TY - JOUR
T1 - Scratching Induces Overactivity in Motor-Related Regions and Reward System in Chronic Itch Patients
AU - Mochizuki, Hideki
AU - Papoiu, Alexandru D.P.
AU - Nattkemper, Leigh A.
AU - Lin, Andrew C.
AU - Kraft, Robert A.
AU - Coghill, Robert C.
AU - Yosipovitch, Gil
N1 - Funding Information:
This study was funded by NIH (NIAMS) grant 5ARO155904.
PY - 2015/11/1
Y1 - 2015/11/1
N2 - Scratching evokes a rewarding and pleasurable sensation, particularly in chronic itch patients. To date, no study has investigated the cerebral activity during scratching in chronic itch patients and whether it differs from that in healthy subjects. Using arterial spin labeling functional magnetic resonance imaging, we analyzed and compared the cerebral mechanism of self-scratching and its correlation with pleasurability in 10 patients with chronic itch and in 10 healthy controls. Cowhage was applied to the right forearm to induce itch. Scratching significantly attenuated the itch sensation (P<0.001) and evoked an associated pleasurability. Scratching-induced pleasurability significantly activated the reward system in the chronic itch and healthy groups, confirming that this reward system has a crucial role in scratching-induced pleasurability. A higher activity during scratching in chronic itch patients, versus healthy controls, was noted in brain regions related to motor control and motivation to act, including the supplementary motor area, premotor cortex, primary motor cortex, and midcingulate cortex, as well as the caudate nucleus involved in the reward system. This overactivity may be associated with the addictive scratching and/or neural hypersensitization.
AB - Scratching evokes a rewarding and pleasurable sensation, particularly in chronic itch patients. To date, no study has investigated the cerebral activity during scratching in chronic itch patients and whether it differs from that in healthy subjects. Using arterial spin labeling functional magnetic resonance imaging, we analyzed and compared the cerebral mechanism of self-scratching and its correlation with pleasurability in 10 patients with chronic itch and in 10 healthy controls. Cowhage was applied to the right forearm to induce itch. Scratching significantly attenuated the itch sensation (P<0.001) and evoked an associated pleasurability. Scratching-induced pleasurability significantly activated the reward system in the chronic itch and healthy groups, confirming that this reward system has a crucial role in scratching-induced pleasurability. A higher activity during scratching in chronic itch patients, versus healthy controls, was noted in brain regions related to motor control and motivation to act, including the supplementary motor area, premotor cortex, primary motor cortex, and midcingulate cortex, as well as the caudate nucleus involved in the reward system. This overactivity may be associated with the addictive scratching and/or neural hypersensitization.
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U2 - 10.1038/jid.2015.223
DO - 10.1038/jid.2015.223
M3 - Article
C2 - 26076316
AN - SCOPUS:84947041830
VL - 135
SP - 2814
EP - 2823
JO - Journal of Investigative Dermatology
JF - Journal of Investigative Dermatology
SN - 0022-202X
IS - 11
ER -