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Polysomnography for adults

What is polysomnography?

Polysomnography is the preferred test to study all sleep disorders. It is performed during the night at Biron, under the supervision of a healthcare professional trained in sleep care.

Using sensors applied to various locations on your body, polysomnography can study the physical manifestations during your sleep by recording many signals of electrical activity from your brain, heart, as well as respiratory efforts. It also records the oxygen saturation level in your blood and other parameters for differentiating your sleep cycles and stages. It can detect, quantify and qualify the presence of anomalies such as:

  • Sleep apnea (breathing problems)
  • Periodic leg movements
  • Paradoxical sleep behaviour disorder (physical behaviours linked to dreams)
  • Bruxism (grinding and clenching of the teeth)
  • Narcolepsy (sleepiness and sleep attacks during the day)

The data recorded during your polysomnography will be interpreted by a healthcare professional trained in sleep care and forwarded to your attending physician.

Preparing for the Examination (for adults)

Biron’s healthcare professionals trained in sleep care will accompany you throughout the examination process. They will ensure your comfort and wellbeing.

Follow the steps below to prepare for the test:

  • You may eat a normal meal before 7:00 pm. However, we ask that you refrain from consuming alcohol (e.g. beer, wine) or caffeine (e.g. coffee, tea, cola, chocolate) in the 6 hours before the test
  • Please avoid using face cream or body lotion
  • You may bring comfortable sleep wear and your own pillow. We provide towels, soap and shampoo, but you may also bring your own toiletries.

If necessary, remember to bring your usual medications.

Examination procedure

A polysomnography is risk-free and causes no pain. In rare cases, you may experience temporary skin irritation where sensors were applied to your skin.

The following is the typical process for a polysomnography at on of Biron's clinics.

  • The normal arrival time is between 8:30 and 9:00 pm (please be on time for your appointment)
  • Depending on the time of your appointment and the preparation time, your bedtime may vary between 9:30 and 11:30 pm.
  • When you arrive at the clinic, a healthcare professional will welcome you, show you your private bedroom (with bathroom) and explain the examination procedure. Your bedroom will be dark and quiet so you can relax and fall asleep. It is equipped with an audiovisual system for diagnostic purposes and to ensure your safety. Your sleep will be observed throughout the night by a healthcare professional trained in sleep care, who will monitor proper recording of the data as well as your wellbeing at all times. If you feel the need to go to the bathroom during the night, our health care professional will help you get up.
  • Before your bed time, several sensors will be applied to your scalp, temples, hands, chest and legs. Please note that the sensors will not cause you any pain and will not limit your movements during the night. These record:
    • Electrical brain activity
    • Eye movements
    • Muscle tone
    • Heart rate
    • Nasal flow
    • Breathing movements
    • Blood oxygen level
    • Body position
    • Limb movements
    • Snoring
  • You may rise between 6:00 and 6:15 am to take a shower at the clinic.


The results of the sleep test will be interpreted by one of our specialist physicians trained in sleep health and will be available via MonBiron.

Split night

In some cases, it will be possible, within the same night and according to the established protocol, to carry out a diagnostic phase followed by a treatment phase.

  1. During Phase 1 (first part of the night), we record various parameters linked to your sleep
  2. During Phase 2 (second part of the night), using a continuous positive airway pressure (CPAP) device, a therapy will be initiated to adjust the optimal pressure level required to counter the airway passage obstructions and thus control your sleep apnea

Please note that to move from Phase 1 (diagnosis) to Phase 2 (therapy), the healthcare professional trained in sleep care must observe several criteria, including a minimum number of respiratory events consistent with the split-night protocol during the diagnostic phase.

A medical prescription is required to perform this examination.

For more information on the polysomnography, contact customer service at 1 833 590-2713.