Dr. Kushida:
This is CME on ReachMD, and I'm Dr. Clete Kushida. Here with me today is Dr. Michael Thorpy. We're exploring various approaches to the diagnosis of narcolepsy.

So, Michael, maybe you can discuss what are some good practice habits to reduce the total time to diagnosis for an individual that you suspect of having narcolepsy?

Dr. Thorpy:
Yes, Clete, well, as you're well aware, there is a long delay for many of these patients in getting a diagnosis of narcolepsy, and it can be anything between 5 and 15 years from the onset of symptoms. Narcolepsy typically occurs in children, and that's when it's most often missed, actually, in children. And most children don't get diagnosed until they become adults. So we need to do a better job of recognizing the symptoms of narcolepsy, particularly in children.

Dr. Kushida:
Yes, absolutely. And especially things like depression or other mood disorders. That's often a path that sometimes physicians will take if they notice that the patient is sleepy and fatigued, they'll say, oh, you know, maybe it might be depression. Another one is other sleep disorders, such as obstructive sleep apnea, and so sometimes it, you know, what will happen is they'll do, like, a home sleep test, and if they did an in-laboratory sleep study, it might be a little more revealing.

So, Micheal, maybe you can talk a little bit about how the in-lab sleep study can really aid in the diagnosis coupled with a MSLT?

Dr. Thorpy:
Well, that's right. I mean, I think the first thing is these patients need to be recognized to have a problem, and if any patient has sleepiness which is not relieved, they need to be referred on and preferably to a sleep specialist so they can undergo these sleep studies. And typically, we do an overnight polysomnogram, an overnight sleep study, followed by a daytime 5-nap opportunity test called the multiple sleep latency test, and we look for how quickly these patients will fall asleep during the day and whether they have disturbed REM sleep, because characteristically, these patients have a lot of abnormal REM sleep phenomena, and so that's an important thing in helping to make an early diagnosis in these patients is recognizing that they can have abnormal dream content at night, nightmares, sleep-related hallucinations, or sleep paralysis.

Dr. Kushida:
Yes. And some things that practitioners might miss the cataplexy for are things like you might think that the patient might have syncopal episodes. They might think that the patient might have even epilepsy. So some time could be wasted chasing down those other possible diagnoses. And instead, maybe, as you said, referring them to a sleep specialist would be a good early step.

Michael, maybe we can talk a little bit about how you've seen the field change a little in the recognition and also the diagnosis of narcolepsy.

Dr. Thorpy:
Well, that's right. I mean, I think there is a lot more awareness by the general public and by clinicians about the diagnosis of narcolepsy. In some ways it was a little easier to diagnose narcolepsy earlier on before the advent of so many sleep centers for sleep disorders, because now sleep apnea is a common misdiagnosis in narcolepsy. So anyone seeing a patient with sleep apnea, a patient who has mild sleep apnea but is sleepy during the day, needs to consider that they could have something else, such as narcolepsy. 

Dr. Kushida:
Yes, absolutely. Thanks for a great discussion, Dr. Thorpy, and thanks to our audience for tuning in.