JMIR Ment Health
December 2024
Background: The early detection of mild cognitive impairment (MCI) is crucial for providing treatment before further decline. Cognitive challenge tests such as the Loewenstein-Acevedo Scales for Semantic Interference and Learning (LASSI-L™) can identify individuals at highest risk for cognitive deterioration. Performance on elements of the LASSI-L, particularly proactive interference, correlate with the presence of critical Alzheimer's Disease (AD) biomarkers.
View Article and Find Full Text PDFBackground: Semantic intrusion errors (SIEs) are both sensitive and specific to PET amyloid-β (Aβ) burden in older adults with amnestic mild cognitive impairment (aMCI).
Objective: Plasma Aβ biomarkers including the Aβ42/40 ratio using mass spectrometry are expected to become increasingly valuable in clinical settings. Plasma biomarkers are more clinically informative if linked to cognitive deficits that are salient to Alzheimer's disease (AD).
Neuroimaging and biofluid biomarkers provide a proxy of pathological changes for Alzheimer's disease (AD) and are useful in improving diagnosis and assessing disease progression. However, it is not clear how race/ethnicity and different prevalence of AD risks impact biomarker levels. In this narrative review, we survey studies focusing on comparing biomarker differences between non-Hispanic White American(s) (NHW), African American(s) (AA), Hispanic/Latino American(s) (HLA), and Asian American(s) with normal cognition, mild cognitive impairment, and dementia.
View Article and Find Full Text PDFDementia is a group of symptoms including memory loss, language difficulties, and other types of cognitive and functional impairments that affects 57 million people worldwide, with the incidence expected to double by 2040. Therefore, there is an unmet need to develop reliable biomarkers to diagnose early brain impairments so that emerging interventions can be applied before brain degeneration. Here, we performed biomarker analyses for apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), and amyloid-β 42/40 (Aβ) ratio in the plasma of older adults.
View Article and Find Full Text PDFIntroduction: Commercially available plasma p-tau217 biomarker tests are not well studied in ethnically diverse samples.
Methods: We evaluated associations between ALZPath plasma p-tau217 and amyloid-beta positron emission tomography (Aβ-PET) in Hispanic/Latino (88% of Cuban or South American ancestry) and non-Hispanic/Latino older adults. One- and two-cutoff ranges were derived and evaluated to assess agreement with Aβ-PET.
Front Psychol
June 2024
During the prodromal stage of Alzheimer's disease (AD), neurodegenerative changes can be identified by measuring volumetric loss in AD-prone brain regions on MRI. Cognitive assessments that are sensitive enough to measure the early brain-behavior manifestations of AD and that correlate with biomarkers of neurodegeneration are needed to identify and monitor individuals at risk for dementia. Weak sensitivity to early cognitive change has been a major limitation of traditional cognitive assessments.
View Article and Find Full Text PDFObjective: As the number of individuals diagnosed with dementia increases, so does the need to understand the preferences of persons living with dementia (PLWD) and caregivers for how clinicians can deliver a dementia diagnosis effectively, which can be a difficult process. This study describes the diagnostic communication preferences of PLWD and caregivers.
Methods: We conducted semi-structured individual phone interviews with two groups: PLWD who were diagnosed in the past two years ( = 11) and family caregivers of PLWD ( = 19) living in Florida.
Background And Objectives: Many individuals with dementia and their families report not receiving a dementia diagnosis. Previously published standards for delivering a dementia diagnosis are now more than 10 years old and were developed without patient and caregiver input. The objective of this study was to identify best practices for delivering a diagnosis of dementia using existing literature, involvement of diverse stakeholders, and consensus building through a formal modified Delphi approach.
View Article and Find Full Text PDFIntroduction: Alzheimer's disease studies often lack ethnic diversity.
Methods: We evaluated associations between plasma biomarkers commonly studied in Alzheimer's (p-tau181, GFAP, and NfL), clinical diagnosis (clinically normal, amnestic MCI, amnestic dementia, or non-amnestic MCI/dementia), and Aβ-PET in Hispanic and non-Hispanic older adults. Hispanics were predominantly of Cuban or South American ancestry.
Introduction: Semantic intrusion errors (SI) have distinguished between those with amnestic Mild Cognitive Impairment (aMCI) who are amyloid positive (A+) versus negative (A-) on positron emission tomography (PET).
Method: This study examines the association between SI and plasma - based biomarkers. One hundred and twenty-eight participants received SiMoA derived measures of plasma pTau-181, ratio of two amyloid-β peptide fragments (Aβ42/Aβ40), Neurofilament Light protein (NfL), Glial Fibrillary Acidic Protein (GFAP), ApoE genotyping, and amyloid PET imaging.
Objectives: There is currently a lack of consensus among neuropsychologists about which cognitive assessment paradigms hold the most promise in identifying subtle cognitive deficits in preclinical Alzheimer's Disease (AD) and which are most useful for monitoring risk of cognitive deterioration. Many widely used instruments are older versions of tests originally developed for the assessment of dementia or traumatic brain injury. Current efforts to digitize these measures provides more uniform and remote assessment, which is an advancement, but does not reflect significant changes in paradigmatic underpinnings or recent advances in cognitive neuroscience.
View Article and Find Full Text PDFBackground: LASSI-L is a novel neuropsychological test specifically designed for the early diagnosis of Alzheimer's disease (AD) based on semantic interference.
Objective: To examine the cognitive and neural underpinnings of the failure to recover from proactive semantic and retroactive semantic interference.
Methods: One hundred and fifty-five patients consulting for memory loss were included.
Background: Susceptibility to proactive semantic interference (PSI) and the inability to ameliorate these difficulties with one additional learning trial have repeatedly been implicated as early features of incipient Alzheimer's disease (AD). Unfortunately, persistent failure to recover from PSI (frPSI) after repeated learning trials, are not captured by existing memory measures, or been examined in pre-mild cognitive impairment (PreMCI).
Objective: A novel Cognitive Stress Test (CST) was employed to measure the impact of PSI, initial failure to recover from PSI and persistent effects of PSI, despite multiple learning trials of the new to-be-remembered material (pfrPSI).
Background: Individuals with cognitive impairment and their families place a high value on receiving a dementia diagnosis, but clinician approaches vary. There is a need for research investigating experiences of giving and receiving dementia diagnoses. The current study aimed to investigate clinician approaches to giving dementia diagnoses as part of a larger study investigating patient, caregiver, and clinician experiences during the diagnosis encounter.
View Article and Find Full Text PDFThere is a pressing need to develop measures that are sensitive to the earliest subtle cognitive changes of Alzheimer's disease (AD) to improve early detection and track disease progression. The Loewenstein-Acevedo Scales of Semantic Interference (LASSI-L) has been shown to successfully discriminate between cognitively unimpaired (CU) older adults and those with amnestic mild cognitive impairment (MCI) and to correlate with total and regional brain amyloid load. The present study investigated how the LASSI-L scores change over time among three distinct diagnostic groups.
View Article and Find Full Text PDFIntroduction: Among persons with amnestic mild cognitive impairment (aMCI), intrusion errors on subscales that measure proactive semantic interference (PSI) may be among the earliest behavioral markers of elevated Alzheimer's disease brain pathology. While there has been considerable cross-sectional work in the area, it is presently unknown whether semantic intrusion errors are predictive of progression of cognitive impairment in aMCI or PreMCI (not cognitively normal but not meeting full criteria for MCI).
Methods: This study examined the extent to which the percentage of semantic intrusion errors (PIE) based on total responses on a novel cognitive stress test, the Loewenstein-Acevedo Scales for Semantic Interference and Learning (LASSI-L), could predict clinical/cognitive outcomes over an average 26-month period in older adults initially diagnosed with aMCI, PreMCI, and normal cognition.
Introduction: There is increasing evidence that susceptibility to proactive semantic interference (PSI) and the failure to recover from PSI (frPSI) as evidenced by intrusion errors may be early cognitive markers of both preclinical and prodromal Alzheimer's disease (AD).
Methods: One hundred forty-five participants were administered extensive clinical and neuropsychological evaluations including the Loewenstein-Acevedo Scales for Semantic Interference and Learning (LASSI-L), a sensitive cognitive stress test measuring PSI and frPSI. Participants also underwent structural magnetic resonance imaging (MRI) and amyloid positron emission tomography/computed tomography (PET/CT) imaging.
The Coronavirus Disease 2019 (COVID-19) pandemic prompted the need for a teleneuropsychology protocol for the cognitive assessment of older adults, who are at increased risk for both COVID-19 and dementia. Prior recommendations for teleneuropsychological assessment did not consider many of the unique challenges posed by COVID-19. The field is still in need of clear guidelines and standards of care for the assessment of older adults under the current circumstances.
View Article and Find Full Text PDFBackground: Understanding patterns of multimorbidity in the US older adult population and their relationship with mortality is important for reducing healthcare utilization and improving health. Previous investigations measured multimorbidity as counts of conditions rather than specific combination of conditions.
Methods: This cross-sectional study with longitudinal mortality follow-up employed latent class analysis (LCA) to develop clinically meaningful subgroups of participants aged 50 and older with different combinations of 13 chronic conditions from the National Health Interview Survey 2002-2014.
Objective: To examine the direct and indirect effects of age, APOE ϵ4 genotype, amyloid positivity, and volumetric reductions in AD-prone brain regions as it relates to semantic intrusion errors reflecting proactive semantic interference (PSI) and the failure to recover from proactive semantic interference (frPSI) on the Loewenstein-Acevedo Scales of Semantic Interference and Learning (LASSI-L), a cognitive stress test that has been consistently more predictive of preclinical and prodromal Alzheimer's disease (AD) than traditional list-learning tests.
Design: Cross-sectional study.
Setting: 1Florida Alzheimer's Disease Research Center baseline study.
Background: Plasma NfL (pNfL) levels are elevated in many neurological disorders. However, the utility of pNfL in a clinical setting has not been established.
Objective: In a cohort of diverse older participants, we examined: 1) the association of pNfL to age, sex, Hispanic ethnicity, diagnosis, and structural and amyloid imaging biomarkers; and 2) its association to baseline and longitudinal cognitive and functional performance.
Background: The Loewenstein-Acevedo Scales for Semantic Interference and Learning (LASSI-L) is an increasingly utilized cognitive stress test designed to identify early cognitive changes associated with incipient neurodegenerative disease.
Objective: To examine previously derived cut-points for cognitively unimpaired older adults that were suggestive of performance impairment on multiple subscales of the LASSI-L. These cut-points were applied to a new sample of older adults who were cognitive healthy controls (HC: n = 26) and those on the Alzheimer's disease (AD) continuum from early stage mild cognitive impairment (EMCI: n = 28), late stage MCI (LMCI: n = 18) to mild AD (AD: n = 27).