Neural networking : investigating brain communication and wind-up phenomenon in acute low back pain patients

Background and aims: The wind-up phenomenon, characterized by heightened sensory perception from repeated sensory stimulation, significantly contributes to the persistence of low back pain (LBP). To optimize intervention, it‘s crucial to enhance understanding of sensorimotor processing and pain modulation mechanisms in acute LBP. Methods: Using functional MRI, we have demonstrated that lumbar spine stimulation activates brain regions, serving as a proxy for anticipatory postural control. This explorative fMRI study applied pain free mechanosensory stimulation to the lumbar spine. We examined functional connectivity resulting from this stimulation and its correlation with the clinically assessed wind-up phenomenon. Pinprick stimulation was administered bilaterally on the lower back, and the subsequent wind-up was quantified. Results: The study included 19 participants experiencing acute LBP, with a mean moderate pain intensity of 4.5/10 and mild associated disability. Within the salience network, functional connectivity within opercular regions correlated positively with the wind-up phenomenon. In the sensorimotor network, strong correlations were observed between the postcentral-opercular cortex connectivity and the wind-up phenomenon. Within the limbic network, a correlation was found between the wind-up phenomenon and the hippocampus-frontal gyrus and supramarginal gyrus associations. Conclusions: The present results revealed the association of the wind-up phenomenon with regions involved in sensory processing, pain modulation, and affective pain perception. This refined understanding should empower clinicians to leverage this knowledge to prevent potential symptom persistence and exert control over these mechanisms.