Biomarkers

Area of Science:

• Neuroscience
• Biomarker Development
• Genetics

Background:

• Colombia has the largest Autosomal-Dominant Alzheimer's Disease (ADAD) kindred due to the PSEN1-E280A variant.
• Electroencephalography (EEG) is an under-development biomarker for ADAD, aiding in understanding brain function and electrophysiological changes.
• Dual-task (DT) paradigms are useful for detecting cognitive impairments in neurodegenerative diseases like ADAD.

Purpose of the Study:

• To evaluate the effectiveness of EEG and DT paradigms as biomarkers for identifying individuals with the PSEN1-E280A variant.
• To assess brain function and electrophysiological changes in asymptomatic carriers versus non-carriers.
• To explore non-invasive, portable tools for early ADAD detection.

Main Methods:

• EEG data were collected from asymptomatic PSEN1-E280A carriers (n=37) and non-carriers (n=42) using the OpenBCI system.
• A dual-task paradigm involved motor tasks (single-task) and combined motor-cognitive tasks (subtraction or verbal fluency).
• Dual-task cost (DTC) was calculated, and spectral and neural dynamics features were extracted and statistically analyzed.

Main Results:

• Significant effect sizes were observed in entropy for Beta1 and Beta3 bands (frontal regions) during cognitive tasks (DTS7, DTS1).
• Relative power in Beta2 (C4) during DTAN and Theta/Alpha1 modulation (frontal) during DTS7 showed notable differences.
• Alpha2 modulations in frontal regions during DTS7 were also significant.

Conclusions:

• The experimental approach successfully extracted brain information distinguishing PSEN1-E280A carriers from non-carriers.
• DTC values in alpha and beta bands (frontal and central regions) showed larger effect sizes, indicating sensitivity to preclinical differences.
• This combination of EEG and DT paradigms offers enhanced, non-invasive tools for preclinical ADAD carrier identification.