Early-onset Alzheimer's Disease Phenotypes: Neuropsychology and Neural Networks

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT03153371

Acronym

EOAD-Subtype

Enrollment

180

Registered

2017-05-15

Start date

2016-04-04

Completion date

2021-08-31

Last updated

2025-04-30

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Alzheimer Disease, Alzheimer Disease, Early Onset, Alzheimer Disease, Late Onset, Corticobasal Degeneration, Dementia, Alzheimer Type, Executive Dysfunction, Ideomotor Apraxia, Logopenic Progressive Aphasia, Posterior Cortical Atrophy, Primary Progressive Aphasia, Visuospatial/Perceptual Abilities

Keywords

Alzheimer's disease, Young-onset, variant, visuospatial, language, apraxia, control, dementia, memory, MRI, neurology, neuropsychology, brain

Brief summary

This study attempts to identify two types of AD by using clinical and cognitive tasks and brain imaging. The subtypes of AD are separated into a typical group (memory loss) and a variant group (language, visuospatial, and other cognitive difficulties). Performance on the clinical tasks and brain imaging will be compared among the young-onset Alzheimer's disease group, a late-onset Alzheimer's disease group, and a control group.

Detailed description

Unlike the usual late-onset Alzheimer's disease (LOAD), early-onset AD (EOAD), with onset before age 65, includes a high percentage of phenotypic variants. These non-familial, variants (vEOAD) present, not with progressive memory loss, but with language, visuospatial, or other cognitive difficulties. AD is now understood as a disorder that manifests with disturbed cognition reflecting disturbed neural networks. A multivariate analysis of neuropsychological tests, the gold standard for objectively defining neurocognitive impairments, coupled with structural and functional neuroimaging analysis of connectomes, can identify the neurocognitive-neural network profiles of vEOAD patients, compared to those with typical AD. This knowledge can increase our understanding of the heterogeneity of AD and how it causes disease. This study hopes to show that vEOAD constitutes a Type 2 AD, by (1) defining the neuropsychological components of Type 2 AD, and (2) understanding the anatomy and atrophy of the brains of vEOAD patients. Together, these components can outline the neurocognitive-neural network profile of Type 2 AD. In addition to information that can help in the diagnosis and management of EOAD, this study can stimulate novel research into the reasons for this neurobiological heterogeneity in AD and could potentially lead to interventions based on alternate neurocognitive-neural network profiles.

Interventions

None listed

Study design

Observational model

CASE_CONTROL

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

50 Years to 85 Years

Healthy volunteers

Yes

Inclusion criteria

* Inclusion criteria for patients with Alzheimer's disease (AD): 1. Meet criteria for AD. 2. Meet clinical criteria for either typical amnestic AD or variant phenotypes of early-onset (EOAD, or Type 2 AD). 3. Mild-moderate dementia severity 4. Sufficient English fluency to complete neuropsychological testing in English. 5. Ability to provide consent for participation, or willingness to provide assent and a legally-authorized representative willing to provide surrogate consent. 6. Availability of a caregiver informant for participation *

Exclusion criteria

for patients with Alzheimer's disease (AD): 1. Complicating medical illnesses. 2. Significant primary visual impairments. 3. Major psychiatric illness not due to the dementia. 4. Confounding medications. * Inclusion criteria for control participants: 1. Score 28/30 or higher on the Folstein Mini-Mental Status Exam. 2. Age 40-85 years old 3. Able to provide consent for participation and express willingness to participate in one-year follow-up visits. 4. Have sufficient English fluency to complete neuropsychological testing in English. *

Design outcomes

Primary

Measure	Time frame	Description
Alzheimer's disease Subtype	Performed at baseline	Neuropsychological testing results for use in a two-stage multivariate diagnostic method that combines the (weighted) test results in order to best discriminate Type 2 AD and typical AD.

Secondary

Measure	Time frame	Description
Change in overall Neurological profile	Performed at baseline and 1-year follow-up visit	Change in performance on neurological tasks between baseline visit and follow-up visit.
Brain atrophy in MRI - Magnetic Resonance Imaging of the brain	Performed at baseline visit	Images from initial MRI scan taken at baseline visit will be analyzed for atrophy and white matter tract integrity
Change in overall Neuropsychological profile	Performed at baseline and 1-year follow-up visit	Change in neuropsychological performance over time.

Countries

United States

Outcome results