title: Abnormal changes of synaptic excitability in migraine with aura.
abstract: Migraine patients are characterized by altered cortical excitability and information processing between attacks. The relationship between these abnormalities is still poorly understood. In this study, visual evoked potentials (VEP) and proton magnetic resonance spectroscopy were recorded simultaneously in migraineurs and healthy subjects. In order to investigate the homeostatic-like plasticity in the visual cortex, cortical excitability was modified using transcranial direct current stimulation (tDCS). Before any stimulation, migraineurs showed significantly higher glutamate/creatine ratios (Glx/Cr) than healthy subjects. In healthy subjects, excitatory (anodal) tDCS caused an increase and inhibitory (cathodal) tDCS a decrease in the Glx/Cr ratio. Subsequent photic stimulation (PS) reversed the changes in Glx/Cr ratios, which returned back to baseline, demonstrating homeostatic-like metaplasticity in the control group. In migraine patients, both anodal and cathodal tDCS decreased the Glx/Cr ratio, which did not return to baseline after PS. While healthy subjects showed an increase in VEP amplitude under anodal and a reduction under cathodal tDCS, the modifiability of VEP under tDCS was reduced in migraineurs. The results demonstrate a reduced responsiveness of the occipital cortex to interventions that change cortical excitability in migraine. Moreover, altered glutamatergic neurotransmission seems to mediate the relation between abnormal cortical information processing and excitability in migraineurs.
authors.affiliation: Neuropediatric Department, Christian Albrecht University, D-24105 Kiel, Germany. m.siniatchkin@pedneuro.uni-kiel.de
authors.forename: Michael
authors.initials: M
authors.lastname: Siniatchkin
authors.forename: Mascha
authors.initials: M
authors.lastname: Sendacki
authors.forename: Friederike
authors.initials: F
authors.lastname: Moeller
authors.forename: Stephan
authors.initials: S
authors.lastname: Wolff
authors.forename: Olav
authors.initials: O
authors.lastname: Jansen
authors.forename: Hartwig
authors.initials: H
authors.lastname: Siebner
authors.forename: Ulrich
authors.initials: U
authors.lastname: Stephani
mesh_terms: D000328:Adult; D005074:Evoked Potentials, Visual; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D020325:Migraine with Aura / Q000503:physiopathology*; D009433:Neural Inhibition; D009473:Neuronal Plasticity; D018377:Neurotransmitter Agents / Q000378:metabolism*; D011522:Protons; D009435:Synaptic Transmission
chemical_list: D018377:Neurotransmitter Agents; D011522:Protons