Assessment of Three-dimensional Vision Alteration in Parkinson Disease.
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 36
- 试验地点
- 2
- 主要终点
- performance (in percent error) in a 2D/3D categorization task of both parkinsonian patients (OFF treatment) and control subjects.
研究概览
简要总结
Parkinson's disease is characterized by motor deficits, improved by dopaminergic intakes. Besides motor symptoms, visual troubles are observed in patients with Parkinson's disease, in particular spatial orientation problems including 3D vision. However, although these visual disturbances are commonly reported by the patients and their family in our clinical experience, they have not been the subject of specific clinical studies yet.
Parkinsonian patients report deficits in 3D vision leading to a loss of visuomotor ability, locomotor functions and to falls. Despite these frequent complaints, little is known about 3D vision in Parkinson's disease. The investigators want in this project to precisely estimate 3D deficits in parkinsonian patients by assessing their psychophysical performances in 3D vision tasks to compare to age matched control subjects' performances.
详细描述
This is a monocentric and prospective study that will compare Parkinsonian patients versus healthy subjects on the execution of psychophysical tests and Visual Evoked Potentials without and with L Dopa. The comparison will focus on one hand between PD patients and control subjects (matched by age and sex to parkinsonian patients) and on the other hand between parkinsonian patients in ON and OFF drug conditions.
Psychophysical measurements of 3D perception will be performed during this study. This will be done by asking the subjects to indicate with a joystick whether they perceived the stimulus presented on the screen placed in front of them like being 2D or 3D. Two "depth conditions" will be tested; 2D for flat stimuli and 3D for in depth stimuli. Two "3D-cues" conditions will be tested: binocular cues (retinal disparity) and monocular cues (perspective). Their performances will be assessed in both L Dopa ON and OFF conditions randomly determined.
While subjects will be performing the psychophysical tasks, we will record the visual potentials evoked by the presentation of the 2D/3D visual stimuli. Visual Evoked Potentials are obtained by extracting from the EEG the electrical signals temporally locked to the visual stimulations.
3D perception is at the intersection of pure visual perception and navigation; indeed, any movement in a familiar or unfamiliar environment requires an adequate balance between the reality of the three-dimensional environing space and its mental representation. So one of the major roles of the visual system is to convert the two-dimensional retinal images into 3 dimensions. With both binocular (retinal disparity, eye vergence) and monocular (perspective, shading ...) cues, the 3D vision can estimate (1) the distance between objects (2) distance between an object and itself, (3) relief or depth of an object. Altering that perception affects the postural and locomotor functions and thus must worsen motor disorders. So far, no systematic studies have been conducted in parkinsonian patients to quantify their 3D perception. Because of the interaction between 3D perception and motor outcomes, we want, in this project, to estimate the 3D visual deficits, to understand the underlying altered processes, to test the effect of L Dopa on these deficits and to specify the relationship between 3D visual and motor deficits.
3D psychophysical performances using a categorization task and their underlying neuronal mechanisms measured with VEP will be assessed in both Parkinsonian patients and control subjects in a randomized and comparative study.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- None
入排标准
- 年龄范围
- 50 Years 至 75 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Patients with idiopathic Parkinson's disease of both sex,
- •aged between 50 and 75 with an equivalent corrected vision of minimum 7/10 in both eyes. Patients with vision less than 7/10 in one or both eyes.
- •Patients with a normal binocular fusion (Bagolini test).
- •Control subjects of both sex,
- •aged between 50 and 75 with an equivalent corrected vision of minimum 7/10 in both eyes.
排除标准
- •Patients with non idiopathic Parkinson's disease.
- •Patients with vision less than 7/
- •Patients with significant tremor during periods of blocking (OFF) or abnormal involuntary movements (dyskinesia) during periods of release (ON).
- •Patients with visual hallucinations.
- •Patients with impaired cognitive function
结局指标
主要结局
performance (in percent error) in a 2D/3D categorization task of both parkinsonian patients (OFF treatment) and control subjects.
时间窗: 12 hours after levodopa intake
before and after levodopa intake for PD patients and once for healthy volunteers
次要结局
- measure of early visual evoked potentials components latency, recorded in parkinsonian patients, in ON and OFF L Dopa conditions, and in control subjects(12 hours after levodopa intake)
- assessment of 3D psychophysical performance of parkinsonian patients in both ON and OFF L Dopa conditions(12 hours after levodopa intake)
- search for correlation between the severity of motor impairment of parkinsonian patients and the percentage of error in categorization tasks(12 hours after levodopa intake)
- search for correlation between the severity of motor impairment of parkinsonian patients and the increase of early visual evoked potentials components latency(12 hours after levodopa intake)