Differences in short-term primary motor cortex synaptic potentiation as assessed by repetitive transcranial magnetic stimulation in migraine patients with and without aura.
To find out more about glutamatergic and gabaergic transmission in migraine, in this study we investigated glutamate-dependent short-term synaptic potentiation and GABA-dependent inhibitory cortical interneuron excitability as assessed by 5Hz-rTMS delivered over primary motor cortex (M1) (motor evoked potential, MEP, amplitude facilitation and cortical silent period, CSP, duration lengthening) in migraine patients with (MA) and without aura (MwoA) and healthy controls. We studied 37 patients with migraine (19 MA and 18 MwoA) and 19 healthy control subjects. 5Hz-rTMS was delivered at 120% resting motor threshold to the hand motor area of the left hemisphere with the target muscle at rest and during contraction. Three of the MA patients were also tested at the end of visual aura during a spontaneous migraine attack. ANOVA showed that the MEP significantly increased in size and CSP significantly lengthened during 5Hz-rTMS in the three groups tested. The 5Hz-rTMS-induced MEP facilitation differed significantly being highest in MA patients. In the three patients tested both ictally and interictally the MEP increased during the interictal session but remained unchanged when the visual aura ended. Our study shows that the neurophysiological feature that differentiates MA patients from MwoA patients and healthy controls is an abnormal M1 susceptibility to 5Hz-rTMS both outside and during the attack suggesting that glutamate-dependent short-term M1 cortical potentiation patterns differ in migraine with and without aura.
Department of Neurological Sciences and Neuromed Institute, "Sapienza", University of Rome, Rome, Italy Headache and Pain Unit, Department of Neurological, Motor and Sensorial Sciences, IRCSS San Raffaele Pisana, Rome, Italy Department of Neurological Sciences, "Sapienza", University of Rome, Rome, Italy Neurology and Neurophysiopathology Unit, S. Pertini Hospital, Rome, Italy.
Antonella
A
Conte
Piero
P
Barbanti
Vittorio
V
Frasca
Elisa
E
Iacovelli
Maria
M
Gabriele
Elena
E
Giacomelli
Cinzia
C
Aurilia
Floriana
F
Pichiorri
Francesca
F
Gilio
Maurizio
M
Inghilleri
D000328:Adult; D000704:Analysis of Variance; D013181:Cortical Spreading Depression / Q000502:physiology*; D004576:Electromyography / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020325:Migraine with Aura / Q000473:pathology*; D020326:Migraine without Aura / Q000473:pathology*; D009044:Motor Cortex / Q000503:physiopathology*; D050781:Transcranial Magnetic Stimulation