Lourdes DelRosso, MD, Associate Professor of Pediatrics at University of Washington School of Medicine, talks about a sleep disorder newly diagnosed in kids.
Explain a little bit about restless sleep disorder. What is it exactly?
DELROSSO: Restless sleep disorder (RSD) has recently been accepted as a new pediatric diagnosis. It is really a primary sleep disorder that consists of children moving frequently during their sleep. Parents usually complain that the child is moving, changing positions, thrashing the bed sheets, and sometimes falling out of bed. The main characteristic is that this pattern of restless sleep affects daytime behaviors. They either are sleepy during the day, have difficulty concentrating, or difficulty in school.
What causes restless sleep disorder?
DELROSSO: That is something we’re looking into and have a couple of hypotheses, but the most accepted hypothesis is iron deficiency. Iron deficiency has been associated with other motor disorders, such as restless leg syndrome. We studied iron levels in children with restless sleep disorder and found the levels of a protein called ferritin, which transports iron through the body, were low. Now, iron is a very important cofactor in the production of a neurotransmitter called dopamine, and dopamine has been implicated in other sleep-related movement disorders such as restless leg syndrome. So, it makes sense to investigate iron deficiency first. We found out that if we supplemented iron in children with RSD, their symptoms got better. We are also looking into other potential causes like sympathetic activation at night or sleep instability and finding some clues.
How many of the kids had iron deficiencies?
DELROSSO: In the patients with restless sleep disorder that we studied in California and Seattle Children’s Hospital, we found that all of them had low ferritin levels. About 7.7% of children have restless sleep disorder, but this is a population of children that are referred to us for a sleep problem. We still do not know what the actual prevalence is in the general population. This is why it is very important to bring awareness to the community that this is a new disorder so parents are aware that restless sleep can cause sleep disruption and daytime symptoms.
How can parents tell the difference between RSD and other sleep disorders?
DELROSSO: During my years as a pediatric sleep doctor, I listen to parents because they are great historians about children and their sleep. This is how restless sleep disorder became known to me because parents would say, there’s something wrong with one of my children. They are thrashing the bed and moving all night and their sleep is not restful. So, parents have been our best advocates for good sleep in their children. They also pay attention to their sleep disruption. We commonly see children wake up through the night and come to the parent’s bedroom. That is very easy for parents to really notice and bring to our attention or the attention of their primary care physician. Sometimes, parents also pick up on snoring. They hear them snoring and are concerned about obstructive sleep apnea, which can be seen in children as well.
I know you study kids, but is restless sleep disorder seen in adults as well?
DELROSSO: We have not studied adults yet, but there is an international group of experts that are interested and that will be the next step to see how this has evolved through older adolescents’ transition to adulthood. We’re missing some of our adult patients that have daytime symptoms and have restless sleep as well.
You talked about supplementing iron for RSD. Are there other things you’re prescribing to help with this disorder?
DELROSSO: So far, iron has been the most effective. Sometimes a child cannot tolerate oral iron because it has a lot of side effects like constipation or teeth staining. If it’s liquid form or if a child has a gastrointestinal condition that they cannot take iron, we offer intravenous iron. We recommend for all children to have regular bedtime routines, to avoid caffeinated products, and avoid any products that could be activating at night like high sugar, caffeine, chocolate, iced tea. Sometimes parents do not realize that chocolate can have high levels of caffeine and can last for about six hours. So, we recommend no caffeine after about 2:00 in the afternoon. It is very important for children to have a consistent bedtime routine and an adequate sleep environment. We have found out that some substances, even temperature, if the room is too hot or too cold, that sleep may not be restful. It is not uncommon for us to identify untreated asthma, uncontrolled asthma, or eczema as a contributor to restless sleep. Other sleep disorders, such as obstructive sleep apnea, restless leg syndrome, kicking or insomnia can also give the impression of restless sleep. We need a sleep study to diagnose the disorder and be able to rule out other sleep disorders.
Are there other ways parents can make the environment more suitable for kids to get to sleep on time and get restful sleep?
DELROSSO: Absolutely. We usually recommend to start dimming the lights about an hour before bedtime and this will vary by child or age. We have a clock in our brain, this circadian clock, that responds to light. If we have bright light in front of our eyes, we’re going to be telling our brain that it’s daytime and our brain won’t produce a substance called melatonin that helps us sleep. We have done studies that show if you have the TV on or electronics or bright lights in front of you, it usually takes up to an hour to start producing melatonin. The sleep onset in children that have bright lights will be definitely delayed compared to dimming the light and starting to prepare an environment to sleep. For some children, it is reading a story, singing. For other children, it might just be brushing teeth, getting into PJs, but having a structured routine and a set bedtime is helpful. Also, a quiet environment, avoiding sounds or noises. It’s very important for us to identify the social determinants, or social aspects of sleep, like the neighborhoods, the noise, the lights that can affect sleep in both children and adults.
Is there a certain temperature range that parents should focus on?
DELROSSO: Most studies have shown that we sleep better in cool temperatures. That’s still a little bit subjective. I always tell parents to experiment what kind of bedsheets the child feels comfortable. We all have a little bit of a sensitivity to bedsheets, or to materials. Some children may like a heavier blanket than others. Some children do not like any bedsheet. So, it is very specific, and this is where it comes into account, really knowing what makes sleep comfortable. I remember some parents coming to the sleep lab and observing the environment in the sleep lab, like what is our temperature or what is our bedsheets? And sometimes, we have children that sleep better in a lab environment than at home, regardless of all the sensors that we put on them. It may be because of the environment like the darkness of the room, the bedsheets and that we do not have any dust like stuffed animals or carpets, which is important in children with allergies.
When you tell parents to give their children more iron, is it in a pill form? Is it based on diet? How are they getting the extra iron?
DELROSSO: We usually do a blood test and check the iron levels, ferritin levels, and full iron panel. We recommend it to be taken fasting because iron levels go up high in the blood after a meal. Depending on those levels, we can recommend dietary supplements and give them a list of iron-enriched cereals, spinach, liver. If the ferritin levels are a little bit on the moderate to lower side, then we recommend an iron supplementation depending on age and the ability to swallow a pill. We can either prescribe liquid forms, or gummy, or a tablet, or a pill that they can swallow. The dose is usually about three milligrams per kilogram, so it varies per child. Usually in adults, we recommend one full tablet, 325 milligrams, which is about 65 milligrams of elemental iron for adults or for teenagers that have body weight more than 50 kilograms.
How can this affect the kid’s quality of life and the parent’s quality of life?
DELROSSO: Something that is interesting is that the child may not have any problem falling asleep, but the quality of sleep gets disrupted by all the movement. For many years, pediatric sleep doctors have been recommending teenagers get about nine hours of sleep, and school age children get 10 to 11 hours to meet the adequate sleep requirement by age. But right now, we’re emphasizing not just the amount of sleep but the quality of sleep. So, it is very important for parents that if the child wakes up unrefreshed, or if there are daytime symptoms, or if there are school problems or behavioral problems, or the parents notice that the child is changing their character and is a little bit more irritable, then think about a sleep disorder as an underlying cause and bring it to the attention of your pediatrician. We may do a sleep study, or we may screen for other sleep disorders such as obstructive apnea. When the child gets good amount and restful sleep, then the parents will tell me he’s like a completely different child and is doing better in school, is participating, is friendly. So, it is very rewarding to treat restless sleep disorder.
How can RSD affect a child’s heart rate?
DELROSSO: We looked at heart rate variability as a marker of sympathetic activation. Our nervous system has two branches. We have a sympathetic system that usually gives us a boost for energy. Then we have the parasympathetic system that is a little more on the quiet side, more of the when you’re relaxed. In the very first stages of sleep, we have a parasympathetic predominance, which means that our heart rate and blood pressure becomes a little bit lower and our breathing becomes more stable. What we have found out in children with RSD is that they may have a predominantly sympathetic activity and that’s why they may be moving more during sleep, or it may be that these movements cause a little bit of a sleep disruption and wakes them up, causing a sympathetic burst. This is also a marker for us that it is not restful sleep and that children may be at higher risk of having some cardiovascular problems in the future. For example, when children go to sleep and have some breathing problem that wakes them up through the night and have pulses in their sleep that are characteristic of obstructive sleep apnea, we are seeing these children are at a higher risk for a higher heart rate, elevated blood pressure and sympathetic activation.
So, how can parents distinguish between insomnia versus other disorders?
DELROSSO: We have a lot of referrals in our sleep center for children that are considered to have insomnia. There are different types of insomnia. We have the difficulty falling asleep or the multiple awakenings, or once you fall asleep you wake up and then you can’t go back to sleep, or you’re waking up through the night, or you have early awakening. With insomnia, it’s very important to rule out other sleep disorders as some sleep disorders can mimic it.
Are there any strategies to help parents get their kids to sleep earlier or is this more of a lost cause at that point?
DELROSSO: Usually, adolescents and teenagers naturally start having a delayed sleep cycle. So, what happens is that you have a toddler that starts going to bed at 7 o’clock at night and waking up at 4 in the morning or 5 in the morning and that’s a naturally earlier circadian cycle. Then for a few years, you enjoy a child with a normal 9p to 7a schedule, and then when they grow into adolescent years, this circadian is delayed until 11p and sometimes midnight. What happens very often is that teenagers start using electronics or know that they have this energy at night, so they stay up late, perpetuating the cycle. So, it slowly starts moving to 1 o’clock and 2 o’clock in the morning. Then, what happens on the weekends is they sleep until 10a or 11a, or sometimes noon. One of the strategies I recommend is to keep a consistent wake-up time. If the child wakes up usually at 8 o’clock or 7 o’clock, then the latest at 10 o’clock on the weekend so the circadian cycle doesn’t really go that off. We also have another contributor to sleep, which is a homeostatic pressure. It’s called the need to sleep increases with a longer time that you’re awake. This is what happens when you take a nap in the afternoon, for example, and then you can’t go to sleep at night. That pressure to sleep gets diminished. Sometimes, we have used a low dose melatonin, like half a milligram to a milligram. We give it about one to two hours before the actual bedtime.
Is there anything I didn’t ask you that you feel people should know?
DELROSSO: I believe that a healthy sleep pattern contributes a lot for a child and then adult performance during the day. We have a lot of parents that see us just to optimize their sleep for their children to have better school performance, to do better in school, and to have better attention. I think putting the emphasis on a good night’s sleep, both amount of sleep, time and quality of sleep, is what we want to do for both children and adults to have healthy children and adults in society.
Interview conducted by Ivanhoe Broadcast News.
END OF INTERVIEW
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