Year: 2026
Type: preprint
Study design: Observational Study
Abstract: Brain differences in chronic pain are almost always measured after years of pain experience, leaving unresolved whether they create vulnerability to pain or result from it. Uniquely, menstrual pain has a developmentally scheduled onset (menarche, the first menstrual period), allowing the brain to be characterized before and after pain exposure occurs. Here we used longitudinal 64-channel EEG to measure resting brain activity in adolescents once before (n=250) and twice after (n=161, n=140) menarche. Before their first period, adolescents who later reported higher menstrual pain (30 or greater on a 0 to 100 VAS) already showed faster occipital peak alpha frequency compared to those who reported lower menstrual pain, a difference that persisted in the early (3 to 14 months) post-menarche time period. In contrast, oscillatory power and functional connectivity did not differ by menstrual pain group, suggesting that the widespread functional brain alterations reported in adults with painful periods take years to emerge. Peak alpha frequency increased, and theta power and connectivity decreased across the menarchal transition, consistent with typical adolescent maturation. However, longitudinal analyses stratified by higher and lower menstrual pain group suggested group specific timings for these neurodevelopmental changes. Overall, these findings suggest that early menstrual pain is not associated with widespread alterations in neural oscillations, but aspects of menstrual pain susceptibility may be reflected in resting peak alpha frequency. To our knowledge, this is the first neurophysiological trait shown to precede the onset of menstrual pain.
Source: medRxiv
Institutions: Endeavor Health, 23andMe (United States)
Language: English
Field: Medicine
Domain: Health Sciences
Open Access status: green
Funder: National Institutes of Health
OpenAlex ID: W7223199527