Eye Center, Renmin Hospital of Wuhan University, Wuhan, 430060 Hubei, China.
Department of Radiology, Renmin Hospital of Wuhan University, Wuhan, 430060 Hubei, China.
Biomed Res Int. 2020 Jun 20;2020:1913805. doi: 10.1155/2020/1913805. eCollection 2020.
Previous neuroimaging studies demonstrated that visual deprivation triggers significant crossmodal plasticity in the functional and structural architecture of the brain. However, prior neuroimaging studies focused on the static brain activity in blindness. It remains unknown whether alterations of dynamic intrinsic brain activity occur in late blindness (LB). This study investigated dynamic intrinsic brain activity changes in individuals with late blindness by assessing the dynamic amplitude of low-frequency fluctuations (dALFFs) using sliding-window analyses. Forty-one cases of late blindness (LB) (29 males and 12 females, mean age: 39.70 ± 12.66 years) and 48 sighted controls (SCs) (17 males and 31 females, mean age: 43.23 ± 13.40 years) closely matched in age, sex, and education level were enrolled in this study. The dALFF with sliding-window analyses was used to compare the difference in dynamic intrinsic brain activity between the two groups. Compared with SCs, individuals with LB exhibited significantly lower dALFF values in the bilateral lingual gyrus (LING)/calcarine (CAL) and left thalamus (THA). LB cases also showed considerably decreased dFC values between the bilateral LING/CAL and the left middle frontal gyrus (MFG) and between the left THA and the right LING/cerebelum_6 (CER) (two-tailed, voxel-level < 0.01, Gaussian random field (GRF) correction, cluster-level < 0.05). Our study demonstrated that LB individuals showed lower-temporal variability of dALFF in the visual cortices and thalamus, suggesting lower flexibility of visual thalamocortical activity, which might reflect impaired visual processing in LB individuals. These findings indicate that abnormal dynamic intrinsic brain activity might be involved in the neurophysiological mechanisms of LB.
先前的神经影像学研究表明，视觉剥夺会引发大脑功能和结构的显著跨模态可塑性。然而，先前的神经影像学研究主要集中在盲态下的大脑静态活动。目前尚不清楚在晚期失明（late blindness，LB）中是否会发生动态内在脑活动的改变。本研究通过使用滑动窗口分析评估低频波动的动态幅度（dynamic amplitude of low-frequency fluctuations，dALFF），来研究晚期失明个体的动态内在脑活动变化。本研究纳入了 41 例晚期失明（late blindness，LB）患者（29 名男性和 12 名女性，平均年龄：39.70±12.66 岁）和 48 例视力正常对照（sightseeing controls，SCs）（17 名男性和 31 名女性，平均年龄：43.23±13.40 岁），两组在年龄、性别和教育水平上相匹配。使用滑动窗口分析比较了两组之间的动态内在脑活动差异。与SCs 相比，LB 患者双侧舌回（lingual gyrus，LING）/楔前叶（calcarine，CAL）和左侧丘脑（thalamus，THA）的 dALFF 值明显较低。LB 患者还表现出双侧 LING/CAL 与左侧额中回（middle frontal gyrus，MFG）之间以及左侧 THA 与右侧 LING/小脑 6（cerebellum_6，CER）之间的 dFC 值显著降低（双侧，体素水平<0.01，高斯随机场（Gaussian random field，GRF）校正，簇水平<0.05）。本研究表明，LB 患者视觉皮质和丘脑的 dALFF 时间变异性较低，提示视觉丘脑皮质活动的灵活性较低，这可能反映了 LB 患者的视觉处理受损。这些发现表明，异常的动态内在脑活动可能参与了 LB 的神经生理机制。
