Murphy Nicholas, Killen Alison, Gupta Rajnish Kumar, Graziadio Sara, Rochester Lynn, Firbank Michael, Baker Mark R, Allan Charlotte, Collerton Daniel, Taylor John-Paul, Urwyler Prabitha
Faculty of Medical Sciences, Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, United Kingdom.
Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, Houston, TX, United States.
Front Neurol. 2021 Jan 28;11:579113. doi: 10.3389/fneur.2020.579113. eCollection 2020.
Visual hallucinations (VH) are a common symptom of Parkinson's disease with dementia (PDD), affecting up to 65% of cases. Integrative models of their etiology posit that a decline in executive control of the visuo-perceptual system is a primary mechanism of VH generation. The role of bottom-up processing in the manifestation of VH in this condition is still not clear although visual evoked potential (VEP) differences have been associated with VH at an earlier stage of PD. Here we compared the amplitude and latency pattern reversal VEPs in healthy controls ( = 21) and PDD patients ( = 34) with a range of VH severities. PDD patients showed increased N2 latency relative to controls, but no significant differences in VEP measures were found for patients reporting complex VH (CVH) ( = 17) compared to those without VH. Our VEP findings support previous reports of declining visual system physiology in PDD and some evidence of visual system differences between patients with and without VH. However, we did not replicate previous findings of a major relationship between the integrity of the visual pathway and VH.
视幻觉（VH）是帕金森病痴呆（PDD）的常见症状，高达65%的病例会出现。其病因的综合模型认为，视觉感知系统执行控制能力的下降是视幻觉产生的主要机制。尽管在帕金森病早期视觉诱发电位（VEP）差异与视幻觉有关，但在这种情况下自下而上加工对视幻觉表现的作用仍不清楚。在此，我们比较了健康对照者（n = 21）和不同视幻觉严重程度的PDD患者（n = 34）的振幅和潜伏期模式翻转VEP。与对照组相比，PDD患者的N2潜伏期延长，但报告复杂视幻觉（CVH）的患者（n = 17）与无视幻觉的患者相比，VEP测量结果无显著差异。我们的VEP研究结果支持了之前关于PDD患者视觉系统生理功能下降的报道，以及一些有无视幻觉患者之间视觉系统差异的证据。然而，我们并未重现之前关于视觉通路完整性与视幻觉之间主要关系的研究结果。
