Sleep Physiology

Question 1

What is sleep?

Answer 1

normal, recurring reversible state with loss of ability to respond to the external environment

Question 2

When does NREM sleep occur?

Answer 2

start of the night

3/4 of sleep in young adults

Question 3

What EEG changes are seen in NREM sleep?

Answer 3

synchronised, rhythmic EEG activity
partial muscle relaxation
reduced cerebral blood flow

Question 4

When does REM sleep occur?

Answer 4

mostly at end of the night

Question 5

What EEG changes are seen in REM sleep?

Answer 5

fast activity, fMRI shows increased brain activity similar to wakefulness

Question 6

When does narrative dreaming occur?

Answer 6

REM sleep

Question 7

What happens in deep sleep?

Answer 7

the cortex recovers

Question 8

Which drugs suppress REM sleep?

Answer 8

tricyclic antidepressants

Question 9

Is Rem sleep essential?

Answer 9

mainly for easy brain development

suppressed REM sleep has no effect

Question 10

What is the sleep pattern of neonates like?

Answer 10

16 hours a day asleep

50% REM sleep, shorter cycles

Question 11

What is sleep patterns in elderly like?

Answer 11

increased awakenings
reduced REM latency
reduced total sleep time
daytime napping

Question 12

What kind of rhythm controls sleep-wake, appetite and hormone secretion?

Answer 12

Circadian rhythm

Question 13

In which type of sleep is memory consolidated?

Answer 13

REM sleep

Question 14

When is cortisol level highest?

Answer 14

Early morning when waking

Question 15

When is cortisol level lowest?

Answer 15

sleep - midnight

Question 16

How long does normal Circadian rhythm last?

Answer 16

24:20-25 hours

Question 17

What cells are involved in regulating the body clock?

Answer 17

non-rod, non-cone cells

Question 18

Which phase of sleep does protein synthesis and cell division happen?

Answer 18

NREM sleep

Question 19

Does sleep help with tissue repair? OR muscle repair?

Answer 19

tissue yes

muscle no evidence

Question 20

What happens to the brain in sleep deprivation?

Answer 20

irritable and suspicious
visual illusions
micro sleeps
concentration lapses

Question 21

What is the normal acceptable amount of sleep?

Answer 21

7-7.5 hours

Question 22

What does a 15 minute afternoon nap equate to in overnight sleep?

Answer 22

90 mins

Question 23

What are some examples of non-REM parasomnias

Answer 23

non-dreaming 
confessional arousals 
sleep walking 
sleep terrors and paralysis 
restless legs 
bruxism

Question 24

What is bruxism?

Answer 24

grinding teeth and clenching jaw

Question 25

What are some examples of REM parasomnias?

Answer 25

dreaming, simpler behaviour, latter third of the night

Question 26

Which part of the night do REM parasomnias occur?

Answer 26

latter third

Question 27

Which condition commonly has REM sleep parasomnias preceding clinical features?

Answer 27

Parkinson’s

Question 28

How does Narcolepsy present?

Answer 28

daytime sleepiness 
cataplexy 
hypnagogic hallucinations 
sleep paralysis 
RBD

Question 29

What is cataplexy?

Answer 29

loss of muscle tone triggered by emotion

Question 30

What are hynagogic hallucinations?

Answer 30

hallucinations at sleep onset

Question 31

What effects can narcolepsy have on an individual?

Answer 31

reduced academic and social performance
loss of jobs
increased risk of RTA

Question 32

What investigations can be useful in narcolepsy?

Answer 32

overnight polysomnography

multiple sleep latency test

Question 33

Why is Lumbar Puncture useful in Narcolepsy patients?

Answer 33

CSF hypocretin levels below 110pg/ml are consistent with narcolepsy