Pediatric Narcolepsy is Plagued by Misdiagnosis Despite Its Rarity

Kiran Maski, MD, MPH

Although pediatric narcolepsy is an uncommon condition, ensuring physicians in sleep medicine and neurology can ascertain its presence is important for patient outcomes.

This is especially true considering some estimates show that only 25% of total patients with narcolepsy will be diagnosed and treated.¹ Additionally, those who get the diagnosis are often diagnosed very late, and sometimes pediatric patients are misdiagnosed altogether.

To help address this, at the Child Neurology Society’s annual meeting, Kiran Maski, MD, MPH, gave a detailed presentation about the current state of therapies and strategies for the condition. She also spoke about management of the condition’s symptoms and how to include behavioral tactics into the treatment strategy.

To gain more insight into her assessment and what the clinician community should look for, NeurologyLive spoke with the director of the sleep clinic and assistant professor of neurology at Harvard Medical School in an interview.

NeurologyLive: At the Child Neurology Society annual meeting, you presented an update on pediatric narcolepsy’s treatment and management. What did that entail?

Kiran Maski, MD, MPH: I highlighted sort of some of the management, not just from a pharmacologic standpoint but behavioral management, of pediatric narcolepsy symptoms. Pediatric narcolepsy is a rare neurologic condition—about 0.2% of the population, essentially, has narcolepsy, but usually, the onset is about 10 to 20 years of age. It usually starts in the pediatric domain, but there are problems with delayed diagnosis.

Unfortunately, there’s no way to recognize symptoms so oftentimes patients aren’t diagnosed until 5 to 10 years later, and oftentimes there are high degrees of school failure or even driving issues or driving safety issues because of it. Part of the presentation that Merrill Wise, MD, gave was how to evaluate for narcolepsy, what are the symptoms of most concern, how does narcolepsy present in children—which turns out to be a little different than adult presentations.

Often there’s a misdiagnosis. One of the symptoms, for instance, is cataplexy—this symptom of motor weakness that’s usually triggered by an emotion such as laughter—and this can get misdiagnosed as epilepsy. There’s a high degree of exposure with the wrong medications in this population. Sleepiness is something that you can see in many conditions, including depression, for instance. I personally see a lot of kids who are mislabeled as depressed and put on medications because of that, and in the younger population, sleepiness can manifest as hyperactivity or impulsivity, so we also see a good chunk of patients being diagnosed with ADHD. There’s a lot of learning that needs to go about pediatric narcolepsy.

In terms of treatments, for years all we’ve had are just traditional stimulants. Specifically, amphetamines are the only FDA medication for the treatment of daytime sleepiness in narcolepsy. We just recently had the first randomized controlled for sodium oxybate for the treatment of pediatric narcolepsy, which I was one of the site investigators for and was recently published in The Lancet, showing really good benefit for narcolepsy and cataplexy and daytime sleepiness.

What should clinicians be looking out for in the pediatric patient population in regard to narcolepsy?

For diagnosis, the core symptom that patients present with is daytime sleepiness. That’s a very common symptom among everyone, normally due to sleep deprivation. Really, the critical question to ask is how much sleep is there during the night. Even taking a couple weeks and getting a sleep log to find out if they’re really going to bed at 8-9 PM, or if it’s actually closer to midnight. Those are really important things to tease apart before going down this diagnostic journey of narcolepsy. I would say that, in the vast majority of cases, when people are sent for daytime sleepiness, it’s due to insufficient sleep or a medication that’s contributing to daytime sleepiness. But assuming that those things are ruled out, and there are no other sleep disturbances—meaning like a concern for sleep apnea or restless legs or other things that may be waking or preventing patients that may be falling asleep—narcolepsy is something to consider.

The supporting symptoms of narcolepsy would be something called sleep paralysis—waking up and feeling like you can’t move your body for a couple of minutes. That presents in about 25% of patients with narcolepsy. Hypnogogic or hypnopompic hallucinations—where sort of a visual image right before the child is waking up—as well. Oftentimes in kids, it’s like a scary image where they think they saw something in the room that wasn’t there, or more commonly that their brother took something from them. It can be benign or really threatening, and that also presents in 25% to 30% of kids. Then, cataplexy is probably the most specific symptom of narcolepsy, but that only presents in about 50% to 70% of kids and that’s a symptom that’s quite unique there’s actually a loss of muscle tone, so it can cause things from head drooping and slurring of speech, to full knee buckling and falls. That’s usually associated with an emotional trigger such as being upset or embarrassed.

Transcript edited for clarity.

REFERENCE

1. Narcolepsy Fast Facts. Narcolepsy Network website. Updated June 2015. narcolepsynetwork.org/about-narcolepsy/narcolepsy-fast-facts. Accessed January 2, 2018.