[40] Studies exploring the interactions between these two motion-sensitive cortical areas and such a cortical network

have identified spatial and temporal differences in activation of these regions selective to motion direction and speed.[35, 41] Interestingly, area V3 was suggested to be the source of a CSD-like phenomenon in one subject at the onset of visual aura.[42] These findings suggest an involvement of these functional cortical areas of visual processing in migraine matching structural alterations described in these regions: Granziera et al found increased cortical thickness of motion-processing visual areas V5 and V3 in patients with migraine compared CP-868596 in vitro with healthy controls.[43] However, using highly sensitive surface-based morphometry, these findings have recently been challenged.[44] We also found a AZD8055 cell line larger activation in the right precuneus in migraine patients, an area known to be involved in a number of complex tasks including visuo-spatial imagery and sensitivity

to visual motion.[45, 46] However, this finding has to be considered cautiously because of the only small number of voxels detected. Using fMRI, we found a significant lateralization to the right hemisphere in controls as well as in MA, reflecting a right hemispheric dominance for visuo-spatial and especially optokinetic processing as reported earlier.47-51 Interestingly, the fMRI study of horizontal and vertical optokinetic stimulation in healthy subjects found a right hemispheric predominance in the visual motion-sensitive and ocular motor areas, but not in the primary visual cortex,[47] similar to our findings in the control group. This lateralization was not as distinct in our MA group and in the analysis of the group difference of BOLD fMRI effects during visual stimulation, the largest cluster identified was located in the left hemisphere. These findings suggest a differential processing Avelestat (AZD9668) in extrastriate visual areas in migraine. As in a previous series of 70 MA patients, we did not find evidence for an increased VEFR% in MA by using fTCD.[3] One possible explanation for this might be the vascular

anatomy, as essential parts of the extrastriate visual processing are more likely to be supplied by both the middle cerebral artery and the PCA. While the analyses of our fTCD data also demonstrated higher VEFR% values on the right side compared with the left side – corresponding to the observed right accentuated activation in fMRI – this finding did not reach significant levels. It needs to be stated that in the previous fTCD study, we did find an asymmetry of functional vasomotor reactivity responses from bilateral TCD PCA recordings, with a significant VEFR% side-difference matched with the hemisphere affected by aura symptoms.[3] However, this observation could not be verified in this series, possibly due to the smaller number of patients.