scholarly journals Measuring cerebral perfusion with [11C]-PiB R1 in down syndrome: associations with amyloid burden and longitudinal cognitive decline

2020 ◽  
Author(s):  
Elijah Mak ◽  
Monika Grigorova ◽  
Jessica Beresford-Webb ◽  
Maura Malpetti ◽  
Madeline Walpert ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Cognitive Impairment ◽  
Cortical Thickness ◽  
Cerebral Perfusion ◽  
Structural Data ◽  
Amyloid Burden ◽  
Reference Tissue ◽  
Pittsburgh Compound B ◽  
Simplified Reference Tissue Model ◽  
The Impact

Abstract PET imaging of glucose hypometabolism and amyloid deposition are two well-established methods to evaluate preclinical changes in Alzheimer’s disease and people with Down syndrome. However, the use of both imaging modalities may overburden participants, particularly those with intellectual disabilities and cognitive impairment. The relative tracer delivery of the [11C]-Pittsburgh Compound B has been proposed as a viable surrogate for cerebral perfusion. Here, we studied the impact of amyloid pathology on perfusion changes in Down syndrome and evaluated its associations with cognitive impairment. 47 adults with Down syndrome underwent the [11C]-Pittsburgh Compound B imaging and structural imaging. The structural data were processed with Freesurfer to obtain anatomical segmentations and cortical thickness. The relative tracer delivery from [11C]-Pittsburgh Compound B was derived using a simplified reference tissue model. The sample was stratified into those with minimal amyloid burden (n = 25) and those with elevated amyloid (n = 22). We found significant and widespread reductions of cerebral perfusion in those with elevated amyloid burden, independent of age, gender, cognitive function and cortical thickness. In addition, cerebral perfusion was associated with the cognitive impairment amongst the Down syndrome group with elevated amyloid burden. These findings highlight the promising utility of the relative tracer delivery of the [11C]-Pittsburgh Compound B as a surrogate index in clinical trials for monitoring disease progression or tracking physiologic changes over time in Down syndrome.

scholarly journals Reduced acquisition time PET pharmacokinetic modelling using simultaneous ASL–MRI: proof of concept

2018 ◽  
Vol 39 (12) ◽  
pp. 2419-2432 ◽  
Author(s):  
Catherine J Scott ◽  
Jieqing Jiao ◽  
Andrew Melbourne ◽  
Ninon Burgos ◽  
David M Cash ◽  
...  
Keyword(s):  
Blood Flow ◽  
Amyloid Β ◽  
Acquisition Time ◽  
Amyloid Burden ◽  
Pharmacokinetic Modelling ◽  
Reference Tissue ◽  
Positron Emission ◽  
Magnetic Resonance Imaging Mri ◽  
Simplified Reference Tissue Model ◽  
Dynamic Acquisition

Pharmacokinetic modelling on dynamic positron emission tomography (PET) data is a quantitative technique. However, the long acquisition time is prohibitive for routine clinical use. Instead, the semi-quantitative standardised uptake value ratio (SUVR) from a shorter static acquisition is used, despite its sensitivity to blood flow confounding longitudinal analysis. A method has been proposed to reduce the dynamic acquisition time for quantification by incorporating cerebral blood flow (CBF) information from arterial spin labelling (ASL) magnetic resonance imaging (MRI) into the pharmacokinetic modelling. In this work, we optimise and validate this framework for a study of ageing and preclinical Alzheimer's disease. This methodology adapts the simplified reference tissue model (SRTM) for a reduced acquisition time (RT-SRTM) and is applied to [18F]-florbetapir PET data for amyloid-β quantification. Evaluation shows that the optimised RT-SRTM can achieve amyloid burden estimation from a 30-min PET/MR acquisition which is comparable with the gold standard SRTM applied to 60 min of PET data. Conversely, SUVR showed a significantly higher error and bias, and a statistically significant correlation with tracer delivery due to the influence of blood flow. The optimised RT-SRTM produced amyloid burden estimates which were uncorrelated with tracer delivery indicating its suitability for longitudinal studies.

P2-426: HIPPOCAMPAL TEXTURE IN HEALTHY COGNITION AND MILD COGNITIVE IMPAIRMENT: THE IMPACT OF AMYLOID BURDEN AND SEX

2006 ◽  
Vol 14 (7S_Part_16) ◽  
pp. P874-P875
Author(s):  
Jessica Z.K. Caldwell ◽  
Akshay Pai ◽  
Lauge Sørensen ◽  
Jaeson Kaylegian ◽  
Jeffrey L. Cummings ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Amyloid Burden ◽  
The Impact

scholarly journals In Vivo Cortical Microstructure - A Proxy for Tauopathy & Cognitive Impairment

2021 ◽  
Author(s):  
John A.E. Anderson ◽  
Christin Schifani ◽  
Arash Nazeri ◽  
Aristotle N. Voineskos
Keyword(s):  
Older Adults ◽  
Cognitive Impairment ◽  
Cortical Thickness ◽  
Free Water ◽  
Multiple Factor Analysis ◽  
Mediation Analyses ◽  
Positron Emission ◽  
Proxy Measure ◽  
The Impact

Aggregation of hyperphosphorylated tau protein is currently one of the most reliable indicators of Alzheimer's pathology and cognitive impairment in older adults. However, it would be useful to have a non-invasive, accessible proxy measure that does not rely on Positron Emission Tomography (PET). We used data from multi-shell diffusion-weighted imaging (DWI) to assess indices from the Neurite Orientation Dispersion and Density Imaging (NODDI) model to determine possible proxies for tau and relationship with cognitive impairment. After controlling for age, sex, and the time difference between the scan acquisitions (DWI vs. PET), we used multiple factor analysis (MFA) to assess the fit between NODDI indices (orientation dispersion [ODI], neurite density [NDI], and free-water [fISO]), cortical thickness, and tau binding (via PET). We used data from 80 participants from the ADNI-3 sample who had a multi-shell DWI and an [18F]AV-1451 (tau) PET scan. Of these 80, 49 individuals were considered cognitively normal older adults (age ~74 years), 26 individuals had a diagnosis of mild cognitive impairment (age ~75 years), and five individuals had Alzheimer's dementia (age ~78 years). fISO and tau shared a large amount of spatial overlap, and both strongly correlated with the first MFA dimension. Macrostructural features (such as cortical thickness and subcortical volume) introduced in a follow-up analysis were less related to this first MFA dimension than fISO and eight percent less than tau. Subsequent mediation analyses demonstrated that fISO mediated the relationship between cortical thickness and tau, explaining all of the variance. Microstructural features derived from advanced DWI acquisitions such as fISO may be useful proxies for tau. Cortical fISO, rather than cortical thickness, may represent the impact of tau on the brain (and, by extension, cognition).

scholarly journals The impact of hypertension on cerebral perfusion and cortical thickness in older adults

2014 ◽  
Vol 8 (8) ◽  
pp. 561-570 ◽  
Author(s):  
Michael L. Alosco ◽  
John Gunstad ◽  
Xiaomeng Xu ◽  
Uraina S. Clark ◽  
Donald R. Labbe ◽  
...  
Keyword(s):  
Older Adults ◽  
Cortical Thickness ◽  
Cerebral Perfusion ◽  
The Impact

Cognitive Impairment and Physical Activity in Old Age: The Impact on All-Cause Mortality in a 15-Year Follow-Up of the Bambuí Cohort Study of Aging

2020 ◽  
Author(s):  
Erico Castro-Costa ◽  
Jerson Laks ◽  
Cecilia Godoi Campos ◽  
Josélia OA Firmo ◽  
Maria Fernanda Lima-Costa ◽  
...  
Keyword(s):  
Physical Activity ◽  
Cohort Study ◽  
Cognitive Impairment ◽  
Old Age ◽  
All Cause Mortality ◽  
The Impact

MHealth Applications for People with Cognitive Impairment and Their Caregivers: A Scoping Review (Preprint)

2020 ◽  
Author(s):  
Qing Zhao ◽  
Pei Chen ◽  
Yu Zhang ◽  
Haining Liu ◽  
Xianwen Li
Keyword(s):  
Cognitive Impairment ◽  
Sample Size ◽  
Research Design ◽  
Scoping Review ◽  
Life Support ◽  
Small Sample ◽  
Mobile Technologies ◽  
Control Group ◽  
Caregiver Support ◽  
The Impact

BACKGROUND Mobile health application has become an important tool for healthcare systems. One such tool is the delivery of assisting in people with cognitive impairment and their caregivers. OBJECTIVE This scoping review aims to explore and evaluate the existing evidence and challenges on the use of mHealth applications that assisting in people with cognitive impairment and their caregivers. METHODS Nine databases, including PubMed, EMBASE, Cochrane, PsycARTICLES, CINAHL, Web of Science, Applied Science & Technology Source, IEEE Xplore and the ACM Digital Library were searched from inception through June 2020 for the studies of mHealth applications on people with cognitive impairment and their caregivers. Two reviewers independently extracted, checked synthesized data independently. RESULTS Of the 6101 studies retrieved, 64 studies met the inclusion criteria. Three categories emerged from this scoping review. These categories are ‘application functionality’, ‘evaluation strategies’, ‘barriers and challenges’. All the included studies were categorized into 7 groups based on functionality: (1) cognitive assessment; (2) cognitive training; (3) life support; (4) caregiver support; (5) symptom management; (6) reminiscence therapy; (7) exercise intervention. The included studies were broadly categorized into four types: (1) Usability testing; (2) Pilot and feasibility studies; (3) Validation studies; and (4) Efficacy or Effectiveness design. These studies had many defects in research design such as: (1) small sample size; (2) deficiency in active control group; (3) deficiency in analyzing the effectiveness of intervention components; (4) lack of adverse reactions and economic evaluation; (5) lack of consideration about the education level, electronic health literacy and smartphone proficiency of the participants; (6) deficiency in assessment tool; (7) lack of rating the quality of mHealth application. Some progress should be improved in the design of smartphone application functionality, such as: (1) the design of cognitive measurements and training game need to be differentiated; (2) reduce the impact of the learning effect. Besides this, few studies used health behavior theory and performed with standardized reporting. CONCLUSIONS Preliminary results show that mobile technologies facilitate the assistance in people with cognitive impairment and their caregivers. The majority of mHealth application interventions incorporated usability outcome and health outcomes. However, these studies have many defects in research design that limit the extrapolation of research. The content of mHealth application is urgently improved to adapt to demonstrate the real effect. In addition, further research with strong methodological rigor and adequate sample size are needed to examine the feasibility, effectiveness, and cost-effectiveness of mHealth applications for people with cognitive impairment and their caregivers.

The Oxford Handbook of Adult Cognitive Disorders

2019 ◽  
Keyword(s):  
Cognitive Impairment ◽  
Cognitive Function ◽  
Neurodevelopmental Disorders ◽  
Brain Aging ◽  
Cognitive Disorders ◽  
Diverse Range ◽  
Medical Specialties ◽  
Psychiatric Illnesses ◽  
Medical Disorders ◽  
The Impact

The prevalence of cognitive impairment caused by neurodegenerative diseases and other neurologic disorders associated with aging is expected to rise dramatically between now and year 2050, when the population of Americans aged 65 or older will nearly double. Cognitive impairment also commonly occurs in other neurologic conditions, as well as in non-neurologic medical disorders (and their treatments), idiopathic psychiatric illnesses, and adult neurodevelopmental disorders. Cognitive impairment can thus infiltrate all aspects of healthcare, making it necessary for clinicians and clinical researchers to have an integrated knowledge of the spectrum of adult cognitive disorders. The Oxford Handbook of Adult Cognitive Disorders is meant to serve as an up-to-date, scholarly, and comprehensive volume covering most diseases, conditions, and injuries resulting in impairments in cognitive function in adults. Topics covered include normal cognitive and brain aging, the impact of medical disorders (e.g., cardiovascular, liver, pulmonary) and psychiatric illnesses (e.g., depression and bipolar disorder) on cognitive function, adult neurodevelopmental disorders (e.g., Down Syndrome, Attention Deficit/Hyperactivity Disorder), as well as the various neurological conditions (e.g., Alzheimer’s disease, chronic traumatic encephalopathy, concussion). A section of the Handbook is also dedicated to unique perspectives and special considerations for the clinicians and clinical researchers, covering topics such as cognitive reserve, genetics, diversity, and neuroethics. The target audience of this Handbook includes: (1) clinicians, particularly psychologists, neuropsychologists, neurologists (including behavioral and cognitive neurologists), geriatricians, and psychiatrists (including neuropsychiatrists), who provide clinical care and management for adults with a diverse range of cognitive disorders; (2) clinical researchers who investigate cognitive outcomes and functioning in adult populations; and (3) graduate level students and post-doctoral trainees studying psychology, clinical neuroscience, and various medical specialties.

Sign in / Sign up

Export Citation Format

Share Document