A 16-year-old female presents to her pediatrician for a routine check-up, reporting difficulty waking up for school at 6:30 AM. She states she can’t fall asleep until around 2 AM despite trying to go to bed earlier. She feels groggy and occasionally dozes off during morning classes but is alert after lunch. She plays soccer after school, which keeps her energized until 7 PM, and she naps for an hour some afternoons. On weekends, she sleeps from 2 AM to noon without issue. She keeps a sleep log for two weeks, showing 5-6 hours of sleep on weekdays and 10-11 hours on weekends. She avoids caffeine, has no screen time after 10 PM, and denies snoring. Physical exam reveals a healthy teenager with a BMI of 21 kg/m², normal blood pressure, and no signs of depression or anxiety. What is the most likely diagnosis for this patient’s sleep difficulties?

Patient Case: Narcolepsy Chief Complaint: “I keep falling asleep during the day, even when I don’t want to.” History of Present Illness: A 20-year-old male college student presents to the sleep clinic with a 1-year history of excessive daytime sleepiness (EDS). He reports frequently falling asleep in class, during conversations, and even while eating. Despite getting 7–8 hours of sleep each night, he feels constantly tired and struggles to stay awake during the day. He also describes episodes where he suddenly loses muscle control and collapses when laughing or feeling excited, though he remains fully conscious during these events. He reports experiencing vivid, dream-like hallucinations just before falling asleep and occasional episodes of waking up unable to move for several seconds. There is no history of head trauma, drug use, alcohol use, or psychiatric illness. He denies snoring, choking sensations during sleep, or frequent nighttime awakenings. Past Medical History: No significant medical conditions Medications: None Family History: No family history of sleep disorders Social History: College student, non-smoker, occasional caffeine use, no recreational drug use Review of Systems: Positive: Excessive daytime sleepiness, sleep paralysis, hypnagogic hallucinations, cataplexy episodes. Negative: No night sweats, no weight loss, no history of depression Physical Examination: • General: Alert and cooperative, appears fatigued • Neurologic: Normal motor strength, reflexes, and coordination • Cardiovascular: Normal heart rate and blood pressure • Respiratory: No signs of upper airway obstruction Diagnostic Workup: 1.Polysomnography (PSG): •Normal nighttime sleep duration •No significant apnea/hypopnea events •Increased sleep fragmentation 2.Multiple Sleep Latency Test (MSLT): •Mean sleep latency: <8 minutes •REM sleep within 15 minutes in ≥2 naps (sleep-onset REM periods, or SOREMPs) 3.Cerebrospinal Fluid (CSF) Hypocretin-1 Levels: Low hypocretin-1 levels (<110 pg/mL) Which of the following is the most appropriate initial pharmacological treatment for this patient’s cataplexy associated with his sleep disorder?

A 25-year-old woman presents with a 2-year history of excessive daytime sleepiness. She states that she often dozes off at work and feels an overwhelming urge to sleep. She also describes vivid hallucinations when she is falling asleep and has had occasional episodes where she wakes up but is unable to move. She denies muscle weakness triggered by emotions. Polysomnography reveals a decreased sleep latency and rapid onset of REM sleep. What is the most appropriate next step in confirming the diagnosis?

A 19-year-old college student presents to the clinic with excessive daytime sleepiness that has been worsening over the past year. He reports falling asleep suddenly during lectures despite getting 7–8 hours of sleep at night. He also describes sudden episodes of muscle weakness triggered by laughter, lasting a few seconds. Additionally, he has experienced vivid, dream-like hallucinations when falling asleep and occasional episodes where he wakes up but cannot move. His neurological exam is unremarkable. Which of the following is the most likely cause of this patient’s condition?

A 22-year-old man presents to the sleep clinic with excessive daytime sleepiness. He reports frequently dozing off during lectures despite getting 7–8 hours of sleep at night. He also describes experiencing vivid dream-like hallucinations just before falling asleep and occasionally waking up unable to move for a few seconds. Upon further questioning, he recalls multiple episodes where he suddenly collapses to the ground after laughing but remains fully conscious during these episodes. Which of the following symptoms is most specific for narcolepsy?

A 35-year-old pilot presents to her physician with complaints of difficulty falling asleep after long-haul flights. She reports frequent international travel and trouble adjusting to different time zones. She prefers to avoid prescription medications and asks if there is a natural supplement that could help regulate her sleep-wake cycle. The physician recommends an over-the-counter supplement that is naturally produced in the body and helps regulate circadian rhythms. Where in the body is this substance primarily produced?