Sleep& sleep deprivation Flashcards
1
Q
What are the functions of sleep?
A
- Conservation of effort& energy
- Production of hormones
- Augmentation of immune system
- Memory consolidation
- Mood regulation
- Promotion of optimal performance
- Cleans the brain of toxins (mainly beta amyloid, cleared on a higher rate during sleep)
2
Q
Outline the REM stage of sleep
A
- Occurs 90mins after being awake
- Your body goes through several REM stages, first one is the shortest
- Your brain& body are energized and dreaming occurs
- Thought to be involved in the process of storing memories, learning and balancing your mood
- Muscle tone declines during REM sleep
3
Q
How do we enter sleep and why?
A
- Sleep is entered through NREM.
- If it is entered through REM, the person is either depressed, sleep deprived or has narcolepsy
4
Q
Outline the basics of sleep
A
- SWS (slow wave sleep/deep sleep) dominates in the first third of the night
- REM predominates in the last third of the night
- Wakefulness in sleep is usually less than 5% of the night
- stage 2= the majority of sleep
- NREM= 75-80% of sleep
- REM=20-25% of sleep
5
Q
Describe HR in NREM vs REM sleep
A
- NREM= regular
- REM=irregular
6
Q
Describe BP in NREM vs REM sleep
A
- NREM=regular
- REM=variable
7
Q
Describe RR in NREM vs REM sleep
A
NREM= regular REM= irregular
8
Q
Describe responses to o2& co2 changes in NREM vs REM sleep
A
NREM= decreased
REM=significantly depressed
9
Q
Describe skeletal muscle tone in NREM vs REM sleep
A
NREM= preserved REM= absent
10
Q
Describe brain o2 consumption & CBF in NREM vs REM sleep
A
NREM= reduced REM= increased
11
Q
Describe thermoregulation in NREM vs REM sleep
A
NREM= Homeothermic
REM=poikilothermic
12
Q
Describe penile tumescence/vaginal engorgement in NREM vs REM sleep
A
NREM= infrequent
REM= frequent
All men without physiological erectile dysfunction experience nocturnal penile tumescence, usually three to five times during the night, typically during REM sleep
13
Q
Describe how sleep architecture changes with age.
A
- SWS decreases by 2% per decade until age 60
- loss of 30 mins per decade in TST(total sleep time) from 16-83 years
- Reduced time in N3, with corresponding increases in N1& N2
- REM sleep shifts to slightly earlier at night
- All non-pathological changes
14
Q
What is the deepest stage of sleep
A
- REM
- but N3 is the deepest stage of NREM sleep
15
Q
Describe the changes in sleep as part of the ageing process
A
- Decrease in TST, less SWS (loss of synaptic density), advanced sleep-wake phase, less homeostatic drive, napping returns
- Co-morbidities associated with ageing apart from age-related changes
- Medical, psychiatric, social, environmental factors & polypharmacy may have an impact on sleep.
16
Q
Outline what Circadian rhythm sleep disorders are
A
- Mismatch between endogenous biological rhythms& required social time
- This results in an impairment in sleep& wake functioning
- Sleep is normal when patients can sleep at their desired time
- Divided into intrinsic( primary) and extrinsic (secondary)
17
Q
Describe Intrinsic (primary) Circadian rhythm sleep disorders.
A
- Alterations of the circadian timekeeping system
- May result from:
- DSPD(delayed sleep phase disorder)=a sleep disorder that occurs when a person’s circadian ryhthm (sleep/wake cycle) is delayed from the typical day/night cycle
- ASPD(advanced sleep phase disorder)=characterized by a recurrent pattern of early evening (e.g. 7-9 pm) sleepiness and early morning awakening.
- Non-24h e.g in blindness
- Irregular e.g dementia
18
Q
Describe Extrinsic (secondary) Circadian rhythm sleep disorders.
A
-Misalignment between intrinsic& extrinsic signals
May result from:
-Shift work disorder
-Jet lag disorder
19
Q
What is delayed sleep phase?
A
- Sleep is out of phase with socially acceptable sleep-wake times
- Evening chronotype preference
- About 9.25 hours of sleep required
- Sleep deprivation may lead to worse academic performance, health & well-being
20
Q
What are the clinical features of DSPD?
A
- Unable to sleep advance onset
- Restriction to conventional bedtimes results in sleep deprivation
- Insomnia &/or excessive sleepiness
- Sleep is normal when they can sleep at their desired times
- Symptoms are chronic
- History of hypnotic use, alcohol at bed time, psychiatric interventions( e.g antidepressants, psychotherapy)
- 70% will have a comorbid psychological/ psychiatric disorder
21
Q
What is the treatment of DSPD?
A
combination of:
- Phototherapy
- Melatonin
- CBT-I
- examine for psychiatric co-morbidity
22
Q
Outline shift work disorder(SWD)
A
- Insomnia/excessive sleepiness with a recurring work schedule that overlaps the usual time for sleep
- Symptoms are associated with work schedule for 1 month
- Sleep disturbance is not otherwise explained by another sleep disorder, medication or substance misuse
- Supported by sleep log or actigraphy
23
Q
What are some short-term consequences of SWD?
A
- sleepiness at night
- Mood disturbances
- short day time sleep
- Higher risks at night( e.g accidents)
- GI problems
24
Q
What are some long-term consequences of SWD?
A
- Sleep disorder
- Mood disorder
- Cardiovascular risk
- Alcohol/drug abuse
- Cancer(breast- circadian disruption appears to be carcinogenic
25
Define sleep deprivation
-A sufficient lack of restorative sleep over a cumulative period so as to cause physical or psychiatric symptoms and affect daily performance
26
What are some effects of sleep deprivation
- irritability
- Cognitive impairment
- Memory lapses/loss
- Impaired moral judgement
- Severe yawning
- Hallucinations
- Symptoms similar to ADHD
- Impaired immune system
- Risk of diabetes type 2
- Increased HR variability
- Decreased reaction time& accuracy
- Tremors
- Aches
- Growth suppression
- risk of obesity
- Decreased temp.
27
Outline hallucinations in sleep deprivation
- Occur at the sleep/wake transition
- Hypnagogic hallucinations= occur on going to sleep
- Hypnopompic hallucinations= occur on waking from sleep
- May occur with isolated sleep paralysis
- Simple visual or auditory hallucinations
- Can be frightening, but insight is retained, and there's no delusional expansion vs those hallucinations occurring in psychotic illnesses
28
Are visual hallucinations in psychotic illnesses common?
NO!
29
What are parasomnias?
- Abnormal behaviours that occur in association with sleep
- occur during NREM & REM sleep
- Diagnostically challenging due to: poor patient recall; limited history if no witness account; routine investigations are often normal
30
Outline NREM parasomnias
- occur in the first 1/3rd of the night
- frequency varies
- Onset in childhood
- Confusional arousal
- Sleep walking (somnabulism)
- Night terrors (pavor nocturnus)
- Sleep-related eating disorders
- Sexsomnia
31
How can we treat night terrors?
-Education. CBT-I to stabilise sleep-wake patterns
-scheduled awakening
-keep the room safe; be aware of new environments
-Only wake fully if the episode lasts>45 mins
Pregablin, Clonazepam
32
How can we distinguish night terrors from nocturnal panic attacks
With nocturnal panic attacks there is...
- Physiologic warning (HR or breathing changes)
- Daytime symptoms of anxiety, panic or agoraphobia
33
How can we distinguish night terrors from nightmares
- Usual recollection
| - Often during REM sleep
34
What are some of the characteristics of NREM parasomnias?
- Family history
- Exacerbated by sleep deprivation, stress, alcohol, OSA(obstructive sleep apnea), fever
- Patient is often amnesic for the event, but may have partial recollection
- partner may describe tearfulness or confusion
35
How can we treat NREM parasomnias?
- Reassurance (benign)
- Education-CBT-I to improve sleep pattern
- avoid triggers
- safety
- anti-depressants(e.g Fluoxetine, Trazadone)
- Clonazepam
- Melatonin
36
Outline REM parasomnias
- Second half of the night
- 1-2 episodes per night
- Frequency varies
- REM sleep behavior disorder
- Nightmares-Rx: stop causative meds( e.g Beta-blockers,L-Dopa), CBT, Prazosin
- Catathrenia-nocturnal groaning
37
What are the characteristics of REM sleep behaviour disorder?
- 2nd half of the night
- Usually a single episode per night
- frequency varies
- Mean age of onset 50-65 years
- Loss of muscle atonia during REM sleep and a history of abnormal behaviours during sleep
- Often correlate with recalled vivid dreams- usually aggressive
- May injure bed partner
38
What can contribute to REM sleep behavior disorder?
- Male gender predilection
- Mean onset age range is 50-65years
- unknown prevalence
- Post-mortem studies suggest Lewy body pathology
- A significant proportion of patients with idiopathic RBD( IRBD) may have mild cognitive impairment at diagnosis
- Anti-depressants can induce RBD or make it worse
- Appears that the anti-depressants unmask a subclinical RBD (except buproprion)
39
What is the association between RBD and Parkinson's disease?
- RBD is the most robost non-motor predictor of developing Parkinson's disease, and it is a predictor of early cognitive impairment
- Present in other neurodegenerative conditions(mainly synucleopathies) such as MSA &DLB
- IRBD could convert to a neurodegenerative disease- risk increases as time since diagnosis increases
- Coexistence of mild cognitive impairment indicates the progression to dementia in less than 5 years
40
How can RBD be diagnoses?
-Clinical history may be highly suggestive but a v-PSG (visual polysomnography) would confirm the diagnosis ( catching an episode or REM without atonia)
41
List some RBD mimics
- Severe OSA
- severe PLMS, RMD
- Sleep talking, confusional arousals, night terrors(possible overlap disorders
- Nocturnal seizures
- Nocturnal dissociative episodes
42
How can we treat RBD?
- Patient education
- If possible, discontinue meds which may be contributing
- Safety e.g separate beds
- Simple home oximetry in the sleep
- medication if necessary...
- Clonazepam (cons= daytime sedation possible, worsens OSA and symptoms return on stopping)
- Melatonin ( typical doses=2-8mg, long lasting symptom relief, better tolerated, restores atonia)
43
Why may melatonin be used to treat a pt with DSPD?
- Hormone made naturally by your body
| - Lets your body know it's night time so that you can relax and fall asleep easier
