American Board of Psychiatry and Neurology ABPN Sleep Medicine and Neurological Disorders 1 — Questions and Answers
Question 1: A patient reports excessive daytime sleepiness, sudden loss of muscle tone triggered by strong emotion, sleep paralysis, and hypnagogic hallucinations. What is the MOST likely diagnosis?
- Idiopathic hypersomnia
- Narcolepsy type 1 (Correct answer)
- Obstructive sleep apnea
- REM sleep behavior disorder
Correct answer: Narcolepsy type 1
Narcolepsy type 1 is characterized by the tetrad of excessive daytime sleepiness, cataplexy, sleep paralysis, and hypnagogic hallucinations, caused by hypocretin/orexin deficiency.
Question 2: Which neurotransmitter deficiency is associated with narcolepsy type 1?
- Dopamine
- Serotonin
- Hypocretin (orexin) (Correct answer)
- Acetylcholine
Correct answer: Hypocretin (orexin)
Narcolepsy type 1 is caused by selective loss of hypocretin (orexin)-producing neurons in the lateral hypothalamus, likely through autoimmune mechanisms.
Question 3: A patient's polysomnography shows repetitive apneas despite preserved respiratory effort, with oxygen desaturation. What type of sleep apnea does this MOST likely represent?
- Central sleep apnea
- Obstructive sleep apnea (Correct answer)
- Mixed sleep apnea
- Cheyne-Stokes respirations
Correct answer: Obstructive sleep apnea
Obstructive sleep apnea is characterized by airway obstruction with continued respiratory effort, in contrast to central sleep apnea where respiratory effort ceases.
Question 4: REM sleep behavior disorder (RBD) is characterized by which polysomnographic finding?
- Sleep spindles and K-complexes during REM
- Loss of normal REM sleep atonia allowing dream enactment (Correct answer)
- Periodic leg movements during NREM sleep
- Sleep-onset REM periods (SOREMPs)
Correct answer: Loss of normal REM sleep atonia allowing dream enactment
RBD is characterized by loss of muscle atonia during REM sleep, causing patients to physically act out their dreams, which can result in injury.
Question 5: Idiopathic REM sleep behavior disorder is MOST strongly associated with future development of which neurodegenerative disease?
- Alzheimer's disease
- Huntington's disease
- Synucleinopathies (Parkinson's disease, Lewy body dementia) (Correct answer)
- ALS (amyotrophic lateral sclerosis)
Correct answer: Synucleinopathies (Parkinson's disease, Lewy body dementia)
Idiopathic RBD is a strong prodromal marker for synucleinopathies; over 80% of patients eventually develop Parkinson's disease, dementia with Lewy bodies, or multiple system atrophy.
Question 6: Which medication is FIRST-LINE for restless legs syndrome (RLS)?
- Benzodiazepines
- Dopamine agonists (e.g., pramipexole, ropinirole) (Correct answer)
- Opioid analgesics
- SSRIs
Correct answer: Dopamine agonists (e.g., pramipexole, ropinirole)
Dopamine agonists are first-line for moderate-to-severe RLS due to their efficacy in reducing the urge to move and sensory discomfort, though augmentation is a long-term concern.
American Board of Psychiatry and Neurology ABPN Sleep Medicine and Neurological Disorders 1
A patient reports excessive daytime sleepiness, sudden loss of muscle tone triggered by strong emotion, sleep paralysis, and hypnagogic hallucinations.
What is the MOST likely diagnosis?