title: Effects of long-acting methylphenidate in adults with attention deficit hyperactivity disorder: a study with paired-pulse transcranial magnetic stimulation.
abstract: BACKGROUND
  Methylphenidate improves attention deficits, hyperactivity and impulsivity in attention deficit hyperactivity disorder (ADHD). Recent investigations into motor cortex excitability with paired-pulse transcranial magnetic stimulation (ppTMS) technique have shown inhibition deficits in ADHD which correlate with clinical symptomatology. Therefore, we investigated the neurophysiological effects of long-acting methylphenidate (LA-Mph) with the ppTMS technique in adult patients with ADHD.
  
  
  METHODS
  Thirteen right-handed adult ADHD patients who were first diagnosed with ADHD were included in this ppTMS study. Measurements took place before and during treatment with LA-Mph (30-54 mg/day). Statistical analyses were performed to investigate treatment effects and correlations with clinical symptomatology.
  
  
  RESULTS
  LA-Mph significantly decreased the relative short intracortical motor inhibition (SICI) magnetically evoked potential (MEP) amplitude at 3-ms interstimulus interval (conditioned/unconditioned MEP amplitude: 0.83 ± 0.76 drug-free vs. 0.29 ± 0.19 with LA-Mph; p=0.020). The relative intracortical facilitation MEP amplitude at 11 ms interstimulus interval (conditioned/unconditioned MEP amplitude: 1.51 ± 0.92 drug-free vs. 1.79 ± 0.95 with LA-Mph) was not significantly increased. The reduced relative SICI MEP amplitude with LA-Mph correlated significantly with the improvement of the psychopathological ADHD self-rating total scores (p=0.046).
  
  
  CONCLUSIONS
  These results show that in adult patients with ADHD, LA-Mph significantly improves motor disinhibition and might have differential stabilizing effects on motor hyperexcitability.
authors.affiliation: Institute for Forensic Psychiatry, University of the Saarland, Homburg, Germany. MSchneider@vvgi.nl
authors.forename: Marc K F
authors.initials: MK
authors.lastname: Schneider
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Retz
authors.forename: Gavril
authors.initials: G
authors.lastname: Gougleris
authors.forename: Willem M A
authors.initials: WM
authors.lastname: Verhoeven
authors.forename: Joke H M
authors.initials: JH
authors.lastname: Tulen
authors.forename: Michael
authors.initials: M
authors.lastname: Rösler
mesh_terms: D000293:Adolescent; D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy* / Q000503:physiopathology / Q000628:therapy*; D002540:Cerebral Cortex / Q000187:drug effects / Q000503:physiopathology; D003131:Combined Modality Therapy / Q000379:methods*; D003692:Delayed-Action Preparations / Q000627:therapeutic use; D005071:Evoked Potentials / Q000187:drug effects / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008774:Methylphenidate / Q000008:administration & dosage / Q000627:therapeutic use*; D008875:Middle Aged; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology; D050781:Transcranial Magnetic Stimulation / Q000379:methods / Q000523:psychology*
chemical_list: D003692:Delayed-Action Preparations; D008774:Methylphenidate