Diagnosing IH When the MSLT Is Normal: Logan Schneider, MD

In part 1 of the interview with The American Journal of Managed Care^® (AJMC^®), Logan Schneider, MD, a sleep medicine specialist and adjunct clinical associate professor of psychiatry and behavioral sciences at Stanford Health Care, explained why narcolepsy and idiopathic hypersomnia (IH) go unrecognized for years and how frontline clinicians can use a sleepiness score and a sleep health framework to prompt earlier referral.

In part 2, Schneider discusses how he diagnoses IH when the Multiple Sleep Latency Test is inconclusive, how open-ended questions and symptom scales capture features such as sleep inertia, and where wearable sleep data may and may not help. He also describes how he frames treatment options for newly diagnosed patients, the outlook for earlier recognition over the next 3 to 5 years, and the clinical clues that help separate a hypersomnolence disorder from depression or anxiety.

This interview has been edited for clarity.

AJMC: IH is a diagnosis of exclusion, and the multiple sleep latency test can be normal in about 30% to 40% of patients.¹ What do you rely on when the test doesn’t give you a clear answer?

Schneider: The interesting thing about idiopathic hypersomnia is that there are 2 criteria that can define it in the diagnostic workup. One is the demonstration of excessive sleepiness, so that’s the hypersomnolence on the multiple sleep latency test. That’s that napping test that you do multiple times, and if you fall asleep too quickly, then that would suggest that you’re excessively sleepy.

The other aspect about idiopathic hypersomnia, by its name, is that hypersomnia is an excessive amount of sleep or excessive need for sleep. So, the other options for diagnosing it include demonstration of excessive amounts of sleep despite adequate sleep preceding it. We can do that either with a 24-hour polysomnogram, which almost nobody orders, but if it shows more than 11 hours of sleep in total, that’s an awful lot of sleep if you already are well slept. Alternatively, you can use an actigraph. Again, it’s not often reimbursed, but this is an activity and rest monitor that we can have the individual wear for 2 weeks, and then we can look at their average amount of sleep, and if that falls above that 660 minutes, or 11 hours of sleep, on average, you’re sleeping away your day, effectively.

So that’s another way to demonstrate it. You can either show excessive sleepiness on the napping test or excessive need for sleep on these longer-term monitoring [tests] to demonstrate that you’re sleeping an awful lot. Those are the 2 main pathways, according to the International Classification of Sleep Disorders, Third Edition, Text Revision, which is the handbook for sleep specialists.²

Now, that being said, there’s also another handbook, which is the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision.³ That’s often relied upon by the psychiatry community. It’s not as rigorous in its diagnostic restrictions [in] finding idiopathic hypersomnia. So, if you truly believe this individual has the sleepiness, but unfortunately the testing, as you mentioned, is not turning up positive and you can’t get reimbursement for, for example, doing a 24-hour polysomnogram or actigraph, you might rely upon the much more clinical impression-type diagnoses or criteria in the Diagnostic and Statistical Manual.

AJMC: IH goes well beyond just sleepiness. It can also have sleep inertia, cognitive fog, fatigue, and longer sleep times. How do you draw those symptoms out in a visit, and which formal scales do you use for these?

Schneider: The question is how do you suss out what is really a syndrome of symptoms rather than just excessive sleep or sleepiness? A lot of patients come in with sleepiness, so you have to really start to delve in a little bit more and pull out those symptoms.

One scale, as you referenced, is very valuable. I think there are many. You can use the Idiopathic Hypersomnia Severity Scale score,⁴ which I think is a fabulous, psychometrically validated instrument to identify a cutoff where you think, “Oh, this person probably is in the domain of an untreated idiopathic hypersomnia patient,” as well as [to] scale and understand the severity of the impact this has on their life. It’s covering multiple domains, like the nighttime sleep, the napping, the daytime dysfunction, and cognitive dysfunction. I think all of those things are very helpful, and it really captures those symptoms, things like inertia that you mentioned, the inability to wake up or feel awake for several hours after awakening from the primary sleep period or napping.

The other is allowing for open-ended questions of patients. “Walk me through your morning.” Those are the folks who can give you the “I set multiple alarms, I use the one that shreds a $100 bill, or it jumps off my counter and runs around, or somebody pulls me out of bed, splashes water on my face.” That’s not a normal awakening experience for most people.

Another open-ended one, which came from Robert Thomas, is not asking people “how much do you sleep” because generally that’s constrained by social mores. Instead, ask, “How much can you sleep?” And they’re like, “Whoa, well, if I was given the opportunity, let me tell you.” So, it’s really giving them the opportunity to clarify their day, the reasonings behind what’s going on. Napping sometimes is avoided by these folks as a result of the fact that when they wake up, they won’t feel refreshed, despite hours of napping, and so their day is gone, but then they feel worse when they wake up than when they went to sleep.

So, understanding not just the absence of napping or the duration of sleep, but the why. Why are you getting as much sleep as you are, or why are you not getting as much sleep as you feel like you need? Opening up those open-ended questions really helps people express their reasoning for it instead of just, “Oh, you’re not napping?” Instead of, “Why aren’t you napping if you need this much sleep?”

AJMC: Your research has touched on wearable sleep data and machine learning. Could these tools realistically help flag underdiagnosed hypersomnia, and are they better suited for other sleep disorders?

Schneider: Just to be clear from a conflict-of-interest perspective, because I helped develop those types of technologies, I’m not at liberty to promote them or suggest that they have any sort of clinical application that they don’t. In fact, the FDA is very clear on [its] stance, and so is the American Academy of Sleep Medicine and other bodies like the World Sleep Federation. The point is that they are not diagnostic tools in their own right.⁵

But to the question that you asked, can they be helpful? Yeah, I think in the hands of the right folks. That means clinicians who can interpret not just the data itself but the clinical context through asking the right questions and understanding the patient’s lived experience. Certainly, they can be helpful tools to support that, particularly if you don’t get reimbursement or support for doing something that the clinical community thinks is reasonable, which is an actigraph, which is less fidelity than the consumer sleep technologies because it’s just activity and light levels. These consumer sleep technologies have a lot more, and they seem to perform better on estimations of sleep and wake.

That being said, if somebody knows how to use this data or can interpret it adequately, having longitudinal data, for example, if somebody is demonstrated to be sleeping with a consumer sleep technology 12 hours a day and they fit the picture of an idiopathic hypersomnia, that might prompt a clinician, through discussion and history taking, to say, “I actually think you already have what’s going on; let’s just confirm that diagnosis,” rather than just coming in blind and saying, “Oh, tell me about your story.” So, it certainly is helpful to have objective data that you can use as a contrast or supplement to whatever you’re gathering from a patient encounter.

AJMC: In narcolepsy, clinicians can choose between oxybates, such as Xywav, Xyrem, and Lumryz, as well as pitolisant (Wakix), solriamfetol (Sunosi), and modafinil (Provigil) or armodafinil (Nuvigil). But Xywav is the only FDA-approved therapy for IH.⁶ How do you frame these options for newly diagnosed patients?

Schneider: The choice of medication in newly diagnosed patients of any of the chronic disorders of hypersomnolence is part of shared decision-making. I always want to present, on a fair and balanced level, the pros and cons of each of the medications. Many of them don’t have comparative claims, meaning that they haven’t been studied head-to-head to say which one benefits an individual more or less, and oftentimes [patients] will need multiple medications to control all of the symptoms. I generally just try and make sure that the patient understands the risks and benefits of every medication.

I try and tailor that to their specific circumstances. For example, some of these medications interact with hormonal birth control, so women of childbearing age certainly have a specific thing I need to talk about, or certain individuals who have medications that might interact, or clinical conditions like liver metabolism problems, need to have additional information characterized. So, you have to understand that patient to inform not only just a balanced discussion but also how it specifically applies and which ones might actually weigh in favor or against [a medication] in their specific situation. Again, I can’t go through that process here, because it’s a very extensive one, and each patient’s discussion is unique.

But I often present, “Here’s the menu of options that we have. Here are the society guidelines that talk about the strength of using any of these medications.”⁷ And then we focus on what the patient’s most valuing. What symptoms are most important for them to treat now, and how can we get the biggest bang for our buck? Meaning, use the least number of medications to get the greatest effect. And then what other personal circumstances relate to what would change our choice of medication, for example, pregnancy or childbearing status, and what have you?

AJMC: Looking ahead to about 3 to 5 years, what would most change how quickly these patients are recognized, whether it is biomarkers, targeted therapies, better primary care screening, or something else?

Schneider: The thing that will get the greatest change is recognition. That’s awareness within individuals [of] what is abnormal and what isn’t abnormal, and then, again, on those frontline providers. That can be primary care providers or other people that these individuals see as touchpoints, like psychiatrists, having awareness and comfort asking about sleep to know what’s normal sleepiness and what’s abnormally sleepy, and when to refer on. That’s the most valuable.

I don’t think biomarkers are really on the horizon. We’ve gotten, fortunately, [one] with the hypocretin/orexin deficiency in type 1 narcolepsy. I think there’s a lot of work that needs to be done in the field before we can do that for type 2 or idiopathic hypersomnia. But just getting people to be recognized and sent over to get the right care is certainly the most important thing we can do to date.

References

Cleveland Clinic. Case Study: Extended Polysomnography Confirms an Idiopathic Hypersomnia Diagnosis. October 20, 2023. Accessed October 13, 2026. https://consultqd.clevelandclinic.org/case-study-extended-polysomnography-confirms-an-idiopathic-hypersomnia-diagnosis

American Academy of Sleep Medicine. International Classification of Sleep Disorders. 3rd ed. text rev. American Academy of Sleep Medicine; 2023.

American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision, 2022.

Dauvilliers Y, Evangelista E, Barateau L, et al. Measurement of symptoms in idiopathic hypersomnia: The Idiopathic Hypersomnia Severity Scale. Neurology. 2019;92(15):e1754-e1762. doi:10.1212/WNL.0000000000007264

Khosla S, Deak MC, Gault D, et al. Consumer Sleep Technology: An American Academy of Sleep Medicine Position Statement. J Clin Sleep Med. 2018;14(5):877-880. Published 2018 May 15. doi:10.5664/jcsm.7128

Gavidia M. FDA Approves Jazz Pharmaceuticals’ Xywav for Idiopathic Hypersomnia. AJMC. August 12, 2021. Accessed October 13, 2026. https://www.ajmc.com/view/fda-approves-jazz-pharmaceuticals-xywav-for-idiopathic-hypersomnia

Maski K, Trotti LM, Kotagal S, et al. Treatment of central disorders of hypersomnolence: an American Academy of Sleep Medicine clinical practice guideline. J Clin Sleep Med. 2021;17(9):1881-1893. doi:10.5664/jcsm.9328