The Effect of Methylphenidate on Neurological Soft Signs in ADHD

OBJECTIVE: Neurological soft signs are very common in children with the attention deficit hyperactivity disorder (ADHD), and the first line medication of this disorder is methylphenidate. The aim of the study was to assess the effect of methylphenidate on the neurological soft signs in children and adolescents suffering from ADHD depending on the dose of methylphenidate. METHODS: Thirty five patients with ADHD were investigated by the ADHD RS-IV parent version questionnaire and the Revised Neurological Examination for Subtle Signs before treatment adjustment and after four weeks of methylphenidate medication. The changes in hyperactivity symptomatology, neurological soft signs during therapy and the influence of the methylphenidate dose were statistically analyzed. RESULTS: A significant decrease in hyperactivity symptomatology was found after one month of methylphenidate medication (p=0.0001) and significant decrease in neurological soft signs was demonstrated in 21 from a total of 26 items (p<0.05). Correlation analysis showed no relationship between the dose of methylphenidate and the improvement of neurological soft signs. Similarly, the improvement of ADHD symptomatology had not correlation with the improvement of neurological soft signs. CONCLUSION: The study demonstrated the positive effect of methylphenidate on neurological soft signs in which improvement occurred independently of the dose, indicating that their progress may be due to methylphenidate treatment of any dose. The unrelated effect of methylphenidate on the attention deficit hyperactivity disorder and neurological soft signs suggest that methylphenidate might be useful in the therapy of clumsy child syndrome and in ADHD treatment of non-responders.