Sleep Medicine

Question 1

Narcolepsy: symptoms (tetrad)

Answer 1

• Bimodal age distribution
• Hypersomnolence
• Cataplexy: episodic weakness often triggered by emotion (laughing)
  
  • consciousness is intact
  • Type 1 if present; type 2 if absent
• Sleep paralysis: loss of tone when pt wakes up
  
  • atonia of REM sleep is dissociated from REM and occurs w/ wakefulness
• Hypnogogic hallucinations: vivid hallucinations often w/ auditory/tactile components
• Impaired sleep quality
  *

Question 2

Narcolepsy: diagnosis

Answer 2

• Polysomnogram = usually unremarkable, may show frequent arousals
• Multiple sleep latency test:
  
  • 4-5 20 minute naps @ 2 hr intervals
  • REM sleep will occur in at least 2/5 naps
  • Shorter sleep latency (fall asleep fast)
  • Sleep paralysis may be present

Question 3

Narcolepsy: pathophysiology

Answer 3

• Hypocretin (ORX): neuropeptide produced in posterolateral hypothalamus
  
  • normally released during wakefulness and activate wakefulness promoting regions
• ORX levels are diminshed or absent in narcolepsy
  
  • this causes increased “sleep” signals
  • REM-associated sleep phenomena can intrude into wakefulness
• Genetic susceptibility possible
• Loss of ORX neurons may be auto-immune attack
  
  • immune response triggered by environmental/infectious agent

Question 4

Narcolepsy: treatment

Answer 4

• Hypersomnolence:
  
  • stimulants, naps
• Cataplexy:
  
  • drugs to suppress REM sleep (SSRIs/SNRIs)
  • gamma hydroxybutyrate: allows pt to get a good night sleep which minimizes cataplexy during day

Question 5

Parasomnia: definition, symptoms

Answer 5

• Undesirable behavioral, motor, sensory phenomenon occurring intermittently during sleep
• Some are considered normal (nightmares, sleep talking)
• lack of recall
• positive family history common
• Continuum of severity
  
  • confusional arousals
  • sleep walking
  • sleep terrors

Question 6

Parasomnia: pathophysiology

Answer 6

• Emerge from NREM
  
  • boundary not defined b/t Wake and NREM
• More common in children perhaps due to maturation issue
• These pathways can break down in adults too

Question 7

Parasomnia: treatment

Answer 7

• Reassurance – kids grow out of it
• Secure environment
• Warning device
• Avoid ETOH, stress, sleep deprivation…
• Benzodiazepines –> puts patietns into more well-defined sleep state

Question 8

REM sleep behavior disorder: def, anatomy, epi, associations, tx

Answer 8

• Dissociated state b/t Wake and REM
• Violent, dream-enacting behavior
• Excessive mm activity in REM sleep
• Absence of epileptiform activity
• Diagnose w/ history or polysomnogram
• Potentially localized to dysfunction in Pons
• Epi: males, 50s/60s
• RBD associated w/ PD, LBD, Multi-system atrophy (synucleinopathies)
• Tx: clonazapam, melatonin, secure environment

Question 9

Periodic leg movements

Answer 9

• involuntary sleep related motor phenomenon
• can be isolated symptom or occur w/ RLS
• may or may not require treatment

Question 10

Restless leg syndrome: symptoms and diagnosis

Answer 10

• Awake sensory phenomenon w/ volitional motor response
• Clinical diagnosis:
  
  • Urge to move legs
  • Rest/inactivity precipitates urge
  • Getting up (movement) gives partial/total relief
  • Evenings = worse symptoms
• 80-90% of RLS pt also have periodic limb movements
• Family history (primary RLS)
• Secondary RLS
• Worse w/ stress, confinement, caffeine, poor sleep
• Epi: women, older indiv, europeans,

Question 11

Restless leg syndrome: pathophys, tx

Answer 11

• Secondary RLS:
  
  • Iron deficiency
  • Pregnancy
  • Chronic Renal Failure
• May be due to impaired central dopaminergic transmission
  
  • iron deficiency could cause this
• Tx:
  
  • dopamine agonists (low dose)
  • opiates
  • iron
  • benzodiazapines
  • ** may not require tx if it doesn’t affect sleep