release cortisol
helps the SCN send signals for melatonin release at an earlier and more appropriate sleeping time, promoting sleep
what is ASPD
advanced sleep phase disorder is a circadian rhythm sleep disorder characterised by an advance in the timing of sleep onset and awakening compared to the desired timing
how does ASPD occur?
internal body clock is set earlier than normal, making them feel tired earlier in the evening and causing them to wake up earlier in the morning
give an example of ASPD
instead of sleeping at 10 and waking at 8, they sleep at 8 and wake at 6
when they attempt to adhere to a later bedtime what occurs?
they will continue to have an early wake time due to the shift in circadian rhythm
how is ASPD perpetuated
a persons adverse exposure to light can maintain their undesired advance circadian rhythm. by going to bed early and then waking early, a person isn’t exposed to the regular evening low light and morning bright light signals maintain the disorder
what are some symptoms and how can they increase in severity?
symptoms can get more severe when work or social demands require a schedule that doesn’t match the persons natural sleep-wake cycle