No Easy Answers when Treating Children with RLS

RLS in children requires special considerations, with difficulties arising in diagnosis and safety concerns, which limit treatment. The possible association between RLS, PLMS, PLMD, and ADHD was discussed many times throughout APSS, including at a breakfast "Meet the Professor" session, at the postgraduate course on Sunday, and at a symposium on Wednesday morning.

Diagnostic Difficulties in Children
Recent data indicate that children also suffer from RLS, although the signs and symptoms are often different than those reported in adults, according to Daniel Picchietti, MD, from the University of Illinois in Urbana, Ill. Children often come to the attention of sleep specialists because they are not sleeping at night, and are suffering from daytime effects, such as cognitive impairment, ADHD behaviors, irritability, or oppositional behaviors.

Expert Perspectives...Cases are commonly missed, according to Philip M. Becker, MD,
and Clete Kushida, MD, PhD. Because children usually sleep very well and have no leg movements, reports that the child is having trouble falling asleep or staying asleep should be addressed. However, few children say that they're sleepy, and sleep problems generally manifest as behavioral or cognitive problems or irritability.

URGE Criteria in Children
Arthur S. Walters, MD, from the New Jersey Neuroscience Institute at JFK Medical Center in Edison, NJ, reviewed the NIH Consensus Criteria for diagnosing RLS in children, that were published in 2003. These criteria state that either a child must meet all four essential adult URGE criteria and be able to describe the leg sensations in their own words OR the child must meet all four essential adult URGE criteria and have two of the three following: sleep disturbance relative to age, a parent or sibling with documented RLS, or PLMSI > 5/hour of sleep.

Expert Perspectives...In discussing this issue, Clete Kushida, MD, PhD, noted that diagnosing RLS in children is a particularly difficult challenge for a number of reasons, primarily because children do not usually fulfill all of the URGE criteria. Dr. Philip Becker, MD, expanded on this issue, noting that children rarely report dysesthesia, but often report that the sensation to move is often seen during the day as well as in the evening or at bedtime. Young children may be unable to describe their symptoms, although 20% to 25% of these children report the sensation of ants or spiders in their legs, and others report an urge to kick. Becker noted that many parents of children with RLS deny that their children have kicking movements while sleeping. Cases are commonly missed, according to these experts. Because children usually sleep very well and have no leg movements, reports that the child is having trouble falling asleep or staying asleep should be addressed.

Is RLS Associated with ADHD?
Dr. Walters reviewed the theoretic relationships between RLS and ADHD. Children with RLS look like they have ADHD because they cannot sit still due to leg discomfort; chronic sleep disruption from RLS can produce hyperactivity; and both ADHD and RLS/PLMS may share a common dopaminergic deficit based on observations that RLS and ADHD respond to methylphenidate and levodopa. Since sleep problems in children often manifest as behavioral or cognitive problems or irritability, some clinicians believe that correcting the sleep problem, in this case RLS, will correct these other issues.

The relationship, if any, between RLS, PLMS, and ADHD is controversial, according to Rosalia Silvestri, MD, of Brigham and Women's Hospital in Boston, Mass, who led a "Meet the Professor" breakfast session. She reviewed studies by Picchietti and others, who have shown that 20% to 40% of patients with ADHD also have >5 PLMS/hour and that children with more severe ADHD may have even higher levels of PLMS. In a group of 16 children with PLMS > 25, 15 met diagnostic criteria for ADHD, 4 had RLS, 10 had a parent with RLS, all had significant sleep disturbances, and symptoms resolved for both conditions with dopaminergic treatment. Dr. Silvestri suggested that ADHD in children with PLMS may actually be related to coexisting sleep apnea and, therefore, sleep laboratory evaluation may benefit children with ADHD by revealing treatable sleep disorders that, in turn, may help the ADHD.

Expert Perspectives..."Sleepy kids can be hyperactive," commented Barbara Phillips, MD, MSPH, "whether the sleepiness is due to RLS, sleep apnea, or other reasons." She believes that sleep-disordered breathing may be more related to ADHD than RLS is. Dr. Phillips indicated that much of the data about RLS and ADHD actually rely on studies looking at ADHD and PLMS. She questions the significance of PLMS suggesting that for children, as in adults, the presence of PLMS is neither necessary nor sufficient to make a diagnosis of RLS.

Treatment of RLS in Children
Clonidine has been used as the cornerstone of treatment in pediatric RLS, but good sleep hygiene and behavior modification are also key components of therapy. Clonazepam is also used for RLS, but should be avoided if there is co-morbid ADHD, because it may have a paradoxical alerting effect. The use of dopaminergic agents for RLS is not recommended for children, although there is an ongoing controlled trial under way to look at this question. Children with RLS may also have iron deficiency, although there are no established guidelines for treating this.

Expert Perspectives...Barbara Phillips, MD, MSPH, was "surprised" to hear that clinicians were treating children as young as 6 months of age for RLS. She takes a conservative approach and discourages pharmacologic treatment of children for RLS, especially without the availability of data from controlled clinical trials and in the absence of an FDA-approved drug to treat RLS in any age group!