DTI findings during spontaneous migraine attacks

Previous functional neuroimaging studies showed that the brainstem may have an important role in migraine and recently, DTI studies demonstrated that structural alterations in migraineurs may extend beyond the normal appearing brain tissue. The aim of our study was to find out if DTI may detect any abnormality during the spontaneous migraine attacks.

The DTI images obtained in a 3T system during spontaneous migraine episodes. Patients with any systemic or metabolic disorder and abnormal signal intensity in conventional sequences were excluded. We measured the FA and ADC values of red nuclei, periaquaductal gray matter, thalami, posterior limbs of internal capsules and subcortical white matter. Fifteen healthy volunteers served as control group.

Fourteen patients enrolled in the study. The only site where we found an abnormality was the red nuclei, where the ADC values in migraineurs were statistically higher than in healthy volunteers. There was no statistical correlation between the DTI measurements and patients' ages, duration of disease, frequency of attacks and localization of pain.

Our findings supported the findings of previous functional neuroimaging studies, which concluded that the brainstem might have a role in the pathogenesis of a migraine episode. We think that the increase of ADC values in red nuclei may reflect vasogenic edema, which cannot be detected in conventional sequences. However, the exact underlying mechanism for this observation is unclear and we do not know whether these changes are responsible for triggering an attack or if they are the consequents of the attack itself.