Browsing by Author "Fouto, A."
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- Cognition in menstrually related migraine: neural correlates of working memory along the cyclePublication . Ruiz-Tagle, A.; Fouto, A.; Caetano, G.; Domingos, C.; Esteves, I.; Gil-Gouveia, R.; Nunes, R.; Martins, I. Pavão; Figueiredo, P.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.
- Dynamic functional connectivity in migraine during the interictal phase: a resting-state fMRI studyPublication . Esteves, I.; Fonseca, C.; Xavier, M.; Fouto, A.; Ruiz-Tagle, A.; Caetano, G.; Nunes, R.; Gil-Gouveia, R.; Cabral, J.; Martins, I. Pavão; Rosa, A; Figueiredo, P.Question: Migraine is a cyclic and complex disorder, characterized by attacks of headache, sensory and cognitive disturbances1. Thalamocortical connectivity in migraine has been found to be transiently abnormal2. Our aim was to assess if the dynamical properties of the migraine brain are affected during the interictal phase. Methods: Resting-state functional MRI data was collected from 14 menstrual migraine patients without aura (interictal phase) and 12 healthy controls (menstrual post-ovulation phase). fMRI data processing included3: motion and distortion correction, temporal highpass filter, regression of motion and physiological confounds, spatial smoothing, and parcellation with the Desikan atlas. Dynamic functional connectivity (dFC) between regions was computed using phase coherence, and recurrent dFC states were identified by kmeans clustering (k ranging between 3 and 15) of the leading eigenvectors of dFC in each time point4. Permutation tests were performed to evaluate statistically significant differences between patients and controls in the probability of occurrence and the mean lifetime of the dFC states. Results: Similar dFC states were found consistently across different numbers of clusters, k, which resembled the canonical resting-state networks as expected. Compared to healthy controls, migraine patients show a significantly lower mean lifetime in one dFC state, when grouping in 4, 5 and 6 clusters. No differences were found for the probability of occurrence. Conclusions: Migraine may be linked to a disruption of brain networks dynamics. This emphasizes the need to adopt time-resolved methods, in addition to static, to study functional connectivity, to better understand the mechanisms of migraine. Our next step will be to assess the dynamics of the migraine brain throughout the migraine cycle.
- White-matter microstructural changes in episodic menstrual migraine compared with hormonal controlsPublication . Fouto, A.; Nunes, R.; Ruiz-Tagle, A.; Esteves, I.; Caetano, G.; Silva, N. A.; Vilela, P.; Gil-Gouveia, R.; Figueiredo, P.Question: Do patients with episodic menstrual migraine exhibit white-matter microstructural changes? Methods: 14 women with episodic menstrual migraine (35±8yrs) were assessed during interictal phase together with 11 healthy women (29±10yrs) during a matching phase of their menstrual cycle (post-ovulation). 2D-EPI multi-shell DWI data were acquired on a 3T Siemens Vida (64-ch coil) and preprocessed using DESIGNER [1]. Diffusion tensor / kurtosis imaging (DTI/DKI) parameter maps were estimated and skeletonised [2] and histogram-metrics were computed for each subject: median, peak height, width, and value. Results: Voxelwise statistical analysis [3] revealed multiple whitematter regions with lower MD and AD in patients, with no differences in FA and RD. Interestingly, migraineurs showed increased MK, AK and RK. Moreover, significant groups differences (Mann- Whitney test with Bonferroni correction) were found in histogram-metrics MD peak value, AD median and peak height and AK median. Median AK was positively associated (Spearman correlation) with disease duration but not with attack frequency and pain intensity. Conclusion: Our findings extended previous reports of whitematter microstructural changes in migraineurs across multiple brain regions [4, 5]. DKI histogram-metrics showed potential as disease biomarkers.