Sleep Study (Polysomnography)

A Sleep Study, also known as Polysomnography (PSG), is a test to diagnose sleep disorders. It records brain waves, blood oxygen levels, heart rate, breathing, and eye and leg movements while you sleep.

Why Conduct a Sleep Study?

A Sleep Study helps identify sleep disorders and their severity. It also aids in developing a treatment plan if needed. By monitoring your sleep stages and cycles, doctors can pinpoint disruptions and their causes.

Conditions That May Require a Sleep Study

• Sleep Apnea: Breathing stops repeatedly, disrupting sleep.
• Periodic Limb Movement Disorder: Involuntary leg movements during sleep.
• Narcolepsy: Excessive daytime sleepiness and sudden sleep attacks.
• REM Sleep Behavior Disorder: Acting out dreams while asleep.
• Chronic Insomnia: Difficulty falling or staying asleep.
• Other Sleep Behaviors: Walking or moving unusually during sleep.

Types of Sleep Studies

1. Nocturnal Polysomnography (PSG): Conducted in a hospital or sleep center.
2. Home Sleep Test: Conducted at home using portable monitoring devices.

How Sleep Disorders are Diagnosed

A healthy sleep pattern starts with non-rapid eye movement (NREM) sleep and progresses to rapid eye movement (REM) sleep, where most dreaming occurs. During a sleep study, brain waves, eye movements, and other factors are recorded to observe this cycle.

Key Measurements in PSG

• Respiratory Disturbance Index (RDI): Measures apnea (breathing stops) and hypopnea (shallow breathing) events per hour of sleep.
• Heart and Breathing Rate: Monitored to ensure they are within normal ranges.
• Blood Oxygen Levels: Measured to check for any drops during sleep.

Nocturnal Polysomnography (PSG)

This common and accurate sleep test is usually done in a hospital or sleep center. The patient arrives in the evening, and various monitors track their sleep. The test is non-invasive, painless, and complications are rare.

What to Expect During PSG

• Preparation: Avoid napping, alcohol, and caffeine on the day of the test.
• Sleep Center Stay: You'll sleep in a private, comfortable room with a monitoring system.
• Monitoring: Sensors on your scalp, chest, and legs will record data while you sleep.

During the Study

• Technologist Assistance: Technologists monitor your sleep and can assist if needed.
• PAP Machine: If sleep apnea is detected, a Positive Airway Pressure (PAP) machine may be used to improve breathing.

Home Sleep Test

A Home Sleep Test is a simpler alternative done at home. You'll use portable devices to measure heart rate, blood oxygen levels, and breathing patterns. It's less comprehensive than PSG but more convenient for some patients.

Comparing Home Sleep Test and PSG

• Accuracy: PSG provides more detailed information and is more accurate.
• Convenience: Home Sleep Tests are more convenient but may miss certain disorders.
• Cost Efficiency: PSG might be more cost-effective in the long run due to fewer repeat tests.

Other Sleep Tests

• Multiple Sleep Latency Test (MSLT): A daytime test following a PSG to further investigate sleep disorders.
• Maintenance of Wakefulness Test (MWT): Measures your ability to stay awake during the day.