scholarly journals Visuospatial alpha and gamma oscillations scale with the severity of cognitive dysfunction in patients on the Alzheimer’s disease spectrum

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Alex I. Wiesman ◽  
Daniel L. Murman ◽  
Pamela E. May ◽  
Mikki Schantell ◽  
Sara L. Wolfson ◽  
...  

Abstract Background Entrainment of neural oscillations in occipital cortices by external rhythmic visual stimuli has been proposed as a novel therapy for patients with Alzheimer’s disease (AD). Despite this increased interest in visual neural oscillations in AD, little is known regarding their role in AD-related cognitive impairment and in particular during visuospatial processing. Methods We used source-imaged magnetoencephalography (MEG) and an established visuospatial processing task to elicit multi-spectral neuronal responses in 35 biomarker-confirmed patients on the AD spectrum and 20 biomarker-negative older adults. Neuronal oscillatory responses were imaged to the level of the cortex, and group classifications and neurocognitive relationships were modeled using logistic and linear regression, respectively. Results Visuospatial neuronal oscillations in the theta, alpha, and gamma ranges significantly predicted the classification of patients on the AD spectrum. Importantly, the direction of these effects differed by response frequency, such that patients on the AD spectrum exhibited weaker alpha-frequency responses in lateral occipital regions, and stronger gamma-frequency responses in the primary visual cortex, as compared to biomarker-negative older adults. In addition, alpha and gamma, but not theta, oscillations robustly predicted cognitive status (i.e., MoCA and MMSE scores), such that patients with neural responses that deviated more from those of healthy older adults exhibited poorer cognitive performance. Conclusions We find that the multi-spectral neural dynamics supporting visuospatial processing differentiate patients on the AD spectrum from cognitively normal, biomarker-negative older adults. Oscillations in the alpha and gamma bands also relate to cognitive status in ways that are informative for emerging clinical interventions.

2019 ◽  
Vol 31 (5) ◽  
pp. 607-615 ◽  
Author(s):  
Laura Dewitte ◽  
Mathieu Vandenbulcke ◽  
Jessie Dezutter

ABSTRACTObjectives:To examine whether previously established associations between experiences of meaning in life on the one hand and life satisfaction and depressive symptoms on the other hand are transferable to a population of older residential care residents with Alzheimer’s disease (AD).Design:Cross-sectional study using questionnaires administered in a structured interview format.Setting:Nine residential care settings in Flanders, Belgium.Participants:Convenience sample of 138 older adults (+65) living in residential care with a diagnosis of AD.Measurements:Meaning in life was measured using the Presence of Meaning (PoM) subscale of the Meaning in Life Questionnaire-Short Form, life satisfaction was measured using the Satisfaction With Life Scale (SWLS), depressive symptoms were measured using a five-item short form of the Geriatric Depression Scale (GDS), and general cognitive status was measured using the Mini-Mental State Examination (MMSE).Results:Controlling for demographic variables (age, sex, and marital status) and cognitive status, meaning in life scores were positively predictive of life satisfaction scores and negatively predictive of depressive symptoms. Post-hoc analyses suggested a possible interaction between meaning in life and cognitive status in predicting both outcomes of psychological functioning (GDS and SWLS).Conclusion:The presence of meaning in life is related to important well-being outcomes for older adults with AD living in residential care. More awareness for the importance of existential themes and interventions fostering meaning might be warranted for this population.


2020 ◽  
Vol 77 (3) ◽  
pp. 1291-1304
Author(s):  
Danielle L. Sanchez ◽  
Kelsey R. Thomas ◽  
Emily C. Edmonds ◽  
Mark W. Bondi ◽  
Katherine J. Bangen ◽  
...  

Background: Increasing evidence indicates that cerebrovascular dysfunction may precede cognitive decline in aging and Alzheimer’s disease (AD). Reduced cerebral blood flow (CBF) is associated with cognitive impairment in older adults. However, less is known regarding the association between CBF and functional decline, and whether CBF predicts functional decline beyond cerebrovascular and metabolic risk factors. Objective: To examine the association between regional CBF and functional decline in nondemented older adults. Method: One hundred sixty-six (N = 166) participants without dementia from the Alzheimer’s Disease Neuroimaging Initiative underwent neuropsychological testing and neuroimaging. Pulsed arterial spin labeling magnetic resonance imaging was acquired to quantify resting CBF. Everyday functioning was measured using the Functional Assessment Questionnaire at baseline and annual follow-up visit across three years. Results: Adjusting for age, education, sex, cognitive status, depression, white matter hyperintensity volume, cerebral metabolism, and reference (precentral) CBF, linear mixed effects models showed that lower resting CBF at baseline in the medial temporal, inferior temporal, and inferior parietal lobe was significantly associated with accelerated decline in everyday functioning. Results were similar after adjusting for conventional AD biomarkers, including cerebrospinal fluid (CSF) amyloid-β (Aβ) and hyperphosphorylated tau (p-tau) and apolipoprotein E (APOE) ɛ4 positivity. Individuals who later converted to dementia had lower resting CBF in the inferior temporal and parietal regions compared to those who did not. Conclusion: Lower resting CBF in AD vulnerable regions including medial temporal, inferior temporal, and inferior parietal lobes predicted faster rates of decline in everyday functioning. CBF has utility as a biomarker in predicting functional declines in everyday life and conversion to dementia.


2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 141-141
Author(s):  
Tina Brinkley ◽  
Samuel Lockhart ◽  
Bonnie Sachs ◽  
Maryjo Cleveland ◽  
Benjamin Williams ◽  
...  

Abstract Mid-life obesity is associated with a higher risk for Alzheimer’s disease (AD). However, this association is attenuated or even reversed in late-life, when weight loss may be a preclinical sign of AD. While neuropathological changes likely occur alongside aging-related changes in body composition, this has not been largely investigated. We aimed to determine the association between adiposity and a specific pattern of reduced cortical thickness associated with AD risk and progression. Global and regional adiposity (via dual-energy x-ray absorptiometry) and AD-signature cortical thickness (via surface-based cortical analysis of 3T brain MRI scans) were measured in 35 middle-aged and older adults from the Wake Forest Alzheimer’s Disease Clinical Core (mean age: 69.4±7.8 years, 80% female, 91% White, 29% cognitively impaired). Partial correlations adjusted for age, sex, and cognitive status were examined overall and stratified by age (0.59, p≤0.05). No significant associations were observed in middle-aged adults. These findings suggest that AD-related cortical thinning may be accompanied by a global reduction in body fat among older adults.


Salud Mental ◽  
2019 ◽  
Vol 42 (6) ◽  
pp. 281-287
Author(s):  
Sara Gloria Aguilar-Navarro ◽  
Alberto José Mimenza-Alvarado ◽  
Rafael Martínez-Sánchez ◽  
Silvia Mejía-Arango ◽  
Lidia Gutiérrez-Gutiérrez ◽  
...  

Introduction. “Episodic” memory problems are common in people with cognitive impairment due to Alzheimer’s disease and related disorders. Dubois et al. developed the Five-Word Test (5WT) to evaluate episodic memory, which has proved to be an easy and valid test for identifying cognitive disorders. However, its validation and cultural adaptation from French to Spanish has not been undertaken and its usefulness in Mexican population is unknown. Objective. Validation and cultural adaptation of the 5WT for screening minor and major neurocognitive disorder (ND) in Mexican older adults with probable Alzheimer’s disease. Method. Two hundred and fifteen participants (70 cognitively healthy subjects, 73 with minor ND and 72 with major ND were included). The cognitive status (gold standard) was determined using current clinical criteria and neuropsychological evaluation. The Spearman coefficient, ROC curve, and multinomial logistic regression models were used to determine the concurrent validity of the 5WT. Results. The correlation between the 5WT and the Mini-Mental State Exam (MMSE) was .58, whereas for the clock face test it was -.37 (p < .001). The area under the 5WT curve was .97 (95% CI [.94, .99]), with a cut-off point of ≤ 16/20 for the diagnosis of major ND (89% sensitivity, 98% specificity) and .77 (95% CI [.70, .85]) for minor ND with a cut-off point of ≤ 18/20 (66% sensitivity, 77% specificity). Discussion and conclusion. Since the 5WT is a simple, valid instrument for the identification of neurocognitive disorders like Alzheimer’s disease, it could be a practical screening test.


2019 ◽  
Vol 42 ◽  
Author(s):  
Colleen M. Kelley ◽  
Larry L. Jacoby

Abstract Cognitive control constrains retrieval processing and so restricts what comes to mind as input to the attribution system. We review evidence that older adults, patients with Alzheimer's disease, and people with traumatic brain injury exert less cognitive control during retrieval, and so are susceptible to memory misattributions in the form of dramatic levels of false remembering.


Author(s):  
Eun Jin Paek ◽  
Si On Yoon

Purpose Speakers adjust referential expressions to the listeners' knowledge while communicating, a phenomenon called “audience design.” While individuals with Alzheimer's disease (AD) show difficulties in discourse production, it is unclear whether they exhibit preserved partner-specific audience design. The current study examined if individuals with AD demonstrate partner-specific audience design skills. Method Ten adults with mild-to-moderate AD and 12 healthy older adults performed a referential communication task with two experimenters (E1 and E2). At first, E1 and participants completed an image-sorting task, allowing them to establish shared labels. Then, during testing, both experimenters were present in the room, and participants described images to either E1 or E2 (randomly alternating). Analyses focused on the number of words participants used to describe each image and whether they reused shared labels. Results During testing, participants in both groups produced shorter descriptions when describing familiar images versus new images, demonstrating their ability to learn novel knowledge. When they described familiar images, healthy older adults modified their expressions depending on the current partner's knowledge, producing shorter expressions and more established labels for the knowledgeable partner (E1) versus the naïve partner (E2), but individuals with AD were less likely to do so. Conclusions The current study revealed that both individuals with AD and the control participants were able to acquire novel knowledge, but individuals with AD tended not to flexibly adjust expressions depending on the partner's knowledge state. Conversational inefficiency and difficulties observed in AD may, in part, stem from disrupted audience design skills.


2010 ◽  
Vol 15 (1) ◽  
pp. 4-11 ◽  
Author(s):  
Sridhar Krishnamurti

Alzheimer's disease is neurodegenerative disorder which affects a growing number of older adults every year. With an understanding of auditory dysfunction in Alzheimer's disease, the speech-language pathologist working in the health care setting can provide better service to these individuals. The pathophysiology of the disease process in Alzheimer's disease increases the likelihood of specific types of auditory deficits as opposed to others. This article will discuss the auditory deficits in Alzheimer's disease, their implications, and the value of clinical protocols for individuals with this disease.


GeroPsych ◽  
2020 ◽  
pp. 1-6
Author(s):  
Molly Maxfield ◽  
Jennifer R. Roberts ◽  
JoAnna Dieker

Abstract. Two clients seeking neuropsychological assessment reported anxiety about their cognitive status. We review the cases to increase our understanding of factors contributing to dementia-related anxiety. Case 1 met the criteria for mild neurocognitive disorder; the client’s memory was impaired, and she had a high genetic risk for Alzheimer’s disease. The client reported anxiety about negative perceptions of quality of life among individuals diagnosed with Alzheimer’s disease. Case 2 did not meet the criteria for a neurocognitive disorder. Anxiety about this client’s cognitive status appeared attributable to generalized anxiety disorder, given his anxiety about diverse topics. Both clients reported embarrassment about forgetfulness and social withdrawal. Dementia-related anxiety is believed to be relatively common, to exist on a continuum, to have unique social implications, and to stem from various sources, necessitating differing interventions.


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