title: Impaired glutamatergic neurotransmission in migraine with aura? Evidence by an input-output curves transcranial magnetic stimulation study.
abstract: OBJECTIVE
  An imbalance between activity of inhibitory and facilitatory intracortical circuits could play a central role in migraine etiology. We used input-output curves to achieve further information about intracortical excitability of motor cortex in migraine with aura.
  
  
  METHODS
  Input-output curves were measured in the right abductor pollicis brevis muscle at rest in 12 patients suffering from migraine with aura and 8 healthy subjects. Stimuli were delivered at intensity ranging from 100% to 160% of resting motor threshold with 10-second inter-stimulus intervals. Seven patients were studied before and during treatment with levetiracetam.
  
  
  RESULTS
  Results showed a greater motor-evoked potential amplitude in response to increasing intensity of stimuli in patients compared to controls (P < .02). This increased facilitatory effect was abolished by levetiracetam (P < .005).
  
  
  CONCLUSIONS
  Our findings support the hypothesis of an interictal cortical hyper-responsivity in migraine patients that appears to be normalized by levetiracetam. This effect could support the potential therapeutic role of levetiracetam in migraine with aura prevention.
authors.affiliation: Department of Experimental Biomedicine and Clinical Neurosciences, Università di Palermo, Palermo, Italia.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Cosentino
authors.forename: Brigida
authors.initials: B
authors.lastname: Fierro
authors.forename: Simone
authors.initials: S
authors.lastname: Vigneri
authors.forename: Simona
authors.initials: S
authors.lastname: Talamanca
authors.forename: Antonio
authors.initials: A
authors.lastname: Palermo
authors.forename: Angela
authors.initials: A
authors.lastname: Puma
authors.forename: Filippo
authors.initials: F
authors.lastname: Brighina
mesh_terms: D000328:Adult; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D005973:Glutamine / Q000378:metabolism; D006801:Humans; D008297:Male; D020325:Migraine with Aura / Q000378:metabolism / Q000503:physiopathology*; D009044:Motor Cortex / Q000503:physiopathology*; D009435:Synaptic Transmission / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation
chemical_list: D005973:Glutamine