Clinical Manifestations

Area of Science:

• Gerontology and Neurodegenerative Diseases
• Genetics and Developmental Disabilities
• Clinical Assessment and Diagnostics

Background:

• Individuals with Down syndrome (DS) face a substantially elevated risk for Alzheimer's disease (AD) compared to the neurotypical (NT) population.
• The inherent intellectual disability (ID) in DS necessitates specialized assessment tools for detecting cognitive decline in DS-associated AD (DS-AD).

Purpose of the Study:

• To investigate international perspectives on the utility and application of assessment tools for DS-AD.
• To evaluate the effectiveness of existing DS-AD assessment tools across varying levels of intellectual disability.

Main Methods:

• A survey was distributed to 51 international DS-AD clinicians and researchers.
• Analysis included 43 complete submissions, focusing on the utility and appropriateness of ten DS-AD assessment tools (five informant-based, five direct assessments).
• Survey queried clinical staging of mild cognitive impairment in DS (MCI-DS) and DS-AD Dementia.

Main Results:

• Over 95% of respondents agreed that NT-designed AD tools are unsuitable for detecting MCI-DS and DS-AD Dementia, particularly in individuals with moderate-to-severe ID.
• Informant-based assessments were highly rated for usefulness and appropriateness across all ID severity levels (mild to profound).
• Direct assessments were deemed highly useful primarily for mild-to-moderate ID, with significantly lower appropriateness ratings for severe and profound ID.

Conclusions:

• There is a strong consensus on the limited utility of NT-designed AD tools for DS-AD diagnosis, highlighting the critical need for specialized DS tools.
• Informant-based tools are recommended for broader applicability across ID spectrums, while direct assessments are best suited for milder ID.
• Regional variations in tool awareness underscore the need for a global framework to standardize DS-AD assessment and ensure evidence-based care.