Sample Sleep Exam #1 - Polysomnography

Explanation
In accepted sleep scoring standards, if other scoring criteria are met, PLM (Periodic Limb Movement), Spindle, and K-Complex activities that are 0.5 seconds in duration are considered events. Arousal activity, on the other hand, is not considered an event in this case.

Explanation
Sinus arrhythmia is the correct answer because it is characterized by an irregular R-R rhythm without any alterations to the P, QRS, and T waves. In sinus arrhythmia, the heart rate varies with respiration, leading to irregularity in the R-R intervals. This is a normal finding and commonly seen in young individuals, especially during inspiration. It is important to differentiate sinus arrhythmia from other arrhythmias such as premature atrial contractions, which would show abnormal P waves, or AV blocks, which would show alterations in the conduction of the electrical impulses.

Explanation
The vertical position of the pens with the polysomnograph amplifiers turned off is referred to as the time axis. This term describes the position on a graph where time is represented along the vertical axis. The time axis is used to measure and analyze the duration and timing of various events or signals in a given system or experiment.

Explanation
The MSLT (Multiple Sleep Latency Test) is used to measure a person's tendency to fall asleep during the day. In this case, the patient never initiates sleep during the nap. The MSLT nap is typically terminated after 20 minutes if the patient does not fall asleep. Since the nap starts at epoch 28, which is 20 minutes into the test, the nap should be terminated on epoch 48.  

Explanation
The narcolepsy tetrad consists of four main symptoms associated with narcolepsy: excessive daytime sleepiness, cataplexy, sleep paralysis, and hypnagogic hallucinations. Nocturnal myoclonus, on the other hand, is not a symptom commonly associated with narcolepsy. It refers to sudden, involuntary muscle jerks or twitches that occur during sleep. While it is a sleep-related movement disorder, it is not considered part of the narcolepsy tetrad.