The Relationship of Modulation Generated in Brain Intrinsic Connectivity Networks by Simple Sensory Stimuli and...

Area of Science:

• Neuroscience
• Medical Imaging
• Cognitive Science

Background:

• Alzheimer's disease continuum (ADC) involves progressive cognitive decline.
• Functional connectivity networks are crucial for brain function.
• Early detection of ADC is vital for timely intervention.

Purpose of the Study:

• To investigate how simple sensory stimuli modulate brain intrinsic connectivity networks in ADC.
• To compare fMRI data from resting state versus sensory stimulation in ADC.
• To identify potential imaging biomarkers for early cognitive decline.

Main Methods:

• fMRI and neuropsychological data from 88 participants across the ADC spectrum (ADD, MCI, SCI) were analyzed.
• fMRI data acquired during resting state and 20 Hz flickering light stimulation.
• Functional connectivity analyses performed using CONN software with Bonferroni correction.

Main Results:

• Resting-state fMRI showed decreased connectivity in default mode and salience networks in Alzheimer's disease dementia (ADD) compared to subjective cognitive impairment (SCI) and mild cognitive impairment (MCI).
• 20 Hz flickering light stimulation revealed increased frontoparietal network connectivity in MCI compared to SCI, a pattern not seen in resting-state data.
• Sensory stimulation fMRI identified altered connectivity patterns potentially missed by resting-state scans.

Conclusions:

• Increased frontoparietal network connectivity in early ADC stages might represent a compensatory mechanism.
• fMRI with simple sensory stimuli appears more sensitive to early cognitive decline than resting-state fMRI.
• Sensory-stimulated fMRI holds potential as a sensitive biomarker for early Alzheimer's disease detection.