Critical Flicker Fusion Threshold in patients with Alzheimer's disease and vascular dementia

Curran, Stephen; Wilson, Simon; Musa, Shabir; Wattis, John

doi:10.1002/gps.1134

Cited by 21 publications

(20 citation statements)

References 24 publications

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“…In the ascending method, the LED frequency was set at 15 Hz and gradually increased, and the subject had to report when the flickering LED became continuous. In the descending method, the LED frequency was set at 60 Hz and gradually decreased, and the subject had to report when the continuous LED started to flicker [10], [30], [31]. The threshold was defined as the average of the three consecutive measurements.…”

Section: Methodsmentioning

confidence: 99%

Inferior Parietal Lobule Encodes Visual Temporal Resolution Processes Contributing to the Critical Flicker Frequency Threshold in Humans

et al. 2014

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The measurement of the Critical Flicker Frequency threshold is used to study the visual temporal resolution in healthy subjects and in pathological conditions. To better understand the role played by different cortical areas in the Critical Flicker Frequency threshold perception we used continuous Theta Burst Stimulation (cTBS), an inhibitory plasticity-inducing protocol based on repetitive transcranial magnetic stimulation. The Critical Flicker Frequency threshold was measured in twelve healthy subjects before and after cTBS applied over different cortical areas in separate sessions. cTBS over the left inferior parietal lobule altered the Critical Flicker Frequency threshold, whereas cTBS over the left mediotemporal cortex, primary visual cortex and right inferior parietal lobule left the Critical Flicker Frequency threshold unchanged. No statistical difference was found when the red or blue lights were used. Our findings show that left inferior parietal lobule is causally involved in the conscious perception of Critical Flicker Frequency and that Critical Flicker Frequency threshold can be modulated by plasticity-inducing protocols.

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Section: Methodsmentioning

confidence: 99%

Inferior Parietal Lobule Encodes Visual Temporal Resolution Processes Contributing to the Critical Flicker Frequency Threshold in Humans

et al. 2014

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“…Whether the navigational impairments in these cognitive normal older adults may be a pre-clinical sign of AD may require further longitudinal assessments, possibly in combination with genetic risk factors. In addition, further studies are required to delineate the relationship between motion processing impairments in AD and what may be a fundamental insensitivity to the temporal dynamics of visual stimuli (204, 205), possibly linked to underlying retinal pathology (192, 206), and genetic risk factors for AD.…”

Section: Visual System In Aging and Admentioning

confidence: 99%

At the interface of sensory and motor dysfunctions and Alzheimer's disease

Albers

Gilmore

Kaye

et al. 2014

Alzheimer's & Dementia

482

379

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Recent evidence indicates that sensory and motor changes may precede the cognitive symptoms of Alzheimer’s disease (AD) by several years and may signify increased risk of developing AD. Traditionally, sensory and motor dysfunctions in aging and AD have been studied separately. To ascertain the evidence supporting the relationship between age-related changes in sensory and motor systems and the development of AD and to facilitate communication between several disciplines, the National Institute on Aging held an exploratory workshop titled “Sensory and Motor Dysfunctions in Aging and Alzheimer’s Disease”. The scientific sessions of the workshop focused on age-related and neuropathological changes in the olfactory, visual, auditory, and motor systems, followed by extensive discussion and hypothesis generation related to the possible links among sensory, cognitive, and motor domains in aging and AD. Based on the data presented and discussed at this workshop, it is clear that sensory and motor regions of the CNS are affected by Alzheimer pathology and that interventions targeting amelioration of sensory-motor deficits in AD may enhance patient function as AD progresses.

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“…In one study, CFFF was able to differentiate between AD (n = 30) and VaD (n = 16), but these results need to be replicated. 75 …”

Section: Motion Perceptionmentioning

confidence: 99%

Oculo‐visual changes and clinical considerations affecting older patients with dementia

Armstrong

Kergoat

2015

Ophthalmic Physiologic Optic

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Purpose Dementia is associated with various alterations of the eye and visual function. Over 60% of cases are attributable to Alzheimer's disease, a significant proportion of the remainder to vascular dementia or dementia with Lewy bodies, while frontotemporal dementia, and Parkinson's disease dementia are less common. This review describes the oculo‐visual problems of these five dementias and the pathological changes which may explain these symptoms. It further discusses clinical considerations to help the clinician care for older patients affected by dementia. Recent findings Visual problems in dementia include loss of visual acuity, defects in colour vision and visual masking tests, changes in pupillary response to mydriatics, defects in fixation and smooth and saccadic eye movements, changes in contrast sensitivity function and visual evoked potentials, and disturbance of complex visual functions such as in reading ability, visuospatial function, and the naming and identification of objects. Pathological changes have also been reported affecting the crystalline lens, retina, optic nerve, and visual cortex. Clinically, issues such as cataract surgery, correcting the refractive error, quality of life, falls, visual impairment and eye care for dementia have been addressed. Summary Many visual changes occur across dementias, are controversial, often based on limited patient numbers, and no single feature can be regarded as diagnostic of any specific dementia. Nevertheless, visual hallucinations may be more characteristic of dementia with Lewy bodies and Parkinson's disease dementia than Alzheimer's disease or frontotemporal dementia. Differences in saccadic eye movement dysfunction may also help to distinguish Alzheimer's disease from frontotemporal dementia and Parkinson's disease dementia from dementia with Lewy bodies. Eye care professionals need to keep informed of the growing literature in vision/dementia, be attentive to signs and symptoms suggestive of cognitive impairment, and be able to adapt their practice and clinical interventions to best serve patients with dementia.

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Critical Flicker Fusion Threshold in patients with Alzheimer's disease and vascular dementia

Abstract: CFFT could be useful as a screening instrument for early AD when combined with other measures and could facilitate the decision to commence antidementia treatment at an early stage. Further longitudinal work is needed to establish this.

Cited by 21 publications

References 24 publications

Inferior Parietal Lobule Encodes Visual Temporal Resolution Processes Contributing to the Critical Flicker Frequency Threshold in Humans

Inferior Parietal Lobule Encodes Visual Temporal Resolution Processes Contributing to the Critical Flicker Frequency Threshold in Humans

At the interface of sensory and motor dysfunctions and Alzheimer's disease

Oculo‐visual changes and clinical considerations affecting older patients with dementia

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