Supplemental Digital Content is Available in the Text. Using magnetic resonance spectroscopy in vivo, we show GABA and glutamate alterations in children aged 7 to 13 years with migraine, which are associated with migraine characteristics.

Background Migraine affects roughly 10% of youth aged 5–15 years, however the underlying mechanisms of migraine in youth are poorly understood. Multiple structural and functional alterations have been shown in the brains of adult migraine sufferers. This study aims to investigate the effects of migraine on resting-state functional connectivity during the period of transition from childhood to adolescence, a critical period of brain development and the time when rates of pediatric chronic pain spikes. Methods Using independent component analysis, we compared resting state network spatial maps and power spectra between youth with migraine aged 7–15 and age-matched controls. Statistical comparisons were conducted using a MANCOVA analysis. Results We show (1) group by age interaction effects on connectivity in the visual and salience networks, group by sex interaction effects on connectivity in the default mode network and group by pubertal status interaction effects on connectivity in visual and frontal parietal networks, and (2) relationships between connectivity in the visual networks and the migraine cycle, and age by cycle interaction effects on connectivity in the visual, default mode and sensorimotor networks. Conclusions We demonstrate that brain alterations begin early in youth with migraine and are modulated by development. This highlights the need for further study into the neural mechanisms of migraine in youth specifically, to aid in the development of more effective treatments.

Despite migraine being one of the top five most prevalent childhood diseases, a lack of knowledge about pediatric migraine limits effective treatment strategies; standard adult pharmaceutical therapies are less effective in children and can carry undesirable side-effects. Non-pharmacological therapies have shown some success in adults; however, to appropriately apply these in children we need to understand pediatric migraine's underlying biology. One theory is that migraine results from an imbalance in cortical excitability. Magnetic resonance spectroscopy (MRS) studies show changes in GABA and glutamate levels (the primary inhibitory and excitatory neurotransmitters in the brain, respectively) in multiple brain regions. Although there is indirect evidence of abnormal excitability in pediatric migraine, GABA and glutamate levels have yet to be assessed.The purpose of this study was to measure levels of GABA and glutamate in the thalamus, sensorimotor cortex and visual cortex of children with migraine using MRS. We found that children with migraine and aura had significantly lower glutamate levels in the visual cortex as compared to control children, opposite to results seen in adults. Additionally, we found significant correlations between metabolite levels and migraine characteristics; higher GABA levels were associated with a higher migraine burden. We also found that higher glutamate in the thalamus and higher GABA/Glx ratios in the sensorimotor cortex were associated with duration since diagnosis, i.e., having migraines longer. Lower GABA levels in the sensorimotor cortex were associated with being closer to their next migraine attack. Together this indicates that GABA and glutamate disturbances occur early in migraine pathophysiology and emphasizes that evidence from adults with migraine cannot be immediately translated to paediatric sufferers. This highlights the need for further mechanistic studies of migraine in children, to aid in the development of more effective treatments.