The findings provide new insights into the brain mechanisms underlying juvenile fibromyalgia, a chronic pain disorder that affects between 2% and 6% of children and adolescents. By combining detailed behavioural assessments with advanced brain imaging, the authors have defined patient subtypes that could explain why this disease is more disabling in some cases than in others.

The study opens up new avenues for improving diagnosis and developing more personalized therapeutic strategies to address a paediatric disease that is still difficult to characterize and manage.

Juvenile fibromyalgia: how does the brain respond during sensory stimulation?

Juvenile fibromyalgia is a complex and often misunderstood condition. It mainly affects adolescent girls, and symptoms can persist into adulthood and significantly impact daily life. Although pain is the most visible symptom, many patients also experience severe discomfort in response to everyday sensory stimuli. The neural mechanisms behind these manifestations and their clinical relevance in those affected are not yet well understood.

A study published by the team in the journal Pain reveals that adolescents with fibromyalgia show significantly greater sensitivity to visual, auditory, and tactile stimuli, as well as greater discomfort during multisensory stimulation.

The study did not detect any deficits in hearing or basic auditory attention processes, confirming that sensory hypersensitivity is not due to peripheral sensory impairment. Instead, brain imaging revealed that increased activation in brain regions involved in sensory integration and cognitive-emotional regulation — particularly the prefrontal areas — was closely associated with pain severity, functional disability, and overall symptom burden.
The study also reveals that altered brain processing of non-painful sensory stimuli plays a central role in the clinical expression of the disease from an early age, before the pain has become chronic over decades.

“Teenagers with fibromyalgia may perceive even everyday sounds as louder; this is not due to any hearing impairment, but rather to the amplification and coordination of sensory signals in the brain. This intensified neural processing helps explain why the condition can be so disabling, affecting pain levels and daily functioning from a very young age,” says PhD student Laura Martín-Herrero, first author of the study.

More personalized treatments to address chronic paediatric pain

In a previous article published in the Journal of Pediatric Psychology, the authors described how sensory hypersensitivity is not uniform among all patients and identified two subgroups of adolescents with juvenile fibromyalgia: one with pronounced multisensory hypersensitivity and another with sensory profiles similar to those of adolescents not affected by the condition.

In the first subgroup, patients showed more severe core symptoms, including a greater degree of functional disability and fatigue. However, surprisingly, this group did not differ in levels of anxiety, depression, or psychological coping, indicating that their sensory hypersensitivity was primarily associated with sensory rather than affective symptoms. At the brain level, during multisensory stimulation, greater activation was detected in regions such as the primary motor cortex and the amygdala. This indicates a higher motor and emotional response to stimuli that, on the other hand, would not be painful.

“Our results suggest that, in adolescents with fibromyalgia, the brain may amplify everyday sensory experiences. This can make daily life (social environments, classrooms, sports, etc.) overstimulating and sometimes overwhelming for these individuals. Therefore, it is important to highlight the importance of therapies that help young people manage sensory overload and its impact on everyday activities and experiences,” explains Professor Marina López-Solà, principal investigator and senior author of the studies.

“Understanding how the brain processes everyday sensory information in juvenile fibromyalgia could ultimately help reduce symptom burden and improve quality of life for affected young people,” the researchers conclude.