Cognition in menstrually related migraine: neural correlates of working memory along the cycle

QUESTION: Hormones play a preponderant role in triggering migraine attacks, with women having higher prevalence and severity of migraine due to their influence along the reproductive cycle1. The preictal, ictal and postictal phases tend to include cognitive executive difficulties along with the rest of the attack symptoms2. Fluctuations in neural sensitivity observed in migraine could underlie such difficulties3. On the other hand, functional and structural changes in brain structures related to cognitive processes along the menstrual cycle have also been documented4. We aim to use functional Magnetic Resonance Imaging (fMRI) to evaluate working memory at different stages of the migraine cycle and compare to a non-migraine population while controlling for their menstrual phases. METHODS: A clinical sample of 15 women suffering from episodic migraine with menstrual-related attacks were recruited. They underwent fMRI sessions with a verbal N-back task in different phases of the migraine cycle, namely, preictal, ictal, postictal and interictal phase. 15 nonmigraine controls matched for gender and age were assessed during premenstrual and post ovulation phase. A neuropsychological battery and questionnaires quantifying clinical symptoms and attack description at the time of the exam were also applied. RESULTS: We report results for 70 sessions of acquisition in whole brain group analysis using a cluster threshold of z > 2.3. We observed left orbital prefrontal areas with significantly higher activation during preictal (z =3.44), ictal (z=3.49) and interictal (z=3.3) phases compared to postictal phase. CONCLUSIONS: The brain activation observed in prefrontal regions during the migraine attack phases could be related to cognitive inhibition while performing a working memory task.