INTRODUCTION Whether different mechanisms, particularly ocular pathology, could lead to the emergence of visual hallucinations (VH) (defined as false perceptions with no external stimulus) versus visual illusions (VI) (defined as a misperception of a real stimulus) in Parkinson's disease (PD) remains debated. We assessed retinal, clinical and structural brain characteristics depending on the presence of VH or VI in PD. METHODS In this case-control study, we compared retinal thickness using optical coherence tomography (OCT), between PD patients with: VI (PD-I; n = 26), VH (PD-H; n = 28), and without VI or VH (PD-C; n = 28), and assessed demographic data, disease severity, treatment, anatomical and functional visual complaints, cognitive and visuo-perceptive functions and MRI brain volumetry for each group of PD patients. RESULTS Parafoveal retina was thinner in PD-H compared to PD-C (p = 0.005) and PD-I (p = 0.009) but did not differ between PD-I and PD-C (p = 0.85). Multivariate analysis showed that 1/retinal parafoveal thinning and total brain gray matter atrophy were independently associated with the presence of VH compared to PD-I; 2/retinal parafoveal thickness, PD duration, sleep quality impairment and total brain gray matter volume were independent factors associated with the presence of VH compared to PD-C; 3/anterior ocular abnormalities were the only factor independently associated with the presence of illusions compared to PD-C. CONCLUSION These findings reinforce the hypothesis that there may be different mechanisms contributing to VH and VI in PD, suggesting that these two entities may also have a different prognosis rather than simply lying along a continuous spectrum. REGISTRATION NUMBER Clinicaltrials.gov number NCT01114321.

中文翻译：

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帕金森病中的视觉幻觉和错觉：眼部病理学的作用。

引言 不同的机制，尤其是眼部病理，是否会导致帕金森病中出现幻视（VH）（定义为没有外部刺激的错误感知）与视错觉（VI）（定义为对真实刺激的误解）。 PD）仍然存在争议。我们根据 PD 中 VH 或 VI 的存在评估了视网膜、临床和大脑结构特征。方法 在这项病例对照研究中，我们使用光学相干断层扫描 (OCT) 比较了以下 PD 患者的视网膜厚度：VI（PD-I；n = 26）、VH（PD-H；n = 28）和没有 VI或 VH（PD-C；n = 28），并评估每组 PD 患者的人口统计数据、疾病严重程度、治疗、解剖和功能性视觉不适、认知和视觉感知功能以及 MRI 脑容量。结果 与 PD-C (p = 0.005) 和 PD-I (p = 0.009) 相比，PD-H 的中央凹旁视网膜更薄，但 PD-I 和 PD-C (p = 0.85) 之间没有差异。多变量分析表明，与 PD-I 相比，1/视网膜中央凹旁变薄和全脑灰质萎缩与 VH 的存在独立相关；2/与 PD-C 相比，视网膜中央凹旁厚度、PD 持续时间、睡眠质量损害和总脑灰质体积是与 VH 存在相关的独立因素；与 PD-C 相比，3/前眼部异常是与幻觉存在独立相关的唯一因素。结论 这些发现强化了以下假设，即可能存在不同的机制导致 PD 中的 VH 和 VI，这表明这两个实体也可能有不同的预后，而不是简单地位于一个连续的范围内。注册号 Clinicaltrials.gov 编号 NCT01114321。