Page 156 - Migraine, the heart and the brain

Chapter 8
disCussion
Migraineurs often complain about cognitive impairment shortly after a migraine attack. Studies showed evidence of profound post-ictal effects on cognitive tests after epileptic attacks, however this has not been demonstrated after migraine attacks. The aim of this study was to assess the degree to which a recent migraine attack affects cognitive functions at different processing levels. We tested migraineurs in various, theoretically motivated experimental tasks at three points in time post-ictally and compared their performance with healthy controls. Three results of this study are particularly noteworthy.
First, we did not nd evidence for any reliable changes in cognitive performance during the postattack phase, as indicated by the absence of any interaction between session, group, and cognitive measures. In other words, no temporal negative effect on cognitive function after the attack was found. This observation is in line with the one previous study reporting no negative influence during the post-ictal phase of a migraine attack (2). However, while Mulder et al. (2) tested participants who still had mild headache during testing, we de ned the post-ictal phase by the absence of headache. Moreover, while Mulder et al. (2) recruited their participants from a student population, we recruited migraine patients from the outpatient headache, which resulted in a higher mean age.
Second, reliable and stable differences between migraine patients and controls were observed with respect to the organization of local and global visual stimuli. The controls showed the standard global precedence effect (14) with better performance on global than on local stimulus features (trend). Interestingly, this standard global precedence effect was not present in migraineurs. The fact that this dif culty did not change across sessions suggests that it is not caused by, or associated with, the migraine attack per se but, rather, seems to be associated with the (enduring) migraine disposition.
Third, none of the remaining measures (N-back, ANT) showed any hint of an interaction with group (migraineurs vs. controls). Even though null effects need to be interpreted with the necessary caution, it is important to point out that the tasks as such worked very well i.e., we were able to replicate all the standard effects and yet we found no association between migraine and alerting, orientation, executive control, and working memory measures. Thus, even though more systematic research on this issue is required, we tentatively conclude that alerting, orientation, executive control, and working memory do not play a role in, and do not seem to be impaired
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