Abnormality of visual neuromagnetic activation in female migraineurs without aura between attacks

Abstract

ObjectiveThe present study aimed to preliminary explore the abnormal neuromagnetic activation in female migraine patients between attacks using magnetoencephalography (MEG) and pattern reversed visual evoked magnetic fields (PR-VEFs).MethodsA total of 17 female migraine subjects during the headache-free phase and 17 healthy controls (HC) were studied using a 275-channel magnetoencephalography (MEG) system. In this study, visual evoked magnetic fields (VEFs) were generated by a pattern-reversal check as the visual stimulus. The average of 100 VEFs was evolved by different half patterns were averaged and used to analyze waveform, spectrum, and source location within two frequency ranges (5–100 and 100–1000 Hz), respectively.ResultsIn migraine subjects, the latency of second peak of VEFs (VIIs) showed significant prolongations when compared with HC. On the sensor level, the cortical spectral power in migraine subjects was similar to that of HC in the 5–100 Hz range and was lower in the 1000–1000 Hz range. There was a decrement of source strength in the visual cortex in migraine patients when compared to HC in both the 5–100 and 100–1000 Hz frequency range. Moreover, there was a similar odds of activation in 5–100 and 100–1000 Hz frequency ranges in the area beyond the primary visual cortex between the two groups. In addition, no correlation was observed between clinical data (intensity of headache, headache-history duration, the frequency of headaches) and MEG results.ConclusionsThe findings presented in the current study, suggested that interictal cortical activation following a visual stimulus was low in female migraine patients. The low pre-activation was detected in the visual cortex using VEF and MEG in both low and high-frequency band. Our results add to the existing evidence that cortical interictal excitability change may be relative to the pain-module mechanism in migraine brains. Thus, our data improved the apprehension of the cortical disorder of migraine in the high-frequency domain.

Sex Differences of Periaqueductal Grey Matter Functional Connectivity in Migraine

“…We also found a stronger PAG-FC with visual cortex including cuneus, calcarine and superior occipital gyrus. In a previous study, these regions had a stronger paininduced PAG-FC in migraineurs compared to controls (41), and our results on sex differences might suggest that in migraine this increased connectivity might contribute to the increased interictal sensory sensitivity for females (42) that could lead to an increased vulnerability for migraine attacks (43). Impaired attentive processing of visual stimuli was also observed in female migraineurs compared to males suggesting that neurocognitive processing is affected by migraine in females (44).…”