14.7 - sleep disorders Flashcards
what are the three major categories of sleep disorders
- insomnia - all disorders of falling and staying asleep
- hypersonic - all disorders of excessive sleep or sleepiness
- All those disorders that are specifically related to REM sleep dysfunction
what are disorders are commonly associated with insomnia and hyper Sonia
depression and bipolar
what percentage of respondents report sleep related problems
- are most of these clinically significant?
- give an example
around 30
- no, most of these people have sleep that is normal in sleep labs
- many people sleep 6 hours or less and function properly, but people tell them to get more sleep so they spend more time in bed than they should and have difficulty falling asleep/
what tends to hinder, and what tends to help people with minor sleep problems?
- anxiety associated with inability to sleep makes it even harder for them to sleep
- counselling that persuades them to goto bed only when they are sleepy
- doesn’t work on everyone!!
define iatrogenic and relate it to insomnia
means physician created, and in terms of insomnia many cases are iatrogenic bc the prescription of benzos are a major cause
- tend to function well at first, but soon become. trapped in a spiral of drug use as tolerance develops and more and more is required, too eventually they have withdrawals a symptom of which is insomnia
what is the different between the reported and actual time it takes insomniacs to fall asleep and how much sleep they get?
reported - 1 hr to fall asleep, 4.5 hr of sleep
actual - average sleep latency of 15 mints, sleep an average of 6.5 hours
what did we used to call people who said they were insomniacs but slept more than 6.5 hours?
- why dont we say this anymore?
neurotics!
- because some of those with neurotic pseudo insomnia were found to have sleep apnea, nocturnal myoclonus or other sleep disturbing problems - so they had enough sleep but not enough undisturbed sleep
describe sleep apnea
- why are they so often misdiagnosed (2)
patients stop breathing several times each night, when the patient will awaken and breathe again, then fall back asleep
- leads to a sense of sleeping poorly, often misdiagnosed as insomnia
- often unaware of their awakenings and instead companion of excess sleepiness, and get diagnosed with hypersonic
what are the two types of sleep apnea?
- obstructive sleep apnea - obstruction of the respiratory passages by muscle spasms or atone and often occurs in vigorous snorers
- central sleep apnea - failure of the CNS to stimulate respiration
what are the risk factors for sleep apnea
- male
- overweight folks
- the elderly
what is periodic limb movement disorder?
- what do patients with this disorder complain of?
characterized by periodic, involuntary movements of the labs often involving twitches of the legs during sleep.
- complain of poor sleep and daytime sleepiness, unaware of the nature of their problem
what is restless leg syndrome?
tension or uneasiness in heir legs keeping ppl from falling asleep
are there any treatments for the two leg induced sleep disroders
no, they are both chronic once they start, however l-dopa can sometimes help
what is sleep restriction therapy
one of the most effective treatments for insomnia
- ammt of time an insomniac is allowed to spend in bed is reduced
- after a period of sleep restriction, the amount of time spent in bed is increased in small increments as long as sleep latency remains normal
- helps even servers insomniacs
explain narcolepsy
- prevalence
- symptoms
1/200
two prominent symptoms:
1. severe daytime sleepiness, repeated, brief (10-15 minute) sleep episodes at inappropriate times, even tho they only sleep an extra hour or so per day
2. cataplexy - recurring loses of muscle tone during wakefulness, often due to emotional experience.
- when mild, can force patients to sit down
- when sever - patients become totally mobile but fully conscious for a few minutes
what are the two other symptoms associated with narcolepsy?
- sleep paralysis - inability to move as one is falling asleep or waking up
- hypnagogic hallucinations - dreamlike experiences during wakefulness
- both can be experienced in normal ppl
what are the three lines of evidence that suggest narcolepsy is the result of an abnormality in the mechanisms that trigger REM?
- those. w narcolepsy go straight into REM when they fall asleep
- experience dream like states during wakefulness
- experience loss of muscle tone during wakefulness
what gene causes nnrcolepsy?
what is the concordance rate for monozygotic twins?
orexin, sometimes called hypocretin, which exists in both orexin A and orexin B forms.
- only around 25%
what are the two correlational findings between orexin and narcolepsy?
- decreased orexin in CSF and in the brains of dead ppl with the disorder
- number of orexin releasing neurones has been found to be reduced in the brains of pe=pl with narcolepsy
what is a common explanation for the decreased umber of orexin releasing neurons inn the brains of ppl with nercolepsy?
autoimmune response
where is orexin synthesized in the brain? where do these neurons project
neurons inn the posterior hythal (associated with wakefulness)
- project diffusely throughout. the brain, but show many connections in the other wakefulness promoting area - the reticular formation
how do we typically treat narcolepsy?
stimulants - bad side effects and potential for addiction
what are now often used to treat narcolepsy (2)
- anti hypnotic stimulant modafinil - effective in some cases
- antidepressants can be effective against cataplexy
do we always classify narcolepsy as a hypersomnic disorder?
No, we sometimes say its a rem sleep related disorder
why are disorders where REM is completely abolished important?
their theoretical implications.- people tend not to be adversely effected by the lack of REM, which implies its not of the utmost importance.
what is REM-sleep behaviour disorder?
those who experience REM sleep without core muscle atonia
- causes people to act out their dreams
in what disorder is REM-sleep behaviour disorder most commonly found?
Parkinsons
what is the. likely neurological cause of rem sleep behaviour disorder?
damage to the nucleus magnocellularis or an interruption of its output
what is the nucleus magnocellularis
- what. is the evidence?
structure in the caudal RF that evolved to control muscle relaxation during REM
- in normal dogs, active only during rem
- in narcoleptic dogs, active also during attacks of cataplexy
