title: Antipsychotic treatment with quetiapine increases the cortical silent period.
abstract: BACKGROUND
  Measurement of motor cortex excitability with single and paired pulse transcranial magnetic stimulation has become an established method for in vivo characterization of the effects of central-acting drugs. The comparison of drug-free and medicated patients with schizophrenia suggests an association of neuroleptics intake and prolongation of the cortical silent period (CSP). However all available data come from cross-sectional non-randomized studies. Thus it is not clear whether the observed difference is an effect of medication or reflects differences in disease severity or both.
  
  
  OBJECTIVE
  We aimed to investigate whether the CSP or other parameters of cortical excitability change, when cortical excitability is measured in drug-free patients with acute psychosis before and after 3week intake of the atypical neuroleptic quetiapine.
  
  
  METHODS
  Different parameters of cortical excitability were studied in 24 drug-free patients with acute psychosis before and after 3weeks of treatment with a mean dose of 352±199mg quetiapine.
  
  
  RESULTS
  We observed a significant prolongation of the cortical silent period (CSP) after three week treatment with quetiapine. Other parameters of cortical excitability such as motor threshold (MT), short intracortical inhibition (SICI) and intracortical facilitation (ICF) remained unaffected. There was a significant improvement in clinical parameters (PANS, GAF) but no significant correlation between clinical improvement and changes in cortical excitability.
  
  
  CONCLUSIONS
  These longitudinal data are in line with previous reports from cross-sectional studies. The excitability changes induced by three-week intake of quetiapine in acute psychotic patients confirm the notion that neuroleptic treatment is associated with an increase in CSP.
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Regensburg, Universitaetsstraße 84, D-93053 Regensburg, Germany.
authors.forename: Elmar
authors.initials: E
authors.lastname: Frank
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Regensburg, Universitaetsstraße 84, D-93053 Regensburg, Germany; Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, Social Foundation, Bamberg, Bamberg, Germany; Department of Psychiatry, Psychosomatics and Psychotherapy, kbo-Lech-Mangfall-Klinik Agatharied, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Landgrebe
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Regensburg, Universitaetsstraße 84, D-93053 Regensburg, Germany.
authors.forename: Timm B
authors.initials: TB
authors.lastname: Poeppl
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Regensburg, Universitaetsstraße 84, D-93053 Regensburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Schecklmann
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Regensburg, Universitaetsstraße 84, D-93053 Regensburg, Germany.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Kreuzer
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Regensburg, Universitaetsstraße 84, D-93053 Regensburg, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Prasser
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Regensburg, Universitaetsstraße 84, D-93053 Regensburg, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Rupprecht
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Regensburg, Universitaetsstraße 84, D-93053 Regensburg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Eichhammer
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Regensburg, Universitaetsstraße 84, D-93053 Regensburg, Germany; Department of Psychiatry, Psychosomatic Medicine and Psychotherapy, Social Foundation, Bamberg, Bamberg, Germany.
authors.forename: Göran
authors.initials: G
authors.lastname: Hajak
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Regensburg, Universitaetsstraße 84, D-93053 Regensburg, Germany. Electronic address: Berthold.Langguth@medbo.de.
authors.forename: Berthold
authors.initials: B
authors.lastname: Langguth
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D003987:Dibenzothiazepines / Q000627:therapeutic use*; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D009433:Neural Inhibition / Q000187:drug effects*; D011569:Psychiatric Status Rating Scales; D000069348:Quetiapine Fumarate; D012559:Schizophrenia / Q000188:drug therapy* / Q000503:physiopathology; D050781:Transcranial Magnetic Stimulation / Q000379:methods; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents; D003987:Dibenzothiazepines; D000069348:Quetiapine Fumarate
keywords: Atypical neuroleptic; Cortical silent period; Excitability; Human motor cortex; Neuroplasticity; Transcranial magnetic stimulation