What is an MSLT?
A Multiple Sleep Latency Test (MSLT) is a specialised sleep study designed to measure daytime sleepiness and assess for conditions such as narcolepsy. It evaluates how quickly you fall asleep during the day and whether you enter REM (rapid eye movement) sleep during short naps.
What Does the MSLT Measure?
The MSLT measures two key aspects of sleep:
- Sleep latency – the time it takes for you to fall asleep during scheduled daytime naps.
- REM sleep occurrence – whether you enter REM sleep during these naps, which can indicate certain sleep disorders.
Who Needs an MSLT?
Your doctor may recommend an MSLT if you experience excessive daytime sleepiness or symptoms of narcolepsy, such as sudden episodes of muscle weakness (cataplexy) or sleep paralysis. The test is commonly used to diagnose:
- Narcolepsy
- Idiopathic hypersomnia
- Other sleep disorders affecting wakefulness
What is the Process of an MSLT?
The MSLT is conducted the day after an overnight sleep study (polysomnography) to ensure accurate results. The test follows these steps:
- Overnight Sleep Study – You will stay overnight at the sleep clinic to monitor your sleep quality and rule out other sleep disorders.
- Daytime Nap Trials – The next day, you will have five scheduled nap opportunities, each lasting about 20 minutes, with two-hour breaks in between.
- Monitoring – Sensors will measure brain activity, eye movements, muscle tone, and sleep patterns.
- Results Analysis – Sleep specialists will analyse the time taken to fall asleep and the occurrence of REM sleep to determine if a sleep disorder is present.
How to Prepare for an MSLT
To ensure accurate results, follow these preparation guidelines:
- Follow Normal Sleep Patterns – Maintain a regular sleep schedule for at least a week before the test. You may be asked to track your sleep with a diary or actigraphy.
- Avoid Stimulants – Caffeine, nicotine, and certain medications can affect test results. Your doctor will advise on any necessary medication adjustments.
- No Napping Before the Test – Avoid napping on the day of the study to ensure accurate measurements of daytime sleepiness.
- Bring Comfort Items – As you spend the day at the clinic, bring reading material, snacks, and anything else to help pass the time between naps.
Book Your MSLT at Manse Medical
If you have concerns about excessive daytime sleepiness or suspect a sleep disorder, our expert team at Manse Medical can help. Contact us today to schedule a consultation and determine if an MSLT is right for you.