Visual dysfunction in Parkinson disease without dementia
ABSTRACT To determine the profiles of visual dysfunction and their relationship to motor and cognitive dysfunction and to disability in mild to moderate Parkinson disease (PD) without dementia.
Seventy-six independently living participants with mild to moderate PD and 161 neurologically normal older adults were studied using a comprehensive battery to assess visual acuity, contrast sensitivity (CS), visual speed of processing and attention, spatial and motion perception, visual and verbal memory, visuoconstructional abilities, executive functions, depression, and motor function.
Participants with PD scored significantly worse on all tests of vision and cognition compared with normal elderly persons. Reduced CS contributed to deficits on tests of spatial and motion perception and attention in participants with PD. Impairments in visual attention and spatial perception predicted worse cognitive function. Worse performances on tests of visual speed of processing and attention, spatial and motion perception, visual construction, and executive functions correlated with measures of postural instability and gait difficulty (in the Motor section of the Unified Parkinson's Disease Rating Scale). Impairments in motor function, visual memory, mood, and executive functions predicted worse disability as measured by Schwab-England Activities of Daily Living Scale.
Patients with mild to moderate Parkinson disease showed impaired visual perception and cognition compared with elderly control subjects. Visual dysfunction contributes to parkinsonian disability through its influences on cognition and locomotion.
- SourceAvailable from: Arash Yazdanbakhsh[Show abstract] [Hide abstract]
ABSTRACT: Parkinson's disease (PD) and normal aging have been associated with changes in visual perception, including reliance on external cues to guide behavior. This raises the question of the extent to which these groups use visual cues when disambiguating information. Twenty-seven individuals with PD, 23 normal control adults (NC), and 20 younger adults (YA) were presented a Necker cube in which one face was highlighted by thickening the lines defining the face. The hypothesis was that the visual cues would help PD and NC to exert better control over bistable perception. There were three conditions, including passive viewing and two volitional-control conditions (hold one percept in front; and switch: speed up the alternation between the two). In the Hold condition, the cue was either consistent or inconsistent with task instructions. Mean dominance durations (time spent on each percept) under passive viewing were comparable in PD and NC, and shorter in YA. PD and YA increased dominance durations in the Hold cue-consistent condition relative to NC, meaning that appropriate cues helped PD but not NC hold one perceptual interpretation. By contrast, in the Switch condition, NC and YA decreased dominance durations relative to PD, meaning that the use of cues helped NC but not PD in expediting the switch between percepts. Provision of low-level cues has effects on volitional control in PD that are different from in normal aging, and only under task-specific conditions does the use of such cues facilitate the resolution of perceptual ambiguity. (JINS, 2015, 21, 1-10).Journal of the International Neuropsychological Society 03/2015; 21(02):1-10. DOI:10.1017/S1355617715000065 · 3.01 Impact Factor
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ABSTRACT: Background In early stages of idiopathic Parkinson's disease (IPD), lower order vision (LOV) deficits including reduced colour and contrast discrimination have been consistently reported. Data are less conclusive concerning higher order vision (HOV) deficits, especially for facial emotion recognition (FER). However, a link between both visual levels has been hypothesized. Objective To screen for both levels of visual impairment in early IPD. Methods We prospectively recruited 28 IPD patients with disease duration of 1.4 +/− 0.8 years and 25 healthy controls. LOV was evaluated by Farnsworth-Munsell 100 Hue Test, Vis-Tech and Pelli-Robson test. HOV was examined by the Ekman 60 Faces Test and part A of the Visual Object and Space recognition test. Results IPD patients performed worse than controls on almost all LOV tests. The most prominent difference was seen for contrast perception at the lowest spatial frequency (p = 0.0002). Concerning FER IPD patients showed reduced recognition of “sadness” (p = 0.01). “Fear” perception was correlated with perception of low contrast sensitivity in IPD patients within the lowest performance quartile. Controls showed a much stronger link between “fear” perception” and low contrast detection. Conclusion At the early IPD stage there are marked deficits of LOV performances, while HOV performances are still intact, with the exception of reduced recognition of “sadness”. At this stage, IPD patients seem still to compensate the deficient input of low contrast sensitivity, known to be pivotal for appreciation of negative facial emotions and confirmed as such for healthy controls in this study.Journal of the neurological sciences 03/2014; 338(1-2). DOI:10.1016/j.jns.2013.12.047 · 2.26 Impact Factor
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ABSTRACT: We explored the effect and the difference between types of navigation maps (north-up map versus track-up map), landmarks, and the map complexity on the wayfinding abilities of Alzheimer’s disease (AD) patients. Our study included 48 participants (12 patients with AD, 12 patients with mild cognitive impairment (MCI), and 24 normal elderly subjects). We developed a virtual maze with 3Dmax and an interface with Virtools. Our results showed that the wayfinding abilities were worse in the AD group compared with the MCI group and the normal elderly. However, with the support of track-up maps, the AD group and the MCI group had similar performance as the normal elderly. The time spent on wayfinding decreased when using less complex maps and maps with no landmarks. All cognitive tests which we performed were significantly correlated with wayfinding abilities. Our study helped to establish future electric navigation maps built for patients with cognition impairment.11/2013; 30(6):394-404. DOI:10.1080/21681015.2013.846944