Sleep Study Test (Polysomnography)

Why Is Polysomnography Conducted?

Have you found yourself constantly waking up tired, gasping for breath in the night, or perhaps your partner has noticed you snoring excessively or experiencing pauses in breathing? Maybe you’ve felt unusually sleepy during the day, struggled with concentration, or even fallen asleep unintentionally. These signs could indicate an underlying sleep disorder. A polysomnography test can uncover exactly what’s happening while you sleep, providing doctors with the essential information needed to tailor an effective treatment plan specifically for you.

Obstructive Sleep Apnea (OSA): When your breathing repeatedly stops and starts due to airway obstruction, often leading to loud snoring and daytime fatigue.

Narcolepsy: A neurological disorder that disrupts your sleep-wake cycle, causing excessive daytime sleepiness and sudden sleep attacks.

Insomnia: Chronic difficulty falling or staying asleep, which can impact mental and physical health.

Periodic Limb Movement Disorder (PLMD): Uncontrollable leg jerks or twitches during sleep that can repeatedly wake you up.

REM Sleep Behaviour Disorder (RBD): A condition where you physically act out vivid dreams because your body doesn’t experience the usual muscle paralysis during REM sleep—the stage of sleep where most dreams happen.

Evaluating Treatment Efficacy

If you have already been diagnosed with a sleep disorder and are undergoing treatment—such as using a CPAP machine for sleep apnea or taking medication for insomnia—PSG helps assess whether the treatment is effective. It allows doctors to see if your symptoms are improving, if adjustments are needed, or if an alternative approach might be more beneficial.

By providing a full picture of your sleep patterns, polysomnography plays a crucial role in improving both sleep quality and overall well-being.

Preparation Before the Test

There’s no intense prep required, but a few simple steps can help ensure accurate results:

• Stick to your usual routine on the day of the test.
• Avoid caffeine and alcohol, as they can interfere with sleep.
• Skip naps to ensure you’re naturally tired at bedtime.
• Inform your doctor about any medications you’re taking, as some might affect sleep patterns.
• If you’re undergoing an in-lab study, bring comfortable sleepwear and personal items to help you relax.

During the Sleep Study

Setting and Environment

Polysomnography can be conducted in a sleep lab or, for certain conditions like sleep apnea, through home-based testing.

• In-Lab Sleep Study: The room is designed like a comfortable bedroom, with a quiet, controlled environment to promote natural sleep. A technician will be nearby to monitor the equipment and assist if needed.
• Home Sleep Apnea Testing (HSAT): If you qualify for a home test, you’ll be given portable monitoring equipment to wear while sleeping in your own bed. This option is typically used for suspected sleep apnea.

Monitoring Equipment

To track your sleep patterns, several small sensors are placed on your body. These sensors monitor key physiological functions, including:

• Brain activity (EEG): Measures electrical activity in your brain to track sleep stages.
• Eye movement (EOG): Helps detect when you enter REM sleep.
• Muscle activity (EMG): Identifies muscle tone and movements during sleep.
• Heart rate and rhythm (ECG): Monitors cardiovascular function.
• Breathing patterns: Tracks airflow, snoring, and chest movement.
• Oxygen levels (pulse oximetry): Ensures you’re getting enough oxygen while you sleep.

The sensors are painless and non-invasive, though they may take some getting used to.

Sleep Stages and Data Collection

Polysomnography records the different sleep cycles you go through, including:

• Light sleep (Stages 1 & 2): Your body starts to relax, and brain activity slows.
• Deep sleep (Stages 3 & 4): This is the most restorative phase, important for physical health and recovery.
• REM sleep: The stage where dreams occur, memory consolidates, and brain activity becomes more active.

By analysing these stages, doctors can determine if your sleep patterns are disrupted and why.

Post-Study Process

Once the sleep study is complete, the data is reviewed by a sleep specialist. This process typically involves:

1. Data Analysis: The collected information is examined to detect irregularities in breathing, movement, and sleep cycles.
2. Report Generation: A detailed summary of your sleep patterns is compiled.
3. Follow-Up Consultation: Your doctor will discuss the results with you, explain any findings, and recommend the next steps—whether that means lifestyle changes, medical treatment, or further testing.

A polysomnography test is a valuable tool in diagnosing and treating sleep disorders, providing key insights that can help you achieve healthier, more restful sleep.

In-Lab Polysomnography

This is the most comprehensive type of sleep study, conducted overnight in a controlled sleep lab. It provides real-time monitoring of brain activity, breathing patterns, heart rate, muscle movements, and oxygen levels. Since a trained technician is present, adjustments can be made if needed, ensuring the most accurate results. In-lab studies are recommended for complex sleep disorders, such as narcolepsy or REM sleep behaviour disorder.

Home Sleep Apnea Testing (HSAT)

If your doctor suspects obstructive sleep apnea (OSA), you may qualify for a home sleep apnea test. HSAT is a more convenient and cost-effective option that allows you to sleep in your own bed while wearing a portable device that tracks breathing and oxygen levels. While it’s useful for diagnosing OSA, it doesn’t capture brain waves or sleep stages, so it may not be suitable for detecting other sleep disorders.

Discomfort and Adaptation

Wearing sensors and sleeping in an unfamiliar environment may feel uncomfortable at first. Some people find it harder to fall asleep under these conditions. However, sleep specialists account for this, and even a few hours of recorded sleep can provide valuable data for diagnosis.

Interpreting Results

One sleep study might not capture the full picture. If your symptoms persist but the results are inconclusive, your doctor may recommend additional testing or an alternative approach to better understand your sleep patterns.

Understanding the different sleep study options and potential challenges can help you feel more prepared and comfortable if you need to undergo a polysomnography test.