Sleep and Sleep Disorders

Question 1

What are the stages of sleep and when do they occur?

Answer 1

Non REM stages 1-4 where brain waves slow down

Then REM sleep which mostly occurs at the end of the night

Question 2

non-REM sleep is ______ sleep

Answer 2

deep sleep

Question 3

Describe vitals when in non-REM sleep?

Answer 3

Synchronised rhythmic EEG activity, partial muscle relaxation, reduced cerebral blood flow
Reduced heart rate, blood pressure and tidal volumes

Question 4

Describe dreaming in non-REM sleep?

Answer 4

Some non-narrative images (dream of picture attached to an emotion and awake not remembering more than that)

Question 5

Describe vitals when in REM sleep?

Answer 5

• EEG shows fast activity, fMRI shows increased brain activity
  
  • Similar to wakefulness
  • Atonic muscles (except diaphragm which is obviously for breathing but also extraocular muscles, purpose of this is unknown)
  • Cerebral blood flow is increased , there is impaired thermoregulation

Question 6

Describe dreaming in REM sleep?

Answer 6

This is when narrative dreaming takes place

Question 7

What is the most important part of sleep? Explain how we know this?

Answer 7

Non-REM sleep
The only part of lost sleep regained after sleep loss is deep sleep
Tricyclics actually suppress people REM sleep and there is no adverse effect

Question 8

Describe how REM sleep proportion changes as we get older and the theories behind this?

Answer 8

• Neonates spend 16hrs per day asleep and have almost 50% REM sleep, time asleep decreases as get older but not much from Non REM, the time is lost from REM sleep mainly
  
  • REM sleep is thought to act for a substitute for wakefulness in children, having children awake all the time would be difficult for humans evolutionary to constantly stimulate them, so instead REM sleep provides this for them
  • As they get older they make more interactions with the external environment and therefore less REM and less sleep

Question 9

During the 1st decade, percentage REM sleep __1__, REM latency ___2__

Answer 9

1) falls

2) increases

Question 10

What are the 3 things thought to be important in sleep onset?

Answer 10

homeostatic response
emotional response
circadian rhythm

Question 11

What controls sleepiness?

Answer 11

the circadian rhythm

Question 12

What two times of the day do we experience peak sleepiness?

Answer 12

2PM and 4AM

Question 13

Describe the differences in sleep pattern between children, adolescents and the elderly?

Answer 13

children sleep earlier and wake earlier
adolescents have a delayed sleep pattern so sleep later and wake later
elderly have an advanced sleep pattern, wake early and sleep early

Question 14

Apart from sleepiness what other things does circadian rhythm help control?

Answer 14

appetite, body temperature, hormone secretions and alertness

Question 15

What do we need to reset our body clock every day?

Answer 15

natural light (hence we feel sluggish in winter)

Question 16

Describe the known functions of sleep?

Answer 16

no evidence of muscle recovery during sleep but it does help with tissue repair (cell division peaks during sleep)
cortex can’t fully rest when awake so sleep allows it to recover

Question 17

Describe what sleep deprivation does and doesn’t affect?

Answer 17

Sleep deprivation can slightly alter personality an can also get visual illusions and micro sleeps/ concentration lapses
Sleep deprivation does not affect old and well rehearsed tasks, routine behaviour or logic tasks but it DOES impair alterness

Question 18

Missing one day of sleep performance is equivalent to _____

Answer 18

3 pints of beer

Question 19

Most RTAs are caused by what type of sleep deprivation?

Answer 19

acute deprivation ie one night lost sleep

Question 20

Parasomnias are?

Answer 20

disorders of sleep

can be REM or non REM

Question 21

Describe non REM parasomnias?

Answer 21

Non dreaming, often complex behaviours 
e.g. Confusional arousals
Sleep walking 
Sleep terrors and paralysis 
Bruxism (teeth grinding)
Restless legs and PLMs

Question 22

Describe REM parasomnias?

Answer 22

Often seen preceding parkinsons disease but can occur by themselves
Involve dreaming
Much simpler behaviour usually occur in later third of the night

Question 23

What causes narcolepsy?

Answer 23

Abnormalities of brain neurotransmitters hypocretin/ orexin which is a regulator of sleep

Question 24

What 4 things is narcolepsy characterised by?

Answer 24

• Daytime sleepiness: involuntary somnolence during eating/ talking, may be severe and impossible to resist
  
  • Cataplexy: present in 70% of patients, loss of muscle tone, triggered by emotion (fall to the floor) they are actually awake but unresponsive
  • Hypnagogic hallucinations: hallucinations occurring at sleep onset
  • Sleep paralysis: unable to move upon falling asleep or awakening with retained consciousness

Question 25

Investigations for narcolepsy?

Answer 25

overnight polysomnography

multiple sleep latency test shows a rapid transition from wakefulness to sleep and a short time to onset of REM sleep

Question 26

Management of narcolepsy?

Answer 26

Good sleep hygiene advice, modanfinil dexamfetamine or methylphenidate for EDS, tricyclic antidepressants (particularly clomipramine) or SSRIs can improve cataplexy

Question 27

Describe acute insomnia?

Answer 27

Usually due to emotion e.g. bereavement and responds well to benzodiazepams

Question 28

Describe chronic insomnia and treatment?

Answer 28

If chronic > 3 months it is called psychophysiological insomnia
Treatment for chronic is sleep deprivation methods
Stay in bed for 30 mins, get up do something boring, come back when sleepy, stay for 30 mins, repeat
This stops the stress of not sleeping being associated with the bed