During sleep studies, what do we monitor using electrooculography (EOG)?

Electrooculography (EOG) is specifically utilized to monitor eye movements during sleep studies, which is crucial for identifying different sleep stages, particularly rapid eye movement (REM) sleep. During REM sleep, the eyes exhibit characteristic rapid movements, which can be detected by EOG. This is essential in differentiating between REM and non-REM sleep stages, thereby providing valuable information regarding a patient's sleep architecture.

In sleep studies, other physiological variables such as heart rhythms, body temperature, and snoring can be important, but they are assessed using different modalities. For instance, heart rhythms are monitored using electrocardiography (ECG), while temperature monitoring typically involves thermistors or similar devices. Snoring patterns would generally be evaluated through sound waveform analysis or airflow monitoring, not EOG. Therefore, EOG's role focuses specifically on eye movement detection, making the monitoring of eye movements to distinguish between REM and non-REM sleep stages the correct answer.