Intracortical inhibition and facilitation in migraine - A transcranial magnetic stimulation study

Objective.-Migraine is a disease of altered cortical excitability between attacks. However, the mechanisms of abnormal excitability in migraine are insufficiently investigated. Hence, the aim of the study was to investigate intracortical inhibition/facilitation of the motor circuit in migraine. Methods.-Sixteen women suffering from migraine without aura and 15 healthy women were investigated using a suprathreshold transcranial magnetic stimulation (TMS) in the paired-pulse paradigm with long interstimulus intervals (ISI = 20, 60, 120 ms) and measurement of the cortical silent period. Results.-We found no differences for the cortical silent period and for the long intracortical inhibition between the groups. Concerning intracortical facilitation, this ability was significantly more pronounced in patients suffering from migraine compared with healthy controls. Conclusion.-Migraineurs produce an increased intracortical facilitation. The results may be discussed in line of glutamatergic mechanisms in migraine, which could be related to altered facilitation.