Centro de Investigación en Red de Enfermedades Neurodegenerativas (CIBERNED), Hospital Clínic de Barcelona, Spain.
J Neurol Sci. 2011 Nov 15;310(1-2):79-81. doi: 10.1016/j.jns.2011.06.019. Epub 2011 Jun 25.
The presence of visual hallucinations (VH) is a significant predictor of dementia in Parkinson's disease (PD) and it is associated with a more rapid cognitive decline. Non-demented PD patients with VH present greater neuropsychological impairment than those without VH in domains such as verbal and visual memory, language comprehension, and visuospatial and visuoperceptive functions. Frontal dysfunction has also been described in PD with VH, including deficits in verbal fluency, sustained attention, and inhibition. In PD with VH, structural and functional abnormalities within the primary visual system and visual association areas, including ventral and dorsal pathways, have been reported. Structural MRI studies have shown that non-demented PD patients with VH present grey matter reduction in parieto-occipital areas and the hippocampal head. A follow-up study performed at a mean of 30 months revealed that unlike PD patients without VH, PD patients with VH frequently develop dementia associated with progressive atrophy in limbic, paralimbic and neocortical areas. Functional MRI (fMRI) studies have revealed altered activation in occipito-temporal and frontal areas in response to simple and complex visual stimuli in PD patients with VH, suggesting a marked impairment in bottom-up visual processing, as well as an attentional deficit in the pathophysiology of VH in PD.
视幻觉（VH）的存在是帕金森病（PD）痴呆的重要预测指标，并且与认知功能下降更快有关。与无 VH 的 PD 患者相比，有 VH 的非痴呆 PD 患者在言语和视觉记忆、语言理解以及视空间和视知觉功能等领域表现出更大的神经心理损伤。PD 伴 VH 也存在额功能障碍，包括言语流畅性、持续注意力和抑制缺陷。在 PD 伴 VH 中，已经报道了初级视觉系统和视觉联合区域内的结构和功能异常，包括腹侧和背侧通路。结构 MRI 研究表明，有 VH 的非痴呆 PD 患者在顶枕区域和海马头部存在灰质减少。一项平均 30 个月的随访研究表明，与无 VH 的 PD 患者不同，有 VH 的 PD 患者经常出现与边缘、旁边缘和新皮质区域进行性萎缩相关的痴呆症。功能 MRI（fMRI）研究表明，在 PD 伴 VH 患者对简单和复杂视觉刺激的反应中，枕颞和额区的激活发生改变，表明在 PD 中 VH 的病理生理学中存在明显的下行视觉处理损伤以及注意力缺陷。
