Narcolepsy Diagnosis Requires Appropriate Testing
How do you get tested for narcolepsy? Finding the right type of doctor and getting the right tests are key to an accurate diagnosis.
Polysomnography (PSG) and a multiple sleep latency test (MSLT) are needed for a narcolepsy diagnosis
To confirm a diagnosis of narcolepsy, the sleep specialist will have a patient stay overnight at a sleep laboratory to conduct these 2 tests. Each patient is given a private room with a video/audio system to communicate with the technologists.
What is polysomnography (PSG)?
PSG is performed overnight. A sleep lab technologist places sensors on the patient’s scalp, chest, and legs. As the patient sleeps, a computer records his or her brain waves, blood oxygen level, heart rate, breathing, and eye and leg movements.
What is a multiple sleep latency test (MSLT)?
The MSLT measures how quickly a patient falls asleep during the day and monitors how quickly and how often the patient enters rapid eye movement (REM) sleep. The MSLT starts in the morning after the PSG. The patient is asked to nap for 20 minutes every 2 hours throughout the day. Brain activity and oxygen levels continue to be monitored.
A home sleep test cannot detect narcolepsy
Home sleep apnea tests (HSATs or HSTs) are used to diagnose obstructive sleep apnea (OSA) in people with a high probability of having moderate to severe OSA. These tests are becoming more common because insurance companies sometimes require them before approving PSG/MSLT.
HSATs/HSTs do not screen for narcolepsy, and, according to the American Academy of Sleep Medicine, should not even be used to check for sleep apnea in children or in people who may have other sleep disorders, such as narcolepsy.
So if you want to know whether you or your child has narcolepsy, an HST will NOT help you find out.
Sleep testing in children
The American Academy of Sleep Medicine recommends overnight PSG followed by an MSLT for pediatric patients whose doctors suspect they may have narcolepsy. How long your child is asked to sleep during the PSG may be different than for adults because how much sleep someone needs varies with age.
The MSLT may be a little more difficult to perform in children, and normal test result values for very young children have not been established. Nonetheless, overnight PSG followed by MSLT is considered standard testing for children with suspected narcolepsy.