Motor problems in children with ADHD and clinical effects of Methylphenidate as assessed with the MFNU
Year: 2009
Type: dissertation
Abstract: The Motor Function Neurological Assessment (MFNU) has been developed over a 25 year period based on clinical observations and\nassessments of children referred for evaluation of possible Attention Deficit Hyperactivity Disorder (ADHD)/Hyperkinetic disorder (HKD).\nThe sub-tests of the MFNU were constructed to demonstrate these motor problems to parents and teachers of these children, and to make\nchanges in motor performance observable when the child was medicated with Methylphenidate (MPH, Ritalin©). The reliability and\nusefulness of this instrument as a clinical assessment tool has been demonstrated through many years of clinical practice with hundreds of\nchildren at the Birkelid Resource Centre prior to the start of the research. However, the MFNU was not originally constructed as a\nresearch tool. Since the usefulness of the instrument in this respect is of\ncrucial importance to the validity of our research findings, much effort was put into development of a user manual and DVD with precise\ninstructions for test administration on each subtest, together with rules\nof interpretation and scoring.\nThe aim of the research projects was to investigate possible relationships between ADHD symptoms and certain motor problems\nobserved in children with this diagnosis.\nThe first research question of our studies, using the MFNU as our research tool, was to establish to what extent the MFNU discriminates\nbetween children with and without ADHD. In the first study 25 drugnaïve boys, aged 8-12 years and recently diagnosed as HKD F90.0, and\n27 controls without ADHD participated. Highly significant differences\nbetween the groups were found on all the MFNU sub-tests. A high\npercentage of ‘severe problems’ was found in the ADHD group. The\ncontrol group typically presented few, if any severe problems. When\nthe ‘moderate problems’ and ‘severe’ scores were combined, the\nADHD group presented problems within a range of 80 to 96%.\nThe second research question was to investigate the effect of MPH on\nmotor problems in children with ADHD. Twenty-five drug-naïve boys,\naged 8-12 years and recently diagnosed as HKD F90.0 participated. A\ndouble-blind, placebo controlled, cross-over design was applied, using\nMPH or placebo capsules. The children were assessed individually with\nthe MFNU twice a day on two different days, with at least one day\nSummary\n- 12 -\ninterval. The first trial each day was baseline and the second was the\nexperimental condition. Significant improvements were found on all\nsub-tests when comparing Baseline to the MPH trial. A Cohen’s d of\n1.27 was found, applying ‘Total score’ from the MPH and the Baseline\ntrials. The most pronounced improvements with MPH compared to\nBaseline were observed on sub-tests assessing high muscular tone.\nThe third research question was to investigate to what extent motor\nproblems are present in positive responders to MPH on their core\nbehavioural problems of ADHD, compared to non-responders. The\nstudy group consisted of 73 children. They were retrospectively divided\ninto two sub-groups based on their response to MPH on their core\nADHD problems: ‘Medicine responders’ and ‘Non medicine\nresponders’. Highly significant differences were found between the\ngroups on MFNU sub-tests and the ‘Total Score’. The responder group\nobtained a significantly higher median score than the nonresponder\ngroup on all sub-tests. No significant gender or age differences were\nfound in the responder group, nor in the nonresponder group, on any of\nthe MFNU sub-tests.\nA case study describes changes in motor function on MPH medication\nin children who did not fully satisfy the ADHD criteria, but were\npositive medicine responders. The two children were diagnosed with\n47, XYY syndrome. The MFNU served as an important supplement in\nthe evaluation of MPH treatment in these children. This shows that the\nMFNU is valuable in assessment of other syndromes than ADHD.\nWe have shown that the MFNU is a sensitive instrument in the\nassessment of motor inhibition and high muscle tone in trunk,\nshoulders, hips and legs in boys with ADHD-C/HKD. The results from\nthe research presented in this thesis support our clinical observations\nregarding specific motor problems in children with ADHD. We found\nsuch problems both in the diagnostic group in general and in children\nwith ADHD, who respond positively to central stimulant medicine, in\nparticular. A single dose of MPH in boys diagnosed as ADHD-C\nyielded a significant improvement of the motor problems. There was a\ncorresponding weaning effect after the metabolisation of the MPH\nwhich is very similar to what is seen in the behavioural symptoms of\nthe syndrome. The results support our suggestion that there may be a\nclose relationship between the motor problems measured by the MFNU\nand the neurofunctional causes of ADHD.\n\nThe MFNU is still in need of further validation research, particularly\nregarding the use in diagnostic assessment.
Author: Liv Larsen Stray
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2469847973