Restless legs syndrome in attention deficit-hiperactivity disorder: What about the role of treatment? A multicenter study

Abstract

In our clinical practice we find a high co-morbidity of Attention Deficit-Hyperactivity Disorder (ADHD) and Restless Legs Syndrome (RLS). Our aim is to describe the prevalence of RLS in children diagnosed of ADHD, as well as find out if ADHD treatment plays a role in RLS symptoms and prevalence. Observational descriptive cross- sectional study in children diagnosed of ADHD referred from Neuropediatrics and Child Psychiatry to Clinical Neurophysiology departments in two hospitals (in Cuenca and Valencia, Spain): n = 36, ages 5–17. These were divided in non-treated ( n = 16) and treated ( n = 20) subgroups. Measures: questionnaire based on Owen’s test for RLS and Periodic Leg Movements (PLM), answered by parents by phone or live interviews. International RLS Study Group criteria for RLS (2002) were followed. Global RLS prevalence in our ADHD patients: 36.1%. Among them, criteria of definite RLS are fulfilled in 30.8%, probable RLS in 46.1% and possible RLS in 23.1%. RLS prevalence in non-treated group: 50.0%. Definite RLS in 12.5%, probable in 62.5% and possible in 25.0% of them. RLS prevalence in treated group: 25.0%. Definite RLS in 60.0%, probable in 20.0% and possible in 20.0%. The prevalence of RLS symptoms in children with ADHD is higher than in normal population, according to the reviewed literature. In treated ADHD, overall RLS prevalence is only 50% of that in non-treated group, while “Definite RLS” prevalence is 4.8 times higher. These findings suggest: The symptoms of ADHD and RLS may be overlapping and lead to misdiagnosis of both disorders. In the same way, a lower prevalence of RLS in treated ADHD could be explained by an improvement in ADHD or in RLS symptoms. Further studies are needed to better understand these findings, as well as the specific role of the different drugs commonly used in ADHD. This study has been supported by a grant given by FISCAM. Special thanks also to our colleagues Dr. García-Bellón, M. and Dr. De las Heras- Martínez, E.