Migraine is a chronic, multifactorial and neurovascular disease
manifested by recurrent attacks of headaches that promote disability
and dysfunction of the autonomic nervous system [1]. The identification
of preventive treatment that effectively controls this common neurovascular
disorder has been very difficult since the pathophysiological
mechanisms for migraine are still not entirely elucidated [2]. It is widely
accepted that abnormal excitability of occipital cortex appears to play a
pivotal role in migraine pathophysiology. Therefore, it has been proposed
that excitability level of visual cortex neurons in migraine can
drive appropriate therapeutic approaches [3].
Recently, non-invasive brain stimulation has been used to induce
durable changes in cortical excitability and potentially correct the
neural activity abnormalities found in migraine patients. However, as
it is not clear whether the symptoms of migraine result on a hyper- [4,
5] or a hypoexcitability of the visual cortex [6–8] different stimulation
paradigms have been applied depending on the author's hypothesis
whether the migraine brain is hyper- or hypoexcitable. For instance, in
order to decrease or prevent symptoms of the disease, some authors
applied inhibitory stimulations over the visual cortex to correct an
eventual cortical hyperexcitability [9,10]. In contrast, excitatory stimulation
to increase a supposed abnormal hypoexcitability is also used
[3,8]. Therefore, the lack of positive outcomes resulting from brain stimulation,
as seen by Conforto et al. [11], could eventually be due to an
incorrect baseline excitability assumption.
We performed a 2-step trial: on the first step we compared the
interictal excitability of the visual cortex in migraine patients, with
and without aura, on healthy subjects. On the second step, we modulated
the impaired interictal excitability in migraineurs according to firststep
findings and observed its clinical implications. To study cortical