Huggins Ashley A, Harvey Ashleigh M, Miskovich Tara A, Lee Han-Joo, Larson Christine L
University of Wisconsin-Milwaukee, Department of Psychology, PO Box 413, Milwaukee, WI 53201, USA.
VA Northern California Health Care System, Martinez, CA, USA.
J Obsessive Compuls Relat Disord. 2020 Jul;26. doi: 10.1016/j.jocrd.2020.100551. Epub 2020 Jun 13.
Pathological skin picking (excoriation) is a relatively common disorder. Although it has been hypothesized to share a similar pathophysiological basis as other obsessive-compulsive (OC) spectrum disorders, to date, little work has specifically examined the precise neurobiological mechanisms involved in excoriation. Disruption in functional circuits involving the right inferior frontal gyrus (rIFG) and supplementary motor area (SMA) may be particularly relevant to skin-picking pathology as these regions have been implicated in other OC-spectrum disorders for their roles in response inhibition and voluntary motor action, respectively. To this end, the present study examined the associations between skin-picking symptom severity and resting-state functional connectivity of the rIFG and bilateral SMA. Participants endorsing elevated symptoms of excoriation completed a self-report measure of symptom severity and resting-state functional magnetic resonance imaging scan. Results indicated that symptom severity was associated with weaker connectivity between the SMA and clusters within the orbitofrontal cortex and angular gyrus. Contrary to hypotheses, there were no effects of symptom severity on functional connectivity of the rIFG. Overall, these findings suggest that skin-picking symptom severity may be associated with disruption in higher-order motor networks contributing to deficits in top-down regulation of motor behavior.
病理性皮肤搔抓（皮肤搔抓症）是一种相对常见的疾病。尽管有人推测它与其他强迫性（OC）谱系障碍具有相似的病理生理基础，但迄今为止，很少有研究专门探讨皮肤搔抓症所涉及的确切神经生物学机制。涉及右侧额下回（rIFG）和辅助运动区（SMA）的功能回路破坏可能与皮肤搔抓病理特别相关，因为这些区域分别在其他OC谱系障碍中因在反应抑制和自主运动动作中的作用而受到牵连。为此，本研究考察了皮肤搔抓症状严重程度与rIFG和双侧SMA静息态功能连接之间的关联。认可皮肤搔抓症状加剧的参与者完成了一份症状严重程度的自我报告测量以及静息态功能磁共振成像扫描。结果表明，症状严重程度与SMA和眶额皮质及角回内的簇之间的连接较弱有关。与假设相反，症状严重程度对rIFG的功能连接没有影响。总体而言，这些发现表明，皮肤搔抓症状严重程度可能与高阶运动网络的破坏有关，导致运动行为自上而下调节出现缺陷。
