Sleep

Question 1

Parasomnia

Answer 1

A sleep disorder that involves unusual and undesirable physical events or experiences that disrupt your sleep.

A parasomnia can occur before or during sleep or during arousal from sleep. If you have a parasomnia, you might have abnormal movements, talk, express emotions, or do unusual things.

Question 2

Examples of parasomnias that happen during Non-REM sleep

Answer 2

Sleep terrors
Sleepwalking
Confusional arousals
Sleep-related eating disorder

Question 3

Examples of parasomnias that happen during REM sleep

Answer 3

Nightmare disorder
Recurrent isolated sleep paralysis
REM sleep behaviour disorder (RSBD)

Question 4

REM sleep behaviour disorder (RSBD)

Answer 4

If you have this sleep disorder, you act out, vocalize (e.g., talk, swear, laugh, shout), or make aggressive movements (e.g., punching, kicking, grabbing) as a reaction to a violent dream.

Question 5

Recurrent isolated sleep paralysis

Answer 5

You can’t move your body or limbs during sleep. Scientists think the paralysis might be caused by an extension of REM sleep – a stage in which muscles are already in a relaxed state. This happens either before you fall asleep or as you are waking up.

Question 6

Narcolepsy

Answer 6

A rare long-term brain condition that causes a person to suddenly fall asleep at inappropriate times.

Question 7

Features of narcolepsy

Answer 7

excessive daytime sleepiness 
sleep attacks 
cataplexy
sleep paralysis 
excessive dreaming and waking in the night

Question 8

Cataplexy

Answer 8

Temporary loss of muscle control resulting in weakness and possible collapse, often in response to emotions such as laughter and anger

Question 9

Investigations for narcolepsy

Answer 9

i. Overnight polysomnography
ii. Multiple sleep latency test EEG
iii. Lumbar puncture

CSF hypocretin levels can also be checked, with low CSF hypocretin levels (less than 110pg/ml or 1/3 of the mean control value) are consistent with narcolepsy

Question 10

What CSF hypocretin levels are associated with narcolepsy?

Answer 10

CSF hypocretin levels can also be checked, with low CSF hypocretin levels (less than 110pg/ml or 1/3 of the mean control value) are consistent with narcolepsy

Question 11

Management of narcolepsy

Answer 11

Daytime stimulants (e.g. modafinil) and night-time sodium oxybate

Question 12

Modafinil mechanism of action

Answer 12

Acts as an atypical, selective, and weak dopamine reuptake inhibitor which indirectly activates the release of orexin neuropeptides and histamine from the lateral hypothalamus and tuberomammillary nucleus, respectively all of which may contribute to heightened arousal.