Sleep Studies or Polysomnogram

Sleep study or Polysomnogram

A polysomnogram (PSG), also known as a sleep study, is a comprehensive diagnostic test used to monitor and analyze sleep patterns and disorders. In children, a polysomnogram can be particularly useful for diagnosing a variety of sleep-related conditions, including obstructive sleep apnea, restless leg syndrome, parasomnias (like sleepwalking or night terrors), and other sleep disorders.

What to expect in your child’s Sleep study.

Child is taken to a sleeping unit or a room and explained about the test. It is advised tha st the parents inform the child about the test beforehand.

The sleep technician makes the child comfortable in the room by checking the temperature and provides blankets etc. Parents are advised to carry the child’s sleepy toys (if any), pillows, blankets so that the child feels more comfortable. Child is not sedated in this study.

Several small areas of your child’s scalp, face, chest and legs are prepared for the test by gently rubbing with a ear bud and mild cleanser. Small round discs, called electrodes, are then attached to the scalp using gauze squares and glue.

Sensor belts are strapped around child’s chest and abdomen. These belts are adjustable are not tight.

The wires of the electrodes and sensors are connected to a box which can be easily detached from the main machine in case the child wants to use the bathroom at night.

Usually children sleep well with these electrodes. The body sensors are put on so that the child can turn and move around during the night. Children probably don’t even know the sensors are on after wearing them for a short time.

A battery of parameters are monitored with the use of sensors and electrodes. The electrodes do not hurt the child. The following parameters are measured overnight in a complete polysomnogram.

Breathing– sensors are placed near the mouth and nose to measure the flow of air. Small elastic belts are put around the chest and waist to track when the child breathes in and out.

O2 (oxygen) saturatio– a sensor is put on a finger or toe to check oxygen levels

ETCO2 monitor– a sensor is placed near the nose to measure the amount of carbon dioxide when the child breathes out.

For an EEG these electrode discs are put on the scalp to measure brain activity.

For an ECG the disks are put on the chest to measure the heartbeats.

Eye movements– electrodes are put above and below the eyes

Muscle movements– electrodes are put on the chin.

Limb movements– electrodes are put on the legs or arms

In some children, only a cardiorespiratory polysomnogram is done in which the eye, muscle and limb movements are not recorded and a complete EEG is not done.

Audio and video recording of the entire study is done with a camera and a microphone.

After the child wakes up in the morning the electrodes and sensors are removed and the child is sent home. The glue used to stick the electrodes is easily removed by normal shampoo.

Common Sleep Disorders in Children Diagnosed by PSG:

Obstructive Sleep Apnea (OSA): This is one of the most common conditions detected in children through PSG. It occurs when the airway becomes partially or completely blocked during sleep, leading to breathing pauses and low oxygen levels. It can result in fragmented sleep, daytime sleepiness, and behavioral issues.

Restless Legs Syndrome (RLS) and Periodic Limb Movement Disorder (PLMD): Both of these conditions involve involuntary movements during sleep, leading to disrupted rest. PSG can help confirm these diagnoses.

Parasomnias: These are abnormal behaviors during sleep, such as sleepwalking, night terrors, and confusional arousals. While they may not always disrupt the sleep cycle significantly, PSG can help distinguish these disorders from other sleep problems.

Narcolepsy: A condition characterized by excessive daytime sleepiness, which can sometimes be diagnosed using a PSG along with a multiple sleep latency test (MSLT) to assess daytime sleep patterns.

Insomnia: PSG can help rule out underlying sleep disorders when a child presents with difficulty falling asleep or staying asleep.

Process of the Polysomnogram for Children:

Preparation: The child may be asked to avoid caffeine or other stimulants before the test. The child should also follow their normal bedtime routine, and parents may be asked to bring comfort items (like a favorite blanket or stuffed animal) to help the child feel at ease.

The Night of the Test: The child will typically be hooked up to various electrodes and sensors while they sleep. The technician will monitor the data throughout the night, and parents are usually allowed to stay in the room with the child (depending on the age and comfort of the child).

Duration: The test usually takes place overnight, allowing the technician to capture a full night's sleep cycle (typically 6-8 hours).

Reporting a polysomnogram

A polysomnogram tracing from the study is given to the pediatric pulmonologist who then analyses the overnight study and marks episodes of hypopneas (decreased breathing effort during sleep) and apneas (complete cessation of breathing) during the study. These hypopneas and apneas are then counted and a apnea-hypopnea index is calculated that tells us about the severity of sleep related breathing disorder.

Pediatric seep studies must be analysed by a pediatric pulmonologist to reduce errors on diagnosis.

Frequently Asked Questions

What are risks involved with a polysomnogram study?

Polysomnogram or sleep study is an absolutely safe test. The electrodes attached to the child are harmless and do not pose any danger to the child.

Can sleep study be done at home?

Home sleep studies use less number of electrodes and give limited data. There can also be some technical difficulties with home sleep study like displacement of sensors and thus can result in poor quality test. We recommend in lab sleep studies for children.

Do we need EEG electrodes in all sleep studies?

IN children with neurological problems or parasomnias like night terrors, night seizures, EEG recording is unavoidable. In case of suspected obstructive sleep apnea, sometimes a cardiorespiratory sleep study is sufficient.

Can a parent stay with the child at night in sleep lab?

Yes of course, a parent must sleep with the child. Every effort should be made to make the child comfortable in the sleep lab.

When do we get the results of sleep study?

A pediatric pulmonologist analyses the sleep study graphs and patterns and prepares a report based on the findings and use of different calculations. It may take up to 3-4 days for the final report. The report is discussed by the parents in detail by the doctor.