American Board of Psychiatry and Neurology ABPN Sleep Medicine and Neurological Disorders 2 — Questions and Answers
Question 1: A 55-year-old with a history of alcohol use disorder presents with ophthalmoplegia, ataxia, and confusion. What is the MOST likely diagnosis and its cause?
- Wernicke encephalopathy due to thiamine (B1) deficiency (Correct answer)
- Korsakoff syndrome due to folic acid deficiency
- Hepatic encephalopathy due to liver failure
- Cerebellar degeneration due to direct ethanol toxicity
Correct answer: Wernicke encephalopathy due to thiamine (B1) deficiency
Wernicke encephalopathy is caused by thiamine deficiency, classically presenting with the triad of ophthalmoplegia, ataxia, and confusion in the setting of alcohol use disorder.
Question 2: Which sleep stage is characterized by high-amplitude, slow (< 2 Hz) delta waves on EEG and is considered essential for physical restoration?
- Stage N1 (light NREM)
- Stage N2 (intermediate NREM)
- Stage N3 (slow-wave/deep NREM) (Correct answer)
- REM sleep
Correct answer: Stage N3 (slow-wave/deep NREM)
Stage N3 slow-wave sleep is characterized by delta waves and is associated with physical restoration, growth hormone release, and memory consolidation.
Question 3: Obstructive sleep apnea is MOST strongly associated with which neuropsychiatric condition?
- Schizophrenia
- Depression and cognitive impairment (Correct answer)
- Bipolar disorder
- Panic disorder
Correct answer: Depression and cognitive impairment
OSA is strongly associated with depression, cognitive impairment, and executive dysfunction due to intermittent hypoxemia and sleep fragmentation.
Question 4: Which term describes a sleep disorder characterized by confusional arousals, sleepwalking, and sleep terrors arising from NREM slow-wave sleep?
- REM parasomnias
- NREM parasomnias (disorders of arousal) (Correct answer)
- Circadian rhythm disorders
- Hypnic disorders
Correct answer: NREM parasomnias (disorders of arousal)
NREM parasomnias (disorders of arousal) include sleepwalking, sleep terrors, and confusional arousals, all arising from incomplete awakening from deep NREM sleep.
Question 5: A patient with delayed sleep phase disorder characteristically shows what sleep pattern?
- Falls asleep and wakes up earlier than socially desired
- Falls asleep and wakes up much later than desired but sleeps a normal duration (Correct answer)
- Randomly variable sleep-wake timing with no consistent pattern
- Excessive total sleep time regardless of schedule
Correct answer: Falls asleep and wakes up much later than desired but sleeps a normal duration
Delayed sleep phase disorder involves a delayed circadian rhythm, causing inability to fall asleep until very late at night and difficulty waking in the morning.
Question 6: Which neurotransmitter/hormone is MOST involved in regulating the sleep-wake circadian rhythm and is secreted by the pineal gland?
- Adenosine
- Serotonin
- Melatonin (Correct answer)
- Cortisol
Correct answer: Melatonin
Melatonin, secreted by the pineal gland in response to darkness, entrains the circadian clock and promotes sleep onset; its secretion is suppressed by light.
American Board of Psychiatry and Neurology ABPN Sleep Medicine and Neurological Disorders 2
A 55-year-old with a history of alcohol use disorder presents with ophthalmoplegia, ataxia, and confusion.
What is the MOST likely diagnosis and its cause?