Flashcards in MISC - Sleep disorders Deck (42)
What (11) are the causes of daytime sleepiness?
•Sleep Breathing Disorders
•RLS/Periodic limb movement disorder
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
–Upper airway and respiratory pump muscle tone: Upper airway resistance increases
•CHEMICAL CONTROL IS THE MAJOR REGULATOR OF BREATHING DURING SLEEP
Symptoms of Sleep Apnoea
- (3) cardinal features
- (3) nocturnal
- (5) daytime
3 cardinal features:
•Excessive daytime somnolence
•disrupted / restless/ unrefreshed sleep
•nocturnal choking, gasping
•headaches - nocturnal / morning
•memory / cognitive / concentration deficit
•mood change - depression / irritability
•sexual dysfunction - reduced libido / impotence
(5) Neuropsychological effects of obstructive sleep apnoea
–In children, behavioural problems, poor school performance, ADHD
What (2) do the consequences of OSA relate to?
-> reduced productivity, sociability & increased car/work accidents
(5) Cardiorespiratory effects of obstructive sleep apnoea
–Arrhythmias / Sudden death
5 major OSA risk factors
•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.
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
Complete cessation of airflow for 10 seconds or longer regardless of oxygen desaturarion
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
(3) types of sleep disordered breathing
•Central Sleep Apnea
Discuss central sleep apnoea
Apnoeas or hypopneas caused by reduction in central respiratory drive (CNS)
•cardiac failure (Cheyne Stokes Respiration)
•CNS disorders - e.g. CVA
Mx of central sleep apnoea
- Cheyne Stokes as its cause
•treat heart failure
•CPAP ( Naughton 1995)
•Servoadaptive ventilatory support
–? Non invasive ventilation
(5) causes of hypoventilation
•Reduced respiratory centre activity
–Suppression of activity by drugs, trauma, vascular accidents etc
–nerve paralysis (drugs, polio, Guillian- Barre, trauma etc)
–muscle weakness (drugs, motor neurone disease, muscular dystrophy)
•Chest wall deformity (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?
Describe chronic insomnia
•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
•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 ...
•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
(8) Non-pharmacological Rx of insomnia
•Treat Comorbid disorders
•Stimulus Control Therapy
•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
•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
–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
- Secondary (Fe deficiency, renal failure, peripheral neuropathy, lumbosacral radiculopathy, pregnancy etc)
- May be familial (AD)
Effects/consequences of restless legs syndrome
•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
•Avoid aggravating factors
–Pharmacological - opiods, benzodiazepines, dopamine agonists
- due to deficiency of...
- 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
Mx of narcolepsy
- general measures
- (2) pharmacological
•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)
–Amphetamines: Dexamphetamine, methylphenidate
•REM suppressing drugs
–SSRI’s: Flouxetine, Venlafaxine
Describe idiopathic hypersomnia
- 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
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
•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
•L tryptophan for sleep terrors
(3) types of REM parasomnias
•REM behaviour disorder
•Isolated Sleep Paralysis