Clinical characteristics of Korean pediatric patients with restless legs syndrome

Objectives: Restless legs syndrome (RLS) is a common neurological disorder but it is not sufficiently recognized in children and adolescents. It often overlaps with growing pains in children, and as a result the clinical characteristics of pediatric RLS are not well studied, especially in Asia. The purpose of this study is to investigate the clinical characteristics of pediatric RLS patients in Korea and compare it to those of adult RLS patients. Methods: We retrospectively reviewed the medical records of all pediatric RLS patients (<= 18 years) from January 2015 to December 2018 in a regional tertiary hospital sleep center. We randomly selected adult primary RLS patients without comorbid medical disorders from our sleep center's dataset as controls. The number of controls was determined to be twice the number of pediatric RLS patients according to sample size calculation. The clinical and polysomnographic (PSG) characteristics of both groups were compared. The independent t-test, chi-squared test, and Fisher's exact test were used for analyzing quantitative data between the two groups and p < 0.05 was considered statistically significant. Results: Twenty-nine primary pediatric RLS patients and 57 adult RLS patients were enrolled. Pediatric RLS patients showed equal prevalence between sexes, as opposed to adults where there is female predominance. Ferritin level was significantly lower in pediatric patients, although it remained within the normal range. Also, pediatric RLS patients showed less severe RLS symptoms and had better sleep quality than adults did in both objective and subjective measures. In addition, PLMS was shown to be less common in pediatric RLS patients compared to adults. Conclusions: Pediatric RLS patients showed relatively mild to moderate RLS symptoms and a smaller likelihood of experiencing PLMS than adult patients, which is comparable to similar western studies. Long-term evaluation of a patient's clinical course through multicenter clinical studies is strongly suggested for the future. (C) 2020 Elsevier B.V. All rights reserved.