A fMRI study in brain activation evoked by mechanical stimulation induced pruritus

Objective To explore the functional activation cerebral areas evoked by mechanical stimulation induced pruritus perception imitating physiological process. Methods Scratching the planta gently to induce pruritus with brush pen wool in a group of 16 healthy volunteers, scanning BOLD-fMRI serials with a block design on a 3.0 T MR machine, and identifying the functional cerebral areas evoked by pruritus with SPM8 software for analysis.Student's t test was used to compare the difference of incidences with P<0.05 for statistical significance. Results Several brain regions were activated by pruritus stimulus. The strongest activation evoked by pruritus was found at the contralateral thalamus and paracentral lobule(t=5.26, 5.23), the most activation volumes were found at the contralateral paracentral lobule, postcentral gyrus and prefrontal lobule(146, 151 and 326 volumes). Different degrees of activation were discovered at bilateral insula, precentral and postcentral gyrus, thalamus, lentiform nucleus and cingulated gyrus. Conclusion The postcentral gyrus, paracentral lobule, insula, precentral gyrus and frontal lobe were the functional activation cerebral areas of pruritus perception evoked by mechanical stimulation. Key words: Pruritus; Functional magnetic resonance imaging; Brain