What it is
Polysomnography is an overnight sleep study. It records sleep stages together with breathing effort, airflow, oxygen level, heart rate and movement. It is different from an EEG ordered mainly to investigate seizures, although some scalp electrodes may also record brain activity during sleep.
Why it may be requested
- Snoring, pauses in breathing or suspected obstructive sleep apnoea
- Unusual sleep behaviours or movements
- Excessive daytime sleepiness or disrupted sleep
- Sleep concerns in a child with a neurological or neuromuscular condition
What to expect
Sensors are placed on the scalp, face, chest, abdomen and legs, with a small oxygen sensor on a finger or toe. A caregiver usually stays according to the sleep unit’s policy. The child sleeps as normally as possible while signals are recorded.
Approximate duration
This is usually an overnight study. Arrival is generally in the evening and discharge the next morning, but the confirmed times come from the booking instructions.
How to prepare
Follow the sleep unit’s instructions. Hair and skin should be clean and free of oils. Bring usual nightwear, medicines, comfort items and anything the child normally needs overnight. Avoid caffeine if instructed.
Sedation considerations
Sedation is not used for a diagnostic sleep study because it changes natural sleep and breathing. Contact the practice beforehand if your child may not tolerate sensors.
Results and reports
The large amount of overnight data must be reviewed and scored before a report is issued. The report is discussed or sent through the agreed clinical pathway.