Research

Methylphenidate improves motor functions in children diagnosed with Hyperkinetic Disorder

Liv Larsen Stray^1,2 , Torstein Stray^1,2 , Synnøve Iversen² , Anne Ruud¹ and Bjørn Ellertsen²

¹  Department of Child and Adolescent Health, Sørlandet Hospital, Norway

²  The Reading Centre, Faculty of Education and Arts, University of Stavanger, Norway

author email corresponding author email

Behavioral and Brain Functions 2009, 5:21doi:10.1186/1744-9081-5-21

Published:	13 May 2009

Abstract

Background

A previous study showed that a high percentage of children diagnosed with Hyperkinetic Disorder (HKD) displayed a consistent pattern of motor function problems. The purpose of this study was to investigate the effect of methylphenidate (MPH) on such motor performance in children with HKD

Methods

25 drug-naïve boys, aged 8–12 yr with a HKD-F90.0 diagnosis, were randomly assigned into two groups within a double blind cross-over design, and tested with a motor assessment instrument, during MPH and placebo conditions.

Results

The percentage of MFNU scores in the sample indicating 'severe motor problems' ranged from 44–84%, typically over 60%. Highly significant improvements in motor performance were observed with MPH compared to baseline ratings on all the 17 subtests of the MFNU 1–2 hr after administration of MPH. There were no significant placebo effects. The motor improvement was consistent with improvement of clinical symptoms.

Conclusion

The study confirmed our prior clinical observations showing that children with ADHD typically demonstrate marked improvements of motor functions after a single dose of 10 mg MPH. The most pronounced positive MPH response was seen in subtests measuring either neuromotor inhibition, or heightened muscular tone in the gross movement muscles involved in maintaining the alignment and balance of the body. Introduction of MPH generally led to improved balance and a generally more coordinated and controlled body movement.