Final answer:
Niles is most likely suffering from narcolepsy, which is marked by sudden and uncontrollable sleep episodes during the day, often accompanied by cataplexy and potentially dream-like hallucinations.
Step-by-step explanation:
Niles is most likely suffering from narcolepsy, which is characterized by the irresistible urge to fall asleep during waking hours. This sleep disorder can lead to individuals falling asleep at inopportune or inappropriate times, similar to what Niles is experiencing. Narcolepsy often includes symptoms such as cataplexy, which involves a sudden loss of muscle tone and may be accompanied by vivid, dream-like hallucinations.
Additionally, parasomnias are sleep disorders involving unwanted motor activity or experiences throughout the sleep cycle, but these do not typically result in sudden daytime sleepiness as seen in narcolepsy. Insomnia, on the other hand, involves difficulty falling or staying asleep, which does not align with Niles' symptoms. Sleep apnea causes interruptions in breathing during sleep and excessive daytime sleepiness, but not the sudden sleep attacks characteristic of narcolepsy. Restless leg syndrome causes discomfort and urges to move the legs while resting, particularly during the evening and night, and this too does not match Niles' situation.