Overview of sleep Flashcards
How do we measure sleep in a sleep lab
Polysomogram:
Electro-encephalogram (EEG) (changes in neuronal activity)
Electro-myogram (EMG)(muscles)
electrooculogram (EOG) -eye movement
What does the EEG pick up
Different electrical activity -beta alpha theta delta
What happens to Tau in sleep
Tau usually accumulates and forms tangles
In healthy brains it is cleared during sleep
If adolescents don’t have enough sleep what could this lead to
Increase chance of catching common cold
If you don’t get enough sleep what is the adverse effects on body
Adverse metabolic, CV and inflammatory effects
What genes are unregulated during sleep
Those involved in synthesis and maintenance of cell membranes and myelin and immunity
What does sleep deprivation lead to
Increased sleep propensity, compensated by subsequent increased sleep intensity and/or duration
What does sleep deprivation do to glucose metabolism
Decreased glucose metabolism in prefrontal and parietal cortices
What does sleep deprivation do to tau in blood
Increase
May the effects on cognition from sleep deprivation be recognised by the individual
No
What is insomnia
the perception of insufficient or inadequate sleep for 3 weeks or more
What are the types of insomnia
Transient - acute stress, jet lag
Short term: situationl stress (bereavement, conflict at work, pain)
Long term- underlying psychiatric illness, chronic alcohol or drug abuse
What is a good treatment for insomnia for long term change
Non-pharmacological treatment
What is progressuve relaxation therapy
Provides a means for reducing autonomic activity
How is CbT used for insomnia Pre-sleep
Pre-sleep thoughts promote cognitive arousal
CBT provides strategies with:
- a range of strategies that can prevent or interrupt maladaptive thoughts
- ->thought blodking and distraction
- ->Cognitive restructuring (beliefs and attitudes)
When is melatonin secreted
Around 9. Peaks around 2am which is where you have the deepest sleep
How does melatonin secretion change during night
Changes during night. Decreases as you reach morning.
What governs the sleep-wake cycle
Suprachiasmatic nucleus within the hypothalamus
Function of suprachiasmatic nucleus
Encourages production of melatonin to induce tiredness with levels peak between 2-4am
How does the suprachiasmatic nucleus induce wakefullness
Triggers release of cortisol
When is Ach active
Where is it active
During wakefulness and REm sleep
Acctive in forebrain and brainstem
Where is noradrenaline and norepinephrine produced
What does it do
Locus coeruleus
Generates arousal fight/flight response
What does hiistamine do in sleep
Where is it activated
Promotes wakefulness, reducing REM and NREM
Activated in tuberomammillary nucleus
What does 5-HT do
Promotes wakefllness and suppresses REM sleep
What does dopamine do
Exerts potent wake promoting effecrs
What is REM sleep behaviour disorder
Mostly a disorder of older men
They gain activity during REM cycle of sleep e.g. when fighting in their dreams, they can fight in real life too
How do you diagnose REM sleep behaviour disorder
Clinical history
Poysomnogram (increased muscle tone in REM sleep)
Must rule out obstructive sleep apnoea
Symptoms of erstless legs syndrome
uncomfortable feeling in legs and feet (itchy,twitchy, throbbing etc)
Powerful urge to move the legs to reduce uncomfortable feeling
Worsened at night when lying or sitting down
Causes of restless legs syndrome
Dopamine dysfunction
Genetics
Medications (e.g. antipsychotics, antidepressants, anti-nausea)
Chronic illness
Vitamin and mineral deficiencies
Pregnancy
Sleep deprivation
What are the type of hypnotics
Short acting (6h half life) -Benzodiazepines or related Z-drugs
Antihistamines-H1 receptor antagonists
Sedative antidepressants
Valerian (plant) extracts
melatonin/melatonin receptor (MT1/MT2) agonists
What ype of benzodiazepines are best for sleep managemtn
Short acting (hypnotics)
How long can you use benzidiazepines
Only for short term use
Advantages of benzodiazepines
Lethal dose very high
Small effect on sleep pattern (induces ‘normal’ sleep
Do not induce enzymes
Although tolerance and dependance occurs (therefore only to be administered in crisis and short term use)
What is coontraindicated with hypnotics such as temazepam
Alcohol
Respiratory depression in combination with alchol
Disadvantages with benzodiazepines
hang-over effect
Some dependence and withdrawal
Sudden medication stop–? anxiety;insomnia;unsteadiness;seizures
How do you control the withdrawal of benzodiazepines
take them off the drug slowly
Mode of acion of ‘Z’ drugs
Bind to benzodiazepine binding site on the GABAa receptor (however they are not benzodiazepines)
Advantages of ‘Z’ drughs
Short half life
Pharmacokinetics not altered by age
No change in REM
little reported rebound or withdrawal effects
No abuse potential
Why are benzodiazepines not recommended fort elderly patients
There is a chance for impaired renal or hepatic function
-could have an effect on the pharmacokinetics
before mebarking on sleep drugs, how should you manage bad sleep
Address sleep hygiene and use CBT
What do hypnotics do to sleep
Induce sleep but do not alter sleep pattern
How should you treat insomnia
treat cause
