What does an EMG monitor during a sleep study?

An EMG, or electromyography, is specifically designed to measure muscle activity. During a sleep study, it is typically used to monitor muscle activity in locations such as the chin or legs. This monitoring is crucial for assessing conditions like REM sleep behavior disorder, where patients may physically act out their dreams. By tracking muscle movements, the EMG provides valuable information about the levels of muscle tone, particularly during the different stages of sleep.

In contrast, brain activity is monitored using EEG, heart rates are tracked through ECG, and respiratory patterns are assessed with various types of sensors dedicated to measuring airflow, effort, and oxygen levels. Each of these functions serves a distinct purpose in a sleep study, highlighting the specialized role of the EMG in evaluating muscle activity.