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Flashcards in MISC - Sleep disorders Deck (42)

What (11) are the causes of daytime sleepiness?

•Sleep Breathing Disorders
•RLS/Periodic limb movement disorder
•Neurological Disease
•Idiopathic hypersomnia
•Circadian disorders
•psychiatric disorders


How (3) does Respiratory Control Change at Sleep Onset?

•Loss of the wakefulness drive to breathe and behavioural influences
•Several other respiratory control mechanisms are down-regulated
–Respiratory reflexes
–Upper airway and respiratory pump muscle tone: Upper airway resistance increases



Symptoms of Sleep Apnoea
- (3) cardinal features
- (3) nocturnal
- (5) daytime

3 cardinal features:
•Heavy snoring
•Excessive daytime somnolence
•Witnessed apnoeas

•disrupted / restless/ unrefreshed sleep
•nocturnal choking, gasping

•headaches - nocturnal / morning
•memory / cognitive / concentration deficit
•mood change - depression / irritability
•sexual dysfunction - reduced libido / impotence
•Uncontrolled hypertension


(5) Neuropsychological effects of obstructive sleep apnoea

–Excessive sleepiness
–Psychologic problems
–In children, behavioural problems, poor school performance, ADHD


What (2) do the consequences of OSA relate to?

Sleep fragmentation

-> reduced productivity, sociability & increased car/work accidents


(5) Cardiorespiratory effects of obstructive sleep apnoea

–Cor Pulmonale
–Myocardial infarction
–Arrhythmias / Sudden death


5 major OSA risk factors

•Male Gender
•Upper Airway Morphology including nasal obstruction


(4) Pathogenesis of OSA

•Anatomically narrow upper airway
–Wakefulness - reflex dilator tone - patency
–Sleep - loss of this tone → Obstruction

•Jaw Muscles: abnormally large decrease of upper airway dilators c/w Respiratory pump muscles in sleep → Obstruction

•Respiratory Control – propensity to develop cyclical breathing

•Arousal threshold :reduced threshold → cycling


Describe the pathophysiology of OSA

Sleep -> reduced upper airway dilator activity -> airway "closes" -> snoring.

Reduced PO2, increased PCO2 -> increased respiratory effort -> arousal.

With arousal, airway "opens" & increased upper airway dilator activity -> back to sleep.

Cycles again.


How do you diagnose OSA?

AHI (apnoea-hypopnea index) >5 events per hour (events/total sleep time)

Severity by AHI:
- 5-15: mild
- 15-30: moderate
- >30 severe


Define apnoea

Complete cessation of airflow for 10 seconds or longer regardless of oxygen desaturarion


Define hypopnoea

30% or more reduction in airflow associated with 3% oxygen desaturation or an alpha wave arousal from sleep


Mx of OSA

–Deciding to treat
–Conservative treatments: weight loss, avoid alcohol, tobacco, sedatives, body position. Treat nasal congestion & medical disorders e.g. hypothyroidism
–Oral appliances


(3) types of sleep disordered breathing

•Central Sleep Apnea
•Sleep Hypoventilation


Discuss central sleep apnoea
- define
- aetiology

Apnoeas or hypopneas caused by reduction in central respiratory drive (CNS)

•cardiac failure (Cheyne Stokes Respiration)
•High altitude
•CNS disorders - e.g. CVA


Mx of central sleep apnoea
- Cheyne Stokes as its cause
- Idiopathic

•treat heart failure
•CPAP ( Naughton 1995)
•? O2
•Servoadaptive ventilatory support

–? Non invasive ventilation


(5) causes of hypoventilation

•Reduced respiratory centre activity
–Reduced drive
–Suppression of activity by drugs, trauma, vascular accidents etc

•Neuromuscular disease
–nerve paralysis (drugs, polio, Guillian- Barre, trauma etc)
–muscle weakness (drugs, motor neurone disease, muscular dystrophy)

•Chest wall deformity (gross)

•Obesity (gross)

•Increased Ventilatory Requirements

ALL forms of hypoventilation are worse in sleep


•22 yo male
•Difficulty sleeping since early teens
•Sleep onset insomnia mainly
•Once asleep sleeps well, but has to get up for work after 4 hours
•Describes ‘cannot get comfortable’ in bed
•Non snorer, thin
•Minimal alcohol, no illicit drugs, 1 coffee daily

What might be stopping this man from getting to sleep?

Chronic Insomnia


Describe chronic insomnia
- define
- Px
- epidemiology

•Subjective dissatisfaction with sleep quality or duration, difficulty falling asleep at bedtime, waking up in the middle of the night or too early in the morning, or non-restorative or poor quality sleep.
•Associated daytime symptoms
•Functional impairments
•6–10% meet criteria for an insomnia disorder. F:M 2:1 (Australian estimate 4.2% (Knox 2008)


What are associated features of insomnia that have bidirectional links?

Disorders of anxiety, mood, impulse control & substance abuse


What genetic factor may play a role in insomnia?

Serotonin receptor abnormalities



Describe 'primary' insomnia
- disorder of ...
- define
- pathogenesis
- Px

•Disorder of “hyperarousal”
•Increased anxiety, increased HPA axis activity, increased hypertension, increased ANS activity in sleep, changes in sleep EEG with more faster frequency waves, increased brain glucose uptake in sleep.

•Predisposed individual -> stressor -> Poor sleep -> anxiety about sleep -> arousal at bedtime -> trying hard to sleep -> poor sleep

•Maladaptive responses (increasing time in bed, napping, alcohol use etc etc)


Contributing disorders of insomnia

OSA, Circadian Disorders, Restless Legs, Psychiatric Disorders (50%), Substance abuse, Pain, Urinary problems, Medications


Ix of insomnia

Sleep diary


(8) Non-pharmacological Rx of insomnia

•Treat Comorbid disorders
•Stimulus Control Therapy
•Sleep Restriction
•Paradoxical intention
•Sleep Hygiene!!
•Short term hypnotics


Pharmacological Rx of insomnia
- (3) types of meds
- first choice of treatment
- comment on its period of usage
- how to taper dose

»Benzodiazepines - temazepam
»Non-benzodiazepines - zolpidem
»Other - antidepressants, valerian, antihistamines

–Hypnotic medications should NOT be the first choice of treatment
–Short term management of idiopathic or psycho-physiological insomnia
–Combined with non-pharmacological measures when tapering dose


What could cause circadian disorders?

•Delayed Sleep Phase Syndrome
•Advanced Sleep Phase Syndrome
•Non-24 hour circadian rhythm
•Free-running rhythm
•Jet Lag
•Shift Work Disorder
•Seasonal Affective Disorder


What (4) are the criteria for restless legs syndrome?

–Desire to move the extremities often associated with paresthesias or dysesthesias
–Motor restlessness
–Worsening of symptoms at rest with at least partial and temporary relief during activity
–Worsening of symptoms in the evening or at night


Causes of Restless legs syndrome

- Primary
- Secondary (Fe deficiency, renal failure, peripheral neuropathy, lumbosacral radiculopathy, pregnancy etc)
- May be familial (AD)


Effects/consequences of restless legs syndrome

•sleep disturbances
•tiredness or fatigue during daytime
•reduced emotional well-being/QOL
•avoidance of social activities
•possibly higher incidence of CVS risk factors/ CVS disease


Describe restless legs syndrome

Aka. Willis-Ekbom disease (WED) or Wittmaack-Ekbom syndrome

= a neurological disorder characterized by an irresistible urge to move one's body to stop uncomfortable or odd sensations.
- most commonly affects the legs, but can affect the arms, torso, head, and even phantom limbs
- Moving the affected body part modulates the sensations, providing temporary relief.
- RLS sensations range from pain or an aching in the muscles, to "an itch you can't scratch," an unpleasant "tickle that won't stop," or even a "crawling" feeling.
- The sensations typically begin or intensify during quiet wakefulness, such as when relaxing, reading, studying, or trying to sleep.

- Additionally, most individuals with RLS suffer from periodic limb movement disorder (limbs jerking during sleep) -> sleep disruption.
- It can be caused by low iron levels.

- Treatment is often with levodopa or a dopamine agonist such as pramipexole.


Describe periodic limb movement disorder

–Repetitive movements of the limbs (usually legs) that occur during sleep and may be associated with arousal
–PLM index on polysomnography
–Associated with RLS - 80% with RLS have PLM, >50% PLMS have RLS


Rx of restless legs syndrome & periodic limb movement disorder

–Non pharmacological
•Fe replacement
•Avoid aggravating factors

–Pharmacological - opiods, benzodiazepines, dopamine agonists


Describe narcolepsy
- define
- due to deficiency of...
- epidemiology
- genetics inheritance

–Disorder of sleep regulation
•Intrusion of some REM sleep into wakefulness
•Abnormal regulation sleep timing
–Deficiency in the neurotransmitter OREXIN
– F=M, begins in the teens and twenties, but can occur after forty
–Autosomal dominant with incomplete penetrance
–HLA DQB1*0602 positive


What are main features of narcolepsy?

Excessive daytime sleepiness (100%)
–“sleep attacks”, ESS>15, refreshed following nap
–Abnormally timed REM sleep
–Multiple Sleep Latency Test

Manifestations related to REM sleep
•Hypnagogic/Hypnopompic hallucinations (30%)
•Sleep paralysis (25%): Complete inability to move for 1- 2 minutes after awakening
•Cataplexy (60%)


Mx of narcolepsy
- general measures
- (2) pharmacological

General Measures
•Avoid shifts in sleep schedule
•Avoid heavy meals and alcohol intake
•Regular timing of nocturnal sleep
•Naps: Strategically timed naps, if possible (e.g., 15 min at lunchtime, 15 min at 5:30 PM)
•Career counseling

Pharmacological Mx:
–Amphetamines: Dexamphetamine, methylphenidate
•REM suppressing drugs
–SSRI’s: Flouxetine, Venlafaxine


Describe idiopathic hypersomnia
- diagnostic criteria
- pathogenesis
- Dx
- Rx

Diagnostic criteria
–Complaint of EDS and prolonged, often unrefreshing naps
–Difficulty waking up in the morning or after a nap (sleep drunkenness)
–Insidious onset prior to age 30
–Duration of at least 6 months
–Exclusion of conditions that may cause the same symptoms

Unknown pathogenesis
Diagnosis of exclusion
Rx: stimulants. 1/4 spontaneously improve


What are parasomnias?

Undesirable behaviour or experiences in sleep or in transition to or from sleep


Discuss disorders of arousal
- arises from ... wave sleep
- mixed state b/w...
- when during the night
- exacerbating factors
- Px if woken
- common when
- risk factors
- DDx

•Arising from slow wave sleep
•A mixed state between sleep and wakefulness
•First third of night
•Exacerbated by factors deepening sleep and also by factors disturbing sleep
•Confused if woken, mentation slow but complex activity possible
•Much commoner in childhood
•Strong familial component
•Main differential diagnosis is from seizure disorder


Rx of disorders of arousal

•Alter sleep environment for safety
•Avoidance of Precipitants
•Treat Stress
•Sleep Extension
•Scheduled Wakenings
•L tryptophan for sleep terrors


(3) types of REM parasomnias

•REM behaviour disorder
•Frequent Nightmares
•Isolated Sleep Paralysis


Describe REM behaviour disorder
- epidemiology
- Px
- faliure of ...
- types of forms (idiopathic, acute)
- association with ... disorders
- Rx
- good response to which drug

•Elderly men predominantly, 0.5 % prevalence
•Dream enactment behaviour, violent
•Failure of REM atonia / locomotor quiescence
•Idiopathic/Secondary forms
•Acute form precipitated by injury/CVA/SSRIs
•Association with neurodegenerative disorders
•Treat associated conditions/ stop meds
•80-90% response to clonazepam (benzodiazepine)
•Also melatonin, others

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