Sleep disorders Flashcards
What does REM stand for?
Rapid eye movement
Describe REM sleep
consider why it occurs, when, types of dreams and what happens to the body
Its role is mostly for early brain development
Similar to wakefulness - narrative dreaming
Mostly occurs at the end of the night
Breathing becomes irregular, BP rises, fast EEG activity, cerebral blood flow is increase, loss of muscle tone (paralysis)
Describe non-REM sleep
consider why it occurs, when, types of dreams and what happens to the body
Its role is for protein synthesis, cell division and growth
Majority of sleep
Mostly occurs at the start of the night
Rythmic EEG activity, cerebral blood flow is reduced, partial relaxation of muscles
Which kind of sleep is more important, REM or NREM?
NREM
REM sleep is mostly for early brain development
Describe how REM sleep changes with age
Neonates have 50% REM sleep, this decreases with age
How long is the normal circadian rhythm?
25 hours
NB not 24
How much sleep is enough?
7-7.5 hours per night
Mid afternoon nap of 15 minutes is equivalent to 90 minutes overnight
Give some examples of sleep disorders
Parasomnias
Narcolepsy
Insomnia
What are parasomnias?
Sleep disorders that involve abnormal and unnatural movements, behaviors, dreams e.t.c that occur while falling asleep/ sleeping/ waking up
Give some examples of how a NREM parasomnia might present
Confusional arousals (motor parts of the brain wake up first)
Sleep walking
Sleep paralysis (awareness is intact but can’t move)
Bruxism (teeth grinding)
Give some examples of how a REM parasomnia might present
Simple behaviours
Dreaming
What is narcolepsy?
A disorder which affects the control of sleep and wakefullness
What affects can narcolepsy have on daily life?
Impairment of social and academic performance
Death by vehicle accidents
What are the 5 main signs/ symptoms of narcolepsy
NB patients won’t always have all 4
Daytime sleepiness
Cataplexy
Hypnagogic hallucinations
Sleep paralysis
RBD (REM behaviour disorder)
Describe how ‘daytime sleepiness’ in narcolepsy presents
Patient may have involuntary sleeping throughout the day “sleep attacks” which can occur at any time, e.g while eating or talking.
They don’t actually sleep more than is normal in a 24 hour period.
Describe cataplexy, a symptom of narcolepsy
Emotions, such as laughing or anger trigger a loss of muscle tone, causing the patient to collapse
Describe sleep paralysis, a symptom of narcolepsy
The patient is unable to move on falling asleep or waking up.
Typically lasts a couple of minutes.
Can be very scary for the patient, especially if it is accompanied by the symptom of hallucinations.
What are hypnagogic hallucinations, a symptom of narcolepsy?
Hallucinations which occur at sleep onset (when falling asleep)
What investigation can be done for narcolepsy?
Overnight polysomnography
Multiple sleep latency test
LP (low CSF hypocretin levels)
Describe how the multiple sleep latency test can be performed
(this can be done to investigate for narcolepsy)
4x 25 minute naps are scheduled 2 hours apart
EEG, muscle activity and eye movements are recorded
Time from the start of the nap to the first signs of sleep (sleep latency) are measured
What would you expect the multiple sleep latency test to show in patients with narcolepsy?
Patients fall asleep very quickly with REM sleep at the start of the sleep
What can cause insomnia?
Loss of association between bed and sleep (e.g using bed to study, use technology e.t.c)
Emotional distractions
What drugs can suppress REM sleep with no effect?
Tricyclic drugs
How is light transmitted to the brain to influence the circadian rhythm?
Light is transmitted to the brain via retinal ganglion cells which protect to the suprachiasmatic nucleus
What part of the brain remains unaffected by lack of sleep and what tasks is this part of the brain responsible for?
Prefrontal brain
Prefrontal brain is important for well rehearsed tasks and routine behaviour
REM sleep paraomnias are often seen preceding which condition?
Parkinson’s disease
What scale can be used for self-reported sleepiness to estimate if a person is abnormally tired?
Epworth scale
