Polysomnography (PSG)

Overview

Polysomnography (PSG), or a sleep study, is a diagnostic test used to evaluate sleep patterns and identify sleep disorders. It involves monitoring various physiological parameters while you sleep in a controlled environment. This test is crucial for diagnosing conditions that disrupt sleep quality and quantity.

Key Concepts

What is Monitored?

During PSG, several bodily functions are recorded:

• Brain waves (EEG): To determine sleep stages.
• Eye movements (EOG): Also helps identify REM sleep.
• Muscle activity (EMG): Detects leg movements and muscle tone.
• Heart rate and rhythm (ECG): Checks for cardiac issues during sleep.
• Breathing effort and airflow: Identifies pauses in breathing.
• Blood oxygen levels (SpO2): Monitors oxygen saturation.

Deep Dive into Sleep Stages

PSG distinguishes between different sleep stages:

• Non-Rapid Eye Movement (NREM) sleep: Consists of stages N1, N2, and N3 (deep sleep).
• Rapid Eye Movement (REM) sleep: Characterized by vivid dreams and muscle paralysis.

The cyclical progression through these stages provides insights into sleep architecture.

Applications and Disorders Diagnosed

PSG is the gold standard for diagnosing various sleep disorders, including:

• Sleep Apnea: Such as Obstructive Sleep Apnea (OSA) and Central Sleep Apnea (CSA).
• Narcolepsy: Excessive daytime sleepiness.
• Restless Legs Syndrome (RLS): Uncomfortable sensations in the legs.
• Periodic Limb Movement Disorder (PLMD): Repetitive limb movements during sleep.
• Insomnia: Chronic difficulty falling or staying asleep.

Challenges and Misconceptions

A common misconception is that PSG is uncomfortable. While sensors are attached, most patients adapt well. Another challenge can be the interpretation of complex data by sleep specialists. The goal is accurate diagnosis, not just data collection.

FAQs

Is PSG painful?

No, the procedure is painless. Sensors are attached to the skin using adhesive or paste.

How long does a PSG take?

Typically, a PSG lasts for one full night’s sleep, usually around 6-8 hours.

What happens after the test?

A sleep specialist analyzes the data and discusses the results and treatment options with you.