Contrast sensitivity impairment in drug-naïve Parkinson's disease patients associates with early cognitive decline

Influence of Dementia on Vision-Related Functional Performance Among Patients With Type 2 Diabetes

IMPORTANCE

Complications of Type 2 diabetes mellitus (T2DM) leading to vision loss may increase the risk of dementia. The relationship between diabetic retinopathy severity and visual acuity (VA) has been explored, but the impact of dementia on vision-related functional performance in patients with T2DM is less understood.

OBJECTIVE

To investigate the association of diabetes-related eye problems with dementia and the impact of dementia on vision-related quality of life (VRQoL) and activities of daily living (ADLs) in patients with T2DM.

DESIGN

Retrospective cohort and nested case-control study.

SETTING

Health care institution.

PARTICIPANTS

Substudy 1 included 4,454 patients with T2DM. In Substudy 2, 33 patients with T2DM and dementia (male, n = 15; M age = 78.7 yr) were compared with 67 matched control participants (male, n = 36; M age = 76.6 yr).

OUTCOMES AND MEASURES

Patients with and without dementia were assessed with the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ 25) and the Revised Self-Report Assessment of Functional Visual Performance (R-SRAFVP).

RESULTS

Substudy 1 showed a borderline significant association between proliferative diabetic retinopathy and dementia. In Substudy 2, functional vision, particularly in the overall scales and three subscales of the R-SRAFVP and four subscales of the NEI-VFQ 25, declined significantly among patients with T2DM and dementia, but no significant differences were found in VA.

CONCLUSIONS AND RELEVANCE

The findings illustrate the complex relationships among T2DM, dementia, VRQoL, and vision-dependent ADL and suggest that occupational therapists who care for patients with T2DM and dementia should pay close attention to patients' functional vision. Plain-Language Summary: Complications of Type 2 diabetes mellitus (T2DM) that lead to vision loss may increase the risk of dementia. People with T2DM and dementia show a significant decline in functional vision. This study investigated the relationship between diabetes-related eye problems and dementia as well as the impact of dementia on vision-related quality of life and activities of daily living for patients with T2DM. The study demonstrates the complex relationships among dementia, T2DM, eye conditions, and vision-related function. The results highlight the importance of a functional vision assessment for patients with T2DM and dementia. Occupational therapists who care for patients with T2DM and dementia should pay close attention to patients' functional vision, which will guide them in assessment and intervention planning.

Regional cerebral cholinergic vesicular transporter correlates of visual contrast sensitivity in Parkinson's disease: Implications for visual and cognitive function

Visual and visual processing deficits are implicated in freezing, falling, and cognitive impairments in Parkinson's disease (PD). In particular, contrast sensitivity deficits are common and may be related to cognitive impairment in PD. While dopaminergic deficits play a role in PD-related visual dysfunction, brain cholinergic systems also modulate many aspects of visual processing. The aim of this study was to explore regional cerebral cholinergic terminal density correlates of contrast sensitivity in PD. Ninety-one PD subjects underwent contrast sensitivity testing, motor testing, cognitive testing, and brain MRI and [18F]-fluoroethoxybenzovesamicol [18F]-FEOBV PET imaging. Whole brain false discovery error-corrected (p < 0.05) correlations revealed significant associations between VAChT deficits in pericentral, limbic, and visual processing regions and contrast sensitivity performance, independent of disease duration and dopaminergic medication doses. These results suggest that brain cholinergic deficits correlate with contrast sensitivity deficits in PD. Additionally, decreased Rabin contrast sensitivity scores were associated with lower total scores in the Parkinson's Disease Cognitive Rating Scale. These findings suggest that diminished cognitive performance correlated with contrast sensitivity partly reflects underlying vulnerabilities of brain cholinergic systems.

Narrative Review Concerning the Clinical Spectrum of Ophthalmological Impairments in Parkinson's Disease

Ophthalmic non-motor impairments are common in Parkinson's disease patients, from the onset of the neurodegenerative disease and even prior to the development of motor symptoms. This is a very crucial component of the potential for early detection of this disease, even in its earliest stages. Since the ophthalmological disease is extensive and impacts all extraocular and intraocular components of the optical analyzer, a competent assessment of it would be beneficial for the patients. Because the retina is an extension of the nervous system and has the same embryonic genesis as the central nervous system, it is helpful to investigate the retinal changes in Parkinson's disease in order to hypothesize insights that may also be applicable to the brain. As a consequence, the detection of these symptoms and signs may improve the medical evaluation of PD and predict the illness' prognosis. Another valuable aspect of this pathology is the fact that the ophthalmological damage contributes significantly to the decrease in the quality of life of patients with Parkinson's disease. We provide an overview of the most significant ophthalmologic impairments associated with Parkinson's disease. These results certainly constitute a large number of the prevalent visual impairments experienced by PD patients.

Multimodal brain and retinal imaging of dopaminergic degeneration in Parkinson disease

Parkinson disease (PD) is a progressive disorder characterized by dopaminergic neurodegeneration in the brain. The development of parkinsonism is preceded by a long prodromal phase, and >50% of dopaminergic neurons can be lost from the substantia nigra by the time of the initial diagnosis. Therefore, validation of in vivo imaging biomarkers for early diagnosis and monitoring of disease progression is essential for future therapeutic developments. PET and single-photon emission CT targeting the presynaptic terminals of dopaminergic neurons can be used for early diagnosis by detecting axonal degeneration in the striatum. However, these techniques poorly differentiate atypical parkinsonian syndromes from PD, and their availability is limited in clinical settings. Advanced MRI in which pathological changes in the substantia nigra are visualized with diffusion, iron-sensitive susceptibility and neuromelanin-sensitive sequences potentially represents a more accessible imaging tool. Although these techniques can visualize the classic degenerative changes in PD, they might be insufficient for phenotyping or prognostication of heterogeneous aspects of PD resulting from extranigral pathologies. The retina is an emerging imaging target owing to its pathological involvement early in PD, which correlates with brain pathology. Retinal optical coherence tomography (OCT) is a non-invasive technique to visualize structural changes in the retina. Progressive parafoveal thinning and fovea avascular zone remodelling, as revealed by OCT, provide potential biomarkers for early diagnosis and prognostication in PD. As we discuss in this Review, multimodal imaging of the substantia nigra and retina is a promising tool to aid diagnosis and management of PD.

Treating hallucinations in Parkinson's disease

Introduction: Hallucinations in Parkinson's disease are common, can complicate medication management and significantly impact upon the quality of life of patients and their carers.Areas covered: This review aims to examine current evidence for the management of hallucinations in Parkinson's disease.Expert opinion: Treatment of hallucinations in Parkinson's disease should be both individualized and multifaceted. Screening, education, medication review and the avoidance of common triggers are important. For well-formed visual hallucinations, acetylcholinesterase inhibitors are recommended first-line. Refractory or severe symptoms may require the cautious use of atypical antipsychotics. Antidepressants may be beneficial in the appropriate setting. Unfortunately, current therapies for hallucinations offer only limited benefits and future research efforts are desperately required to improve the management of these challenging symptoms.