MSLT & MWT Sleep Test in Delhi | Sleep Disorder Diagnosis

MSLT/MWT

MSLT is a daytime sleep test which is used to measure how quickly a person falls asleep in a quiet environment during the day. It helps to diagnose narcolepsy, idiopathic hypersomnia, and excessive daytime sleepiness.

Why is it conducted?

For evaluating the daytime sleepiness.
To diagnose the narcolepsy (especially if sleep-onset REM periods occur).
To assess the hypersomnia disorders.
To support disability or fitness-to-work assessments.

What Happens During the Test?

It is conducted after a full overnight polysomnography to ensure the adequate nighttime sleep and rule out obstructive sleep apnea.
Then the patient is given 4-5 nap opportunities every 2 hours throughout the day.
During each session:
- The patient lies down in a dark, quiet room.
- EEG, EOG, EMG, and ECG all are monitored.
- Test measures how long it takes to fall asleep (sleep latency) and whether REM sleep occurs.
- The test typically lasts for 7-8 hours.

How to prepare for the Study?

You should avoid caffeine, nicotine, and alcohol 24 hours before the test.
Discontinue all the stimulants or sedatives if advised by your doctor.
Maintain a regular sleep-wake schedule for a week before testing.
Bring comfortable clothing and items for a full day at the sleep lab.
Avoid daytime naps before the test.
An actigraphy device or sleep diary may be used 1–2 weeks prior to monitor sleep habits.

MWT – Maintenance of Wakefulness Test

MWT helps to evaluate a person’s ability to stay awake in a quiet, and non-stimulating environment. It is commonly used for fitness-for-duty assessments in safety-sensitive jobs or to evaluate treatment effectiveness for sleep disorders.

Why is it conducted?

To evaluate if a person can stay awake when needed e.g., drivers, pilots, machine operators.
To assess the treatment response in conditions like narcolepsy or sleep apnea.
For legal, occupational, or medical clearance.

What Happens During the Test?

It is conducted the day after an overnight polysomnography.
The patient is asked to stay awake while sitting in a dim, quiet room for 4 sessions spaced 2 hours apart.
Each session lasts up to 40 minutes unless the patient falls asleep.
EEG, EOG, and EMG are monitored to detect sleep.

How to prepare for the Study?

It have same preparation as MSLT:

Avoid caffeine, alcohol, and sleep-altering meds.
Maintain a regular sleep schedule prior to the test.
No napping before or during the test day.
Dress comfortably, and bring items for spending the day at the lab.

Frequently Asked Questions (FAQs)

1. Is MSLT uncomfortable or painful?

No, MSLT is a non-invasive, painless test. It involves placing sensors on the scalp and face to record sleep activity, but there are no needles or painful procedures.

2. How long does the MSLT take?

The test usually takes a full day (about 7–8 hours), with five nap trials every 2 hours. You’ll be monitored in a comfortable, quiet room during each session.

3. What if I accidentally fall asleep during MWT?

That’s okay, as the purpose is to measure your ability to stay awake. Falling asleep is part of the test result and helps to determine your level of daytime alertness.

4. Can I use my phone or read during the MWT test?

No, during the actual sessions, you must sit quietly without stimulation (no phone, reading, or music). Between the sessions, you can relax and use your phone or read.

MSLT/MWT

MSLT/MWT

Why is it conducted?

What Happens During the Test?

How to prepare for the Study?

MWT – Maintenance of Wakefulness Test

What Happens During the Test?

How to prepare for the Study?

Frequently Asked Questions (FAQs)

Symptoms

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