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Sleep disorders such as sleep apnea and narcolepsy can have a significant impact on your daily life. One way to figure out what’s causing your sleep disruption - and determine the best treatment - is by having a sleep study. Sleep medicine specialist Nancy Foldvary, DO, MS discusses what to expect from a sleep study, how you know you need one, and what the results can tell you.

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The Ins and Outs of Sleep Studies with Dr. Nancy Foldvary

Podcast Transcript

Speaker 1:

There's so much health advice out there. Lots of different voices and opinions, but who can you trust? Trust the experts, the world's brightest medical minds, our very own Cleveland Clinic experts. We ask them tough, intimate health question. So you get the answers you need. This is the Health Essentials Podcast brought to you by Cleveland Clinic and Cleveland Clinic Children's. This podcast is for informational purposes only and is not intended to replace the advice of your own physician.

Annie Zaleski:

Hello, and thank you for joining us for this episode of the Health Essentials Podcast. I'm your host, Annie Zaleski. And today we're discussing sleep studies with sleep medicine specialists, Dr. Nancy Foldvary, director of Cleveland Clinic Sleep Disorder Center. The CDC estimates that 70 million Americans live with chronic sleep problems. These can include sleep disorders such as sleep apnea, narcolepsy, insomnia, or parasomnias, a term for many conditions that disrupt your sleep. Sleep disorders can have a significant impact on your daily life and affect your career and relationships. One way to figure out what's going on and determine the best next steps in treatment is by having a sleep study. Dr. Foldvary is here to discuss what it's like having a sleep study, how you know you need one, and what the results of these studies can tell you. Dr. Foldvary, thank you so much for being here today.

Dr. Nancy Foldvary:

Thank you. It's my pleasure.

Annie Zaleski:

So I'd like to start off by having you tell us a little bit about your work here at Cleveland Clinic. What kind of research and clinical work do you do?

Dr. Nancy Foldvary:

Well, I'm a neurologist in the Neurological Institute and I lead the sleep medicine program. And the sleep medicine program is a large, diverse program. We treat patients with a variety of sleep disorders. I also practice epilepsy medicine, and one of my interests is in the intersection between sleep disorders, sleep medicine and other neurological conditions. So I do some research on relationships between sleep and epilepsy, but our team has also broadened that to other neurological conditions. And we also treat common sleep disorders like insomnia and sleep apnea. And our research team here in the Sleep Disorder Center is very extensively involved in interactions between sleep disorders and cardiovascular health, metabolic health, as well as brain health.

Annie Zaleski:

Boy, that's another podcast right there for us to talk about. Fascinating. So today though, we're going to be talking about sleeps studies, which obviously with all of that work, you're very familiar with. So broadly, first off, explain what a sleep study is and what are some common reasons someone might have one done?

Dr. Nancy Foldvary:

Yeah, so historically sleep studies have been performed in sleep laboratories. And of course we still do sleep studies in sleep laboratories. All but one of the sleep laboratories in our system here are in hotels, which we've moved to over many years and which patients really enjoy. They're nicer environments than sleeping in the first generation of sleep labs, which were labs with equipment all over the place and wires hanging out and people sleeping on hospital beds or gurneys. So we've moved toward more pleasant environments so that we can optimize a great experience and ensure that people sleep actually during sleep studies. So the overnight sleep study in a sleep laboratory is attended by a sleep technologist, which means that behind your room in another room, which is called the control room, a technologist is monitoring the patient, monitoring the signals, the brainwaves, the breathing patterns, the oxygen, the carbon dioxide, the body movements, as well as the video of patients sleeping so that the technologist can understand what's going and maybe modify the test in order to optimize the night.

              And so a perfect example of that, which happens very often is that people come into the sleep laboratory for sleep apnea, which is a breathing disturbance in sleep that is highly prevalent. And we diagnose the sleep apnea within a couple of hours, which allows the technologist to put the patient on a CPAP machine or a positive airway pressure device, which is a therapeutic test. So sometimes we can do a diagnostic test and a therapeutic test in the same evening. I think it's important to add a couple more things. One is that in our system, we also see patients with many other kinds of sleep disorders coming to the sleep laboratory, sleep-related movement disorders, sleep-related seizures. And this requires that we tailor the test to the individual needs of the patient or the clinical question. And so every test that we do in our sleep labs is reviewed before the patient arrives at our sleep lab so that we can make sure we've tailored it.

              And that may mean adding wires to the head, more EEG, adding wires to the muscle so that we can record muscle activity appropriately, adding a specific type of carbon dioxide monitor so that we can make sure that the breathing disturbance isn't more complicated than obstructive sleep apnea. So that's the typical laboratory study.

The other is the home sleep apnea test. And so this came out several years ago, we've done home sleep apnea test now for probably about a decade at the Cleveland Clinic. And this is a very specific abbreviated test done in the home for one reason. And it's to confirm the diagnosis of sleep apnea when the clinical presentation suggests the high probability of sleep apnea. So it's not for more complicated sleep disorders, it's not going to very precisely estimate the amount of sleep apnea. It's just going to confirm significant sleep apnea or not. And I think that's an important point because many people will want to come, will want to do test in their home, but there are reasons why that's not the optimal test in many cases.

Annie Zaleski:

Wow. That's so fascinating. And it's amazing how technology has evolved too, that you can do that. It's a lot more complex I would imagine.

Dr. Nancy Foldvary:

Yes. And it requires really that we think about every test, and it's really the responsibility of the physician who's ordering the test, but also the sleep laboratory. So we take that seriously. We want patients to have the right test and that may be the home test, or it may be the in-lab test, but we want to get the right test that will answer the clinical question best for that individual patient.

Annie Zaleski:

So you mentioned sleep apnea and then some other sleep disorders is a couple of the things that sleep studies are for. What other conditions can these help diagnose?

Dr. Nancy Foldvary:

Many patients have sleep-related movement disorders or parasomnias. So parasomnias are abnormal experiences, behaviors, motor activity associated with sleep. And so the classic one that we record increasingly often is for REM sleep behavior disorder. This is a parasomnia where it typically happens in older individuals, men more than women. And the presence of REM behavior disorder is actually a precursor to neurodegenerative conditions. And so this is becoming increasingly important to recognize. When we see people with REM behavior disorder, they have a significant chance of experiencing symptoms of for example, Parkinson's disease years later. And so this requires that we add EMG, which are sensors that capture muscle activity of the upper extremities, a particular muscle in the upper extremities that is not typically recorded in a standard sleep study so that we can measure changes in muscle activity during REM sleep.

              So normally we're paralyzed in REM sleep, and that's a protective function because we can dream very vividly in REM sleep. And if we all had muscle activity, we could be kicking and punching and acting out our dreams. The patient with REM behavior disorder has a lesion, so to speak in a specific part of the brain that allows them to move and act out dreams, which can cause both injury to themselves, as well as injuries to bed partners. And so this is one example of a more advanced kind of sleep study that would require some tailoring in the sleep laboratory.

Annie Zaleski:

Wow. So when someone is having a sleep study, obviously getting a diagnosis, and as you mentioned trying to see maybe with a CPAP machine which settings work then. What are some other goals or aims of a sleep study? Are those kind of the only two things? Is it diagnosis and then making sure that the treatment might be working?

Dr. Nancy Foldvary:

Well, those are two things for obstructive sleep apnea. Many people with obstructive sleep apnea have other sleep disorders, though. So we're looking for abnormal motor activity that might suggest that they may also have a comorbid sleep disorder. We're looking for position changes and state changes that would perhaps identify a different kind of therapy for sleep apnea. So for example, some people will have very simple sleep apnea, but it's only in REM sleep where it's only when they're sleeping on their back as opposed to their side. So we may be able to think about alternative therapies rather than a CPAP machine for those patients. We also will bring patients into the sleep lab to measure the effect of therapies, including oral appliances that are manufactured by a dentist that advance the lower jaw forward, creating space in the back of the throat.

              And this is a nice alternative for many patients with mild to maybe moderate sleep apnea. And then our team is also involved in inspire therapy, which is hypoglossal nerve stimulation, which is a stimulator that's placed in the chest and stimulates a nerve called the hypoglossal nerve, which is the 12th cranial nerve that expands the airway in sleep to treat sleep apnea as well. And we also will treat patients or diagnose patients who have hypersomnia conditions. So these are very different — a completely different category than obstructive sleep apnea. These are people with sleep/wake dysfunction. They have difficulty staying awake during the day. These include patients with narcolepsy and other forms of hypersomnia and they require an overnight sleep study followed by a daytime nap test. So some patients are in our sleep lab for maybe 18, 20, 22 hours to get their full complement of testing to make a diagnosis.

Annie Zaleski:

Wow. That's unbelievable. And it's nice to know that there are so many options though, that if something is going on chances are, there's something — that there's a test for you or something that can be tailored to what's going on. That's great.

Dr. Nancy Foldvary:

Yes, absolutely. We've created a sleep app recently as well. The second version just went live on the App Store last week. And this is a screening app, so anyone with an iPhone can download this and can screen themselves for like four common sleep disorders, including sleep apnea. And you can get a probability score. Like, what's your probability of having significant sleep apnea. And we're using that increasingly to help people sort of understand their own risk for sleep disorders and be able to make their own decisions about whether they think sleep testing is right for them.

Annie Zaleski:

Well, that's great, because that actually goes right into my next questions are, what are some specific signs or symptoms you might be experiencing that you think maybe a sleep study might be helpful?

Dr. Nancy Foldvary:

Yeah, so there are many different sleep disorders. In six broad categories, they include insomnia conditions, hypersomnias that I just mentioned, the sleep disordered breathing, which is sleep apnea, parasomnias, circadian rhythm disorders and movement disorders in sleep. And really each of these are going to present very differently. But most often people will recognize that their sleep quality is poor, they have difficulty either falling asleep staying asleep, and they don't feel refreshed after a night of sleep. And so we begin there with figuring out if it's a problem of sleep quantity or quality and or if it's a problem of wakefulness during the day, and then ask more questions to figure out which direction we're going in. Snoring is a common symptom of sleep apnea as is tiredness and daytime sleepiness. It's sometimes very useful to have a bed partner also contributing to the history because many people with common disorders like sleep apnea are not aware that they stop breathing when they sleep, or that they're pausing or making snoring or snorting sounds really to open up their airway again, after their airway closes on them.

              And so oftentimes for obstructive sleep apnea, the bed partner's history is more valuable than the patient's history. The opposite is probably true for people with narcolepsy, because people with narcolepsy and other hypersomnia conditions can have very elaborate dreams, very unusual things happen to them as they're going in and out of sleep, like feeling paralyzed or feeling like they're hallucinating or acting out dreams. And those are things almost always that are very personal to the patient. And it requires a more detailed sleep history from the patient in order to identify factors that might be suggestive of a condition like narcolepsy.

Annie Zaleski:

Wow. Well, and there's so many different signs and symptoms here. And so how can you tell, with something like snoring, because snoring is very common, when does someone realize, oh geez, this is rising to the level of being a health concern?

Dr. Nancy Foldvary:

Yeah. So many people snore and it's not always easy to know when we're seeing patients in the clinic who might just be a snorer and who might have sleep apnea, because snoring is like the far minimal end of the spectrum of sleep disordered breathing. And again, the clinical history is not always directing us perfectly. And so most people who come to the sleep center who snore end up having other symptoms too, like they're gasping themselves awake at night and it's a sign of sleep apnea. Their bed partner may report something like snoring or gasping or a lot of sounds or pausing in sleep, and they may not feel refreshed during the day. And so those patients would certainly qualify for having a sleep study to make sure they don't have sleep apnea.

              And if we've ruled out sleep apnea, sometimes snoring can be reduced or eliminated with weight loss, with reducing alcohol. Alcohol at nighttime is a central nervous system depressant. So it can make the airway more floppy. And really snoring is caused by the muscles that support the upper airway, getting weak and getting floppy at night. And so sometimes it's as simple as sleeping on your side instead of your back, losing a few pounds, and maybe cutting back on alcohol in the evening. But people who talk about loud snoring, loud, disruptive snoring are more likely to have sleep apnea. So those folks should definitely have sleep studies. And if they don't have sleep apnea, we will often refer them to our sleep medicine board-certified, ear, nose and throat surgeon to do an upper airway examination, identify the site of the airway collapsibility and assess whether or not there may be a surgical procedure that will alleviate the snoring or potentially use an oral appliance that is manufactured by a dentist that can stabilize the upper airway and reduce snoring.

Annie Zaleski:

And that's so interesting because I think a lot of people think that snoring does mean you have sleep apnea. You might not think that it's kind of on a continuum. You might think, oh, this is happening to me, this is always severe, obviously CPAP machine. But something like sleep apnea just from you explaining this, there's so many different solutions. That's so interesting. So how do you know when sleep apnea is mild, moderate, severe, and when is that a problem too?

Dr. Nancy Foldvary:

Yes. So the sleep study helps us determine that. So on an overnight polysomnogram or on a home sleep apnea test, we will quantify the number of times we record either an apnea, which is a complete cessation of breathing for at least 10 seconds, or we call a hypopnea, which is a partial airway obstruction. We quantify these, add the number up by the sleep hour, and we calculate an index which we call the apnea hypopnea index. This is the number of times of significant collapsibility of the upper airway per hour of sleep. The diagnosis of sleep apnea is made when that number is five or greater, mild is five to 15, moderate 15 to 30 and severe 30 and plus. And we know from the literature over decades that people with untreated sleep apnea who are in that moderate or severe range have a much more increased risk of cardiovascular disease, high blood pressure, heart attacks, stroke, heart failure, as well as metabolic disorders like obesity and diabetes and now cognitive impairment and even progression to Alzheimer's disease.

              So when people have mild sleep apnea and they have very few symptoms, we have the luxury of sort of addressing the symptom and maybe not worrying about out those adverse consequences of untreated sleep apnea. But when people are in that 15 and higher range, we really want to make sure that whatever treatment we choose is going to be very highly effective. And for many people that is a positive airway pressure machine at least to start.

Annie Zaleski:

And that, I mean, and that just speaks to how important it is to have any sleep disorders looked at and diagnosed. Or if you suspect you have one to get that checked out.

Dr. Nancy Foldvary:

Right, right. And the home sleep apnea test, while it's convenient and expensive, it also will underestimate the severity of obstructive sleep apnea. So again, it's important that we're choosing the right test for the right clinical question. If there is a concern about measuring the severity of sleep apnea, we may not be able to fully answer that question with a home test and we may prefer an in-lab test.

Annie Zaleski:

And that makes sense. I think with some other tests like tests for colorectal cancer, you have at-home tests, which are good to a certain point, but you want to colonoscopy to really dig into what's kind of going on.

Dr. Nancy Foldvary:

That's right. Exactly.

Annie Zaleski:

Well, let's talk about some of the types of sleep studies then, what they're kind of. How does a doctor determine which one is best for you?

Dr. Nancy Foldvary:

So the home sleep apnea test is a test to confirm the presence of what we call high probability obstructive sleep apnea. So a patient who snores, is tired during the day, has witnessed apneas, meaning breathing pauses that maybe a bed partner recognizes, those are the top three symptoms of obstructive sleep apnea. And if that patient does not also have a suspicion for other sleep disorders that would require an in-lab test or significant heart disease or significant lung disease, then that might be the perfect patient to have a home sleep apnea test. That patient sounds like they have sleep apnea and we want to confirm it and start treating it. On the other hand, if that patient has significant lung disease or heart failure or a neurological condition, and maybe has snoring, but we're not so sure how sleepy they are, that patient would be more appropriate for in-lab tests so that we can measure things with more precision and measure other biological signals that are not included in the home sleep apnea test.

Annie Zaleski:

That makes sense. What are these tests like then? What can people expect with the at-home test for sleep apnea?

Dr. Nancy Foldvary:

So our home tests generally are delivered to the patient. We've made it easier so that we deliver the test on the date that the patient agrees to have the test and it comes in a sterile kit and it comes with instructions and a telephone number to reach out to one of our team members if there's a challenge. And the patient basically hooks up four sensors, they hook up a nasal prong, which goes here to measure airflow. And then the oximetry, which is the fingertip probe to measure oxygen. And then there's a belt around the chest and a belt around the abdomen that measures breathing and that's connected to the recorder. And then they turn it on, go to sleep, wake up in the morning, take it off and ship it back to us. So the home sleep test works very well.

              There is a failure rate, maybe 7% or 8% of the time the device won't work, the patient may forget to turn it on, a critical sensor might not have been placed appropriately. And in those situations we assess whether it's reasonable to send the device back to the patient and try again or have the patient come for an in-lab study. The in-lab studies are scheduled at nighttime, typically 8:00, 8:30, 9:00 PM, depending on the typical bedtime of the patient. And the patient will be greeted by a technologist, will be brought to their sleep room, which is their private room for the night, and will be hooked up to a number of sensors typically over the head to record brainwaves, again at the nose and the airway to record airflow, the belts for breathing, sensors on the arms, legs and under the chin and around the eyes to measure eye movements and body movements, which are important to differentiate sleep stages.

              So we're looking to record various sleep stages in non-REM sleep as well as REM sleep and then record breathing and motor activity during each of those stages so that we can identify various presentations of sleep disorders. And then patients generally go home in the morning. If they wake up by 6:00 in the morning, they can be unhooked and go home. Sometimes we tailor the test to allow the patient to sleep longer, knowing that they have trouble falling asleep and usually sleep until 8:00 or 9:00 in the morning. So we're able to tailor that to make sure that we record the time of sleep that is really most typical for the patient.

Annie Zaleski:

So is that the diagnostic or kind of routine overnight sleep study? I feel like that's what most people have. Is that correct to say?

Dr. Nancy Foldvary:

Yes, yes. That's the typical test. For patients, much less often, for patients who we suspect have a sleep wake disorder that's characterized more by profound daytime sleepiness, then we would do that test and it would be followed by a multiple sleep latency test where the patient would have many of those nighttime sensors removed, we're finished recording breathing, but we keep some of the wires on the head and the eye lids and the chin lid, and we invite the patient to take a nap at two hour intervals five times during the day. And we measure how easy it is for them to fall asleep and if they fall into REM sleep. And that's the test that identifies narcolepsy and some of the other disorders that are characterized more by the daytime sleepiness rather than breathing disorders when they sleep at night.

Annie Zaleski:

Now, does that test have a specific name?

Dr. Nancy Foldvary:

That daytime test is called a multiple sleep latency test. And when we bring patients in for that more comprehensive test, the overnight polysomnogram, which is a sleep study followed by the multiple sleep latency test. In our lab, we will also measure actigraphy for a week or two before they come in the test. So actigraphy is like a motion sensor watch and that's delivered to the patient by our sleep lab and they wear it for a week or two so that we can measure sleep and wake patterns over a broader period of time because sometimes a single night in the lab is not telling the whole story. And so for certain diagnoses, like people who have circadian rhythm disorders, people who have significant insomnia and the hypersomnia disorders, we really need to see what the patient's sleep wake patterns are over a longer period of time and consider that when we're interpreting the overnight sleep study. So you get a sense that we really try to understand what the specific question is or questions for a given patient, and really tailor the experience to answer that specific question.

Annie Zaleski:

Wow. I think there's another test also what called the maintenance of wakefulness test, is that similar to the multiple sleep latency test? Or is that a kind of a separate thing?

Dr. Nancy Foldvary:

It's very similar, only instead of asking the patient to try to take a nap, we ask them in a very dim, comfortable lab environment reclined to try to stay awake. So here we're measuring one's ability to maintain wakefulness in a rather sleep conducive environment. This is not a diagnostic test. It's a test that helps us assess how someone's able to stay awake typically under the influence of wake promoting medications. So for example, the patient with narcolepsy, we may do a sleep study, the overnight sleep study in an MSLT and make a diagnosis and then start to treat the patient with wake promoting medications to help them function better during the day. And sometimes it's hard to know how well they're doing on those medications, or we feel we've tried many medications or maybe a high dose of a medication, but the symptoms persist. And that's a situation where we may order a maintenance of wakefulness test to really objectify that patient's daytime sleepiness.

Annie Zaleski:

Wow. Now, I think there's another positive airway pressure titration study. Now, is that to get like fitted for a CPAP test? Or what is that like?

Dr. Nancy Foldvary:

So that's an overnight sleep study where we're aiming to use positive airway pressure the whole night and change pressures, change the mode of therapy in order to alleviate the sleep disordered breathing, which is sleep apnea. It may also be a more complicated form of sleep disordered breathing where a patient may hypoventilate, they're not breathing efficiently. And so we may use carbon dioxide and oxygen levels and a PAP machine to try to optimize breathing both from the standpoint of airway collapse, as well as from the standpoint of ventilation. And so typically we begin with a CPAP, which is continuous positive airway pressure, where air is flowing to maintain the patency of the upper airway when we inhale and exhale, or maybe a bilevel PAP machine, where there are two settings, an inspiratory setting, which is higher and an expiratory setting, which is lower in order to more efficiently breathe, maybe more comfortably breathe, as well as treat some of these hypoventilation disorders.

              And then yet, there's another more advanced type of positive airway pressure, which we call ASV that also can be titrated in the sleep laboratory. So when we do a PAP titration study, it may be one or all of those modes. We may start with a simple mode and recognize that the patient's not tolerating it, move to bilevel or even move to ASV all in one night with the hope that at the end of that night, we're going to know what kind of machine and what pressure settings that patient needs so that we can order the right kind of machine for the patient's breathing disorder.

Annie Zaleski:

Wow. That's just unbelievable, the range and just how much can be tailored to each individual person and what can actually be measured. That's just incredible.

Dr. Nancy Foldvary:

Yeah. And I think it's important for the patient also and the referring provider to know your sleep lab. So referring providers who are not sleep specialists, may not be as well trained in knowing all these intricacies. So I encourage non-sleep experts, if you're referring patients to a sleep laboratory, get to know the doctors who are working in that sleep laboratory and get to know the variability of tests that they ordered so that you can participate and really tailoring the test for your patient, because all tests are not alike. The in-lab tests for a sleep apnea patient may be very similar from one lab to the other. But if you're referring your patients for more complex problems, it's very important that the lab knows the reason for you referring the patient.

Annie Zaleski:

Awesome. So if someone is going to get a sleep study done then, what do they need to know in terms of like, what should you wear? What do you need to like pack for something if it's an overnight or a 24 hour test?

Dr. Nancy Foldvary:

Yes. So our lab does provide instructions for patients. If patients are staying for like almost a full day, like for narcolepsy or for hypersomnia, then it's important to come prepared and know that you're going to be in the lab until maybe five o'clock the next day. One of the things that can really invalidate that daytime test is just not knowing what you're getting into and thinking, I'm probably going to leave at three o'clock. I've got to pick up my child from school, but oh, no, this test is not going to end until five o'clock. That anxiety alone probably will invalidate that test. We encourage people to bring snacks. We advise people to always bring their medications. Our sleep labs are not generally in hospitals where nurses provide medications. So it's very important that you take the medications you normally would take at bedtime and during the day, unless if advised otherwise by your doctor or the sleep laboratory, it's important to wear something comfortable, but also be aware that you're going to have sensors placed on your chest and under your pajamas.

              And so it's important to wear something that you're going to sleep in, that's going to allow you to move around and allow the technologist to place sensors in the correct places. We also will advise people to not put a lot of hair product in their hair, because they're going to have sensors applied to their scalp and patients who have hair pieces and acrylic nails, we're not going to be able to record the oxygen level through an acrylic nail very well. We're not going to be able to preserve certain types of hairstyles with the amount of paste and sensors that are going to be in your hair. And then beyond that, we really encourage people to try to make themselves comfortable. Some people bring their own pillow. That's perfectly fine. Some people bring things to do that they know will help them fall asleep at night, even their electronics or a book to read, but we also make sure that people are turning electronics off well before lights out. So that electronics don't interfere with the quality of the sleep study.

Annie Zaleski:

So you mentioned sensors and belts as well. Is there any other equipment or things that people can expect during a sleep study? Are there ever face masks used and things like that? What else can people expect?

Dr. Nancy Foldvary:

Yeah. So if you're coming for a sleep apnea diagnosis and it turns out that you have significant sleep apnea, our laboratories will introduce the most common treatment which is positive airway pressure or continuous positive airway pressure, which is CPAP. And that's delivered through some type of interface, either with nasal prongs that fit right into your nostrils or a nasal mask that covers your nose, or even if you're a mouth breather, a full face mask that covers your nose and your mouth. And so that can be a little bit difficult to get acclimated to. And so before the sleep study, while patients are waiting for lights out, we will invite them to watch a video so that they can see what can happen during the sleep study if we do find that they have significant sleep apnea.

              When that does happen, it's actually mostly a very good experience, because a technologist who has a variety of those kinds of masks or interfaces can fit one that is maybe the most comfortable, the right size, and work with you, work with the patient to get them to understand the reason for the therapy and make sure there's no leaking, make sure that they're comfortable, and provide enough education. So that after that test, the patient's much more likely to be receptive to the therapy and succeed with the therapy.

Annie Zaleski:

Oh, wow. That great. Having that even kind of in place too, I would imagine would also kind of reduce anxiety for people because geez, I imagine that you run into a lot of people who are just... They don't know what to expect and they can get very worked up with this. So what else do you kind of do for people who might be anxious or worried about having a sleep test?

Dr. Nancy Foldvary:

Well, we do a lot of education ahead of time. So when a test is ordered, there's a series of educational materials that are made available to the patient. The technologists are excellent at alleviating stress. And our technologists are really great at this for children. I mean, we do sleep studies in people of all ages, and we have toys and gadgets and things for children to get a sense of what this sensor feels like and make them feel part of the experience when they're getting hooked up. None of these sensors are painful in any way. We don't use strong glue. We use paste that is easy to remove the sensors the next day, children and people can kind of touch the sensors before the study is on. We let them know that they can get up anytime during the night, all they've got to do is push for their technologist, push the button and we'll unhook them from the whole device so that they can go into the bathroom and sit on the side of the bed.

              So there are many things that we can do in the lab. We've got a recliner in most of the rooms, so that if a person is more used to sleeping in a recliner, rather than a bed, or just needs to move around, we can make that happen as well. The technologists are experts in making it the most sleep conducive environment, because we know we need to capture several hours of sleep to make that test worthwhile. And so we do what we can, we can extend the recording period, and we can allow the patient to take a break if needed and encourage them to try again so that we can make the most of that nighttime study.

Annie Zaleski:

That's great. And that's, I think good to know because I think a lot of people also might think, oh, if I'm getting a sleep study, I have to be in bed all night. It's good to know that, hey, if you have to go to the bathroom or maybe you're having a little bit of anxiety, you can take a little bit of a break. I think that's really good to know.

Nancy Foldvary:

Yes. And we do overnight sleep studies sometimes during the day for shift workers. So people who are awake at night and normally sleep during the day, we want to record them generally when they're in their regular rhythm. And so we also will have people coming for an overnight, eight hour study to our lab at 7:00 or 8:00 in the morning for a nighttime sleep study. So there's a lot of tailoring that we can do in order to match what we're going record with the patient's usual sleep times in their usual environment.

Annie Zaleski:

What else then do you want people to know before having a sleep study then? And is there anything that people always discover that maybe they wish they knew in advance before having a sleep study?

Dr. Nancy Foldvary:

Well, I think that for most people, they do generally know what they're getting into, but until you've done it, I think it's just a brand new experience. So patients have a lot of anxiety about being monitored by the technologist. Patients are in clean rooms with sterile equipment, the equipment we [use] on patients and the masks we use have never been used by another patient. Everything is brand new, the technologists follow all kinds of protocols to make sure that the equipment is sterile and their interactions are with gloves. And so patients can feel comfortable. Of course, we're masking. And we've had very few instances through the entire COVID pandemic of any kinds of COVID problems in our sleep lab. That's a question that still comes up because I think people are still staying away from medical procedures that may not be viewed as urgent because of concerns about the pandemic. We've had very few challenges with people being sick in our sleep laboratories.

              And so I think people can rest assured that our laboratories are clean, all the equipment is fresh and new, and our technologists are very well-trained in making sure that the procedures are done perfectly appropriately through protocols. And that we also, at the same time, try to make people feel comfortable. And so they should feel comfortable bringing whatever they need to bring, to make their experience as close to home as it would be.

Annie Zaleski:

Awesome. That's great. So after you have a sleep study then, how long does it take for you to get results?

Dr. Nancy Foldvary:

So it takes a couple of days to process the data. Every single 30 second timeframe of an overnight sleep study, which may go on six, seven, eight, even nine hours needs to be scored. And so we have our nighttime technologists do some of that work, we have daytime technologists who process the studies, and then the physician will read the study. And so generally we recommend that patients go back to their referring provider no sooner than a week after the test to make sure that the study has been finalized and it's available for the physician to share the results.

Annie Zaleski:

Wow. So what did the results look like then? Like, what sorts of measurements and things do people kind of receive?

Nancy Foldvary:

So the overnight study is a very detailed report. Actually our report is just the summary of the whole night. There are thousands of variables that can be calculated from an overnight sleep study, literally thousands of them. What we do is we summarize sleep architecture. So this is the time someone took to fall asleep, the number of times they woke up, the time they woke up in the morning, the amount of REM sleep, the amount of non-REM sleep stages, one, two, and three, and the amount of wake time. Then we'll summarize the respiratory variables. So how many times did the patient stop breathing, have a partial airway collapse? How low does the oxygen level go? How many times did oxygen level drop? How high did the carbon dioxide level go?

              And then we'll go into summarizing body movements. How many periodic limb movements occurred? Were these during sleep? Were these during wakefulness? What was the average heart rate? How low did the heart rate go? Were there any arrhythmias associated with the respiratory events? And then we'll do a summary in the impression and categorize the sleep disordered breathing. Is it mild, moderate, or severe? Are there leg movements or other body movements that are significant? Was the study likely to be valid in terms of having captured the right kind of sleep? Did we capture REM sleep? Did we capture people sleeping in the supine position? And then finally what we'll do is we'll look at the patient history either in their medical record or from the questionnaire that the patient completed on the night that they came into the lab. So we have the patients complete a sleep and wake history basically. And we use that information to make sure that we're interpreting the study in the context of the reason why the patient came for the test.

              And then lastly, the patient does an after study or a morning after questionnaire. And here, they can write for us. How close was this to normal? Did I sleep pretty much like I normally do? And if not, how different was it from normal? And that's important too, because sometimes the first experience in the sleep lab is just one of, I know I didn't sleep as well, I know we didn't capture the information that we expected to, and that's important to know what the patient's perception is. If it matches the perception of the physician reading the study, that may be somebody who does need to come for a second study. And we call that first night effect, the variations in sleep quality that lead to a potential for underestimation of a sleep disorder.

Annie Zaleski:

And that was actually going to be one of my questions. I would imagine that sometimes if you don't get the results or the results maybe don't line up with what you think the first time, that's totally normal, and you might have to come back.

Dr. Nancy Foldvary:

Absolutely. And sometimes a referring provider who is not necessarily a sleep medicine board-certified practitioner will refer patients for a sleep medicine consultation. Sometimes the initial reason for the test might be sleep apnea, but in fact, the patient might have a different sleep disorder. And sometimes people with sleep apnea also have other sleep disorders. And so it can get a little bit more complicated than a simple question about sleep apnea.

Annie Zaleski:

So in general, assuming all goes well and you sleep OK then, how accurate are sleep studies?

Dr. Nancy Foldvary:

If the patient slept well and feels that the study was representative of their typical night of sleep, a sleep study's going to be very accurate in identifying sleep disordered breathing, or sleep apnea. The sleep study may vary from night to night in terms of the severity of sleep apnea. So for example, if we were to do two nights of sleep recording in the sleep laboratory, we might find severe sleep apnea one night, moderate sleep apnea the next night. Or on the other extreme, we might find that the patient is normal on the first night, but they meet criteria for mild sleep apnea the second night. So there is some night to night variability, and that's important to recognize if we get a result that surprises us, or is a negative study when we really have a high index of suspicion. And we recommend that that patient come back for another study.

              When it comes to other sleep disorders, like REM behavior disorder, like periodic limb movements, like narcolepsy, it's really important that the patient is well prepared for those studies, that they're not taking medications that are going to suppress or mask findings we're looking for. So very often patients with hypersomnia disorders or even REM behavior disorder really should have medications that may mask findings that we're looking for on the test tapered or discontinued before the study. And for that to happen, sometimes it's best to have them come to the sleep disorders clinic and see the sleep disorders experts so that we can make sure that we're identifying the medicines that really should be discontinued and we're suggesting that those medicines be discontinued in a safe manner, in collaboration with the physicians who prescribed those medications. So we're really prepping for a high quality valid test in advance.

Annie Zaleski:

Wow. So after someone gets results then, what are the next steps?

Dr. Nancy Foldvary:

So the next steps are to review those results with your provider. And it really depends on what the diagnosis is. So for sleep apnea in the moderate to severe range, we very often almost always try positive airway pressure first. This is a therapy that's been out for decades, it's a very effective therapy, full adherence to this kind of therapy and people who are high risk for cardiovascular consequences or brain consequences are very likely to have a reduction in those risks if they can adhere to therapy and the therapy is effective. For people with milder range sleep apnea, it really depends on the severity of symptoms. Some patients may be appropriate to try positive airway pressure therapy. Other patients, sometimes I'll refer them to a dentist who is certified in making oral appliances for sleep apnea and get the opinion of the dentist. Sometimes I'll refer them to our ear, nose and throat surgeon to get an airway exam and think about alternatives if the patient's not really interested in positive airway pressure.

              Sometimes it's a matter of weight loss, reducing alcohol, sleeping on your side with a body position pillow that can kind of keep you from sleeping on your back. And then for patients with other disorders, it's really about what disorder it is. There are medications to treat all the sleep disorders, most are based on FDA approval. Some conditions like the parasomnias and these include people who walk in their sleep and eat in their sleep, there are no FDA-approved drugs, but we have some understanding of the effects of some medications that can improve sleep quality. And so we use the literature as well as the evidence-based literature from clinical trials to identify the most appropriate medication to begin with. Of course, with insomnia, so insomnia patients often don't end up in the sleep laboratory. Insomnia is a sleep disorder that's diagnosed clinically. There's no need for a sleep disorder if a patient has insomnia and does not have a high risk for another sleep disorder.

              And so those patients can be identified clinically and we recommend cognitive behavioral therapy for insomnia. We've got a behavioral sleep medicine team. These are expert psychologists who are certified in the care of insomnia patients. And they do various types of therapy to reduce insomnia. Often we do this without the need for sleep medications. And this kind of therapy is more effective long-term than even using sedative hypnotics for the treatment of insomnia.

Annie Zaleski:

Wow. I feel like a lot of people might not know that then. That's so very interesting.

Dr. Nancy Foldvary:

Yes, many people with insomnia struggle. I mean, 30% of our adult population has some degree of insomnia. And we're lucky at the Cleveland Clinic to have behavioral sleep medicine experts have created both a computerized program so that you can do this in your own home, that's called Go! to Sleep. It can be found on the Wellness Institute of the Cleveland Clinic's website. So we're trying to create things where people can do some self-help on their own, but we've also got this group of behavioral sleep medicine experts who can coach patients through the challenges of managing insomnia as well, either individually or in a group setting.

Annie Zaleski:

Wow. This has been an amazing conversation and extremely comprehensive. Is there anything else you want to add? Are there any other points you want to make?

Dr. Nancy Foldvary:

I think I just like to reinforce how common sleep disorders are. Sleep apnea affects 25% of people, more men than women before menopause, but after menopause, women are equally at risk and they have a lag to diagnosis because they don't present with all the common symptoms. We probably are missing a lot of narcolepsy and hypersomnia because there's not enough awareness in the general public about these conditions. So if you have struggled for more than three months with difficulty, with sleep quality or quantity or difficulty staying awake during the day, it's probably time to go see your doctor and the sleep medicine experts available at the Cleveland Clinic likely we'll be able to make a diagnosis and start you on therapy.

Annie Zaleski:

Wow. Well, Dr. Foldvary, thank you so much for being here today. Like I said, this has been a really great conversation. I think it's going to help a lot of people.

Dr. Nancy Foldvary:

Thank you. It was my pleasure.

Annie Zaleski:

Interested in scheduling a sleep study or seeing a sleep specialist? Call Cleveland Clinic Sleep Disorder Center at 216-636-5860, or visit clevelandclinic.org/sleep.

Speaker 1:

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