Polysomnographic

Polysomnographic, in reference to polysomnography, denotes the comprehensive recording and analysis of multiple physiological signals during sleep used to assess sleep architecture and diagnose sleep disorders. A typical polysomnographic recording includes electroencephalography (EEG) to monitor brain activity, electro-oculography (EOG) for eye movements, and electromyography (EMG), usually of the chin, to determine sleep-wake state. Additional channels often monitor heart rate and rhythm (ECG), respiratory effort via chest and abdominal belts, nasal and oral airflow, pulse oximetry for oxygen saturation, body position, and sometimes snoring sounds. In-lab studies may also include leg EMG to detect periodic limb movements.

The primary purpose is to provide a nocturnal overview of sleep and to identify abnormalities such as obstructive sleep apnea, central sleep apnea, narcolepsy, REM sleep behavior disorder, restless legs syndrome, and other parasomnias. Data are scored in standardized epochs (often 30 seconds) to determine sleep stages (N1, N2, N3, REM) and to derive metrics such as total sleep time, sleep efficiency, sleep onset latency, REM latency, arousal index, and various indices like the apnea-hypopnea index (AHI) and periodic limb movement index. Polysomnographic findings guide diagnosis and treatment planning and may be used to titrate therapies such as continuous positive airway pressure (CPAP) during a dedicated titration study.

The procedure is typically performed by trained technologists in a sleep laboratory, with interpretation by a sleep specialist. Ensuring proper electrode placement and minimizing artifacts are important. While ambulatory or home-based polysomnography increases access, it may have limitations for certain populations. The term "polysomnographic" describes data, measurements, or analyses derived from polysomnography, such as polysomnographic study results or polysomnographic findings.