Background & Aims
Atopic dermatitis (AD) has been increasing in prevalence, and itch is the most frequent symptom. Watching itch-inducing videos could evoke itch sensations (contagious itch phenomenon) in AD patients, as well as healthy controls (HC). It’s still unclear how the brain processes empathic pain differs from that of contagious itch in AD patients, and also how they differ in AD patients compared to HC. We aimed to test whether cortical activation patterns for itch and pain imagery in AD patients are different compared to HC.
Methods
40 AD patients (age 25.08, 20 female) and 40 HC (age 26.29, 20 female) underwent fMRI scanning while viewing pain and itch-related videos, and rated how much they experienced itch and pain sensation.
Results
We found the significant effect of the video types in itch ratings, and the effects of group and video types, and interaction in pain ratings. Itch-evoking videos induced significant itch and pain ratings compared to non-itch videos in both groups. Both groups showed significant pain ratings to painful videos compared to non-painful videos, and AD patients showed significantly less subjective pain ratings to painful videos compared to HC. The left insula, frontal and cingulate cortex were significantly activated while watching itch-related videos compared to watching non-itch videos in AD patients, and significant activity was found in the visual cortex in the same contrast in HC. Insula, thalamus, precuneus, and frontal cortex were significantly activated during watching pain-related videos compared to watching non-painful videos in AD patients only.
Conclusions
We found that the subjective experience of pain and itch was significantly disturbed in AD patients compared to HC while watching pain-evoking videos. In addition, we found that deactivations in the brain regions involved in central pain processing were not significantly deactivated in AD patients, suggesting the altered functions in these regions.
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Presenting Author
In-Seon Lee
Poster Authors
In-Seon Lee, PhD
Ph.D.
Kyung Hee University: Department of Science in Korean Medicine
Lead Author
Topics
- Pain Imaging