Adults have it, and children, too. But how common restless legs syndrome (RLS) actually is in minors has hardly been researched. A study carried out at the University of Potsdam aims to provide greater clarity. In a large-scale project, honorary Prof. Dr. Thomas Erler of Klinikum Westbrandenburg and Anne Schomöller of the outpatient department of the University of Potsdam are researching the extent to which 6 to 18-year-olds are affected by the disorder.
They feel their legs tingling and twitching, on and on. Mostly, the complaints come at night when they want to have a rest. But rarely can they sleep through the night. They have to get up and move, for this is the only way the unpleasant feelings will subside. Consequently, the days are twice as exhausting for people suffering from RLS as they lack the freshness and concentration needed to tackle tasks lying ahead of them well – a vicious circle. In adults, the phenomenon has been studied for a long time, both regarding its prevalence and its severity. Experts assume that currently about 2 million adults in Germany suffer from RLS. And this is the crux of the matter: Recent research suggests that the condition may be congenital. “If this is true, it should also be widespread among children,” Erler says. “Not only seen in a few isolated cases.” Erler wants to find out more. As yet, the number of children and youth diagnosed with RLS is rather small. Could it be that the disease progresses differently in this age group and is therefore rarely diagnosed? The question troubles Erler and Schomöller, and it is also of great interest to the members of the German Restless Legs Association who have given the impetus for the team’s research. Being affected by the syndrome themselves, some of them noticed behavior in their children and grandchildren that made them turn to doctors and researchers.
RLS is difficult to diagnose in children
While RLS is easy to diagnose in adults, it is much more difficult to diagnose in children. Especially the very young ones hardly sleep through a night, crawl out of bed at night, and walk around. They grouch all the more during the day. But does that mean they are all suffering from RLS? Erler is quite sure that the symptoms typically seen in adults cannot be transferred to children and youth one-to-one. And there is yet another point that is quite important to him: the distinction from attention deficit hyperactivity disorder, or ADHD. Children affected by ADHD also have problems maintaining concentration during the day, hardly sit still, and have trouble following lessons at school. “It might well be that some of these children do not suffer from ADHD, but an undiagnosed RLS,” Erler fears. “This is one of the points we are researching in our study.” If the suspicion were confirmed, it would be a serious matter because it would mean that children have been given the wrong treatment. For this reason, as well, Erler and Schomöller want to act quickly. “We need to find out what the indications of RLS are, and how widespread it is,” the researchers agree.
Questionnaires will help
Erler and Schomöller are pinning their hopes on two questionnaires developed by the German Sleep Society (DGSM) a couple of years ago – but never used. By mid-2019, they will distribute them in schools in the Lands of Brandenburg and Sachsen-Anhalt, as well as in Ukraine, where Erler studied. The questionnaires are designed for 6 to 12-year-olds and 13 to 18-year-olds, respectively. In 2018, a pretest was made in which the answers given by 11 school students suffering from RLS were compared to those of a healthy control group. It became clear that both versions of the questionnaire are well suited to collect statements on the frequency of symptoms among respondents.
In total, some 6 000 children and youth will participate in the study. First responses were received from two primary schools in the Spree Neiße district. However, it cannot be said yet whether the 50 returned questionnaires include any cases that need to be medically examined.
The questionnaires are age-appropriate. The one for the younger children is to be filled out by parents, who are to go over the questions with their daughters or sons. Altogether, there are 19 questions, such as “Do you often have a strange or hurting sensation in your legs when you are sitting or lying?”, or “Can you please indicate where exactly you have this strange and hurting sensation?” Drawings are provided to make it easier for participants to answer.
The objective of the questionnaires is not to make remote diagnoses. Rather the team wants to find in the large sample of the study population those who might be affected, i.e. people with a significant RLS risk. “In cases of uncertainty,” Erler explains, “we are planning to conduct further interviews to find out more about a patient’s history.” At the end of the study, there will be a group of subjects with a high likelihood of having RLS. For verification, these boys and girls will be sent to a sleep laboratory. “We are thus using an objective examination method to reliably determine whether a person is affected,” Erler says.
Sleep laboratory will provide final certainty
While the subjects are sleeping in the laboratory, some key parameters are monitored continuously and simultaneously: heart rate, respiration, blood-oxygen level, behavior, brainwaves, and eye movements. Each test lasts until the person wakes up naturally. Nothing is artificially evoked, the sleep is natural. The collected data will help to put together a meaningful overall picture – and identify abnormalities. “For instance, it is well possible that RLS changes the depth of sleep or leg movements pathologically,” Erler says. “If we see these and other indicators in the lab, in combination with striking questionnaire results, we will certainly be able to make the diagnosis.”
But what actually happens in the bodies of people with RLS? The complaints originate from neurotransmitters regulating neural activity insufficiently. As a result, muscles controlled by nerves react abnormally. This comes with pain, tingling, and twitching, often in the legs, sometimes in the arms.
Children can be treated successfully, too
Schomöller and Erler have set themselves the target of conducting a detailed analysis of the symptoms of suspected cases in order to initiate the right therapy, based on an unequivocal RLS diagnosis. What is particularly important to them is to be able, at long last, to treat children and youth misdiagnosed with ADHD effectively. After all, the therapeutic approaches to the two neurological disorders differ fundamentally. While people with ADHD have to find more peace of mind in their everyday lives, RLS patients, unnerved by disturbed night rest, have to be made fit for their tasks at school, in their job, or in their family. In this context, health care professionals use three levels of treatment: enhanced movement therapy while awake, physiotherapeutic massage, and last but not least medication therapy with L-DOPA (dopamine receptor agonist) to influence the regulating mechanism between muscles and nerves.
Schomöller and Erler value the cooperation in the project highly. For them, it combines clinical and scientific expertise in an optimum way. Schomöller has taken on the organization of the overall project and contacts to schools, and the statistical evaluation of the returning questionnaires. “We hope for a response rate of between 30 and 35 percent,” she says. “That depends on how well we succeed in convincing schools of our objective.” As a young researcher, Schomöller not only has a scientific interest in RLS, but a very practical one, too: The outpatient department of the University of Potsdam is involved in the physical examination of applicants at Potsdam’s “Friedrich Ludwig Jahn” sports school. “And among them are also children with ADHD,” she explains. “With the knowledge we have already gained it is well worth taking a closer look.” Erler totally agrees. He is very happy to cooperate with the University and the other partners who illustrate the contents of the study excellently, as he underscores. “In a large field study like ours, you need specialists in medical statistics. The University of Potsdam has them – and researchers focusing on movement physiology as well. A perfect symbiosis!”
Restless Legs Syndrome (RLS) causes a strong urge to move one’s legs, and sometimes tingling, pulling, or stabbing pain. In some patients, the arms are affected as well. The complaints almost always occur while resting, particularly at night, so those affected have their sleep disturbed. When they get up and move, the pain often subsides. RLS is well researched in adults, but not in children.
The Project
Restless Legs Syndrome (RLS) – a Diagnostic and Therapeutic Challenge in Childhood
Funding: Institute/University resources and German Restless Legs Association
Duration: 2017–2019
Participants: Prof. Dr. Thomas Erler, Reena von Barby, Anne Schomöller, Anna Gychka, Prof. Dr. Frank Mayer
The Researchers
Prof. Dr. Thomas Erler studied human medicine at the State Medical University of Lviv (Ukraine). In 1988, he earned his PhD at the Medical Academy of Postgraduate Studies in Berlin and qualified as a university lecturer at Charité Berlin in 2003. Erler is a pediatrician and has been Medical Director of the Clinic for Child and Youth Medicine at Klinikum Westbrandenburg since 2015. Since 2014, he has been an honorary professor at the Faculty of Human Sciences at the University of Potsdam.
E-Mail: Thomas.Erleruklinikumwbpde
Anne Schomöller studied sport science (BA) and clinical exercise science (M.Sc.). Currently, she is working on her doctoral thesis. Prof. Dr. Frank Mayer, Medical Director of the Outpatient Department of the University of Potsdam, is her doctoral supervisor.
E-Mail: schomoeluuni-potsdampde
Text: Petra Görlich
Translation: Monika Wilke
Published online by: Sabine Schwarz
Contact to the online editorial office: onlineredaktionuuni-potsdampde