Which statement about arousal scoring in adults is BEST?

Which statement about arousal scoring in adults is BEST?

• A. Scoring of arousals during stage R requires either an increase in submental EMG or an increase in leg EMG.
• B. The 10 seconds of sleep required prior to scoring an arousal may begin with the preceding epoch, even if that epoch is scored as stage W.
• C. Abrupt shifts in EEG frequency during arousal can include alpha, theta, spindles, and frequencies greater than 16 Hz.
• D. Information should be incorporated from the majority of EEG channels.

Answer: (B)

Arousal scoring hinges on recognizing a brief, EEG-based shift in activity that occurs during sleep, with a specific rule about the preceding sleep interval used to qualify the arousal. The best statement highlights how the required 10 seconds of sleep before an arousal can be counted even if that pre-arousal interval begins in the previous epoch that might be scored as wake. This boundary-crossing allowance ensures arousals near wake–sleep transitions aren’t missed simply because a boundary falls inside the qualifying window. In practice, you look for a sudden rise in EEG frequency (such as alpha, theta, spindles, or faster than 16 Hz) that lasts long enough to meet the criteria, and you verify that there has been a sufficient sleep interval immediately before the arousal, even if that interval spans into the previous epoch. The other statements don’t fit as neatly. The requirement for an EMG increase isn’t a universal mandatory criterion for all arousals, and arousals can occur outside REM periods. Relying on multiple EEG channels isn’t necessary for scoring, and while the EEG changes can include various frequencies, the precise boundary rule about the pre-arousal sleep interval is the key nuance that makes this option the best.

Arousal scoring hinges on recognizing a brief, EEG-based shift in activity that occurs during sleep, with a specific rule about the preceding sleep interval used to qualify the arousal. The best statement highlights how the required 10 seconds of sleep before an arousal can be counted even if that pre-arousal interval begins in the previous epoch that might be scored as wake. This boundary-crossing allowance ensures arousals near wake–sleep transitions aren’t missed simply because a boundary falls inside the qualifying window. In practice, you look for a sudden rise in EEG frequency (such as alpha, theta, spindles, or faster than 16 Hz) that lasts long enough to meet the criteria, and you verify that there has been a sufficient sleep interval immediately before the arousal, even if that interval spans into the previous epoch.

The other statements don’t fit as neatly. The requirement for an EMG increase isn’t a universal mandatory criterion for all arousals, and arousals can occur outside REM periods. Relying on multiple EEG channels isn’t necessary for scoring, and while the EEG changes can include various frequencies, the precise boundary rule about the pre-arousal sleep interval is the key nuance that makes this option the best.