title: Drug-induced changes in cortical inhibition in medication overuse headache.
abstract: BACKGROUND
  We investigated whether chronic headache related to medication overuse (MOH) is associated with changes in brain mechanisms regulating inhibitory cortical responses compared with healthy volunteers and episodic migraineurs recorded between attacks, and whether these changes differ according to the drug overused.
  
  
  METHODS
  We studied 40 MOH patients whose symptoms were related to triptans alone, non-steroidal anti-inflammatory drugs (NSAIDs) or both medications combined, 12 migraineurs and 13 healthy volunteers. We used high-intensity transcranial magnetic stimulation over the primary motor cortex to assess the silent period from contracted perioral muscles.
  
  
  RESULTS
  In MOH patients the cortical silent period differed according to the type of headache medication overused: in patients overusing triptans alone it was shorter than in healthy volunteers (44.7 ± 14.2 vs. 108.1 ± 30.1 ms), but similar to that reported in migraineurs (59.9 ± 30.4 ms), whereas in patients overusing NSAIDs alone or triptans and NSAIDs combined duration of silent period was within normal limits (80.6 ± 46.4 and 103.8 ± 47.2 ms).
  
  
  CONCLUSIONS
  Compared with episodic migraineurs, MOH patients overusing triptans have no significant change in cortical inhibition, whereas those overusing NSAIDs have an increase in cortical inhibitory mechanisms. We attribute these changes to medication-induced neural adaptation promoted by changes in central serotonin neurotransmission.
authors.affiliation: Department of Medical-Surgical Sciences and Biotechnologies, A. Fiorini Hospital, Terracina, LT, Sapienza University of Rome Polo Pontino, Italy. antonio.curra@uniroma1.it
authors.forename: Antonio
authors.initials: A
authors.lastname: Currà
authors.forename: Gianluca
authors.initials: G
authors.lastname: Coppola
authors.forename: Manuela
authors.initials: M
authors.lastname: Gorini
authors.forename: Elisa
authors.initials: E
authors.lastname: Porretta
authors.forename: Martina
authors.initials: M
authors.lastname: Bracaglia
authors.forename: Cherubino
authors.initials: C
authors.lastname: Di Lorenzo
authors.forename: Jean
authors.initials: J
authors.lastname: Schoenen
authors.forename: Francesco
authors.initials: F
authors.lastname: Pierelli
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects* / Q000502:physiology; D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects; D019054:Evoked Potentials, Motor / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006261:Headache / Q000139:chemically induced* / Q000503:physiopathology*; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000187:drug effects / Q000503:physiopathology; D009433:Neural Inhibition / Q000187:drug effects* / Q000502:physiology; D050781:Transcranial Magnetic Stimulation; D014363:Tryptamines / Q000009:adverse effects
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D014363:Tryptamines