Objective: To describe the symptomatology reported by a series of children and adolescents who at initial consultation did not meet full diagnostic criteria for pediatric restless legs syndrome (RLS) but subsequently did so over the course of clinical follow-up.
Methods: Retrospective assessment of all patients with pediatric RLS receiving ongoing care in a pediatric sleep/neurology practice at a large multispecialty clinic (n=50). Eighteen children and adolescents who met inclusion and exclusion criteria were identified by chart review. All but one had undergone polysomnography.
Results: Detailed sleep histories were available for 10 girls and 8 boys, all of whom presented initially with clinical sleep disturbance. Mean age at the initial sleep evaluation was 10.3 years and mean age at RLS diagnosis was 14.7 years. Detailed descriptions of the sensory RLS symptoms were recorded. Retrospective age of onset for chronic clinical sleep disturbance was a mean of 3.1 years, with 10 families reporting onset in infancy. Of the 18, 16 reported chronic sleep-onset problems and eight sleep-maintenance problems at the time of initial evaluation. Ten had a history of growing pains. Thirteen were found to have a family history of RLS. Eleven of 17 had periodic leg movements in sleep (PLMS) > or = 5 per hour. Comorbidities included parasomnias (7), attention-deficit/hyperactivity disorder (ADHD) (13), oppositional defiant disorder (ODD) (4), anxiety disorders (6), and depression (5). Serum ferritin levels of <50ng/mL were found in 16 of 18.
Conclusions: In this group of 18 children and adolescents, clinical sleep disturbance preceded a diagnosis of definite RLS by an average of 11.6 years. Many had a diagnosis of periodic limb movement disorder (PLMD) or met research criteria for probable or possible RLS prior to meeting criteria for definite RLS. These findings suggest that some aspects of RLS can occur long before full diagnostic criteria are present. Comorbidities were common, with parasomnias, ADHD, ODD, anxiety, and depression each found in more than 20% of these cases. The 2003 National Institutes of Health (NIH) diagnostic criteria for pediatric RLS are supported by this work.