American Board of Psychiatry and Neurology ABPN Sleep Medicine and Neurological Disorders 1

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?

Accepted Answer

Narcolepsy type 1

Answer

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?

Accepted Answer

Hypocretin (orexin)

Answer

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?

Accepted Answer

Obstructive sleep apnea

Answer

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?

Accepted Answer

Loss of normal REM sleep atonia allowing dream enactment

Answer

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?

Accepted Answer

Synucleinopathies (Parkinson's disease, Lewy body dementia)

Answer

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.

American Board of Psychiatry and Neurology Practice Test

American Board of Psychiatry and Neurology Practice Test

American Board of Psychiatry and Neurology ABPN Sleep Medicine and Neurological Disorders 1