GIGA-Consciousness, University of Liège, Liège, Belgium.
Coma Science Group, University Hospital of Liège, Liège, Belgium.
PLoS One. 2019 Jul 18;14(7):e0219656. doi: 10.1371/journal.pone.0219656. eCollection 2019.
Charles Bonnet syndrome (CBS) is a rare condition characterized by visual impairment associated with complex visual hallucinations in elderly people. Although studies suggested that visual hallucinations may be caused by brain damage in the visual system in CBS patients, alterations in specific brain regions in the occipital cortex have not been studied. Functional connectivity during resting-state functional magnetic resonance imaging (rs-fMRI; without hallucinations) in CBS patients, has never been explored. We aimed to investigate brain structural and functional changes in a patient with CBS, as compared with late blind (LB) and normally sighted subjects. We employed voxel-based morphometry and cortical thickness analyses to investigate alterations in grey matter characteristics, and rs-fMRI to study changes in functional brain connectivity. Decreased grey matter volume was observed in the middle occipital gyrus and in the cuneus in the CBS patient, and in the middle occipital gyrus and in the lingual gyrus within LB subjects, compared to their respective control groups. Reductions in cortical thickness in associative and multimodal cortices were observed in the CBS patient when comparing with LB subjects. The precuneus exhibited increased functional connectivity with the secondary visual cortex in the CBS patient compared to the controls. In contrast, LB patients showed decreased functional connectivity compared to sighted controls between the DMN and the temporo-occipital fusiform gyrus, a region known to support hallucinations. Our findings suggest a reorganization of the functional connectivity between regions involved in self-awareness and in visual and salience processing in CBS that may contribute to the appearance of visual hallucinations.
查尔斯·邦纳综合征（CBS）是一种罕见的疾病，其特征是视力受损，伴有老年人复杂的视觉幻觉。尽管研究表明，CBS 患者的视觉幻觉可能是由视觉系统的大脑损伤引起的，但枕叶皮层中特定脑区的改变尚未得到研究。在 CBS 患者中，静息状态功能磁共振成像（rs-fMRI；无幻觉）期间的功能连接从未被探索过。我们的目的是研究 CBS 患者与晚期失明（LB）和正常视力受试者相比大脑结构和功能的变化。我们采用基于体素的形态测量学和皮质厚度分析来研究灰质特征的改变，并进行 rs-fMRI 研究以研究功能脑连接的变化。与各自的对照组相比，CBS 患者的中枕叶和楔叶以及 LB 患者的中枕叶和舌回观察到灰质体积减少。与 LB 受试者相比，CBS 患者的联合和多模态皮质的皮质厚度减少。与对照组相比，CBS 患者的楔前叶与次级视觉皮层之间的功能连接增加。相比之下，LB 患者与视力正常的对照组之间的默认网络和颞枕梭状回之间的功能连接减少，该区域已知支持幻觉。我们的研究结果表明，CBS 患者与自我意识和视觉以及显着性处理相关的区域之间的功能连接发生了重新组织，这可能有助于视觉幻觉的出现。
