Sleep

Question 1

What is sleep?

Answer 1

• reversible state
• not conscious or unconscious
• Loss of ability to respond to external environment

Question 2

What does REM sleep stand for?

Answer 2

REM = Rapid Eye Movement Sleep

Question 3

What is the difference between REM sleep and Non-REM sleep?

Answer 3

REM SLEEP

• end of night
• Similar to wakefulness
• Decreased muscle tone (except resp and extraocular)
• Narrative dreaming (following storyline)

Non-REM sleep

• at start of night
• relaxation of muscles
• Reduced heart rate, blood pressure and tidal volumes
• Non-narrative dream images

Question 4

Which of non-REM and REM sleep is most important?

Answer 4

Non-REM sleep (DEEP SLEEP)

Question 5

What is thought to be the function of REM sleep?

Answer 5

substitute stimulation for wakefulness (due to storyline)

=> contributes to early brain development in infants who spend a lot of the day sleeping

Question 6

Certain drugs can suppress REM sleep and this has no effect on the patient. TRUE/FALSE?

Answer 6

TRUE

tri-cyclic antidepressants suppress REM sleep

Question 7

How long do neonates sleep for during the day and how much of this is REM sleep?

Answer 7

16 hours per day asleep

50% REM

Question 8

Why does the homeostatic response cause you to feel “sleepy”?

Answer 8

It means the longer you are awake the more tired you become

Question 9

What is meant by “circadian rhythm”?

Answer 9

your “body clock”

Question 10

What times of the day do we have peaks in sleepiness during the normal circadian rhythm?

Answer 10

4am

then another smaller peak at 2pm

Question 11

Apart from sleep, what else does circadian rhythm control?

Answer 11

appetite

hormone secretion

Question 12

Describe how circadian rhythm differs in children, teens and the elderly?

Answer 12

Children = earlier body clock => wake and sleep earlier
Teens = later body clock => wake and sleep later
Elderly = revert back to child-like body clock

Question 13

Research shows that circadian rhythm actually lasts for how long?

Answer 13

25 hours

=> has to be reset every day

Question 14

How is circadian rhythm reset everyday?

Answer 14

non-rod and non-cone cells (behind the eye) are sensitive to blue light in morning

• these project signals back to the suprachiasmatic nucleus to reset the body clock

Question 15

What behavioural traits can show a chronic sleep deprivation?

Answer 15

Disinhibited
Unaware
Judgement impaired
vsiual hallucinations
psychosis

Question 16

“Dosing” e.g. in front of the television, is a substitute for replacing sleep. TRUE/FALSE?

Answer 16

FALSE

- brain is in quiet readiness => state of wakefullness

Question 17

What does chronic sleep deprivation not affect?

Answer 17

well rehearsed tasks
routine behaviour
logical tasks

Question 18

How is sleep deprivation most likely to kill a person?

Answer 18

they drive tired and cause a road traffic accident

Question 19

What is the minimum amount of sleep required in a night?

Answer 19

7-7.5 hours

Question 20

A “lie in” at the weekend can make up for sleep deprivation. TRUE/FALSE?

Answer 20

FALSE

Question 21

A 15 minute nap in the afternoon is equivalent to how long at night?

Answer 21

90 mins

Question 22

Parasomnias can occur in both REM and Non-REM sleep. TRUE/FALSE?

Answer 22

TRUE

Question 23

Describe how patients act in a REM parasomnia

Answer 23

• takes place in last 1/3 of night
• muscle atonia subsides and patients attempt to take part in their dreams (e.g. kick football)
• REM sleep disorders are very often seen in patients with Parkinsons disease

Question 24

What can occur during a Non-REM sleep parasomnia?

Answer 24

• Non-dreaming
• Confusional arousals
• Sleep walking
• Sleep terrors and paralysis
• Restless legs

Question 25

At what two ages does narcolepsy incidence peak?

Answer 25

15 and 36

Question 26

What are the hallmark features of narcolepsy?

Answer 26

- daytime sleepiness - cataplexy (loss of muscle tone triggered by an emotion e.g. shock) - hallucinations at sleep onset - sleep paralysis - RBD

Question 27

What investigations can potentially be used to diagnose narcolepsy?

Answer 27

- Overnight polysomnography - Multiple sleep latency test (patient falls asleep faster - i.e. within around 10 mins - and they fall straight into REM sleep) - Lumbar puncture also may show slight abnormalities