麻豆传媒

SEATTLE -- Children who have night terrors associated with restless leg syndrome appear amenable to treatment with ferritin supplements, researchers reported here at , the annual meeting of the Associated Professional Sleep Societies.

Eighteen of 31 children diagnosed with parasomnias in addition to restless legs syndrome or periodic limb movement disorder achieved relief from their movement disorders with iron therapy, said a sleep fellow at Cincinnati Children's Hospital.

At her poster presentation, Gurbani reported that 42% also showed a decrease in parasomnia symptoms. "Iron therapy leads to significant improvement in the periodic limb movement index and restless legs syndrome symptoms," she told 麻豆传媒.

"We started off by looking at children with restless legs syndrome and then we wanted to study a subgroup of those children -- children who had parasomnias. Parasomnia is common in our cohort of children with restless legs syndrome and periodic limb movement disorder," she said. Gurbani said that her finding of relief of parasomnias by treating restless legs syndrome could mean that, in some children, the restless legs syndrome/periodic limb movement disorder "may precipitate parasomnia."

In the study, Gurbani and colleagues retrospectively identified 226 children who had been diagnosed with restless legs syndrome/periodic limb movement disorder, of whom 51 also showed parasomnias. The parasomnias observed included leg movements in more than 70% of the children, as well as restlessness, sleep talking, teeth grinding, night terrors, sleep walking, nightmares, restless legs syndrome symptoms and sleep eating.

Oral iron therapy was administered to 31. They all underwent polysomnography prior to being given iron therapy. One child had been on iron therapy prior to the sleep study but required a higher dose after being evaluated in the sleep studies. These children were followed for at least a year at Cincinnati Children's Hospital Medical Center.

Ferritin levels were below 25 ng/mL prior to treatment; these were raised above 50 ng/mL with 6 to 12 months of treatment (P<0.001).

Gurbani noted, "Previous studies have shown an increased frequency of parasomnias such as sleep walking, nightmares, and night terrors and confusional arousals in children with restless legs syndrome/periodic limb movement disorder. Also the disappearance of the parasomnias after treatment leads to speculation that restless legs syndrome may precipitate or worsen parasomnias. However, there is limited data about the effect of iron therapy on parasomnias in children."

She said her team was somewhat surprised that they did not find any effect of treatment on arousal. "I would have expected there to be some differences in that aspect of their sleep, but we did not find anything there," she said.

Gurbani said that the retrospective study did not indicate that any of the children treated with ferritin experienced adverse events from it.

In commenting on the study, director of the Pediatric Sleep and Research Center at SSM Cardinal Glennon Children's Medical Center and assistant professor of pediatrics and internal medicine at Saint Louis University School of Medicine, said that the success rate with ferritin therapy in the children was impressive. "Of the 31 children treated in this trial, 18 got better. That is really good," she said.

"We all see children with restless legs syndrome and parasomnias," she told 麻豆传媒. "This was a retrospective study, but we are planning to do a similar study but as prospective research."

Although the researchers were studying both restless legs syndrome and periodic limb movement disorder together, Paruthi said they are very different disorders. Restless legs syndrome is associated with "a sensation or an urge to move and often includes pain in the legs -- and it really occurs while people are awake. Periodic limb movements occur during sleep and the person may not be aware of it. But if a person's legs are twitching once a minute or so it can cause disruption in sleep.

"We know that if the ferritin levels are less than 50 ng/mL we should treat them," Paruthi said. "They should be treated with an iron supplement for about 12 weeks." Although there were no reported adverse events with ferritin in the study, Paruthi said clinicians should be careful about treating children because in some of them constipation and stomach disorders have occurred.

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