Sleep Disorders | Sleep Review
Standardizing multiple sleep latency tests and maintaining wakefulness tests add value to the results.
By Jane Kollmer
New guidelines from the American Academy of Sleep Medicine (AASM) provide an updated overview of the recommended protocols for assessing daytime sleepiness and alertness in adults.
The Multiple Sleep Latency Test (MSLT) measures the time it takes a person to fall asleep in a quiet environment during the day. It is calculated over a number of napping occasions. The faster the patient falls asleep, the greater the daytime sleepiness. The MSLT is used in diagnosing narcolepsy and idiopathic hypersomnia and can help assess persistent sleepiness after treating other sleep disorders such as obstructive sleep apnea.
The wakefulness maintenance test (MWT) measures a person’s ability to stay awake. For this test, the patient is in a quiet and dark environment, trying to stay awake. The MWT is used to assess response to treatment for disorders associated with excessive sleepiness and to assess the alertness of those who need to stay awake for safety reasons.
The guidelines serve as an update to the 2005 AASM recommendations. The changes to the protocols for both sleep laboratory-based tests include patient preparation, drug and substance use, pre-test sleep, test planning, optimal test conditions, and documentation. They were written by a working group made up of clinical experts in sleep medicine and are based on expert consensus.
Raman K. Malhotra, MD, President of the AASM and Professor of Neurology at Washington University School of Medicine in St. Louis, oversaw and directed the development of the guidelines.
“The main goal is to give practitioners an updated protocol to conduct these two studies,” he says. “A lot has changed since 2005 when it comes to various factors that can affect sleep, whether it be new drugs or the proliferation of cell phones and electronic devices dealing with patients being tested for these conditions.”
One of the concerns of the task force was repeated MSLTs resulting in disparate sleep latency measurements, according to one of the study authors, Donna Arand, PhD, associate professor of neurology at Wright State University’s Boonshoft School of Medicine.
“We felt that by making minor changes to the protocol or adding more guidance, we could remove some of this variability that people were reporting,” says Arand.
The MSLT measures a patient’s propensity to fall asleep under standardized conditions. To get reliable data, it is important that the patient gets adequate sleep before the test. For two weeks prior to the MSLT, the patient is now advised to keep a sleep diary with or without actigraphy. This differs from the 2005 guidelines which suggested that seven days was sufficient.
“We felt that a longer schedule could help detect insufficient sleep, as it also includes two weekend periods when there can be more fluctuations,” says Arand.
The AASM recommends a minimum of 7 hours in bed with at least 6 hours of sleep in order to develop consistency in sleep patterns, which Arand says can add consistency to intermediate sleep latency.
Another change is to stop stimulating activities, including using electronic devices, 30 minutes before testing. Previous exercise parameters made it possible to continue some activities for up to 15 minutes before testing.
“We grappled with the fact that cell phones and laptops are everywhere today, which wasn’t necessarily the case in 2005,” says Arand. Recent studies have shown that using electronic devices before bed can negatively impact sleep, as the blue light they emit can suppress melatonin and stimulate brain activity.
While doing MSLT immediately after polysomnography (PSG) is not a new practice, the authors say the patient does not need to change clothes between tests. Additionally, not all electroencephalography (EEG) leads need to be removed prior to MSLT. The new guidelines recommend keeping the frontal EEG leads – which have become the standard for nocturnal studies – as the record is useful in assessing sleep stages for the MSLT.
The other recommended changes are for factors that could cause incorrect MSLT or MWT results. For patients with obstructive sleep apnea (OSA), the revised protocol states that they should maintain their normal treatment before and during the day of the studies.
Malhotra says, “The concern was that if someone used their CPAP only partially on their sleep apnea, you might get an inappropriately positive study for narcolepsy because their sleep apnea is not treated.”
Drugs with alarming, sedative, and / or REM-modulating properties were also covered in more detail in the updated protocols. Patients who report excessive daytime sleepiness are often treated with stimulants or antidepressants for depression, anxiety, inattention, or fatigue. Because many of these drugs can skew MSLT results, in 2005 experts recommended stopping these drugs two weeks before testing. However, some drugs have a longer half-life and stay in the system longer, and some may take less time to wash out.
To make matters worse, stopping medication can have adverse consequences for an individual patient, which could mean that the risk outweighs the benefit. Therefore, a clinical evaluation should be made for changes to drugs that may affect patient safety.
The task force suggests that clinicians and patients work together to develop a medication management plan to minimize disruptions in the patient’s life and avoid unintended consequences such as withdrawal.
Sleep researcher Alyssa Cairns, PhD, who was not involved in creating the updated protocols, says, “The doctor and patient should be very open about this and develop a plan to stop the medication for an accurate result.”
A key aspect of the new guidelines was addressing medication concerns, as one report found that less than 6% of people would stop their REM-modulating medication before undergoing MSLT. The new protocol document contains a table of the most common drugs that can affect MSLT.
“The AASM makes a bold statement about how to use the appropriate taper for REM-modulating or alarming or sedating compounds,” says Cairns, head of sleep research at BioSerenity.
These compounds include marijuana, as tetrahydrocannabinol is known to have a profound effect on REM sleep, and stopping too close to the test can cause REM rebound. Compared to 2005, marijuana use for therapeutic purposes is much more common (with its legalization in a number of states).
The wakefulness maintenance test is rarely used but can be ordered to provide information about the effectiveness of a treatment or to quantify daytime sleepiness in people who need to stay awake all day. In contrast to the MSLT, the MWT is not a diagnostic test.
Performing a PSG before the MWT was confirmed as optional and left to the discretion of the sleep doctor. Although there are some cases that warrant PSG prior to MWT, the authors conclude that it typically does not always affect the results of MWT or influence its interpretation. However, it is important that the patient get adequate sleep quality and length of sleep the night before the test so that wakefulness can be accurately measured.
Another change to the MWT protocol affects the test environment. Previously, during the test, patients had to sit in a bed surrounded by pillows to avoid injury. The task force recognized that a bed does not reflect the typical daytime environment and that patients may be more comfortable in a chair. In addition, they found no evidence that sitting in a bed or sitting in a chair had any effect on the outcome. So the updated logs contain the ultimate consensus that any option can be used as long as it is used consistently for all wake attempts.
“It just seemed to make sense – if you wanted the MWT to reflect the likelihood that someone would fall asleep at an inappropriateness of the day, such as driving a car, at a desk, or at the computer,” says Arand.
“Following test protocols and standardizing reporting will add value to MSLT and MWT results,” task force chair Lois Krahn, MD, professor of psychiatry at the Mayo Clinic in Arizona, said in a press release. However, the authors remind clinicians that none of the tests should be used as the sole criterion for diagnosing hypersomnia or narcolepsy. Instead, the MSLT or MWT results are a piece of the puzzle that should be considered along with the individual patient history and other relevant data.
Jane Kollmer is a co-owner of Ch / At Communications, which provides writing and editing services to clients in the healthcare and travel industries.
Krahn LE, Arand DL, Avidan AY, et al. Recommended Protocols for the Multiple Sleep Latency Test and the Maintenance of Wakefulness Test in Adults: American Academy of Sleep Medicine Guide. J Clin Sleep Med. 2021 Aug. 23. Online before going to press (expected publication in the December 2021 print edition).
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