Sleep Physiology, hyper somnolence, parasomnias

Question 1

describe the features of non REM sleep?

Answer 1

occur more at the state of the night
synchronised, rhythmic EEG activity
partial muscle relaxation & reduced cerebral blood flow so reduced HR, BP and tidal vol

Question 2

Circadian rhythms

• last how long?
• how does light influence body clock?

Answer 2

• 25 hours
• hits retinal ganglion cells projecting to suprachiasmatic nucleus, non-rod, non-cone cell and these are very sensitive to light and project it into the optic chiasmatic nucleus, need bright light to rest this each morning

Question 3

What part of the brain is effected by sleep deprivation?

Answer 3

prefrontal cortex,

become irritable and suspicious, visual illusions and micro sleeps and concentration lapses

Question 4

How much sleep is necessary?

Answer 4

7-7.5 hours of sleep is enough

Question 5

Parasomnias

• what are they?
• types? (2)
• features of each?

Answer 5

• sleep disorders that involve abnormal movements, behaviors, emotions, perceptions, and dreams that occur while falling asleep, sleeping, between sleep stages, or during arousal from sleep
• REM and Non-REM

-Non-REM
non dreaming
confusional arousal
sleep walking
sleep terror and paralysis 
Bruxism
Restless leg syndrome 

REM
often seen preceding PD
dreaming an much simpler behaviour
latter 1/3 of night

Question 6

Narcolepsy

• what is it?
• characteristics?

Answer 6

-people fall asleep at any time

-daytime sleepiness, during eating/talking
cataplexy-loss f muscle tone triggered by emotion
Hypnagogic hallucinations
Sleep paralysis

Question 7

Investigations in sleep disorders?

Answer 7

overnight polysomnography
Multiple sleep latency test
LP- hypocritin levels can be raised

Question 8

Insomnia

-what is it?

Answer 8

-inability to sleep