Neuroimaging characteristics of pruritus induced by eczema: An fMRI study

Objective: To explore the neuroimaging characteristics of eczema-induced pruritus with resting-state functional Magnetic Resonance Imaging (rs-fMRI). Methods: 42 patients with eczema were recruited in the PE group, and 42 healthy participants were included in the HC group. The Visual Analogue Score (VAS), 12-Item Pruritus Severity Scale (12-PSS), Pittsburgh Sleep Quality Index (PSQI) and Self-rating Anxiety Scale (SAS) were recorded in the PE group. The different values of fraction Amplitude of Low Frequency Fluctuation (fALFF) and functional connectivity(FC) were compared after rs-fMRI scanning. Results: : Compared with the HC group, the fALFF values of the left precentral gyrus, left postcentral gyrus, left supplementary motor area (SMA) and left midcingulate cortex in the PE group were increased. The FC values between the left precentral gyrus and bilateral superior temporal gyrus, bilateral hippocampus, left inferior occipital gyrus in the PE group were decreased. The FC values between left SMA and bilateral superior temporal gyrus in the PE group were decreased. The 12-PSS score was positively correlated with fALFF value of the left precentral gyrus and left postcentral gyrus. Conclusion: Pruritus caused increased spontaneous activity in given cerebral regions, involving the perception of itch, control of scratching movements, and expression of itch-related emotions. Simultaneously, the aberrant fALFF values result in corresponding alterations in networks, primarily characterized by a bilateral decrease in the symmetry of FC values such as the superior temporal gyrus and the hippocampus. Meanwhile, there is a correlation between fALFF values of given cerebral regions and clinical scales, which provided potential neurobiological markers for the future study of pruritus.