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?
