"I know when to stop": sentinels and counterstrategies against drowsy driving in narcolepsy and idiopathic hypersomnia.

Study Objectives: To collect prodromal symptoms experienced by participants with narcolepsy and idiopathic hypersomnia (considered "hypersomnolence experts") prior to drowsy driving and counterstrategies used to maintain alertness.

Methods: Systematic, face-to-face interview (using a semi-structured questionnaire), including clinical measures, frequency of car accidents/near misses, and symptoms experienced before impending drowsy driving episodes and counterstrategies.

Results: Among 61 participants (32 with narcolepsy, 29 with idiopathic hypersomnia; 56 drivers), 61% of drivers had at least one lifetime accident/near miss.