What physiological measure is mainly monitored during a polysomnography study?

During a polysomnography study, the primary physiological measure monitored is Electroencephalography (EEG). EEG is crucial because it provides detailed information about brain activity throughout sleep stages. By measuring electrical activity in the brain, EEG helps to identify different sleep cycles, such as NREM and REM sleep, and can also highlight abnormalities such as sleep disorders.

EEG data is foundational for sleep studies as it allows trained professionals to classify the various stages of sleep and assess overall sleep architecture. This ability to differentiate between the different states of sleep is essential for diagnosing conditions like sleep apnea, narcolepsy, and other sleep-wake disorders.

Other physiological measures like heart rate and oxygen saturation may also be monitored during polysomnography, but they serve adjunct roles in the comprehensive evaluation of a patient's sleep. Emotional state, while relevant to some aspects of sleep health, is not a physiological measure captured directly during a polysomnographic study. The focus is primarily on the brain's electrical activity, making EEG the most critical measure in this context.