Sleep Physiology, Hypersomnolence, Parasomnias Flashcards
What are the characteristics of non-REM sleep ?
- More NREM at start of night - ¾ sleep for young adults is NREM
- Synchronised, rhythmic EEG activity, partial muscle relaxation of muscles, reduced cerebral blood flow
- Reduced heart rate, blood pressure and tidal volumes
- Some non-narrative images
What are the characteristics of REM (rapid eye movement) sleep ?
- Occurs mostly at end of night
- EEG shows fast activity, fMRI shows increased brain activity
- Similar to wakefulness
- Atonic muscles (except diaphragm and extraocular muscles) (no tone i.e. cannot move)
- Cerebral blood flow increased, impaired thermal regulation
- Breathing is irregular and BP rises
- Narrative dreaming
What is the importance of deep sleep (part of non-REM) ?
Allows the cortex to recover after a busy day
Non-REM in general - for protein synthesis and Cell division and growth
What is the importance if any of REM sleep ?
Mainly for early brain development
Likely dispensable - See it as “non-wakefulness, not sleep”:
- Dolphins – no REM sleep
- Common drugs (tricyclics) – suppress REM sleep with no effect
For sleep consolidated memory and possibly deletes unnecessary memory files
Pic is just illustrating the fact that infants have a lot of REM sleep hence link for it being associated with early brain development but as you get older its not really needed so much
How much sleep do we need per night ?
7-7.5 hours is acceptable
What is confusional arousals ?
Is a sleep disorder that causes you to act in a very strange and confused way as you wake up or just after waking. It may appear that you don’t know where you are or what you are doing.
What are sleep terrors ?
Episodes of screaming, intense fear and flailing while still asleep.
What is sleep paralysis ?
A feeling of being conscious but unable to move. It occurs when a person passes between stages of wakefulness and sleep.
What is bruxism ?
Involuntary habitual grinding of the teeth, typically during sleep.
What is restless leg syndrome ?
An overwhelming urge to move your legs and an uncomfortable sensation in your legs.
Uncomfortable sensations include:
- tingling, burning, itching or throbbing
- a “creepy-crawly” feeling
- feeling like fizzy water is inside the blood vessels in the legs
- a painful, cramping sensation in the legs, particularly in the calves
What sleep disorder do the majority of patients with restless leg syndrome have ?
Periodic limb movements in sleep (PLMS)
- Your leg will jerk or twitch uncontrollably, usually at night while you’re asleep.
- The involuntary leg movements can also occur when you’re awake and resting.
When does dreaming occur ?
mainly in REM sleep
Describe the typical presentation of REM sleep behaviour disorder
- This is where paralsysis in REM sleep is absent or incomplete
- This results in the patient acting out dreams that are vivid and violent (with shouting, punching, kicking, flailing etc enough to endanger bed partner)
How is REM sleep behaviour disorder diagnosed ?
On onvernight polysomnogrpahy which shows increased muscle tone during REM sleep (recall tone should decrease here ==> paralysis)
How is REM sleep disorder treated ?
- Sleep alone, remove all dangers from sleep environment
- Clonazapam at bedtime may help
