88. Sleep Disorders

Question 1

Chronic Insomnia

• sx
• pathophys
• tx

Answer 1

Daytime and nighttime sx (common and undiagnosed)
P: genetic vulnerability + precipitating event/stressor = abnormal neurobiological processes = hyperarousal, more intention to sleep, more worry = insomnia = adverse health outcomes = more insomnia (vicious cycle)
Tx: CBT!!!! (sleep hygeine and stim control - but does not help sleep duration); meds (GABA agonist - Zolpidem; Orexin antagonists - “-orexants”; Ramelteon (MT agonist); Doxepin (Antihistamine)), EBB - head cooling to slow frontal lobe metabolism

Question 2

OSA

• describe
• risk factors (3)
• dx
• mallampati score and other causes
• types (Central vs. Obstructive vs. Mixed)
• tx

Answer 2

recurrent cessation of breathing or abnormally shallow breaths
RF: PCOS, high neck circumference, high obesity
Dx: Daytime tiredness and nighttime breathing trouble, 5+ events on polysomnography
Mallampati Score: how crowded airway is (I - IV)
Causes: micro/retrognathia, macroglossia, tonsils

Central: no airflow, no effort in chest/abd to breathe
Obstructive: no airflow, +effort in chest/abd to breathe
Mixed: parts of 1 event look like both

Tx: CPAP!!!! (jaw protrusion retainer, hypoglossal nerve stim)
Central SA: tx with phrenic nerve stim or ASV (adaptive servo ventilation - continuously adjusting)

Question 3

Hypersomnia (General)

• describe
• cause

Answer 3

Excessive daytime sleepiness
Inadequate night sleep - sleep deprivation
Cause: underlying medical disorder, meds, EtOh, Narcotics
If normal sleep quantity/quality - consider primary disorder (narcolepsy, idiopathic hypersomnia)

Question 4

Narcolepsy

• sx
• peak ages of onset
• key dx lab and finding
• tx

Answer 4

sx: fall asleep when mood stimulated; cataplexy; visual hallucinations when falling asleep, sleep paralysis
age: mid-teens and early 30s (M:F 1:1) - ~10yr delay in dx
Lab: low CSF orexin (due to less orexin-synthesizing cells in lateral hypothalamus (autoimmune))
Finding: short sleep periods with multiple REMs in 1 nap
tx: napping, low glucose diet, education to pt/families
Meds: Orexin-stimulating (methylphenidate, amphetamines); Histamine agonist (pitolisant), Sodium Oxybate (high GABA at night for daytime depletion), Antidepressants

Question 5

Idiopathic Hypersomnia

• sx
• tx

Answer 5

sx: like narcolepsy but no cataplexy, no difficulty staying asleep, normal PSG but sleeping 11+ hours
tx: same as narcolepsy or GABA blocker

Question 6

Restless Leg Syndrome

• epidemiology
• dx
• screening
• tx

Answer 6

E: more common in W>M (2:1), and european ancestry (US, Canada, Brazil, EU)
Dx: urge to move legs with uncomfortable leg sensations; temp. relief w/ movement; worsening of sx at rest or at night; impairs normal functioning
Screening: check ferritin, uremia, DM, pregnancy (can exacerbate RLS)
Tx: Ferritin/Iron replacement if serum ferritin <75mcg/L; DA agonist, anticonvulsants

Question 7

Parasomnias

• types of NREM Sleep Disorders
• types of REM Sleep Disorders

Answer 7

NREM: Confusion arousals, sleep walking, sleep terrors, sleep related eating disorder

REM: Nightmares, REM Behavior Disorder (absence of limb paralysis - assoc with negative health outcomes), recurrent isolated sleep paralysis (triggered by sleep deprivation)