Supersaturation of VEP in Migraine without Aura Patients Treated with Topiramate: An Anatomo-Functional Biomarker of the Disease.

Migraine is a primary headache with high prevalence among the general population, characterized by functional hypersensitivity to both exogenous and endogenous stimuli particularly affecting the nociceptive system. The hyperresponsivity of cortical neurons could be due to a disequilibrium in the excitatory/inhibitory signaling. This study aimed to investigate the anatomo-functional pathway from the retina to the primary visual cortex using visual evoked potentials (VEP). Contrast gain protocol was used in 15 patients diagnosed with migraine without aura (at baseline and after 3 months of topiramate therapy) and 13 controls. A saturation (S) index was assessed to monitor the response of VEP's amplitude to contrast gain. Non-linear nor monotone growth of VEP (S < 0.95) was defined as supersaturation. A greater percentage of migraine patients (53%) relative to controls (7%) showed this characteristic. A strong inverse correlation was found between the S index and the number of days separating the registration of VEP from the next migraine attack. Moreover, allodynia measured through the Allodynia Symptoms Check-list (ASC-12) correlates with the S index both at baseline and after 3 months of topiramate treatment. Other clinical characteristics were not related to supersaturation. Topiramate therapy, although effective, did not influence electrophysiological parameters suggesting a non-intracortical nor retinal origin of the supersaturation (with possible involvement of relay cells from the lateral geniculate nucleus). In conclusion, the elaboration of visual stimuli and visual cortex activity is different in migraine patients compared to controls. More data are necessary to confirm the potential use of the S index as a biomarker for the migraine cycle (association with the pain-phase) and cortical sensitization (allodynia).

Plasma Levels of Oxidative Stress Markers, before and after BoNT/A Treatment, in Chronic Migraine.

The pathophysiological mechanisms of migraine transformation are debated. Modifications of plasma oxidative stress biomarkers have been described in chronic migraine. OnabotulintoxinA (BoNT/A) treatment, approved for chronic migraine prophylaxis, possibly reduces pain neurotransmitters release and oxidative stress products. Aims of our study were to investigate differences in the levels of selected plasmatic oxidative stress biomarkers (Advanced Oxidation Protein Products (AOPP), Ferric Reducing Antioxidant Power (FRAP), Thiolic Groups (SH)) comparing chronic migraineurs (CM) and healthy controls (HC). We also explored possible clinical and biochemical modifications in the CM group after six months of treatment with BoNT/A. At the baseline, we found higher values of AOPP (p < 0.001), and lower values of SH (p < 0.001) and FRAP (p = 0.005) in the CM group. At the six-month follow-up we found a reduction of AOPP (p < 0.001) and an increase of FRAP (p < 0.001) and SH (p = 0.023) within the CM group. BoNT/A treatment improved migraine symptoms in the CM group. We confirmed previous reports of imbalanced antioxidant mechanisms in chronic migraine showing lower antioxidant capacities in patients than controls. BoNT/A improved the levels of plasma oxidative stress biomarkers and confirmed its role as an effective prophylactic treatment for CM. Other studies should investigate the potential antioxidant properties of BoNT/A treatment.

Fatigue, sleep-wake pattern, depressive and anxiety symptoms and body-mass index: analysis in a sample of episodic and chronic migraine patients.

Migraine clinical presentation and life-time course can be highly heterogeneous, with a subgroup of patients developing chronic migraine; moreover, migraine clinical spectrum is expanded by the association with different coexisting conditions and interictal dysfunctions. The aim of this study was to systematically evaluate migraine clinical features, daily functioning parameters, sleep pattern, presence of depressive-anxiety symptoms and body mass index (BMI) in a sample of 75 episodic and 75 chronic migraine without aura patients. Migraine-related disability, fatigue, daily sleepiness, subjective sleep quality, anxiety and depressive symptoms were, respectively, evaluated using the following questionnaires: Fatigue Severity Scale (FSS), Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index (PSQI), Generalized Anxiety Disorder 7-item Scale (GAD-7), Patient Health Questionnaire 9-item Scale (PHQ-9). Mean FSS score (p < 0.001), PSQI score (p = 0.015), GAD-7 score (p = 0.019), PHQ-9 score (p < 0.001) and BMI score (p = 0.012) were significantly higher in chronic compared to episodic migraineurs. Additionally, a correlation analysis carried out in the total sample of 150 migraine patients documented a statistically significant, positive correlation between monthly frequency of migraine attacks and FSS score (p < 0.001), PSQI score (p = 0.006), GAD-7 score (p = 0.019), PHQ-9 score (p < 0.001) and BMI score (p = 0.049). Data from the present report seem to expand the concept of migraine as a continuum or spectrum, with greater occurrence of fatigue, poor sleep quality, anxiety-depressive symptoms and higher BMI score in chronic compared to episodic migraine patients; further investigation is certainly necessary to better define the biological basis and mechanisms associated with migraine transformation from episodic to chronic pattern.