MRC Unit on Risk and Resilience in Mental Disorders, Department of Psychiatry, Stellenbosch University, PO Box 241, Cape Town, 8000, South Africa.
Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa.
Brain Imaging Behav. 2020 Dec;14(6):2202-2209. doi: 10.1007/s11682-019-00170-z.
Trichotillomania (TTM) is a disorder characterized by repetitive hair-pulling resulting in hair loss. Key processes affected in TTM comprise affective, cognitive, and motor functions. Emerging evidence suggests that brain matter aberrations in fronto-striatal and fronto-limbic brain networks and the cerebellum may characterize the pathophysiology of TTM. The aim of the present voxel-based morphometry (VBM) study was to evaluate whole brain grey and white matter volume alteration in TTM and its correlation with hair-pulling severity. High-resolution magnetic resonance imaging (3 T) data were acquired from 29 TTM patients and 28 age-matched healthy controls (CTRLs). All TTM participants completed the Massachusetts General Hospital Hair-Pulling Scale (MGH-HPS) to assess illness/pulling severity. Using whole-brain VBM, between-group differences in regional brain volumes were measured. Additionally, within the TTM group, the relationship between MGH-HPS scores, illness duration and brain volumes were examined. All data were corrected for multiple comparisons using family-wise error (FWE) correction at p < 0.05. Patients with TTM showed larger white matter volumes in the parahippocampal gyrus and cerebellum compared to CTRLs. Estimated white matter volumes showed no significant association with illness duration or MGH-HPS total scores. No significant between-group differences were found for grey matter volumes. Our observations suggest regional alterations in cortico-limbic and cerebellar white matter in patients with TTM, which may underlie deficits in cognitive and affective processing. Such volumetric white matter changes may precipitate impaired cortico-cerebellar communication leading to a reduced ability to control hair pulling behavior.
拔毛癖（TTM）是一种以反复性拔发导致脱发为特征的疾病。在 TTM 中受影响的关键过程包括情感、认知和运动功能。新出现的证据表明，额-纹状体和额-边缘脑网络以及小脑的大脑物质异常可能是 TTM 病理生理学的特征。本基于体素的形态测量学（VBM）研究的目的是评估 TTM 全脑灰质和白质体积的改变及其与拔发严重程度的相关性。从 29 名 TTM 患者和 28 名年龄匹配的健康对照者（CTRLs）中获取了高分辨率磁共振成像（3T）数据。所有 TTM 参与者都完成了马萨诸塞州综合医院拔毛量表（MGH-HPS）以评估疾病/拔发的严重程度。使用全脑 VBM，测量了组间区域性脑体积的差异。此外，在 TTM 组内，还检查了 MGH-HPS 评分、疾病持续时间和脑体积之间的关系。所有数据均通过使用 FWE 校正在 p < 0.05 时进行了多重比较校正。与 CTRLs 相比，TTM 患者的海马旁回和小脑的白质体积较大。估计的白质体积与疾病持续时间或 MGH-HPS 总分均无显著相关性。灰质体积无显著组间差异。我们的观察结果表明 TTM 患者皮质-边缘和小脑白质存在区域性改变，这可能是认知和情感处理缺陷的基础。这种体积的白质变化可能会引发皮质-小脑通讯受损，从而导致控制拔发行为的能力降低。
