In a polysomnography study, what is primarily measured to assess sleep stages?

To assess sleep stages in a polysomnography study, brain wave activity is primarily measured because it provides critical insights into the different phases of sleep. The electroencephalogram (EEG) captures electrical activity in the brain, which is essential for distinguishing between the various sleep stages, such as REM (Rapid Eye Movement) and non-REM sleep. These stages can be identified based on specific brain wave patterns, such as the presence of alpha waves in the awake state, theta waves during light sleep, and delta waves during deep sleep. Understanding these brain wave patterns allows technologists to accurately evaluate the sleep architecture and identify any abnormalities in sleep patterns that could indicate sleep disorders.

While the other measures, such as heart rate, muscle tension, and airflow patterns, are important components of a comprehensive sleep study, they serve supportive roles in assessing a patient’s overall sleep health rather than being the main indicators of sleep stage classification.