The Contribution of Bilingualism to Cognitive Functioning and Regional Brain Volume in Normal and Abnormal Aging.

We examined the association between bilingualism, executive function (EF), and brain volume in older monolinguals and bilinguals who spoke English, Spanish, or both, and were cognitively normal (CN) or diagnosed with Mild Cognitive Impairment (MCI) or dementia. Gray matter volume (GMV) was higher in language and EF brain regions among bilinguals, but no differences were found in memory regions. Neuropsychological performance did not vary across language groups over time; however, bilinguals exhibited reduced Stroop interference and lower scores on Digit Span Backwards and category fluency.

Utility of Plasma Neurofilament Light in the 1Florida Alzheimer's Disease Research Center (ADRC).

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.

The Association Between Functional Assessment and Structural Brain Biomarkers in an Ethnically Diverse Sample With Normal Cognition, Mild Cognitive Impairment, or Dementia.

Objective: To investigate the association between the functional activities questionnaire (FAQ) and brain biomarkers (bilateral hippocampal volume [HV], bilateral entorhinal volume [ERV], and entorhinal cortical thickness [ERT]) in cognitively normal (CN) individuals, mild cognitive impairment (MCI), or dementia.

Method: In total, 226 participants (137 females; mean age = 71.76, SD = 7.

Depression and the Diagnosis of MCI in a Culturally Diverse Sample in the United States.

Objective: To analyze (1) whether there are ethnic differences in the severity of depressive symptoms between groups of elders classified as cognitively normal (CN) or amnestic mild cognitive impairment (aMCI) and (2) the influence of depressive symptoms on specific cognitive performance by ethnicity across diagnoses, controlling for covariates.

Methods: 164 Hispanics residing in the United States (HAs) and European Americans (EAs) (100 women; Mage = 72.1, SD = 8.

Types of errors on a semantic interference task in mild cognitive impairment and dementia.

Objective: This research aimed to determine whether qualitative analysis of different types of intrusion errors on a verbal cognitive task was useful in detecting subtle cognitive impairment in preclinical stages prior to the progression to dementia.

Method: Different types of semantic intrusions on the Loewenstein-Acevedo Scales of Semantic Interference and Learning (LASSI-L) were compared across 160 individuals diagnosed as cognitively normal (CN), amnestic Mild Cognitive Impairment (aMCI), and dementia. The sample included Hispanics and non-Hispanic European Americans.

Effects of Bilingualism on Verbal and Nonverbal Memory Measures in Mild Cognitive Impairment.

Objectives: Maintaining two active languages may increase cognitive and brain reserve among bilingual individuals. We explored whether such a neuroprotective effect was manifested in the performance of memory tests for participants with amnestic mild cognitive impairment (aMCI).

Methods: We compared 42 bilinguals to 25 monolinguals on verbal and nonverbal memory tests.

A Brief Computerized Paired Associate Test for the Detection of Mild Cognitive Impairment in Community-Dwelling Older Adults.

Background: Semantic memory interference has been found to be a predictive cognitive marker of incipient AD. This is relevant given that developing assessment paradigms to identify subtle cognitive and functional deficits is a priority in preclinical Alzheimer's disease research.

Objective: To examine the utility of a novel computerized paired associate test in distinguishing between mild cognitive impairment (MCI) and cognitively normal (CN) groups of older adults residing in the community.

A Novel Cognitive Stress Test for the Detection of Preclinical Alzheimer Disease: Discriminative Properties and Relation to Amyloid Load.

Objective: To examine the utility of a novel "cognitive stress test" to detect subtle cognitive impairments and amyloid load within the brains of neuropsychologically normal community-dwelling elders.

Methods: Participants diagnosed as cognitively normal (CN), subjective memory impairment (SMI), mild cognitive impairment (MCI), and preclinical mild cognitive impairment (PreMCI) were administered the Loewenstein-Acevedo Scale for Semantic Interference and Learning (LASSI-L), a sensitive test of proactive semantic interference (PSI), retroactive semantic interference, and, uniquely, the ability to recover from the effects of PSI. Ninety-three subjects (31 men and 62 women) were recruited from three academic institutions in a research consortium.

Proactive Semantic Interference is Associated with Total and Regional Abnormal Amyloid Load in Non-Demented Community-Dwelling Elders: A Preliminary Study.

Objective: To evaluate the relationship between susceptibility to proactive semantic interference (PSI) and retroactive semantic interference (RSI) and brain amyloid load in non-demented elders.

Methods: 27 participants (11 cognitively normal [CN] with subjective memory complaints, 8 CN without memory complaints, and 8 with mild cognitive impairment [MCI]) underwent complete neurological and neuropsychological evaluations. Participants also received the Semantic Interference Test (SIT) and AV-45 amyloid PET imaging.

The utility of age-specific cut-offs for visual rating of medial temporal atrophy in classifying Alzheimer's disease, MCI and cognitively normal elderly subjects.

Background: New research criteria for diagnosing Alzheimer's disease (AD) in the mild cognitive impairment stage (MCI-AD) incorporate biomarkers to assign a level of certainty to the diagnosis. Structural MRI is widely available but greatly under-utilized for assessing atrophy of structures affected in early AD, such as the hippocampus (HP), because the quantification of HP volumes (HP-v) requires special expertise, and normative values have not been established.

Methods: Elderly subjects (n =273) from the Florida ADRC were classified as having no cognitive impairment (cognitively normal, CN), amnestic mild cognitive impairment (aMCI) or AD.

Comparing new templates and atlas-based segmentations in the volumetric analysis of brain magnetic resonance images for diagnosing Alzheimer's disease.

Background: The segmentation of brain structures on magnetic resonance imaging scans for calculating regional brain volumes, using automated anatomic labeling, requires the use of both brain atlases and templates (template sets). This study aims to improve the accuracy of volumetric analysis of hippocampus (HP) and amygdala (AMG) in the assessment of early Alzheimer's disease (AD) by developing template sets that correspond more closely to the brains of elderly individuals.

Methods: Total intracranial volume and HP and AMG volumes were calculated for elderly subjects with no cognitive impairment (n = 103), with amnestic mild cognitive impairment (n = 68), or with probable AD (n = 46) using the following: (1) a template set consisting of a standard atlas (atlas S), drawn on a young adult male brain, and the widely used Montreal Neurological Institute template (MNI template set); (2) a template set (template S set) in which the template is based on smoothing the image from which atlas S is derived; and (3) a new template set (template E set) in which the template is based on an atlas (atlas E) created from the brain of an elderly individual.

An investigation of PreMCI: subtypes and longitudinal outcomes.

Background/aims: To investigate the clinical features and rates of progression of conditions that are not considered to be normal, but do not fulfill criteria for mild cognitive impairment (MCI).

Methods: We longitudinally evaluated 269 elderly subjects who did not meet formal criteria for MCI at baseline but had: (1) a clinical history suggesting MCI without neuropsychological deficits (PreMCI-Clinical); or (2) neuropsychological deficits on one or more memory measures in conjunction with a negative clinical examination (amnestic PreMCI-NP) or were normal on both neuropsychological and clinical examination.

Results: The rate of progression to MCI or dementia over an average of 2- to 3 years was 3.

Volumetric and visual rating of magnetic resonance imaging scans in the diagnosis of amnestic mild cognitive impairment and Alzheimer's disease.

Background: In the diagnosis of Alzheimer's disease (AD), structural magnetic resonance imaging (MRI) scans have been used primarily to exclude non-Alzheimer's causes of dementia. However, the pattern and the extent of medial temporal atrophy on structural MRI scans, which correlate strongly with the pathological severity of AD, can be used to support the diagnosis of a degenerative dementia, especially AD, even in its early predementia stage.

Methods: Elderly subjects (n = 224) were diagnosed with either no cognitive impairment (NCI), amnestic mild cognitive impairment (aMCI), or AD.

Minimal atrophy of the entorhinal cortex and hippocampus: progression of cognitive impairment.

Background: In Alzheimer's disease, neurodegenerative atrophy progresses from the entorhinal cortex (ERC) to the hippocampus (HP), limbic system and neocortex. The significance of very mild atrophy of the ERC and HP on MRI scans among elderly subjects is unknown.

Methods: A validated visual rating system on coronal MRI scans was used to identify no atrophy of the HP or ERC (HP(0); ERC(0)), or minimal atrophy of the HP or ERC (HP(ma); ERC(ma)), among 414 participants.

Pre-MCI and MCI: neuropsychological, clinical, and imaging features and progression rates.

Objective: To compare clinical, imaging, and neuropsychological characteristics and longitudinal course of subjects with pre-mild cognitive impairment (pre-MCI), who exhibit features of MCI on clinical examination but lack impairment on neuropsychological examination, to subjects with no cognitive impairment (NCI), nonamnestic MCI (naMCI), amnestic MCI (aMCI), and mild dementia.

Methods: For 369 subjects, clinical dementia rating sum of boxes (CDR-SB), ApoE genotyping, cardiovascular risk factors, parkinsonism (UPDRS) scores, structural brain MRIs, and neuropsychological testing were obtained at baseline, whereas 275 of these subjects received an annual follow-up for 2-3 years.

Results: At baseline, pre-MCI subjects showed impairment on tests of executive function and language, higher apathy scores, and lower left hippocampal volumes (HPCV) in comparison to NCI subjects.

Severity of medial temporal atrophy and amnestic mild cognitive impairment: selecting type and number of memory tests.

Objective: Medial temporal lobe atrophy (MTA) can be used as a biomarker of pathology that affects mechanisms of episodic memory. The authors compared the strength of this biomarker with performance on four memory measures and examined the influence of demographic factors including age, level of education, and primary language (English or Spanish).

Methods: The Hopkins Verbal Learning Test-revised, Fuld Object Memory Evaluation (FOME), delayed memory for a story passage, and delayed visual reproduction of the Wechsler Memory Scale-revised tests were administered to 281 subjects who were diagnosed as having no cognitive impairment, mild cognitive impairment (MCI), impaired non-MCI, or dementia.

A comparative analysis of structural brain MRI in the diagnosis of Alzheimer's disease.

Dementia is a debilitating and life-altering disease which leads to both memory impairment and decline of normal executive functioning. While causes of dementia are numerous and varied, the leading cause among patients 60 years and older is Alzheimer's disease. The gold standard for Alzheimer's diagnosis remains histological identification of amyloid plaques and neurofibrillary tangles within the medial temporal lobe, more specifically the entorhinal cortex and hippocampus.